Added support for rendering multiple lights, standardized shaders to use snake case for variables and camel case for functions, stubbed PBR material shader include.

.rubocop.yml

@@ -0,0 +1,8 @@
+Style/StringLiterals:
+  EnforcedStyle: double_quotes
+
+Metrics/MethodLength:
+  Max: 40
+
+Style/EmptyMethod:
+  EnforcedStyle: expanded

Gemfile

@@ -1,6 +1,6 @@
 source "https://rubygems.org"
 
-git_source(:github) {|repo_name| "https://github.com/#{repo_name}" }
+git_source(:github) { |repo_name| "https://github.com/#{repo_name}" }
 
 # Specify your gem's dependencies in cyberarm_engine.gemspec
 gemspec

README.md

@@ -1,8 +1,13 @@
-# CyberarmEngine
+![CyberarmEngine](https://raw.githubusercontent.com/cyberarm/cyberarm_engine/master/assets/textures/logo.png)
 
-Welcome to your new gem! In this directory, you'll find the files you need to be able to package up your Ruby library into a gem. Put your Ruby code in the file `lib/cyberarm_engine`. To experiment with that code, run `bin/console` for an interactive prompt.
+Yet Another Game Engine On Top Of Gosu
 
-TODO: Delete this and the text above, and describe your gem
+## Features
+* [Shoes-like](http://shoesrb.com) GUI support
+* OpenGL Shader support (requires [opengl-bindings](https://github.com/vaiorabbit/ruby-opengl) gem)
+* Includes classes for handling Vectors, Rays, Bounding Boxes, and Transforms
+* GameState system
+* Monolithic GameObjects
 
 ## Installation
 
@@ -22,7 +27,33 @@ Or install it yourself as:
 
 ## Usage
 
-TODO: Write usage instructions here
+```ruby
+require "cyberarm_engine"
+
+class Hello < CyberarmEngine::GuiState
+  def setup
+    background Gosu::Color::GRAY
+
+    stack do
+      label "Hello World!"
+
+      button "close" do
+        window.close
+      end
+    end
+  end
+end
+
+class Window < CyberarmEngine::Window
+  def setup
+    self.show_cursor = true
+
+    push_state(Hello)
+  end
+end
+
+Window.new(width: 800, height: 600, fullscreen: false, resizable: true).show
+```
 
 ## Development
 

Rakefile

@@ -7,4 +7,4 @@ Rake::TestTask.new(:test) do |t|
   t.test_files = FileList["test/**/*_test.rb"]
 end
 
-task :default => :test
+task default: :test

assets/shaders/fragment/g_buffer.glsl

@@ -0,0 +1,30 @@
+# version 330 core
+
+layout(location  = 0) out vec3 fragPosition;
+layout (location = 1) out vec4 fragColor;
+layout (location = 2) out vec3 fragNormal;
+layout (location = 3) out vec3 fragUV;
+
+in vec3 out_position, out_color, out_normal, out_uv, out_frag_pos, out_camera_pos;
+out vec4 outputFragColor;
+flat in int out_has_texture;
+
+uniform sampler2D diffuse_texture;
+
+void main() {
+  vec3 result;
+
+  if (out_has_texture == 0) {
+    result = out_color;
+  } else {
+    result = texture(diffuse_texture, out_uv.xy).xyz + 0.25;
+  }
+
+  fragPosition = out_position;
+  fragColor = vec4(result, 1.0);
+  fragNormal = out_normal;
+  fragUV = out_uv;
+
+  float gamma = 2.2;
+  outputFragColor.rgb = pow(fragColor.rgb, vec3(1.0 / gamma));
+}

assets/shaders/fragment/lighting.glsl

@@ -0,0 +1,69 @@
+#version 330 core
+out vec4 frag_color;
+
+@include "light_struct"
+const int DIRECTIONAL = 0;
+const int POINT = 1;
+const int SPOT = 2;
+
+flat in Light out_lights[7];
+in vec2 out_tex_coords;
+flat in int out_light_count;
+
+uniform sampler2D diffuse, position, texcoord, normal, depth;
+
+vec4 directionalLight(Light light) {
+  vec3 norm = normalize(texture(normal, out_tex_coords).rgb);
+  vec3 diffuse_color = texture(diffuse, out_tex_coords).rgb;
+  vec3 frag_pos = texture(position, out_tex_coords).rgb;
+
+  vec3 lightDir = normalize(light.position - frag_pos);
+  float diff = max(dot(norm, lightDir), 0);
+
+  vec3 _ambient = light.ambient;
+  vec3 _diffuse = light.diffuse * diff;
+  vec3 _specular = light.specular;
+
+  return vec4(_diffuse + _ambient + _specular, 1.0);
+}
+
+vec4 pointLight(Light light) {
+  return vec4(0.25, 0.25, 0.25, 1);
+}
+
+vec4 spotLight(Light light) {
+  return vec4(0.5, 0.5, 0.5, 1);
+}
+
+vec4 calculateLighting(Light light) {
+  vec4 result;
+
+  // switch(light.type) {
+  //   case DIRECTIONAL: {
+  //     result = directionalLight(light);
+  //   }
+  //   case SPOT: {
+  //     result = spotLight(light);
+  //   }
+  //   default: {
+  //     result = pointLight(light);
+  //   }
+  // }
+
+  if (light.type == DIRECTIONAL) {
+    result = directionalLight(light);
+  } else {
+    result = pointLight(light);
+  }
+
+  return result;
+}
+
+void main() {
+  frag_color = vec4(0.0);
+
+  for(int i = 0; i < out_light_count; i++)
+  {
+    frag_color += texture(diffuse, out_tex_coords) * calculateLighting(out_lights[i]);
+  }
+}

assets/shaders/include/light_struct.glsl

@@ -0,0 +1,11 @@
+struct Light {
+  int  type;
+  vec3 direction;
+  vec3 position;
+
+  vec3 diffuse;
+  vec3 ambient;
+  vec3 specular;
+
+  float intensity;
+};

assets/shaders/include/material_struct.glsl

@@ -0,0 +1,16 @@
+struct Material {
+  vec3 color;
+  vec3 roughness;
+  vec3 metalic;
+  vec3 specular;
+
+  bool use_color_texture;
+  bool use_roughness_texture;
+  bool use_metalic_texture;
+  bool use_specular_texture;
+
+  sampler2D color_tex;
+  sampler2D roughness_tex;
+  sampler2D metalic_tex;
+  sampler2D specular_tex;
+};

assets/shaders/vertex/g_buffer.glsl

@@ -0,0 +1,28 @@
+# version 330 core
+
+layout(location = 0) in vec3 in_position;
+layout(location = 1) in vec3 in_color;
+layout(location = 2) in vec3 in_normal;
+layout(location = 3) in vec3 in_uv;
+
+uniform mat4 projection, view, model;
+uniform int has_texture;
+uniform vec3 camera_pos;
+
+out vec3 out_position, out_color, out_normal, out_uv;
+out vec3 out_frag_pos, out_view_pos, out_camera_pos;
+flat out int out_has_texture;
+
+void main() {
+  // projection * view * model * position
+  out_position = in_position;
+  out_color = in_color;
+  out_normal= normalize(transpose(inverse(mat3(model))) * in_normal);
+  out_uv    = in_uv;
+  out_has_texture = has_texture;
+  out_camera_pos = camera_pos;
+
+  out_frag_pos = vec3(model * vec4(in_position, 1.0));
+
+  gl_Position = projection * view * model * vec4(in_position, 1.0);
+}

assets/shaders/vertex/lighting.glsl

@@ -0,0 +1,24 @@
+#version 330 core
+@include "light_struct"
+
+layout (location = 0) in vec3 in_position;
+layout (location = 1) in vec2 in_tex_coords;
+
+uniform sampler2D diffuse, position, texcoord, normal, depth;
+uniform int light_count;
+uniform Light lights[7];
+
+out vec2 out_tex_coords;
+flat out int out_light_count;
+flat out Light out_lights[7];
+
+void main() {
+  gl_Position = vec4(in_position.x, in_position.y, in_position.z, 1.0);
+  out_tex_coords = in_tex_coords;
+  out_light_count = light_count;
+
+  for(int i = 0; i < light_count; i++)
+  {
+    out_lights[i] = lights[i];
+  }
+}

cyberarm_engine.gemspec

@@ -1,5 +1,4 @@
-
-lib = File.expand_path("../lib", __FILE__)
+lib = File.expand_path("lib", __dir__)
 $LOAD_PATH.unshift(lib) unless $LOAD_PATH.include?(lib)
 require "cyberarm_engine/version"
 
@@ -9,8 +8,8 @@ Gem::Specification.new do |spec|
   spec.authors       = ["Cyberarm"]
   spec.email         = ["matthewlikesrobots@gmail.com"]
 
-  spec.summary       = %q{Make games quickly and easily with gosu}
-  spec.description   = %q{Yet another game making framework around gosu}
+  spec.summary       = "Make games quickly and easily with gosu"
+  spec.description   = "Yet another game making framework around gosu"
   spec.homepage      = "https://github.com/cyberarm/cyberarm_engine"
   spec.license       = "MIT"
 
@@ -21,16 +20,19 @@ Gem::Specification.new do |spec|
       "public gem pushes."
   end
 
-  spec.files         = `git ls-files -z`.split("\x0").reject do |f|
+  spec.files = `git ls-files -z`.split("\x0").reject do |f|
     f.match(%r{^(test|spec|features)/})
   end
   spec.bindir        = "exe"
   spec.executables   = spec.files.grep(%r{^exe/}) { |f| File.basename(f) }
-  spec.require_paths = ["lib"]
+  spec.require_paths = %w[lib assets]
 
-  spec.add_dependency "gosu", "~> 0.14.0"
+  spec.add_dependency "excon", "~> 0.88"
+  spec.add_dependency "gosu", "~> 1.1"
+  spec.add_dependency "gosu_more_drawables", "~> 0.3"
+  # spec.add_dependency "ffi", :platforms => [:mswin, :mingw] # Required by Clipboard on Windows
 
-  spec.add_development_dependency "bundler", "~> 1.16"
-  spec.add_development_dependency "rake", "~> 10.0"
+  spec.add_development_dependency "bundler", "~> 2.2"
   spec.add_development_dependency "minitest", "~> 5.0"
+  spec.add_development_dependency "rake", "~> 13.0"
 end

lib/cyberarm_engine.rb

@@ -1,35 +1,71 @@
-require "gosu"
+CYBERARM_ENGINE_ROOT_PATH = File.expand_path("..", __dir__)
+
+if ARGV.join.include?("--ffi-gosu")
+  require File.expand_path("../../ffi-gosu/lib/gosu", __dir__)
+else
+  require "gosu"
+end
+require "json"
+require "excon"
+require "gosu_more_drawables"
 
 require_relative "cyberarm_engine/version"
+require_relative "cyberarm_engine/stats"
 
 require_relative "cyberarm_engine/common"
 
 require_relative "cyberarm_engine/game_object"
-require_relative "cyberarm_engine/engine"
+require_relative "cyberarm_engine/window"
 
-require_relative "cyberarm_engine/lib/bounding_box"
-require_relative "cyberarm_engine/lib/vector"
+require_relative "cyberarm_engine/bounding_box"
+require_relative "cyberarm_engine/vector"
+require_relative "cyberarm_engine/transform"
+require_relative "cyberarm_engine/ray"
 require_relative "cyberarm_engine/background"
+require_relative "cyberarm_engine/background_nine_slice"
+require_relative "cyberarm_engine/background_image"
+require_relative "cyberarm_engine/animator"
 
-require_relative "cyberarm_engine/objects/text"
-require_relative "cyberarm_engine/objects/timer"
+require_relative "cyberarm_engine/text"
+require_relative "cyberarm_engine/timer"
+require_relative "cyberarm_engine/config_file"
+
+require_relative "cyberarm_engine/console"
+require_relative "cyberarm_engine/console/command"
+require_relative "cyberarm_engine/console/subcommand"
+require_relative "cyberarm_engine/console/commands/help_command"
+
+require_relative "cyberarm_engine/ui/dsl"
 
 require_relative "cyberarm_engine/ui/theme"
 require_relative "cyberarm_engine/ui/event"
 require_relative "cyberarm_engine/ui/style"
 require_relative "cyberarm_engine/ui/border_canvas"
 require_relative "cyberarm_engine/ui/element"
-require_relative "cyberarm_engine/ui/label"
-require_relative "cyberarm_engine/ui/button"
-require_relative "cyberarm_engine/ui/toggle_button"
-require_relative "cyberarm_engine/ui/edit_line"
-require_relative "cyberarm_engine/ui/image"
-require_relative "cyberarm_engine/ui/container"
-
-require_relative "cyberarm_engine/ui/flow"
-require_relative "cyberarm_engine/ui/stack"
-require_relative "cyberarm_engine/ui/check_box"
-require_relative "cyberarm_engine/ui/dsl"
+require_relative "cyberarm_engine/ui/elements/text_block"
+require_relative "cyberarm_engine/ui/elements/button"
+require_relative "cyberarm_engine/ui/elements/toggle_button"
+require_relative "cyberarm_engine/ui/elements/list_box"
+require_relative "cyberarm_engine/ui/elements/edit_line"
+require_relative "cyberarm_engine/ui/elements/edit_box"
+require_relative "cyberarm_engine/ui/elements/image"
+require_relative "cyberarm_engine/ui/elements/container"
+require_relative "cyberarm_engine/ui/elements/flow"
+require_relative "cyberarm_engine/ui/elements/stack"
+require_relative "cyberarm_engine/ui/elements/check_box"
+require_relative "cyberarm_engine/ui/elements/radio"
+require_relative "cyberarm_engine/ui/elements/progress"
+require_relative "cyberarm_engine/ui/elements/slider"
 
 require_relative "cyberarm_engine/game_state"
 require_relative "cyberarm_engine/ui/gui_state"
+
+require_relative "cyberarm_engine/model"
+require_relative "cyberarm_engine/model_cache"
+require_relative "cyberarm_engine/model/material"
+require_relative "cyberarm_engine/model/model_object"
+require_relative "cyberarm_engine/model/parser"
+require_relative "cyberarm_engine/model/parsers/wavefront_parser"
+require_relative "cyberarm_engine/model/parsers/collada_parser" if RUBY_ENGINE != "mruby" && defined?(Nokogiri)
+
+require_relative "cyberarm_engine/builtin/intro_state"

lib/cyberarm_engine/animator.rb

@@ -0,0 +1,219 @@
+module CyberarmEngine
+  class Animator
+    def initialize(start_time:, duration:, from:, to:, tween: :linear, &block)
+      @start_time = start_time
+      @duration = duration
+      @from = from.dup
+      @to = to.dup
+      @tween = tween
+      @block = block
+    end
+
+    def update
+      @block.call(self, @from, @to) if @block
+    end
+
+    def progress
+      ((Gosu.milliseconds - @start_time) / @duration.to_f).clamp(0.0, 1.0)
+    end
+
+    def complete?
+      progress >= 1.0
+    end
+
+    def transition(from = @from, to = @to, tween = @tween)
+      from + (to - from) * send("tween_#{tween}", progress)
+    end
+
+    def color_transition(from = @from, to = @to, _tween = @tween)
+      r = transition(from.red, to.red)
+      g = transition(from.green, to.green)
+      b = transition(from.blue, to.blue)
+      a = transition(from.alpha, to.alpha)
+
+      Gosu::Color.rgba(r, g, b, a)
+    end
+
+    def color_hsv_transition(from = @from, to = @to, tween = @tween)
+      hue = transition(from.hue, to.hue, tween)
+      saturation = transition(from.saturation, to.saturation, tween)
+      value = transition(from.value, to.value, tween)
+      alpha = transition(from.alpha, to.alpha, tween)
+
+      Gosu::Color.from_ahsv(alpha, hue, saturation, value)
+    end
+
+    # Tween functions based on those provided here: https://github.com/danro/easing-js/blob/master/easing.js
+    # Under MIT / BSD
+
+    def tween_linear(t)
+      t
+    end
+
+    def tween_ease_in_quad(t)
+      t ** 2
+    end
+
+    def tween_ease_out_quad(t)
+      -((t - 1) ** 2) -1
+    end
+
+    def tween_ease_in_out_quad(t)
+      return 0.5 * (t ** 2) if (t /= 0.5) < 1
+      return -0.5 * ((t -= 2) * t - 2)
+    end
+
+    def tween_ease_in_cubic(t)
+      t ** 3
+    end
+
+    def tween_ease_out_cubic(t)
+      ((t - 1) ** 3) + 1
+    end
+
+    def tween_ease_in_out_cubic(t)
+      return 0.5 * (t ** 3) if ((t /= 0.5) < 1)
+      return 0.5 * ((t - 2) ** 3) + 2
+    end
+
+    def tween_ease_in_quart(t)
+      t ** 4
+    end
+
+    def tween_ease_out_quart(t)
+      -((t - 1) ** 4) - 1
+    end
+
+    def tween_ease_in_out_quart(t)
+      return 0.5 * (t ** 4) if ((t /= 0.5) < 1)
+      return -0.5 * ((t -= 2) * (t ** 3) - 2)
+    end
+
+    def tween_ease_in_quint(t)
+      t ** 5
+    end
+
+    def tween_ease_out_quint(t)
+      ((t - 1) ** 5) + 1
+    end
+
+    def tween_ease_in_out_quint(t)
+      return 0.5 * (t ** 5) if ((t /= 0.5) < 1)
+      return 0.5 * ((t - 2) ** 5) + 2
+    end
+
+    def tween_ease_in(t) # sine
+      -Math.cos(t * (Math::PI / 2)) + 1
+    end
+
+    def tween_ease_out(t) # sine
+      Math.sin(t * (Math::PI / 2))
+    end
+
+    def tween_ease_in_out(t) # sine
+      (-0.5 * (Math.cos(Math::PI * t) - 1))
+    end
+
+    def tween_ease_in_expo(t)
+      (t == 0) ? 0 : 2 ** 10 * (t - 1)
+    end
+
+    def tween_ease_out_expo(t)
+      (t == 1) ? 1 : -(2 ** -10 * t) + 1
+    end
+
+    def tween_ease_in_out_expo(t)
+      return 0 if (t == 0)
+      return 1 if (t == 1)
+      return 0.5 * (2 ** 10 * (t - 1)) if ((t /= 0.5) < 1)
+      return 0.5 * (-(2 ** -10 * (t -= 1)) + 2)
+    end
+
+    def tween_ease_in_circ(t)
+      -(Math.sqrt(1 - (t * t)) - 1)
+    end
+
+    def tween_ease_out_circ(t)
+      Math.sqrt(1 - ((t - 1) ** 2))
+    end
+
+    def tween_ease_in_out_circ(t)
+      return -0.5 * (Math.sqrt(1 - t * t) - 1) if ((t /= 0.5) < 1)
+      return 0.5 * (Math.sqrt(1 - (t -= 2) * t) + 1)
+    end
+
+    def tween_ease_in_back(t)
+      s = 1.70158
+      t * t * ((s + 1) * t - s)
+    end
+
+    def tween_ease_out_back(t)
+      s = 1.70158
+      (t = t - 1) * t * ((s + 1) * t + s) + 1
+    end
+
+    def tween_ease_in_out_back(t)
+      s = 1.70158
+      return 0.5 * (t * t * (((s *= (1.525)) + 1) * t - s)) if ((t /= 0.5) < 1)
+      return 0.5 * ((t -= 2) * t * (((s *= (1.525)) + 1) * t + s) + 2)
+    end
+
+    def tween_elastic(t)
+      -1 * (4 ** (-8 * t)) * Math.sin((t * 6 - 1) * (2 * Math::PI) / 2) + 1
+    end
+
+    def tween_swing_from_to(t)
+      s = 1.70158
+      return 0.5 * (t * t * (((s *= (1.525)) + 1) * t - s)) if (t /= 0.5) < 1
+      return 0.5 * ((t -= 2) * t * (((s *= (1.525)) + 1) * t + s) + 2)
+    end
+
+    def tween_swing_from(t)
+      s = 1.70158;
+      t * t * ((s + 1) * t - s)
+    end
+
+    def tween_swing_to(t)
+      s = 1.70158
+      (t -= 1) * t * ((s + 1) * t + s) + 1
+    end
+
+    def tween_bounce(t)
+      if (t < (1 / 2.75))
+        (7.5625 * t * t)
+      elsif (t < (2 / 2.75))
+        (7.5625 * (t -= (1.5 / 2.75)) * t + 0.75)
+      elsif (t < (2.5 / 2.75))
+        (7.5625 * (t -= (2.25 / 2.75)) * t + 0.9375)
+      else
+        (7.5625 * (t -= (2.625 / 2.75)) * t + 0.984375)
+      end
+    end
+
+    def tween_bounce_past(t)
+      if (t < (1 / 2.75))
+        # missing "2 -"?
+        (7.5625 * t * t)
+      elsif (t < (2 / 2.75))
+        2 - (7.5625 * (t -= (1.5 / 2.75)) * t + 0.75)
+      elsif (t < (2.5 / 2.75))
+        2 - (7.5625 * (t -= (2.25 / 2.75)) * t + 0.9375)
+      else
+        2 - (7.5625 * (t -= (2.625 / 2.75)) * t + 0.984375)
+      end
+    end
+
+    def tween_ease_from_to(t)
+      return 0.5 * (t ** 4) if ((t /= 0.5) < 1)
+      return -0.5 * ((t -= 2) * (t ** 3) - 2)
+    end
+
+    def tween_ease_from(t)
+      t ** 4
+    end
+
+    def tween_ease_to(t)
+      t ** 0.25
+    end
+  end
+end

lib/cyberarm_engine/background.rb

@@ -1,12 +1,14 @@
-require "gosu"
-
 module CyberarmEngine
   class Background
     attr_accessor :x, :y, :z, :width, :height, :angle, :debug
     attr_reader   :background
+
     def initialize(x: 0, y: 0, z: 0, width: 0, height: 0, background: Gosu::Color::BLACK, angle: 0, debug: false)
-      @x,@y,@z = x,y,z
-      @width,@height = width,height
+      @x = x
+      @y = y
+      @z = z
+      @width = width
+      @height = height
       @debug = debug
 
       @paint  = Paint.new(background)
@@ -33,8 +35,8 @@ module CyberarmEngine
     end
 
     def update
-      origin_x = (@x + (@width/2))
-      origin_y = (@y + (@height/2))
+      origin_x = (@x + (@width / 2))
+      origin_y = (@y + (@height / 2))
 
       points = [
         @top_left     = Vector.new(@x, @y),
@@ -49,8 +51,8 @@ module CyberarmEngine
 
         # 90 is up here, while gosu uses 0 for up.
         radians = (@angle + 90).gosu_to_radians
-        vector.x = (@x + (@width/2))  + ((temp_x * Math.cos(radians)) - (temp_y * Math.sin(radians)))
-        vector.y = (@y + (@height/2)) + ((temp_x * Math.sin(radians)) + (temp_y * Math.cos(radians)))
+        vector.x = (@x + (@width / 2))  + ((temp_x * Math.cos(radians)) - (temp_y * Math.sin(radians)))
+        vector.y = (@y + (@height / 2)) + ((temp_x * Math.sin(radians)) + (temp_y * Math.cos(radians)))
       end
 
       # [
@@ -69,11 +71,11 @@ module CyberarmEngine
       a = la.x - lb.x
       b = la.y - lb.y
       c = Gosu.distance(la.x, la.y, lb.x, lb.y)
-      p a,b,c
-      d = (a * point.x + b * point.y + c).abs / (Math.sqrt(a * a + b * b))
+      p a, b, c
+      d = (a * point.x + b * point.y + c).abs / Math.sqrt(a * a + b * b)
       puts "Distance: #{d}"
       exit!
-      return d
+      d
     end
 
     def debug_outline
@@ -119,6 +121,7 @@ module CyberarmEngine
 
   class Paint
     attr_accessor :top_left, :top_right, :bottom_left, :bottom_right
+
     def initialize(background)
       set(background)
     end
@@ -126,7 +129,6 @@ module CyberarmEngine
     def set(background)
       @background = background
 
-
       if background.is_a?(Numeric)
         @top_left     = background
         @top_right    = background
@@ -158,9 +160,20 @@ module CyberarmEngine
         @top_right    = background[:top_right]
         @bottom_left  = background[:bottom_left]
         @bottom_right = background[:bottom_right]
+      elsif background.is_a?(Range)
+        set([background.begin, background.begin, background.end, background.end])
       else
         raise ArgumentError, "background '#{background}' of type '#{background.class}' was not able to be processed"
       end
     end
   end
-end
+end
+
+# Add <=> method to support Range based gradients
+module Gosu
+  class Color
+    def <=>(_other)
+      self
+    end
+  end
+end

lib/cyberarm_engine/background_image.rb

@@ -0,0 +1,93 @@
+module CyberarmEngine
+  class BackgroundImage
+    include CyberarmEngine::Common
+    attr_accessor :x, :y, :z, :mode
+    attr_reader :image, :width, :height, :color
+
+    def initialize(image_path: nil, x: 0, y: 0, z: 0, width: 0, height: 0, mode: :fill, color: Gosu::Color::WHITE)
+      @image_path = image_path
+      @image = get_image(image_path) if image_path
+
+      @x = x
+      @y = y
+      @z = z
+      @width = width
+      @height = height
+
+      @mode = mode
+
+      @color = color
+
+      @cached_tiling = nil
+    end
+
+    def image=(image_path)
+      @cached_tiling = nil if image_path != @image_path
+      @image_path = image_path
+      @image = image_path ? get_image(image_path) : image_path
+    end
+
+    def width=(n)
+      @cached_tiling = nil if @width != n
+      @width = n
+    end
+
+    def height=(n)
+      @cached_tiling = nil if @height != n
+      @height = n
+    end
+
+    def color=(c)
+      @cached_tiling = nil if @color != c
+      @color = c
+    end
+
+    def width_scale
+      (@width.to_f / @image.width).abs
+    end
+
+    def height_scale
+      (@height.to_f / @image.height).abs
+    end
+
+    def draw
+      return unless @image
+
+      Gosu.clip_to(@x, @y, @width, @height) do
+        send(:"draw_#{mode}")
+      end
+    end
+
+    def draw_stretch
+      @image.draw(@x, @y, @z, width_scale, height_scale, @color)
+    end
+
+    def draw_tiled
+      @cached_tiling ||= Gosu.record(@width, @height) do
+        height_scale.ceil.times do |y|
+          width_scale.ceil.times do |x|
+            @image.draw(x * @image.width, y * @image.height, @z, 1, 1, @color)
+          end
+        end
+      end
+
+      @cached_tiling.draw(@x, @y, @z)
+    end
+
+    def draw_fill
+      if (@image.width * width_scale) >= @width && (@image.height * width_scale) >= @height
+        draw_fill_width
+      else
+        draw_fill_height
+      end
+    end
+
+    def draw_fill_width
+      @image.draw(@x, @y, @z, width_scale, width_scale, @color)
+    end
+
+    def draw_fill_height
+      @image.draw(@x, @y, @z, height_scale, height_scale, @color)
+    end
+  end
+end

lib/cyberarm_engine/background_nine_slice.rb

@@ -0,0 +1,142 @@
+module CyberarmEngine
+  class BackgroundNineSlice
+    include CyberarmEngine::Common
+    attr_accessor :x, :y, :z, :width, :height, :left, :top, :right, :bottom, :mode, :color
+    attr_reader :image
+
+    def initialize(image_path: nil, x: 0, y: 0, z: 0, width: 0, height: 0, mode: :tiled, left: 1, top: 1, right: 1, bottom: 1, color: Gosu::Color::WHITE)
+      @image = get_image(image_path) if image_path
+
+      @x = x
+      @y = y
+      @z = z
+
+      @width = width
+      @height = height
+
+      @mode = mode
+
+      @left = left
+      @top = top
+      @right = right
+      @bottom = bottom
+
+      @color = color
+
+      nine_slice if @image
+    end
+
+    def image=(image_path)
+      old_image = @image
+      @image = image_path ? get_image(image_path) : image_path
+      nine_slice if @image && old_image != @image
+    end
+
+    def nine_slice
+      # pp [@left, @top, @right, @bottom, @image.width]
+
+      @segment_top_left = @image.subimage(0, 0, @left, @top)
+      @segment_top_right = @image.subimage(@image.width - @right, 0, @right, @top)
+
+      @segment_left = @image.subimage(0, @top, @left, @image.height - (@top + @bottom))
+      @segment_right = @image.subimage(@image.width - @right, @top, @left, @image.height - (@top + @bottom))
+
+      @segment_bottom_left = @image.subimage(0, @image.height - @bottom, @left, @bottom)
+      @segment_bottom_right = @image.subimage(@image.width - @right, @image.height - @bottom, @right, @bottom)
+
+      @segment_top = @image.subimage(@left, 0, @image.width - (@left + @right), @top)
+      @segment_bottom = @image.subimage(@left, @image.height - @bottom, @image.width - (@left + @right), @bottom)
+
+      @segment_middle = @image.subimage(@left, @top, @image.width - (@left + @right), @image.height - (@top + @bottom))
+    end
+
+    def cx
+      @x + @left
+    end
+
+    def cy
+      @y + @top
+    end
+
+    def cwidth
+      @cx - @width
+    end
+
+    def cheight
+      @cy - @height
+    end
+
+    def width_scale
+      scale = (@width.to_f - (@left + @right)) / (@image.width - (@left + @right))
+      scale.abs
+    end
+
+    def height_scale
+      scale = (@height - (@top + @bottom)).to_f / (@image.height - (@top + @bottom))
+      scale.abs
+    end
+
+    def draw
+      return unless @image && @segment_top_left
+
+      @mode == :tiled ? draw_tiled : draw_stretched
+    end
+
+    def draw_stretched
+      @segment_top_left.draw(@x, @y, @z, 1, 1, @color)
+      @segment_top.draw(@x + @segment_top_left.width, @y, @z, width_scale, 1, @color) # SCALE X
+      @segment_top_right.draw((@x + @width) - @segment_top_right.width, @y, @z, 1, 1, @color)
+
+      @segment_right.draw((@x + @width) - @segment_right.width, @y + @top, @z, 1, height_scale, @color) # SCALE Y
+      @segment_bottom_right.draw((@x + @width) - @segment_bottom_right.width, @y + @height - @segment_bottom_right.height, @z, 1, 1, @color)
+      @segment_bottom.draw(@x + @segment_bottom_left.width, (@y + @height) - @segment_bottom.height, @z, width_scale, 1, @color) # SCALE X
+      @segment_bottom_left.draw(@x, (@y + @height) - @segment_bottom_left.height, @z, 1, 1, @color)
+      @segment_left.draw(@x, @y + @top, @z, 1, height_scale, @color) # SCALE Y
+      @segment_middle.draw(@x + @segment_top_left.width, @y + @segment_top.height, @z, width_scale, height_scale, @color) # SCALE X and SCALE Y
+    end
+
+    def draw_tiled
+      @segment_top_left.draw(@x, @y, @z, 1, 1, @color)
+
+      # p [width_scale, height_scale]
+
+      Gosu.clip_to(@x + @segment_top_left.width, @y, @segment_top.width * width_scale, @segment_top.height) do
+        width_scale.ceil.times do |i|
+          @segment_top.draw(@x + @segment_top_left.width + (@segment_top.width * i), @y, @z, 1, 1, @color) # SCALE X
+        end
+      end
+
+      @segment_top_right.draw((@x + @width) - @segment_top_right.width, @y, @z, 1, 1, @color)
+
+      Gosu.clip_to(@x + @width - @segment_top_right.width, @y + @top, @segment_right.width, @segment_right.height * height_scale) do
+        height_scale.ceil.times do |i|
+          @segment_right.draw((@x + @width) - @segment_right.width, @y + @top + (@segment_right.height * i), @z, 1, 1, @color) # SCALE Y
+        end
+      end
+
+      @segment_bottom_right.draw((@x + @width) - @segment_bottom_right.width, @y + @height - @segment_bottom_right.height, @z, 1, 1, @color)
+
+      Gosu.clip_to(@x + @segment_top_left.width, @y + @height - @segment_bottom.height, @segment_top.width * width_scale, @segment_bottom.height) do
+        width_scale.ceil.times do |i|
+          @segment_bottom.draw(@x + @segment_bottom_left.width + (@segment_bottom.width * i), (@y + @height) - @segment_bottom.height, @z, 1, 1, @color) # SCALE X
+        end
+      end
+
+      @segment_bottom_left.draw(@x, (@y + @height) - @segment_bottom_left.height, @z, 1, 1, @color)
+
+      Gosu.clip_to(@x, @y + @top, @segment_left.width, @segment_left.height * height_scale) do
+        height_scale.ceil.times do |i|
+          @segment_left.draw(@x, @y + @top + (@segment_left.height * i), @z, 1, 1, @color) # SCALE Y
+        end
+      end
+
+      Gosu.clip_to(@x + @segment_top_left.width, @y + @segment_top.height, @width - (@segment_left.width + @segment_right.width), @height - (@segment_top.height + @segment_bottom.height)) do
+        height_scale.ceil.times do |y|
+          width_scale.ceil.times do |x|
+            @segment_middle.draw(@x + @segment_top_left.width + (@segment_middle.width * x), @y + @segment_top.height + (@segment_middle.height * y), @z, 1, 1, @color) # SCALE X and SCALE Y
+          end
+        end
+      end
+    end
+  end
+end

lib/cyberarm_engine/bounding_box.rb

@@ -23,7 +23,7 @@ module CyberarmEngine
 
     def ==(other)
       @min == other.min &&
-      @max == other.max
+        @max == other.max
     end
 
     # returns a new bounding box that includes both bounding boxes
@@ -37,7 +37,7 @@ module CyberarmEngine
       temp.max.y = [@max.y, other.max.y].max
       temp.max.z = [@max.z, other.max.z].max
 
-      return temp
+      temp
     end
 
     # returns the difference between both bounding boxes
@@ -46,27 +46,39 @@ module CyberarmEngine
       temp.min = @min - other.min
       temp.max = @max - other.max
 
-      return temp
+      temp
     end
 
-    # returns whether both bounding boxes intersect
+    # returns whether bounding box intersects other
     def intersect?(other)
-      (@min.x <= other.max.x && @max.x >= other.min.x) &&
-      (@min.y <= other.max.y && @max.y >= other.min.y) &&
-      (@min.z <= other.max.z && @max.z >= other.min.z)
+      if other.is_a?(Ray)
+        other.intersect?(self)
+      elsif other.is_a?(BoundingBox)
+        (@min.x <= other.max.x && @max.x >= other.min.x) &&
+          (@min.y <= other.max.y && @max.y >= other.min.y) &&
+          (@min.z <= other.max.z && @max.z >= other.min.z)
+      else
+        raise "Unknown collider: #{other.class}"
+      end
     end
 
     # does this bounding box envelop other bounding box? (inclusive of border)
     def contains?(other)
       other.min.x >= min.x && other.min.y >= min.y && other.min.z >= min.z &&
-      other.max.x <= max.x && other.max.y <= max.y && other.max.z <= max.z
+        other.max.x <= max.x && other.max.y <= max.y && other.max.z <= max.z
     end
 
-    # returns whether the vector is inside of the bounding box
+    # returns whether the 3D vector is inside of the bounding box
+    def inside?(vector)
+      (vector.x.between?(@min.x, @max.x) || vector.x.between?(@max.x, @min.x)) &&
+        (vector.y.between?(@min.y, @max.y) || vector.y.between?(@max.y, @min.y)) &&
+        (vector.z.between?(@min.z, @max.z) || vector.z.between?(@max.z, @min.z))
+    end
+
+    # returns whether the 2D vector is inside of the bounding box
     def point?(vector)
-      vector.x.between?(@min.x, @max.x) &&
-      vector.y.between?(@min.y, @max.y) &&
-      vector.z.between?(@min.z, @max.z)
+      (vector.x.between?(@min.x, @max.x) || vector.x.between?(@max.x, @min.x)) &&
+        (vector.y.between?(@min.y, @max.y) || vector.y.between?(@max.y, @min.y))
     end
 
     def volume
@@ -87,44 +99,44 @@ module CyberarmEngine
 
     def normalize(entity)
       temp = BoundingBox.new
-      temp.min.x = @min.x.to_f * entity.scale
-      temp.min.y = @min.y.to_f * entity.scale
-      temp.min.z = @min.z.to_f * entity.scale
+      temp.min.x = @min.x.to_f * entity.scale.x
+      temp.min.y = @min.y.to_f * entity.scale.y
+      temp.min.z = @min.z.to_f * entity.scale.z
 
-      temp.max.x = @max.x.to_f * entity.scale
-      temp.max.y = @max.y.to_f * entity.scale
-      temp.max.z = @max.z.to_f * entity.scale
+      temp.max.x = @max.x.to_f * entity.scale.x
+      temp.max.y = @max.y.to_f * entity.scale.y
+      temp.max.z = @max.z.to_f * entity.scale.z
 
-      return temp
+      temp
     end
 
     def normalize_with_offset(entity)
       temp = BoundingBox.new
-      temp.min.x = @min.x.to_f * entity.scale + entity.position.x
-      temp.min.y = @min.y.to_f * entity.scale + entity.position.y
-      temp.min.z = @min.z.to_f * entity.scale + entity.position.z
+      temp.min.x = @min.x.to_f * entity.scale.x + entity.position.x
+      temp.min.y = @min.y.to_f * entity.scale.y + entity.position.y
+      temp.min.z = @min.z.to_f * entity.scale.z + entity.position.z
 
-      temp.max.x = @max.x.to_f * entity.scale + entity.position.x
-      temp.max.y = @max.y.to_f * entity.scale + entity.position.y
-      temp.max.z = @max.z.to_f * entity.scale + entity.position.z
+      temp.max.x = @max.x.to_f * entity.scale.x + entity.position.x
+      temp.max.y = @max.y.to_f * entity.scale.y + entity.position.y
+      temp.max.z = @max.z.to_f * entity.scale.z + entity.position.z
 
-      return temp
+      temp
     end
 
     def +(other)
       box = BoundingBox.new
-      box.min = self.min + other.min
-      box.min = self.max + other.max
+      box.min = min + other.min
+      box.min = max + other.max
 
-      return box
+      box
     end
 
     def -(other)
       box = BoundingBox.new
-      box.min = self.min - other.min
-      box.min = self.max - other.max
+      box.min = min - other.min
+      box.min = max - other.max
 
-      return box
+      box
     end
 
     def sum
@@ -135,4 +147,4 @@ module CyberarmEngine
       BoundingBox.new(@min.x, @min.y, @min.z, @max.x, @max.y, @max.z)
     end
   end
-end
+end

lib/cyberarm_engine/builtin/intro_state.rb

@@ -0,0 +1,131 @@
+module CyberarmEngine
+  class IntroState < CyberarmEngine::GameState
+    def setup
+      @display_width  = 800
+      @display_height = 600
+
+      @title_size = 56
+      @caption_size = 24
+
+      @title = CyberarmEngine::Text.new("", size: @title_size, shadow_color: 0xaa_222222, static: true)
+      @caption = CyberarmEngine::Text.new("", size: @caption_size, shadow_color: 0xaa_222222, static: true)
+
+      @spacer_width = 256
+      @spacer_height = 6
+      @padding = 6
+
+      @cyberarm_engine_logo = get_image "#{CYBERARM_ENGINE_ROOT_PATH}/assets/textures/logo.png"
+
+      @gosu_logo = generate_proxy("Gosu",     "Game Library",         0xff_111111)
+      @ruby_logo = generate_proxy("Ruby",     "Programming Language", 0xff_880000)
+      @opengl_logo = generate_proxy("OpenGL", "Graphics API",         0xff_5586a4) if RUBY_ENGINE != "mruby" && defined?(OpenGL)
+
+      base_time = Gosu.milliseconds
+
+      @born_time = Gosu.milliseconds
+      @continue_after = 5_000
+
+      @animators = [
+        Animator.new(start_time: base_time += 1000, duration: 100,   from: 0.0, to: 1.0, tween: :ease_in_out),
+        Animator.new(start_time: base_time += -500, duration: 1_000, from: 0.0, to: 1.0, tween: :ease_in_out),
+        Animator.new(start_time: base_time += 500,  duration: 1_000, from: 0.0, to: 1.0, tween: :ease_in_out),
+        Animator.new(start_time: base_time += 500,  duration: 1_000, from: 0.0, to: 1.0, tween: :ease_in_out),
+        Animator.new(start_time: base_time +  500,  duration: 1_000, from: 0.0, to: 1.0, tween: :ease_in_out),
+        Animator.new(start_time: Gosu.milliseconds + @continue_after - 1_000,  duration: 1_000, from: 0.0, to: 1.0, tween: :ease_in_out),
+
+        Animator.new(start_time: Gosu.milliseconds + 250, duration: 500, from: 0.0, to: 1.0, tween: :swing_to) # CyberarmEngine LOGO
+      ]
+    end
+
+    def draw
+      Gosu.draw_rect(0, 0, window.width, window.height, 0xff_222222)
+
+      scale = (@display_width - @padding * 2).to_f / @cyberarm_engine_logo.width * @animators.last.transition
+
+      @cyberarm_engine_logo.draw_rot(
+        window.width / 2,
+        (window.height) / 2 - @cyberarm_engine_logo.height / 2 - @padding * 2,
+        2,
+        0,
+        0.5,
+        0.5,
+        scale,
+        scale
+      )
+
+      Gosu.draw_rect(
+        window.width / 2 - (@display_width / 2 + @padding),
+        window.height / 2 - @spacer_height / 2,
+        @display_width + @padding,
+        @spacer_height * @animators[0].transition,
+        Gosu::Color::WHITE
+      )
+
+      @title.x = window.width / 2 - @title.text_width / 2
+      @title.y = (window.height / 2 + (@spacer_height / 2) + @padding) * @animators[1].transition
+      @title.text = "Powered By"
+
+      Gosu.clip_to(0, window.height / 2 + (@spacer_height / 2), window.width, @title.height) do
+        @title.draw
+      end
+
+      y = @title.y + @title.height * 2
+
+      Gosu.clip_to(0, y, window.width, @gosu_logo.height) do
+        Gosu.translate(@opengl_logo.nil? ? @ruby_logo.width / 2 : 0, 0) do
+          @gosu_logo.draw(
+            window.width.to_f / 2 - @ruby_logo.width / 2 - (@ruby_logo.width - @padding),
+            y * @animators[2].transition,
+            2
+          )
+          @ruby_logo.draw(
+            window.width.to_f / 2 - @ruby_logo.width / 2,
+            y * @animators[3].transition,
+            2
+          )
+          @opengl_logo&.draw(
+            window.width.to_f / 2 - @ruby_logo.width / 2 + (@ruby_logo.width - @padding),
+            y * @animators[4].transition,
+            2
+          )
+        end
+      end
+
+      Gosu.draw_rect(0, 0, window.width, window.height, Gosu::Color.rgba(0, 0, 0, 255 * @animators[5].transition), 10_000)
+    end
+
+    def update
+      @animators.each(&:update)
+
+      return unless Gosu.milliseconds - @born_time >= @continue_after
+
+      pop_state
+      push_state(@options[:forward], @options[:forward_options] || {}) if @options[:forward]
+    end
+
+    def button_down(_id)
+      @continue_after = 0
+    end
+
+    def generate_proxy(title, caption, color_hint)
+      @title.text = title
+      @caption.text = caption
+
+      width = @spacer_width + 2 * @padding
+      height = @title_size + @caption_size + @spacer_height + 2 * @padding + @spacer_height
+
+      Gosu.record(width.ceil, height.ceil) do
+        @title.x = (width - @padding * 2) / 2 - @title.text_width / 2
+        @title.y = @padding
+        @title.draw
+
+        Gosu.draw_rect(0, @padding + @title_size + @padding, @spacer_width, @spacer_height, Gosu::Color::WHITE)
+        Gosu.draw_rect(1, @padding + @title_size + @padding + 1, @spacer_width - 2, @spacer_height - 2, color_hint)
+
+        @caption.x =  (width - @padding * 2) / 2 - @caption.text_width / 2
+        @caption.y = @padding + @title_size + @padding + @spacer_height + @padding
+        @caption.draw
+      end
+    end
+  end
+end

lib/cyberarm_engine/cache.rb

@@ -0,0 +1,4 @@
+module CyberarmEngine
+  module Cache
+  end
+end

lib/cyberarm_engine/cache/download_manager.rb

@@ -0,0 +1,121 @@
+module CyberarmEngine
+  module Cache
+    class DownloadManager
+      attr_reader :downloads
+
+      def initialize(max_parallel_downloads: 4)
+        @max_parallel_downloads = max_parallel_downloads
+        @downloads = []
+      end
+
+      def download(url:, save_as: nil, &callback)
+        uri = URI(url)
+        save_as ||= "filename_path" # TODO: if no save_as path is provided, then get one from the Cache controller
+
+        @downloads << Download.new(uri: uri, save_as: save_as, callback: callback)
+      end
+
+      def status
+        if active_downloads > 0
+          :busy
+        else
+          :idle
+        end
+      end
+
+      def progress
+        remaining_bytes = @downloads.map { |d| d.remaining_bytes }.sum
+        total_bytes = @downloads.map { |d| d.total_bytes }.sum
+
+        v = 1.0 - (remaining_bytes.to_f / total_bytes)
+        return 0.0 if v.nan?
+
+        v
+      end
+
+      def active_downloads
+        @downloads.select { |d| %i[pending downloading].include?(d.status) }
+      end
+
+      def update
+        @downloads.each do |download|
+          if download.status == :pending && active_downloads.size <= @max_parallel_downloads
+            download.status = :downloading
+            Thread.start { download.download }
+          end
+        end
+      end
+
+      def prune
+        @downloads.delete_if { |d| d.status == :finished || d.status == :failed }
+      end
+
+      class Download
+        attr_accessor :status
+        attr_reader :uri, :save_as, :callback, :remaining_bytes, :total_downloaded_bytes, :total_bytes,
+                    :error_message, :started_at, :finished_at
+
+        def initialize(uri:, save_as:, callback: nil)
+          @uri = uri
+          @save_as = save_as
+          @callback = callback
+
+          @status = :pending
+
+          @remaining_bytes = 0.0
+          @total_downloaded_bytes = 0.0
+          @total_bytes = 0.0
+
+          @error_message = ""
+        end
+
+        def progress
+          v = 1.0 - (@remaining_bytes.to_f / total_bytes)
+          return 0.0 if v.nan?
+
+          v
+        end
+
+        def download
+          @status = :downloading
+          @started_at = Time.now # TODO: monotonic time
+
+          io = File.open(@save_as, "w")
+          streamer = lambda do |chunk, remaining_bytes, total_bytes|
+            io.write(chunk)
+
+            @remaining_bytes = remaining_bytes.to_f
+            @total_downloaded_bytes += chunk.size
+            @total_bytes = total_bytes.to_f
+          end
+
+          begin
+            response = Excon.get(
+              @uri.to_s,
+              middlewares: Excon.defaults[:middlewares] + [Excon::Middleware::RedirectFollower],
+              response_block: streamer
+            )
+
+            if response.status == 200
+              @status = :finished
+              @finished_at = Time.now # TODO: monotonic time
+              @callback.call(self) if @callback
+            else
+              @error_message = "Got a non 200 HTTP status of #{response.status}"
+              @status = :failed
+              @finished_at = Time.now # TODO: monotonic time
+              @callback.call(self) if @callback
+            end
+          rescue StandardError => e # TODO: cherrypick errors to cature
+            @status = :failed
+            @finished_at = Time.now # TODO: monotonic time
+            @error_message = e.message
+            @callback.call(self) if @callback
+          end
+        ensure
+          io.close if io
+        end
+      end
+    end
+  end
+end

lib/cyberarm_engine/common.rb

@@ -1,60 +1,79 @@
 module CyberarmEngine
   module Common
-    def push_state(klass, options={})
-      $window.push_state(klass, options)
+    def push_state(klass, options = {})
+      window.push_state(klass, options)
     end
 
     def current_state
-      $window.current_state
+      window.current_state
     end
 
-    def previous_state
-      $window.previous_state
+    def previous_state(state = nil)
+      raise "Only available for CyberarmEngine::GameState and subclasses" unless is_a?(CyberarmEngine::GameState) || state.is_a?(CyberarmEngine::GameState)
+
+      i = window.states.index(state || self)
+      window.states[i - 1] unless (i - 1).negative?
     end
 
     def pop_state
-      $window.pop_state
+      window.pop_state
+    end
+
+    def shift_state
+      window.shift_state
     end
 
     def show_cursor
-      $window.show_cursor
+      window.show_cursor
     end
 
-    def show_cursor=boolean
-      $window.show_cursor = boolean
+    def show_cursor=(boolean)
+      window.show_cursor = boolean
     end
 
-    def draw_rect(x, y, width, height, color, z = 0)
-      $window.draw_rect(x,y,width,height,color,z)
+    def find_element_by_tag(container, tag, list = [])
+      return unless container
+
+      container.children.each do |child|
+        list << child if child.style.tag == tag
+
+        find_element_by_tag(child, tag, list) if child.is_a?(CyberarmEngine::Element::Container)
+      end
+
+      list.first
+    end
+
+    def draw_rect(x, y, width, height, color, z = 0, mode = :default)
+      Gosu.draw_rect(x, y, width, height, color, z, mode)
     end
 
     def fill(color, z = 0)
-      draw_rect(0, 0, $window.width, $window.height, color, z)
+      draw_rect(0, 0, window.width, window.height, color, z)
     end
 
     def lighten(color, amount = 25)
-      if defined?(color.alpha)
-        return Gosu::Color.rgba(color.red+amount, color.green+amount, color.blue+amount, color.alpha)
+      if color.respond_to?(:alpha)
+        Gosu::Color.rgba(color.red + amount, color.green + amount, color.blue + amount, color.alpha)
       else
-        return Gosu::Color.rgb(color.red+amount, color.green+amount, color.blue+amount)
+        Gosu::Color.rgb(color.red + amount, color.green + amount, color.blue + amount)
       end
     end
 
     def darken(color, amount = 25)
-      if defined?(color.alpha)
-        return Gosu::Color.rgba(color.red-amount, color.green-amount, color.blue-amount, color.alpha)
+      if color.respond_to?(:alpha)
+        Gosu::Color.rgba(color.red - amount, color.green - amount, color.blue - amount, color.alpha)
       else
-        return Gosu::Color.rgb(color.red-amount, color.green-amount, color.blue-amount)
+        Gosu::Color.rgb(color.red - amount, color.green - amount, color.blue - amount)
       end
     end
 
     def opacity(color, ratio = 1.0)
       alpha = 255 * ratio
 
-      return Gosu::Color.rgba(color.red, color.green, color.blue, alpha)
+      Gosu::Color.rgba(color.red, color.green, color.blue, alpha)
     end
 
-    def get_asset(path, hash, klass)
+    def get_asset(path, hash, klass, retro = false, tileable = false)
       asset = nil
       hash.detect do |_asset, instance|
         if _asset == path
@@ -64,28 +83,46 @@ module CyberarmEngine
       end
 
       unless asset
-        instance = klass.new(path)
+        instance = nil
+        instance = if klass == Gosu::Image
+                     klass.new(path, retro: retro, tileable: tileable)
+                   else
+                     klass.new(path)
+                   end
+
         hash[path] = instance
         asset = instance
       end
 
-      return asset
+      asset
     end
 
-    def get_image(path)
-      get_asset(path, Engine::IMAGES, Gosu::Image)
+    def get_image(path, retro: false, tileable: false)
+      get_asset(path, Window::IMAGES, Gosu::Image, retro, tileable)
     end
 
     def get_sample(path)
-      get_asset(path, Engine::SAMPLES, Gosu::Sample)
+      get_asset(path, Window::SAMPLES, Gosu::Sample)
     end
 
     def get_song(path)
-      get_asset(path, Engine::SONGS, Gosu::Song)
+      get_asset(path, Window::SONGS, Gosu::Song)
     end
 
     def window
-      $window
+      CyberarmEngine::Window.instance
+    end
+
+    def control_down?
+      Gosu.button_down?(Gosu::KB_LEFT_CONTROL) || Gosu.button_down?(Gosu::KB_RIGHT_CONTROL)
+    end
+
+    def shift_down?
+      Gosu.button_down?(Gosu::KB_LEFT_SHIFT) || Gosu.button_down?(Gosu::KB_RIGHT_SHIFT)
+    end
+
+    def alt_down?
+      Gosu.button_down?(Gosu::KB_LEFT_ALT) || Gosu.button_down?(Gosu::KB_RIGHT_ALT)
     end
   end
-end
+end

lib/cyberarm_engine/config_file.rb

@@ -0,0 +1,46 @@
+module CyberarmEngine
+  class ConfigFile
+    def initialize(file:)
+      @file = file
+
+      if File.exist?(@file)
+        deserialize
+      else
+        @data = {}
+      end
+    end
+
+    def []=(*keys, value)
+      last_key = keys.last
+
+      if keys.size == 1
+        hash = @data
+      else
+        keys.pop
+        hash = @data[keys.shift] ||= {}
+
+        keys.each do |key|
+          hash = hash[key] ||= {}
+        end
+      end
+
+      hash[last_key] = value
+    end
+
+    def get(*keys)
+      @data.dig(*keys)
+    end
+
+    def serialize
+      JSON.dump(@data)
+    end
+
+    def deserialize
+      @data = JSON.parse(File.read(@file), symbolize_names: true)
+    end
+
+    def save!
+      File.open(@file, "w") { |f| f.write(serialize) }
+    end
+  end
+end

lib/cyberarm_engine/console.rb

@@ -0,0 +1,248 @@
+# frozen_string_literal: true
+
+module CyberarmEngine
+  class Console
+    Z = 100_000
+    PADDING = 2
+    include Common
+
+    attr_reader :text_input
+
+    def initialize(font: Gosu.default_font_name)
+      @text_input = Gosu::TextInput.new
+      @width  = window.width  / 4 * 3
+      @height = window.height / 4 * 3
+
+      @input = Text.new("", x: 4, y: @height - (PADDING * 2), z: Console::Z + 1, font: font)
+      @input.y -= @input.height
+
+      @history = Text.new("", x: 4, z: Console::Z + 1, font: font, border: true, border_color: Gosu::Color::BLACK)
+      update_history_y
+
+      @command_history       = []
+      @command_history_index = 0
+
+      @memory = ""
+
+      @background_color = Gosu::Color.rgba(0, 0, 0, 200)
+      @foreground_color = Gosu::Color.rgba(100, 100, 100, 100)
+      @input_color      = Gosu::Color.rgba(100, 100, 100, 200)
+
+      @showing_cursor = false
+      @active_text_input = nil
+
+      @show_caret = true
+      @caret_last_change = Gosu.milliseconds
+      @caret_interval = 250
+      @caret_color = Gosu::Color::WHITE
+      @selection_color = Gosu::Color.new(0x5522ff22)
+    end
+
+    def draw
+      # Background/Border
+      draw_rect(0, 0, @width, @height, @background_color, Console::Z)
+      # Foregound/History
+      draw_rect(PADDING, PADDING, @width - (PADDING * 2), @height - (PADDING * 2), @foreground_color, Console::Z)
+      # Text bar
+      draw_rect(2, @input.y, @width - (PADDING * 2), @input.height, @input_color, Console::Z)
+
+      @history.draw
+      @input.draw
+      # Caret
+      if @show_caret
+        draw_rect(@input.x + caret_from_left, @input.y, Console::PADDING, @input.height, @caret_color, Console::Z + 2)
+      end
+      # Caret selection
+      if caret_start != caret_end
+        if caret_start < @text_input.selection_start
+          draw_rect(@input.x + caret_from_left, @input.y, caret_selection_width, @input.height, @selection_color, Console::Z)
+        else
+          draw_rect((@input.x + caret_from_left) - caret_selection_width, @input.y, caret_selection_width, @input.height, @selection_color, Console::Z)
+        end
+      end
+    end
+
+    def caret_from_left
+      return 0 if @text_input.caret_pos.zero?
+
+      @input.textobject.text_width(@text_input.text[0..@text_input.caret_pos - 1])
+    end
+
+    def caret_selection_width
+      @input.textobject.text_width(@text_input.text[caret_start..(caret_end - 1)])
+    end
+
+    def caret_pos
+      @text_input.caret_pos
+    end
+
+    def caret_start
+      @text_input.selection_start < @text_input.caret_pos ? @text_input.selection_start : @text_input.caret_pos
+    end
+
+    def caret_end
+      @text_input.selection_start > @text_input.caret_pos ? @text_input.selection_start : @text_input.caret_pos
+    end
+
+    def update
+      if Gosu.milliseconds - @caret_last_change >= @caret_interval
+        @caret_last_change = Gosu.milliseconds
+        @show_caret = !@show_caret
+      end
+
+      if @width != window.width || @height != @height
+        @width  = window.width  / 4 * 3
+        @height = window.height / 4 * 3
+
+        @input.y = @height - (PADDING * 2 + @input.height)
+        update_history_y
+      end
+
+      @input.text = @text_input.text
+    end
+
+    def button_down(id)
+      case id
+      when Gosu::KB_ENTER, Gosu::KB_RETURN
+        return unless @text_input.text.length.positive?
+
+        @history.text += "\n<c=999999>> #{@text_input.text}</c>"
+        @command_history << @text_input.text
+        @command_history_index = @command_history.size
+        update_history_y
+        handle_command
+        @text_input.text = ""
+
+      when Gosu::KB_UP
+        @command_history_index -= 1
+        @command_history_index = 0 if @command_history_index.negative?
+        @text_input.text = @command_history[@command_history_index]
+
+      when Gosu::KB_DOWN
+        @command_history_index += 1
+        if @command_history_index > @command_history.size - 1
+          @text_input.text = "" unless @command_history_index > @command_history.size
+          @command_history_index = @command_history.size
+        else
+          @text_input.text = @command_history[@command_history_index]
+        end
+
+      when Gosu::KB_TAB
+        split = @text_input.text.split(" ")
+
+        if !@text_input.text.end_with?(" ") && split.size == 1
+          list = abbrev_search(Console::Command.list_commands.map { |cmd| cmd.command.to_s }, @text_input.text)
+
+          if list.size == 1
+            @text_input.text = "#{list.first} "
+          elsif list.size.positive?
+            stdin("\n#{list.map { |cmd| Console::Style.highlight(cmd) }.join(', ')}")
+          end
+        elsif split.size.positive? && cmd = Console::Command.find(split.first)
+          cmd.autocomplete(self)
+        end
+
+      when Gosu::KB_BACKTICK
+        # Remove backtick character from input
+        @text_input.text = if @text_input.text.size > 1
+                             @text_input.text[0..@text_input.text.size - 2]
+                           else
+                             ""
+                           end
+
+      # Copy
+      when Gosu::KB_C
+        if control_down? && shift_down?
+          @memory = @text_input.text[caret_start..caret_end - 1] if caret_start != caret_end
+          p @memory
+        elsif control_down?
+          @text_input.text = ""
+        end
+
+      # Paste
+      when Gosu::KB_V
+        if control_down? && shift_down?
+          string = @text_input.text.chars.insert(caret_pos, @memory).join
+          _caret_pos = caret_pos
+          @text_input.text = string
+          @text_input.caret_pos = _caret_pos + @memory.length
+          @text_input.selection_start = _caret_pos + @memory.length
+        end
+
+      # Cut
+      when Gosu::KB_X
+        if control_down? && shift_down?
+          @memory = @text_input.text[caret_start..caret_end - 1] if caret_start != caret_end
+          string  = @text_input.text.chars
+          Array(caret_start..caret_end - 1).each_with_index do |i, j|
+            string.delete_at(i - j)
+          end
+
+          @text_input.text = string.join
+        end
+
+      # Delete word to left of caret
+      when Gosu::KB_W
+        if control_down?
+          split = @text_input.text.split(" ")
+          split.delete(split.last)
+          @text_input.text = split.join(" ")
+        end
+
+      # Clear history
+      when Gosu::KB_L
+        @history.text = "" if control_down?
+      end
+    end
+
+    def button_up(id)
+    end
+
+    def update_history_y
+      @history.y = @height - (PADDING * 2) - @input.height - (@history.text.lines.count * @history.textobject.height)
+    end
+
+    def handle_command
+      string = @text_input.text
+      split  = string.split(" ")
+      command = split.first
+      arguments = split.length.positive? ? split[1..split.length - 1] : []
+
+      CyberarmEngine::Console::Command.use(command, arguments, self)
+    end
+
+    def abbrev_search(array, text)
+      return [] unless text.length.positive?
+
+      list = []
+      Abbrev.abbrev(array).each do |abbrev, value|
+        next unless abbrev&.start_with?(text)
+
+        list << value
+      end
+
+      list.uniq
+    end
+
+    def stdin(string)
+      @history.text += "\n#{string}"
+      update_history_y
+    end
+
+    def focus
+      @active_text_input = window.text_input
+      window.text_input = @text_input
+
+      @showing_cursor = window.needs_cursor
+      window.needs_cursor = true
+
+      @show_caret = true
+      @caret_last_change = Gosu.milliseconds
+    end
+
+    def blur
+      window.text_input  = @active_text_input
+      window.needs_cursor = @showing_cursor
+    end
+  end
+end

lib/cyberarm_engine/console/command.rb

@@ -0,0 +1,158 @@
+# frozen_string_literal: true
+
+module CyberarmEngine
+  class Console
+    module Style
+      def self.error(string)
+        "<c=ff5555>#{string}</c>"
+      end
+
+      def self.warn(string)
+        "<c=ff7700>#{string}</c>"
+      end
+
+      def self.notice(string)
+        "<c=55ff55>#{string}</c>"
+      end
+
+      def self.highlight(string, color = "5555ff")
+        "<c=#{color}>#{string}</c>"
+      end
+    end
+
+    class Command
+      def self.inherited(subclass)
+        @list ||= []
+        @commands ||= []
+        @list << subclass
+      end
+
+      def self.setup
+        @list ||= []
+        @commands = []
+        @list.each do |subclass|
+          cmd = subclass.new
+          if @commands.detect { |c| c.command == cmd.command }
+            raise "Command '#{cmd.command}' from '#{cmd.class}' already exists!"
+          end
+
+          @commands << cmd
+        end
+      end
+
+      def self.use(command, arguments, console)
+        found_command = @commands.detect { |cmd| cmd.command == command.to_sym }
+
+        if found_command
+          found_command.handle(arguments, console)
+        else
+          console.stdin("Command #{Style.error(command)} not found.")
+        end
+      end
+
+      def self.find(command)
+        @commands.detect { |cmd| cmd.command == command.to_sym }
+      end
+
+      def self.list_commands
+        @commands
+      end
+
+      def initialize
+        @store = {}
+        @subcommands = []
+
+        setup
+      end
+
+      def setup
+      end
+
+      def subcommand(command, type)
+        if @subcommands.detect { |subcmd| subcmd.command == command.to_sym }
+          raise "Subcommand '#{command}' for '#{self.command}' already exists!"
+        end
+
+        @subcommands << SubCommand.new(self, command, type)
+      end
+
+      def get(key)
+        @store[key]
+      end
+
+      def set(key, value)
+        @store[key] = value
+      end
+
+      def group
+        raise NotImplementedError
+      end
+
+      def command
+        raise NotImplementedError
+      end
+
+      def handle(arguments, console)
+        raise NotImplementedError
+      end
+
+      def autocomplete(console)
+        split = console.text_input.text.split(" ")
+
+        if @subcommands.size.positive?
+          if !console.text_input.text.end_with?(" ") && split.size == 2
+            list = console.abbrev_search(@subcommands.map { |cmd| cmd.command.to_s }, split.last)
+
+            if list.size == 1
+              console.text_input.text = "#{split.first} #{list.first} "
+            else
+              return unless list.size.positive?
+
+              console.stdin(list.map { |cmd| Console::Style.highlight(cmd) }.join(", ").to_s)
+            end
+
+          # List available options on subcommand
+          elsif (console.text_input.text.end_with?(" ") && split.size == 2) || !console.text_input.text.end_with?(" ") && split.size == 3
+            subcommand = @subcommands.detect { |cmd| cmd.command.to_s == (split[1]) }
+
+            if subcommand
+              if split.size == 2
+                console.stdin("Available options: #{subcommand.values.map { |value| Console::Style.highlight(value) }.join(',')}")
+              else
+                list = console.abbrev_search(subcommand.values, split.last)
+                if list.size == 1
+                  console.text_input.text = "#{split.first} #{split[1]} #{list.first} "
+                elsif list.size.positive?
+                  console.stdin("Available options: #{list.map { |value| Console::Style.highlight(value) }.join(',')}")
+                end
+              end
+            end
+
+          # List available subcommands if command was entered and has only a space after it
+          elsif console.text_input.text.end_with?(" ") && split.size == 1
+            console.stdin("Available subcommands: #{@subcommands.map { |cmd| Console::Style.highlight(cmd.command) }.join(', ')}")
+          end
+        end
+      end
+
+      def handle_subcommand(arguments, console)
+        if arguments.size.zero?
+          console.stdin(usage)
+          return
+        end
+        subcommand = arguments.delete_at(0)
+
+        found_command = @subcommands.detect { |cmd| cmd.command == subcommand.to_sym }
+        if found_command
+          found_command.handle(arguments, console)
+        else
+          console.stdin("Unknown subcommand #{Style.error(subcommand)} for #{Style.highlight(command)}")
+        end
+      end
+
+      def usage
+        raise NotImplementedError
+      end
+    end
+  end
+end

lib/cyberarm_engine/console/commands/help_command.rb

@@ -0,0 +1,43 @@
+# frozen_string_literal: true
+
+module CyberarmEngine
+  class Console
+    class HelpCommand < CyberarmEngine::Console::Command
+      def group
+        :global
+      end
+
+      def command
+        :help
+      end
+
+      def handle(arguments, console)
+        console.stdin(usage(arguments.first))
+      end
+
+      def autocomplete(console)
+        split = console.text_input.text.split(" ")
+        if !console.text_input.text.start_with?(" ") && split.size == 2
+          list = console.abbrev_search(Command.list_commands.map { |cmd| cmd.command.to_s }, split.last)
+          if list.size == 1
+            console.text_input.text = "#{split.first} #{list.first} "
+          elsif list.size > 1
+            console.stdin(list.map { |cmd| Style.highlight(cmd) }.join(", "))
+          end
+        end
+      end
+
+      def usage(command = nil)
+        if command
+          if cmd = Command.find(command)
+            cmd.usage
+          else
+            "#{Style.error(command)} is not a command"
+          end
+        else
+          "Available commands:\n#{Command.list_commands.map { |cmd| Style.highlight(cmd.command).to_s }.join(', ')}"
+        end
+      end
+    end
+  end
+end

lib/cyberarm_engine/console/subcommand.rb

@@ -0,0 +1,100 @@
+# frozen_string_literal: true
+
+module CyberarmEngine
+  class Console
+    class Command
+      class SubCommand
+        def initialize(parent, command, type)
+          @parent = parent
+          @command = command
+          @type = type
+        end
+
+        attr_reader :command
+
+        def handle(arguments, console)
+          if arguments.size > 1
+            console.stdin("to many arguments for #{Style.highlight(command.to_s)}, got #{Style.error(arguments.size)} expected #{Style.notice(1)}.")
+            return
+          end
+
+          case @type
+          when :boolean
+            case arguments.last
+            when "", nil
+              var = @parent.get(command.to_sym) || false
+              console.stdin("#{command}: #{Style.highlight(var)}")
+            when "on"
+              var = @parent.set(command.to_sym, true)
+              console.stdin("#{command} => #{Style.highlight(var)}")
+            when "off"
+              var = @parent.set(command.to_sym, false)
+              console.stdin("#{command} => #{Style.highlight(var)}")
+            else
+              console.stdin("Invalid argument for #{Style.highlight(command.to_s)}, got #{Style.error(arguments.last)} expected #{Style.notice('on')}, or #{Style.notice('off')}.")
+            end
+          when :string
+            case arguments.last
+            when "", nil
+              var = @parent.get(command.to_sym) || "\"\""
+              console.stdin("#{command}: #{Style.highlight(var)}")
+            else
+              var = @parent.set(command.to_sym, arguments.last)
+              console.stdin("#{command} => #{Style.highlight(var)}")
+            end
+          when :integer
+            case arguments.last
+            when "", nil
+              var = @parent.get(command.to_sym) || "nil"
+              console.stdin("#{command}: #{Style.highlight(var)}")
+            else
+              begin
+                var = @parent.set(command.to_sym, Integer(arguments.last))
+                console.stdin("#{command} => #{Style.highlight(var)}")
+              rescue ArgumentError
+                console.stdin("Error: #{Style.error("Expected an integer, got '#{arguments.last}'")}")
+              end
+            end
+          when :decimal
+            case arguments.last
+            when "", nil
+              var = @parent.get(command.to_sym) || "nil"
+              console.stdin("#{command}: #{Style.highlight(var)}")
+            else
+              begin
+                var = @parent.set(command.to_sym, Float(arguments.last))
+                console.stdin("#{command} => #{Style.highlight(var)}")
+              rescue ArgumentError
+                console.stdin("Error: #{Style.error("Expected a decimal or integer, got '#{arguments.last}'")}")
+              end
+            end
+          else
+            raise RuntimeError
+          end
+        end
+
+        def values
+          case @type
+          when :boolean
+            %w[on off]
+          else
+            []
+          end
+        end
+
+        def usage
+          case @type
+          when :boolean
+            "#{Style.highlight(command)} #{Style.notice('[on|off]')}"
+          when :string
+            "#{Style.highlight(command)} #{Style.notice('[string]')}"
+          when :integer
+            "#{Style.highlight(command)} #{Style.notice('[0]')}"
+          when :decimal
+            "#{Style.highlight(command)} #{Style.notice('[0.0]')}"
+          end
+        end
+      end
+    end
+  end
+end

lib/cyberarm_engine/engine.rb

@@ -1,97 +0,0 @@
-module CyberarmEngine
-  class Engine < Gosu::Window
-    IMAGES = {}
-    SAMPLES= {}
-    SONGS  = {}
-
-    attr_accessor :show_cursor
-    attr_reader :current_state, :last_frame_time
-
-    def self.now
-      Gosu.milliseconds
-    end
-
-    def self.dt
-      $window.last_frame_time/1000.0
-    end
-
-    def initialize(width: 800, height: 600, fullscreen: false, update_interval: 1000.0/60, resizable: false)
-      @show_cursor = false
-
-      super(width, height, fullscreen: fullscreen, update_interval: update_interval, resizable: resizable)
-      $window = self
-      @last_frame_time = Gosu.milliseconds-1
-      @current_frame_time = Gosu.milliseconds
-      self.caption = "CyberarmEngine #{CyberarmEngine::VERSION} #{Gosu.language}"
-
-      @states = []
-
-      setup if defined?(setup)
-    end
-
-    def draw
-      current_state.draw if current_state
-    end
-
-    def update
-      current_state.update if current_state
-      @last_frame_time = Gosu.milliseconds-@current_frame_time
-      @current_frame_time = Gosu.milliseconds
-    end
-
-    def needs_cursor?
-      @show_cursor
-    end
-
-    def dt
-      @last_frame_time/1000.0
-    end
-
-    def button_down(id)
-      super
-      current_state.button_down(id) if current_state
-    end
-
-    def button_up(id)
-      super
-      current_state.button_up(id) if current_state
-    end
-
-    def push_state(klass, options={})
-      if klass.instance_of?(klass.class) && defined?(klass.options)
-        @states << klass
-      else
-        @states << klass.new(options) if child_of?(klass, GameState)
-        @states << klass.new if child_of?(klass, Container)
-      end
-    end
-
-    private def child_of?(input, klass)
-      input.ancestors.detect {|c| c == klass}
-    end
-
-    def current_state
-      @states.last
-    end
-
-    def previous_state
-      if @states.size > 1 && state = @states[@states.size-2]
-        return state
-      else
-        return nil
-      end
-    end
-
-    def pop_state
-      @states.pop
-    end
-
-    # Sourced from https://gist.github.com/ippa/662583
-    def draw_circle(cx,cy,r, z = 9999,color = Gosu::Color::GREEN, step = 10)
-      0.step(360, step) do |a1|
-        a2 = a1 + step
-        draw_line(cx + Gosu.offset_x(a1, r), cy + Gosu.offset_y(a1, r), color, cx + Gosu.offset_x(a2, r), cy + Gosu.offset_y(a2, r), color, z)
-      end
-    end
-  end
-end

lib/cyberarm_engine/game_object.rb

@@ -3,56 +3,62 @@ module CyberarmEngine
     include Common
 
     attr_accessor :image, :angle, :position, :velocity, :center_x, :center_y, :scale_x, :scale_y,
-                  :color, :alpha, :mode, :options, :paused, :radius, :last_position
-    def initialize(options={})
-      if options[:auto_manage] || options[:auto_manage] == nil
-        $window.current_state.add_game_object(self)
-      end
+                  :color, :mode, :options, :paused, :radius, :last_position
+    attr_reader :alpha
+
+    def initialize(options = {})
+      window.current_state.add_game_object(self) if options[:auto_manage] || options[:auto_manage].nil?
 
       @options = options
       @image = options[:image] ? image(options[:image]) : nil
-      x = options[:x] ? options[:x] : 0
-      y = options[:y] ? options[:y] : 0
-      z = options[:z] ? options[:z] : 0
+      x = options[:x] || 0
+      y = options[:y] || 0
+      z = options[:z] || 0
       @position = Vector.new(x, y, z)
       @velocity = Vector.new
       @last_position = Vector.new
-      @angle = options[:angle] ? options[:angle] : 0
+      @angle = options[:angle] || 0
 
-      @center_x = options[:center_x] ? options[:center_x] : 0.5
-      @center_y = options[:center_y] ? options[:center_y] : 0.5
+      @center_x = options[:center_x] || 0.5
+      @center_y = options[:center_y] || 0.5
 
-      @scale_x  = options[:scale_x] ? options[:scale_x] : 1
-      @scale_y  = options[:scale_y] ? options[:scale_y] : 1
+      @scale_x  = options[:scale_x] || 1
+      @scale_y  = options[:scale_y] || 1
 
-      @color    = options[:color] ? options[:color] : Gosu::Color.argb(0xff_ffffff)
-      @alpha    = options[:alpha] ? options[:alpha] : 255
-      @mode = options[:mode] ? options[:mode] : :default
+      @color    = options[:color] || Gosu::Color.argb(0xff_ffffff)
+      @alpha    = options[:alpha] || 255
+      @mode = options[:mode] || :default
 
       @paused = false
       @speed = 0
       @debug_color = Gosu::Color::GREEN
-      @world_center_point = Vector.new(0,0)
+      @world_center_point = Vector.new(0, 0)
 
       setup
 
-      @debug_text = Text.new("", color: @debug_color, y: @position.y-(self.height*self.scale), z: 9999)
+      @debug_text = Text.new("", color: @debug_color, y: @position.y - (height * scale), z: 9999)
       @debug_text.x = @position.x
-      if @radius == 0 || @radius == nil
-        @radius = options[:radius] ? options[:radius] : defined?(@image.width) ? ((@image.width+@image.height)/4)*scale : 1
+      if @radius == 0 || @radius.nil?
+        @radius = if options[:radius]
+                    options[:radius]
+                  else
+                    @image.respond_to?(:width) ? ((@image.width + @image.height) / 4) * scale : 1
+                  end
       end
     end
 
     def draw
       if @image
-        @image.draw_rot(@position.x, @position.y, @position.z, @angle, @center_x, @center_y, @scale_x, @scale_y, @color, @mode)
+        @image.draw_rot(@position.x, @position.y, @position.z, @angle, @center_x, @center_y, @scale_x, @scale_y,
+                        @color, @mode)
       end
 
       if $debug
         show_debug_heading
-        $window.draw_circle(@position.x, @position.y, radius, 9999, @debug_color)
+        Gosu.draw_circle(@position.x, @position.y, radius, 9999, @debug_color)
         if @debug_text.text != ""
-          $window.draw_rect(@debug_text.x-10, (@debug_text.y-10), @debug_text.width+20, @debug_text.height+20, Gosu::Color.rgba(0,0,0,200), 9999)
+          Gosu.draw_rect(@debug_text.x - 10, (@debug_text.y - 10), @debug_text.width + 20, @debug_text.height + 20,
+                            Gosu::Color.rgba(0, 0, 0, 200), 9999)
           @debug_text.draw
         end
       end
@@ -63,13 +69,13 @@ module CyberarmEngine
 
     def debug_text(text)
       @debug_text.text = text
-      @debug_text.x = @position.x-(@debug_text.width / 2)
-      @debug_text.y = @position.y-(@debug_text.height + self.radius + self.height)
+      @debug_text.x = @position.x - (@debug_text.width / 2)
+      @debug_text.y = @position.y - (@debug_text.height + radius + height)
     end
 
     def scale
       if @scale_x == @scale_y
-        return @scale_x
+        @scale_x
       else
         false
         # maths?
@@ -79,7 +85,7 @@ module CyberarmEngine
     def scale=(int)
       self.scale_x = int
       self.scale_y = int
-      self.radius = ((@image.width+@image.height)/4)*self.scale
+      self.radius = ((@image.width + @image.height) / 4) * scale
     end
 
     def visible
@@ -96,16 +102,16 @@ module CyberarmEngine
     end
 
     def _x_visible
-      self.x.between?(($window.width/2)-(@world_center_point.x), ($window.width/2)+@world_center_point.x) ||
-        self.x.between?(((@world_center_point.x)-$window.width/2), ($window.width/2)+@world_center_point.x)
+      x.between?((window.width / 2) - @world_center_point.x, (window.width / 2) + @world_center_point.x) ||
+        x.between?((@world_center_point.x - window.width / 2), (window.width / 2) + @world_center_point.x)
     end
 
     def _y_visible
-      self.y.between?(($window.height/2)-(@world_center_point.y), ($window.height/2)+@world_center_point.y) ||
-        self.y.between?((@world_center_point.y)-($window.height/2), ($window.height/2)+@world_center_point.y)
+      y.between?((window.height / 2) - @world_center_point.y, (window.height / 2) + @world_center_point.y) ||
+        y.between?(@world_center_point.y - (window.height / 2), (window.height / 2) + @world_center_point.y)
     end
 
-    def heading(ahead_by = 100, object = nil, angle_only = false)
+    def heading(ahead_by = 100, _object = nil, angle_only = false)
       direction = Gosu.angle(@last_position.x, @last_position.x, @position.x, position.y).gosu_to_radians
 
       _x = @position.x + (ahead_by * Math.cos(direction))
@@ -121,11 +127,11 @@ module CyberarmEngine
     end
 
     def width
-      @image ? @image.width * self.scale : 0
+      @image ? @image.width * scale : 0
     end
 
     def height
-      @image ? @image.height * self.scale : 0
+      @image ? @image.height * scale : 0
     end
 
     def pause
@@ -137,24 +143,20 @@ module CyberarmEngine
     end
 
     def rotate(int)
-      self.angle+=int
-      self.angle%=360
+      self.angle += int
+      self.angle %= 360
     end
 
-    def alpha=int # 0-255
+    def alpha=(int) # 0-255
       @alpha = int
       @alpha = 255 if @alpha > 255
       @color = Gosu::Color.rgba(@color.red, @color.green, @color.blue, int)
     end
 
-    def draw_rect(x, y, width, height, color, z = 0)
-      $window.draw_rect(x,y,width,height,color,z)
-    end
-
     def button_up(id)
     end
 
-    def button_down?(id)
+    def button_down(id)
     end
 
     def find_closest(game_object_class)
@@ -162,14 +164,14 @@ module CyberarmEngine
       best_distance = 100_000_000_000 # Huge default number
 
       game_object_class.all.each do |object|
-        distance = Gosu::distance(self.x, self.y, object.x, object.y)
+        distance = Gosu.distance(x, y, object.x, object.y)
         if distance <= best_distance
           best_object = object
           best_distance = distance
         end
       end
 
-      return best_object
+      best_object
     end
 
     def look_at(object)
@@ -177,80 +179,66 @@ module CyberarmEngine
     end
 
     def circle_collision?(object)
-      distance = Gosu.distance(self.x, self.y, object.x, object.y)
-      if distance <= self.radius+object.radius
-        true
-      else
-        false
-      end
+      distance = Gosu.distance(x, y, object.x, object.y)
+      distance <= radius + object.radius
     end
 
     # Duplication... so DRY.
-    def each_circle_collision(object, resolve_with = :width, &block)
+    def each_circle_collision(object, _resolve_with = :width, &block)
       if object.class != Class && object.instance_of?(object.class)
-        $window.current_state.game_objects.select {|i| i.class == object.class}.each do |o|
-          distance = Gosu.distance(self.x, self.y, object.x, object.y)
-          if distance <= self.radius+object.radius
-            block.call(o, object) if block
-          end
+        window.current_state.game_objects.select { |i| i.instance_of?(object.class) }.each do |o|
+          distance = Gosu.distance(x, y, object.x, object.y)
+          block.call(o, object) if distance <= radius + object.radius && block
         end
       else
-        list = $window.current_state.game_objects.select {|i| i.class == object}
+        list = window.current_state.game_objects.select { |i| i.instance_of?(object) }
         list.each do |o|
           next if self == o
-          distance = Gosu.distance(self.x, self.y, o.x, o.y)
-          if distance <= self.radius+o.radius
-            block.call(self, o) if block
-          end
+
+          distance = Gosu.distance(x, y, o.x, o.y)
+          block.call(self, o) if distance <= radius + o.radius && block
         end
       end
     end
 
     def destroy
-      if $window.current_state
-        $window.current_state.game_objects.each do |o|
-          if o.is_a?(self.class) && o == self
-            $window.current_state.game_objects.delete(o)
-          end
+      if window.current_state
+        window.current_state.game_objects.each do |o|
+          window.current_state.game_objects.delete(o) if o.is_a?(self.class) && o == self
         end
       end
     end
 
     # NOTE: This could be implemented more reliably
     def all
-      INSTANCES.select {|i| i.class == self}
+      INSTANCES.select { |i| i.instance_of?(self) }
     end
 
-    def self.each_circle_collision(object, resolve_with = :width, &block)
+    def self.each_circle_collision(object, _resolve_with = :width, &block)
       if object.class != Class && object.instance_of?(object.class)
-        $window.current_state.game_objects.select {|i| i.class == self}.each do |o|
+        window.current_state.game_objects.select { |i| i.instance_of?(self) }.each do |o|
           distance = Gosu.distance(o.x, o.y, object.x, object.y)
-          if distance <= o.radius+object.radius
-            block.call(o, object) if block
-          end
+          block.call(o, object) if distance <= o.radius + object.radius && block
         end
       else
-        lista = $window.current_state.game_objects.select {|i| i.class == self}
-        listb = $window.current_state.game_objects.select {|i| i.class == object}
+        lista = window.current_state.game_objects.select { |i| i.instance_of?(self) }
+        listb = window.current_state.game_objects.select { |i| i.instance_of?(object) }
         lista.product(listb).each do |o, o2|
           next if o == o2
+
           distance = Gosu.distance(o.x, o.y, o2.x, o2.y)
-          if distance <= o.radius+o2.radius
-            block.call(o, o2) if block
-          end
+          block.call(o, o2) if distance <= o.radius + o2.radius && block
         end
       end
     end
 
     def self.destroy_all
       INSTANCES.clear
-      if $window.current_state
-        $window.current_state.game_objects.each do |o|
-          if o.is_a?(self.class)
-            $window.current_state.game_objects.delete(o)
-          end
+      if window.current_state
+        window.current_state.game_objects.each do |o|
+          window.current_state.game_objects.delete(o) if o.is_a?(self.class)
         end
       end
     end
   end
-end
+end

lib/cyberarm_engine/game_state.rb

@@ -3,22 +3,25 @@ module CyberarmEngine
     include Common
 
     attr_accessor :options, :global_pause
-    attr_reader :game_objects, :containers
+    attr_reader :game_objects
 
-    def initialize(options={})
+    def initialize(options = {})
       @options = options
       @game_objects = []
       @global_pause = false
-      $window.text_input = nil unless options[:preserve_text_input]
+      window.text_input = nil unless options[:preserve_text_input]
 
       @down_keys = {}
-
-      setup
     end
 
     def setup
     end
 
+    # Called immediately after setup returns.
+    # GuiState uses this to set current_theme for ToolTip
+    def post_setup
+    end
+
     def draw
       @game_objects.each(&:draw)
     end
@@ -27,45 +30,27 @@ module CyberarmEngine
       @game_objects.each(&:update)
     end
 
-    def draw_bounding_box(box)
-      x,y, max_x, max_y = box.x, box.y, box.max_x, box.max_y
-
-      color = Gosu::Color.rgba(255, 127, 64, 240)
-
-      # pipe = 4
-      # Gosu.draw_rect(x-width, y-height, x+(width*2), y+(height*2), color, Float::INFINITY)
-      # puts "BB render: #{x}:#{y} w:#{x.abs+width} h:#{y.abs+height}"
-      # Gosu.draw_rect(x, y, x.abs+width, y.abs+height, color, Float::INFINITY)
-
-      # TOP LEFT to BOTTOM LEFT
-      $window.draw_line(
-        x, y, color,
-        x, max_y, color,
-        Float::INFINITY
-      )
-      # BOTTOM LEFT to BOTTOM RIGHT
-      $window.draw_line(
-        x, max_y, color,
-        max_x, max_y, color,
-        Float::INFINITY
-      )
-      # BOTTOM RIGHT to TOP RIGHT
-      $window.draw_line(
-        max_x, max_y, color,
-        max_x, y, color,
-        Float::INFINITY
-      )
-      # TOP RIGHT to TOP LEFT
-      $window.draw_line(
-        max_x, y, color,
-        x, y, color,
-        Float::INFINITY
-      )
+    def needs_redraw?
+      true
     end
 
-    def destroy
-      @options.clear
-      @game_objects.clear
+    def needs_repaint?
+      true
+    end
+
+    def drop(filename)
+    end
+
+    def gamepad_connected(index)
+    end
+
+    def gamepad_disconnected(index)
+    end
+
+    def gain_focus
+    end
+
+    def lose_focus
     end
 
     def button_down(id)
@@ -84,8 +69,56 @@ module CyberarmEngine
       end
     end
 
+    def close
+      window.close!
+    end
+
+    def draw_bounding_box(box)
+      x = box.x
+      y = box.y
+      max_x = box.max_x
+      max_y = box.max_y
+
+      color = Gosu::Color.rgba(255, 127, 64, 240)
+
+      # pipe = 4
+      # Gosu.draw_rect(x-width, y-height, x+(width*2), y+(height*2), color, Float::INFINITY)
+      # puts "BB render: #{x}:#{y} w:#{x.abs+width} h:#{y.abs+height}"
+      # Gosu.draw_rect(x, y, x.abs+width, y.abs+height, color, Float::INFINITY)
+
+      # TOP LEFT to BOTTOM LEFT
+      Gosu.draw_line(
+        x, y, color,
+        x, max_y, color,
+        Float::INFINITY
+      )
+      # BOTTOM LEFT to BOTTOM RIGHT
+      Gosu.draw_line(
+        x, max_y, color,
+        max_x, max_y, color,
+        Float::INFINITY
+      )
+      # BOTTOM RIGHT to TOP RIGHT
+      Gosu.draw_line(
+        max_x, max_y, color,
+        max_x, y, color,
+        Float::INFINITY
+      )
+      # TOP RIGHT to TOP LEFT
+      Gosu.draw_line(
+        max_x, y, color,
+        x, y, color,
+        Float::INFINITY
+      )
+    end
+
+    def destroy
+      @options.clear
+      @game_objects.clear
+    end
+
     def add_game_object(object)
       @game_objects << object
     end
   end
-end
+end

lib/cyberarm_engine/lib/vector.rb

@@ -1,168 +0,0 @@
-module CyberarmEngine
-  class Vector
-    def initialize(x = 0, y = 0, z = 0, weight = 0)
-      @x, @y, @z, @weight = x, y, z, weight
-    end
-
-    def x; @x; end
-    def x=(n); @x = n; end
-
-    def y; @y; end
-    def y=(n); @y = n; end
-
-    def z; @z; end
-    def z=(n); @z = n; end
-
-    def weight; @weight; end
-    def weight=(n); @weight = n; end
-
-    def ==(other)
-      if other.is_a?(Numeric)
-        @x      == other &&
-        @y      == other &&
-        @z      == other &&
-        @weight == other
-      else
-        @x      == other.x &&
-        @y      == other.y &&
-        @z      == other.z &&
-        @weight == other.weight
-      end
-    end
-
-    # Performs math operation, excluding @weight
-    private def operator(function, other)
-      if other.is_a?(Numeric)
-        Vector.new(
-          @x.send(:"#{function}", other),
-          @y.send(:"#{function}", other),
-          @z.send(:"#{function}", other)
-        )
-      else
-        Vector.new(
-          @x.send(:"#{function}", other.x),
-          @y.send(:"#{function}", other.y),
-          @z.send(:"#{function}", other.z)
-        )
-      end
-    end
-
-    # Adds Vector and Numberic or Vector and Vector, excluding @weight
-    def +(other)
-      operator("+", other)
-    end
-
-    # Subtracts Vector and Numberic or Vector and Vector, excluding @weight
-    def -(other)
-      operator("-", other)
-    end
-
-    # Multiplies Vector and Numberic or Vector and Vector, excluding @weight
-    def *(other)
-      operator("*", other)
-    end
-
-    # Divides Vector and Numberic or Vector and Vector, excluding @weight
-    def /(other)
-      # Duplicated to protect from DivideByZero
-      if other.is_a?(Numeric)
-        Vector.new(
-          (@x == 0 ? 0 : @x / other),
-          (@y == 0 ? 0 : @y / other),
-          (@z == 0 ? 0 : @z / other)
-        )
-      else
-        Vector.new(
-          (@x == 0 ? 0 : @x / other.x),
-          (@y == 0 ? 0 : @y / other.y),
-          (@z == 0 ? 0 : @z / other.z)
-        )
-      end
-    end
-
-    def dot(other)
-      product = 0
-
-      a = self.to_a
-      b = other.to_a
-
-      3.times do |i|
-        product = product + (a[i] * b[i])
-      end
-
-      return product
-    end
-
-    def cross(other)
-      a = self.to_a
-      b = other.to_a
-
-      Vector.new(
-        b[2] * a[1] - b[1] * a[2],
-        b[0] * a[2] - b[2] * a[0],
-        b[1] * a[0] - b[0] * a[1]
-      )
-    end
-
-    # returns degrees
-    def angle(other)
-      Math.acos( self.normalized.dot(other.normalized) ) * 180 / Math::PI
-    end
-
-    # returns magnitude of Vector, ignoring #weight
-    def magnitude
-      Math.sqrt((@x * @x) + (@y * @y) + (@z * @z))
-    end
-
-    def normalized
-      mag = magnitude
-      self / Vector.new(mag, mag, mag)
-    end
-
-    def direction
-      # z is pitch
-      # y is yaw
-      # x is roll
-      _x = -Math.sin(@y.degrees_to_radians) * Math.cos(@z.degrees_to_radians)
-      _y = Math.sin(@z.degrees_to_radians)
-      _z = Math.cos(@y.degrees_to_radians) * Math.cos(@z.degrees_to_radians)
-
-      Vector.new(_x, _y, _z)
-    end
-
-    def inverse
-      Vector.new(1.0 / @x, 1.0 / @y, 1.0 / @z)
-    end
-
-    def sum
-      @x + @y + @z
-    end
-
-    # 2D distance using X and Y
-    def distance(other)
-      Math.sqrt((@x-other.x)**2 + (@y-other.y)**2)
-    end
-
-    # 2D distance using X and Z
-    def gl_distance2d(other)
-      Math.sqrt((@x-other.x)**2 + (@z-other.z)**2)
-    end
-
-    # 3D distance using X, Y, and Z
-    def distance3d(other)
-      Math.sqrt((@x-other.x)**2 + (@y-other.y)**2 + (@z-other.z)**2)
-    end
-
-    def to_a
-      [@x, @y, @z, @weight]
-    end
-
-    def to_s
-      "X: #{@x}, Y: #{@y}, Z: #{@z}, Weight: #{@weight}"
-    end
-
-    def to_h
-      {x: @x, y: @y, z: @z, weight: @weight}
-    end
-  end
-end

lib/cyberarm_engine/model.rb

@@ -0,0 +1,213 @@
+module CyberarmEngine
+  class Model
+    attr_accessor :objects, :materials, :vertices, :uvs, :texures, :normals, :faces, :colors, :bones, :material_file,
+                  :current_material, :current_object, :vertex_count, :smoothing
+    attr_reader :position, :bounding_box, :textured_material, :file_path, :positions_buffer_id, :colors_buffer_id,
+                :normals_buffer_id, :uvs_buffer_id, :textures_buffer_id, :vertex_array_id, :aabb_tree,
+                :vertices_count
+
+    def initialize(file_path:)
+      @file_path = file_path
+
+      @material_file  = nil
+      @current_object = nil
+      @current_material = nil
+      @vertex_count = 0
+
+      @objects = []
+      @materials = {}
+      @vertices = []
+      @colors   = []
+      @uvs      = []
+      @normals  = []
+      @faces    = []
+      @bones    = []
+      @smoothing = 0
+
+      @vertices_count = 0
+
+      @bounding_box = BoundingBox.new
+      start_time = Process.clock_gettime(Process::CLOCK_MONOTONIC, :float_millisecond)
+
+      type = File.basename(file_path).split(".").last.to_sym
+      parser = Model::Parser.find(type)
+      raise "Unsupported model type '.#{type}', supported models are: #{Model::Parser.supported_formats}" unless parser
+
+      parse(parser)
+
+      @vertices_count = @vertices.size
+
+      @has_texture = false
+
+      @materials.each do |_key, material|
+        @has_texture = true if material.texture_id
+      end
+
+      allocate_gl_objects
+      populate_vertex_buffer
+      configure_vao
+
+      @objects.each { |o| @vertex_count += o.vertices.size }
+
+      # start_time = Process.clock_gettime(Process::CLOCK_MONOTONIC, :float_millisecond)
+      # build_collision_tree
+      # puts "    Building mesh collision tree took #{((Process.clock_gettime(Process::CLOCK_MONOTONIC, :float_millisecond) - start_time) / 1000.0).round(2)} seconds"
+    end
+
+    def parse(parser)
+      parser.new(self).parse
+    end
+
+    def calculate_bounding_box(vertices, bounding_box)
+      unless bounding_box.min.x.is_a?(Float)
+        vertex = vertices.last
+        bounding_box.min.x = vertex.x
+        bounding_box.min.y = vertex.y
+        bounding_box.min.z = vertex.z
+
+        bounding_box.max.x = vertex.x
+        bounding_box.max.y = vertex.y
+        bounding_box.max.z = vertex.z
+      end
+
+      vertices.each do |vertex|
+        bounding_box.min.x = vertex.x if vertex.x <= bounding_box.min.x
+        bounding_box.min.y = vertex.y if vertex.y <= bounding_box.min.y
+        bounding_box.min.z = vertex.z if vertex.z <= bounding_box.min.z
+
+        bounding_box.max.x = vertex.x if vertex.x >= bounding_box.max.x
+        bounding_box.max.y = vertex.y if vertex.y >= bounding_box.max.y
+        bounding_box.max.z = vertex.z if vertex.z >= bounding_box.max.z
+      end
+    end
+
+    def allocate_gl_objects
+      # Allocate arrays for future use
+      @vertex_array_id = nil
+      buffer = " " * 4
+      glGenVertexArrays(1, buffer)
+      @vertex_array_id = buffer.unpack1("L2")
+
+      # Allocate buffers for future use
+      @positions_buffer_id = nil
+      buffer = " " * 4
+      glGenBuffers(1, buffer)
+      @positions_buffer_id = buffer.unpack1("L2")
+
+      @colors_buffer_id = nil
+      buffer = " " * 4
+      glGenBuffers(1, buffer)
+      @colors_buffer_id = buffer.unpack1("L2")
+
+      @normals_buffer_id = nil
+      buffer = " " * 4
+      glGenBuffers(1, buffer)
+      @normals_buffer_id = buffer.unpack1("L2")
+
+      @uvs_buffer_id = nil
+      buffer = " " * 4
+      glGenBuffers(1, buffer)
+      @uvs_buffer_id = buffer.unpack1("L2")
+    end
+
+    def populate_vertex_buffer
+      pos     = []
+      colors  = []
+      norms   = []
+      uvs     = []
+
+      @faces.each do |face|
+        pos     << face.vertices.map { |vert| [vert.x, vert.y, vert.z] }
+        colors  << face.colors.map   { |color| [color.red, color.green, color.blue] }
+        norms   << face.normals.map  { |vert| [vert.x, vert.y, vert.z, vert.weight] }
+
+        uvs << face.uvs.map { |vert| [vert.x, vert.y, vert.z] } if has_texture?
+      end
+
+      glBindBuffer(GL_ARRAY_BUFFER, @positions_buffer_id)
+      glBufferData(GL_ARRAY_BUFFER, pos.flatten.size * Fiddle::SIZEOF_FLOAT, pos.flatten.pack("f*"), GL_STATIC_DRAW)
+
+      glBindBuffer(GL_ARRAY_BUFFER, @colors_buffer_id)
+      glBufferData(GL_ARRAY_BUFFER, colors.flatten.size * Fiddle::SIZEOF_FLOAT, colors.flatten.pack("f*"),
+                   GL_STATIC_DRAW)
+
+      glBindBuffer(GL_ARRAY_BUFFER, @normals_buffer_id)
+      glBufferData(GL_ARRAY_BUFFER, norms.flatten.size * Fiddle::SIZEOF_FLOAT, norms.flatten.pack("f*"), GL_STATIC_DRAW)
+
+      if has_texture?
+        glBindBuffer(GL_ARRAY_BUFFER, @uvs_buffer_id)
+        glBufferData(GL_ARRAY_BUFFER, uvs.flatten.size * Fiddle::SIZEOF_FLOAT, uvs.flatten.pack("f*"), GL_STATIC_DRAW)
+      end
+
+      glBindBuffer(GL_ARRAY_BUFFER, 0)
+    end
+
+    def configure_vao
+      glBindVertexArray(@vertex_array_id)
+      gl_error?
+
+      # index, size, type, normalized, stride, pointer
+      # vertices (positions)
+      glBindBuffer(GL_ARRAY_BUFFER, @positions_buffer_id)
+      gl_error?
+
+      #                     in_position
+      glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 0, nil)
+      gl_error?
+      # colors
+      glBindBuffer(GL_ARRAY_BUFFER, @colors_buffer_id)
+      #                     in_color
+      glVertexAttribPointer(1, 3, GL_FLOAT, GL_FALSE, 0, nil)
+      gl_error?
+      # normals
+      glBindBuffer(GL_ARRAY_BUFFER, @normals_buffer_id)
+      #                     in_normal
+      glVertexAttribPointer(2, 4, GL_FLOAT, GL_FALSE, 0, nil)
+      gl_error?
+
+      if has_texture?
+        # uvs
+        glBindBuffer(GL_ARRAY_BUFFER, @uvs_buffer_id)
+        #                     in_uv
+        glVertexAttribPointer(3, 3, GL_FLOAT, GL_FALSE, 0, nil)
+        gl_error?
+      end
+
+      glBindBuffer(GL_ARRAY_BUFFER, 0)
+      glBindVertexArray(0)
+    end
+
+    def build_collision_tree
+      @aabb_tree = IMICFPS::AABBTree.new
+
+      @faces.each do |face|
+        box = BoundingBox.new
+        box.min = face.vertices.first.dup
+        box.max = face.vertices.first.dup
+
+        face.vertices.each do |vertex|
+          if vertex.sum < box.min.sum
+            box.min = vertex.dup
+          elsif vertex.sum > box.max.sum
+            box.max = vertex.dup
+          end
+        end
+
+        # FIXME: Handle negatives
+        box.min *= 1.5
+        box.max *= 1.5
+        @aabb_tree.insert(face, box)
+      end
+    end
+
+    def has_texture?
+      @has_texture
+    end
+
+    def release_gl_resources
+      if @vertex_array_id
+
+      end
+    end
+  end
+end

lib/cyberarm_engine/model/material.rb

@@ -0,0 +1,21 @@
+module CyberarmEngine
+  class Model
+    class Material
+      attr_accessor :name, :ambient, :diffuse, :specular
+      attr_reader :texture_id
+
+      def initialize(name)
+        @name    = name
+        @ambient = Color.new(1, 1, 1, 1)
+        @diffuse = Color.new(1, 1, 1, 1)
+        @specular = Color.new(1, 1, 1, 1)
+        @texture = nil
+        @texture_id = nil
+      end
+
+      def set_texture(texture_path)
+        @texture_id = Texture.new(path: texture_path).id
+      end
+    end
+  end
+end

lib/cyberarm_engine/model/model_object.rb

@@ -0,0 +1,131 @@
+module CyberarmEngine
+  class Model
+    class ModelObject
+      attr_reader :id, :name, :vertices, :uvs, :normals, :materials, :bounding_box, :debug_color
+      attr_accessor :faces, :scale
+
+      def initialize(id, name)
+        @id = id
+        @name = name
+        @vertices = []
+        @uvs      = []
+        @normals  = []
+        @faces    = []
+        @materials = []
+        @bounding_box = BoundingBox.new
+        @debug_color = Color.new(1.0, 1.0, 1.0)
+
+        @scale = 1.0
+
+        # Faces array packs everything:
+        #   vertex   = index[0]
+        #   uv       = index[1]
+        #   normal   = index[2]
+        #   material = index[3]
+      end
+
+      def has_texture?
+        @materials.find { |mat| mat.texture_id } ? true : false
+      end
+
+      def reflatten
+        @vertices_list = nil
+        @uvs_list = nil
+        @normals_list = nil
+
+        flattened_vertices
+        flattened_uvs
+        flattened_normals
+      end
+
+      def flattened_vertices
+        unless @vertices_list
+          @debug_color = @faces.first.material.diffuse
+
+          list = []
+          @faces.each do |face|
+            face.vertices.each do |v|
+              next unless v
+
+              list << v.x * @scale
+              list << v.y * @scale
+              list << v.z * @scale
+              list << v.weight
+            end
+          end
+
+          @vertices_list_size = list.size
+          @vertices_list = list.pack("f*")
+        end
+
+        @vertices_list
+      end
+
+      def flattened_vertices_size
+        @vertices_list_size
+      end
+
+      def flattened_uvs
+        unless @uvs_list
+          list = []
+          @faces.each do |face|
+            face.uvs.each do |v|
+              next unless v
+
+              list << v.x
+              list << v.y
+              list << v.z
+            end
+          end
+
+          @uvs_list_size = list.size
+          @uvs_list = list.pack("f*")
+        end
+
+        @uvs_list
+      end
+
+      def flattened_normals
+        unless @normals_list
+          list = []
+          @faces.each do |face|
+            face.normals.each do |n|
+              next unless n
+
+              list << n.x
+              list << n.y
+              list << n.z
+            end
+          end
+
+          @normals_list_size = list.size
+          @normals_list = list.pack("f*")
+        end
+
+        @normals_list
+      end
+
+      def flattened_materials
+        unless @materials_list
+          list = []
+          @faces.each do |face|
+            material = face.material
+            next unless material
+
+            face.vertices.each do # Add material to each vertex
+              list << material.diffuse.red
+              list << material.diffuse.green
+              list << material.diffuse.blue
+              # list << material.alpha
+            end
+          end
+
+          @materials_list_size = list.size
+          @materials_list = list.pack("f*")
+        end
+
+        @materials_list
+      end
+    end
+  end
+end

lib/cyberarm_engine/model/parser.rb

@@ -0,0 +1,74 @@
+module CyberarmEngine
+  TextureCoordinate = Struct.new(:u, :v, :weight)
+  Point = Struct.new(:x, :y)
+  Color = Struct.new(:red, :green, :blue, :alpha)
+  Face  = Struct.new(:vertices, :uvs, :normals, :colors, :material, :smoothing)
+
+  class Model
+    class Parser
+      @@parsers = []
+
+      def self.handles
+        raise NotImplementedError,
+              "Model::Parser#handles must return an array of file extensions that this parser supports"
+      end
+
+      def self.inherited(parser)
+        @@parsers << parser
+      end
+
+      def self.find(file_type)
+        @@parsers.find do |parser|
+          parser.handles.include?(file_type)
+        end
+      end
+
+      def self.supported_formats
+        @@parsers.map { |parser| parser.handles }.flatten.map { |s| ".#{s}" }.join(", ")
+      end
+
+      def initialize(model)
+        @model = model
+      end
+
+      def parse
+      end
+
+      def set_object(id: nil, name: nil)
+        _model = nil
+
+        if id
+          _model = @model.objects.find { |o| o.id == id }
+        elsif name
+          _model = @model.objects.find { |o| o.name == name }
+        else
+          raise "Must provide either an id: or name:"
+        end
+
+        if _model
+          @model.current_object = _model
+        else
+          raise "Couldn't find ModelObject!"
+        end
+      end
+
+      def change_object(id, name)
+        @model.objects << Model::ModelObject.new(id, name)
+        @model.current_object = @model.objects.last
+      end
+
+      def set_material(name)
+        @model.current_material = name
+        @model.current_object.materials << current_material
+      end
+
+      def add_material(name, material)
+        @model.materials[name] = material
+      end
+
+      def current_material
+        @model.materials[@model.current_material]
+      end
+    end
+  end
+end

lib/cyberarm_engine/model/parsers/collada_parser.rb

@@ -0,0 +1,138 @@
+module CyberarmEngine
+  class ColladaParser < Model::Parser
+    def self.handles
+      [:dae]
+    end
+
+    def parse
+      @collada = Nokogiri::XML(File.read(@model.file_path))
+
+      @collada.css("library_materials material").each do |material|
+        parse_material(material)
+      end
+
+      @collada.css("library_geometries geometry").each do |geometry|
+        parse_geometry(geometry)
+      end
+
+      @model.calculate_bounding_box(@model.vertices, @model.bounding_box)
+      @model.objects.each do |o|
+        @model.calculate_bounding_box(o.vertices, o.bounding_box)
+      end
+    end
+
+    def parse_material(material)
+      name = material.attributes["id"].value
+      effect_id = material.at_css("instance_effect").attributes["url"].value
+
+      mat = Model::Material.new(name)
+      effect = @collada.at_css("[id=\"#{effect_id.sub('#', '')}\"]")
+
+      emission = effect.at_css("emission color")
+      diffuse = effect.at_css("diffuse color").children.first.to_s.split(" ").map { |c| Float(c) }
+
+      mat.diffuse = Color.new(*diffuse[0..2])
+
+      add_material(name, mat)
+    end
+
+    def parse_geometry(geometry)
+      geometry_id = geometry.attributes["id"].value
+      geometry_name = geometry.attributes["name"].value
+
+      change_object(geometry_id, geometry_name)
+
+      mesh = geometry.at_css("mesh")
+
+      get_positions(geometry_id, mesh)
+      get_normals(geometry_id, mesh)
+      get_texture_coordinates(geometry_id, mesh)
+
+      project_node(geometry_name)
+      build_faces(geometry_id, mesh)
+    end
+
+    def get_positions(id, mesh)
+      positions = mesh.at_css("[id=\"#{id}-positions\"]")
+      array = positions.at_css("[id=\"#{id}-positions-array\"]")
+
+      stride = Integer(positions.at_css("[source=\"##{id}-positions-array\"]").attributes["stride"].value)
+      list = array.children.first.to_s.split(" ").map { |f| Float(f) }.each_slice(stride).each do |slice|
+        position = Vector.new(*slice)
+        @model.current_object.vertices << position
+        @model.vertices << position
+      end
+    end
+
+    def get_normals(id, mesh)
+      normals = mesh.at_css("[id=\"#{id}-normals\"]")
+      array = normals.at_css("[id=\"#{id}-normals-array\"]")
+
+      stride = Integer(normals.at_css("[source=\"##{id}-normals-array\"]").attributes["stride"].value)
+      list = array.children.first.to_s.split(" ").map { |f| Float(f) }.each_slice(stride).each do |slice|
+        normal = Vector.new(*slice)
+        @model.current_object.normals << normal
+        @model.normals << normal
+      end
+    end
+
+    def get_texture_coordinates(id, mesh)
+    end
+
+    def project_node(name)
+      @collada.css("library_visual_scenes visual_scene node").each do |node|
+        next unless node.attributes["name"].value == name
+
+        transform = Transform.new(node.at_css("matrix").children.first.to_s.split(" ").map { |f| Float(f) })
+
+        @model.current_object.vertices.each do |vert|
+          v = vert.multiply_transform(transform)
+          vert.x = v.x
+          vert.y = v.y
+          vert.z = v.z
+          vert.w = v.w
+        end
+
+        break
+      end
+    end
+
+    def build_faces(_id, mesh)
+      material_name = mesh.at_css("triangles").attributes["material"].value
+      set_material(material_name)
+
+      positions_index = []
+      normals_index = []
+      uvs_index = []
+
+      mesh.at_css("triangles p").children.first.to_s.split(" ").map { |i| Integer(i) }.each_slice(3).each do |slice|
+        positions_index << slice[0]
+        normals_index << slice[1]
+        uvs_index << slice[2]
+      end
+
+      norm_index = 0
+      positions_index.each_slice(3) do |slice|
+        face = Face.new
+        face.vertices = []
+        face.uvs      = []
+        face.normals  = []
+        face.colors   = []
+        face.material = current_material
+        face.smoothing = @model.smoothing
+
+        slice.each do |index|
+          face.vertices << @model.vertices[index]
+          # face.uvs << @model.uvs[index]
+          face.normals << @model.normals[normals_index[norm_index]]
+          face.colors << current_material.diffuse
+
+          norm_index += 1
+        end
+
+        @model.current_object.faces << face
+        @model.faces << face
+      end
+    end
+  end
+end

lib/cyberarm_engine/model/parsers/wavefront_parser.rb

@@ -0,0 +1,154 @@
+module CyberarmEngine
+  class WavefrontParser < Model::Parser
+    def self.handles
+      [:obj]
+    end
+
+    def parse
+      lines = 0
+      list = File.read(@model.file_path).split("\n")
+      list.each do |line|
+        lines += 1
+        line = line.strip
+
+        array = line.split(" ")
+        case array[0]
+        when "mtllib"
+          @model.material_file = array[1]
+          parse_mtllib
+        when "usemtl"
+          set_material(array[1])
+        when "o"
+          change_object(nil, array[1])
+        when "s"
+          set_smoothing(array[1])
+        when "v"
+          add_vertex(array)
+        when "vt"
+          add_texture_coordinate(array)
+
+        when "vn"
+          add_normal(array)
+
+        when "f"
+          verts = []
+          uvs   = []
+          norms = []
+          array[1..3].each do |f|
+            verts << f.split("/")[0]
+            uvs   << f.split("/")[1]
+            norms << f.split("/")[2]
+          end
+
+          face = Face.new
+          face.vertices = []
+          face.uvs      = []
+          face.normals  = []
+          face.colors   = []
+          face.material = current_material
+          face.smoothing = @model.smoothing
+
+          mat   = face.material.diffuse
+          color = mat
+
+          verts.each_with_index do |v, index|
+            if uvs.first != ""
+              face.vertices << @model.vertices[Integer(v) - 1]
+              face.uvs      << @model.uvs[Integer(uvs[index]) - 1]
+              face.normals  << @model.normals[Integer(norms[index]) - 1]
+              face.colors   << color
+            else
+              face.vertices << @model.vertices[Integer(v) - 1]
+              face.uvs      << nil
+              face.normals  << @model.normals[Integer(norms[index]) - 1]
+              face.colors   << color
+            end
+          end
+
+          @model.current_object.faces << face
+          @model.faces << face
+        end
+      end
+
+      @model.calculate_bounding_box(@model.vertices, @model.bounding_box)
+      @model.objects.each do |o|
+        @model.calculate_bounding_box(o.vertices, o.bounding_box)
+      end
+    end
+
+    def parse_mtllib
+      file = File.open(@model.file_path.sub(File.basename(@model.file_path), "") + @model.material_file, "r")
+      file.readlines.each do |line|
+        array = line.strip.split(" ")
+        case array.first
+        when "newmtl"
+          material = Model::Material.new(array.last)
+          @model.current_material = array.last
+          @model.materials[array.last] = material
+        when "Ns" # Specular Exponent
+        when "Ka" # Ambient color
+          @model.materials[@model.current_material].ambient  = Color.new(Float(array[1]), Float(array[2]),
+                                                                         Float(array[3]))
+        when "Kd" # Diffuse color
+          @model.materials[@model.current_material].diffuse  = Color.new(Float(array[1]), Float(array[2]),
+                                                                         Float(array[3]))
+        when "Ks" # Specular color
+          @model.materials[@model.current_material].specular = Color.new(Float(array[1]), Float(array[2]),
+                                                                         Float(array[3]))
+        when "Ke" # Emissive
+        when "Ni" # Unknown (Blender Specific?)
+        when "d"  # Dissolved (Transparency)
+        when "illum" # Illumination model
+        when "map_Kd" # Diffuse texture
+          texture = File.basename(array[1])
+          texture_path = "#{File.expand_path('../../', @model.file_path)}/textures/#{texture}"
+          @model.materials[@model.current_material].set_texture(texture_path)
+        end
+      end
+    end
+
+    def set_smoothing(value)
+      @model.smoothing = value == "1"
+    end
+
+    def add_vertex(array)
+      @model.vertex_count += 1
+      vert = nil
+      if array.size == 5
+        vert = Vector.new(Float(array[1]), Float(array[2]), Float(array[3]), Float(array[4]))
+      elsif array.size == 4
+        vert = Vector.new(Float(array[1]), Float(array[2]), Float(array[3]), 1.0)
+      else
+        raise
+      end
+      @model.current_object.vertices << vert
+      @model.vertices << vert
+    end
+
+    def add_normal(array)
+      vert = nil
+      if array.size == 5
+        vert = Vector.new(Float(array[1]), Float(array[2]), Float(array[3]), Float(array[4]))
+      elsif array.size == 4
+        vert = Vector.new(Float(array[1]), Float(array[2]), Float(array[3]), 1.0)
+      else
+        raise
+      end
+      @model.current_object.normals << vert
+      @model.normals << vert
+    end
+
+    def add_texture_coordinate(array)
+      texture = nil
+      if array.size == 4
+        texture = Vector.new(Float(array[1]), 1 - Float(array[2]), Float(array[3]))
+      elsif array.size == 3
+        texture = Vector.new(Float(array[1]), 1 - Float(array[2]), 1.0)
+      else
+        raise
+      end
+      @model.uvs << texture
+      @model.current_object.uvs << texture
+    end
+  end
+end

lib/cyberarm_engine/model_cache.rb

@@ -0,0 +1,31 @@
+module CyberarmEngine
+  module ModelCache
+    CACHE = {}
+
+    def self.find_or_cache(manifest:)
+      model_file = manifest.file_path + "/model/#{manifest.model}"
+
+      type = File.basename(model_file).split(".").last.to_sym
+
+      if model = load_model_from_cache(type, model_file)
+        model
+      else
+        model = CyberarmEngine::Model.new(file_path: model_file)
+        cache_model(type, model_file, model)
+
+        model
+      end
+    end
+
+    def self.load_model_from_cache(type, model_file)
+      return CACHE[type][model_file] if CACHE[type].is_a?(Hash) && (CACHE[type][model_file])
+
+      false
+    end
+
+    def self.cache_model(type, model_file, model)
+      CACHE[type] = {} unless CACHE[type].is_a?(Hash)
+      CACHE[type][model_file] = model
+    end
+  end
+end

lib/cyberarm_engine/objects/text.rb

@@ -1,116 +0,0 @@
-module CyberarmEngine
-  class Text
-    CACHE = {}
-
-    attr_accessor :x, :y, :z, :size, :factor_x, :factor_y, :color, :shadow, :shadow_size, :options
-    attr_reader :text, :textobject
-
-    def initialize(text, options={})
-      @text = text.to_s || ""
-      @options = options
-      @size = options[:size] || 18
-      @font = options[:font] || "sans-serif"#Gosu.default_font_name
-      @x = options[:x] || 0
-      @y = options[:y] || 0
-      @z = options[:z] || 1025
-      @factor_x = options[:factor_x]  || 1
-      @factor_y = options[:factor_y]  || 1
-      @color    = options[:color]     || Gosu::Color::WHITE
-      @alignment= options[:alignment] || nil
-      @shadow   = true  if options[:shadow] == true
-      @shadow   = false if options[:shadow] == false
-      @shadow   = true if options[:shadow] == nil
-      @shadow_size = options[:shadow_size] ? options[:shadow_size] : 1
-      @shadow_alpha= options[:shadow_alpha] ? options[:shadow_alpha] : 30
-      @textobject = check_cache(@size, @font)
-
-      if @alignment
-        case @alignment
-        when :left
-          @x = 0+BUTTON_PADDING
-        when :center
-          @x = ($window.width/2)-(@textobject.text_width(@text)/2)
-        when :right
-          @x = $window.width-BUTTON_PADDING-@textobject.text_width(@text)
-        end
-      end
-
-      return self
-    end
-
-    def check_cache(size, font_name)
-      available = false
-      font      = nil
-
-      if CACHE[size]
-        if CACHE[size][font_name]
-          font = CACHE[size][font_name]
-          available = true
-        else
-          available = false
-        end
-      else
-        available = false
-      end
-
-      unless available
-        font = Gosu::Font.new(@size, name: @font)
-        CACHE[@size] = {} unless CACHE[@size].is_a?(Hash)
-        CACHE[@size][@font] = font
-      end
-
-      return font
-    end
-
-    def text=(string)
-      @rendered_shadow = nil
-      @text = string
-    end
-
-    def width
-      textobject.text_width(@text)
-    end
-
-    def height
-      @text.lines.count > 0 ? (@text.lines.count) * textobject.height : @textobject.height
-    end
-
-    def draw
-      if @shadow && !ARGV.join.include?("--no-shadow")
-        @shadow_alpha = 30 if @color.alpha > 30
-        @shadow_alpha = @color.alpha if @color.alpha <= 30
-        shadow_color = Gosu::Color.rgba(@color.red, @color.green, @color.blue, @shadow_alpha)
-
-        _x = @shadow_size
-        _y = @shadow_size
-
-        @rendered_shadow ||= Gosu.render((self.width+(shadow_size*2)).ceil, (self.height+(@shadow_size*2)).ceil) do
-          @textobject.draw_markup(@text, _x-@shadow_size, _y, @z)
-          @textobject.draw_markup(@text, _x-@shadow_size, _y-@shadow_size, @z)
-
-          @textobject.draw_markup(@text, _x, _y-@shadow_size, @z, @factor_x)
-          @textobject.draw_markup(@text, _x+@shadow_size, _y-@shadow_size, @z)
-
-          @textobject.draw_markup(@text, _x, _y+@shadow_size, @z)
-          @textobject.draw_markup(@text, _x-@shadow_size, _y+@shadow_size, @z)
-
-          @textobject.draw_markup(@text, _x+@shadow_size, _y, @z)
-          @textobject.draw_markup(@text, _x+@shadow_size, _y+@shadow_size, @z)
-        end
-        @rendered_shadow.draw(@x-@shadow_size, @y-@shadow_size, @z, @factor_x, @factor_y, shadow_color)
-      end
-
-      @textobject.draw_markup(@text, @x, @y, @z, @factor_x, @factor_y, @color)
-    end
-
-    def alpha=(n)
-      @color = Gosu::Color.rgba(@color.red, @color.green, @color.blue, n)
-    end
-
-    def alpha
-      @color.alpha
-    end
-
-    def update; end
-  end
-end

lib/cyberarm_engine/opengl.rb

@@ -0,0 +1,40 @@
+begin
+  require "opengl"
+rescue LoadError
+  puts "Required gem is not installed, please install 'opengl-bindings' and try again."
+  exit(1)
+end
+
+module CyberarmEngine
+  def gl_error?
+    e = glGetError
+    if e != GL_NO_ERROR
+      warn "OpenGL error detected by handler at: #{caller[0]}"
+      warn "    #{gluErrorString(e)} (#{e})\n"
+      exit if Window.instance&.exit_on_opengl_error?
+    end
+  end
+
+  def preload_default_shaders
+    shaders = %w[g_buffer lighting]
+    shaders.each do |shader|
+      Shader.new(
+        name: shader,
+        includes_dir: "#{CYBERARM_ENGINE_ROOT_PATH}/assets/shaders/include",
+        vertex: "#{CYBERARM_ENGINE_ROOT_PATH}/assets/shaders/vertex/#{shader}.glsl",
+        fragment: "#{CYBERARM_ENGINE_ROOT_PATH}/assets/shaders/fragment/#{shader}.glsl"
+      )
+    end
+  end
+end
+
+require_relative "opengl/shader"
+require_relative "opengl/texture"
+require_relative "opengl/light"
+require_relative "opengl/perspective_camera"
+require_relative "opengl/orthographic_camera"
+
+require_relative "opengl/renderer/g_buffer"
+require_relative "opengl/renderer/bounding_box_renderer"
+require_relative "opengl/renderer/opengl_renderer"
+require_relative "opengl/renderer/renderer"

lib/cyberarm_engine/opengl/light.rb

@@ -0,0 +1,50 @@
+module CyberarmEngine
+  class Light
+    DIRECTIONAL = 0
+    POINT = 1
+    SPOT = 2
+
+    attr_reader :light_id
+    attr_accessor :type, :ambient, :diffuse, :specular, :position, :direction, :intensity
+
+    def initialize(
+      id:,
+      type: Light::POINT,
+      ambient: Vector.new(0.5, 0.5, 0.5),
+      diffuse: Vector.new(1, 1, 1),
+      specular: Vector.new(0.2, 0.2, 0.2),
+      position: Vector.new(0, 0, 0),
+      direction: Vector.new(0, 0, 0),
+      intensity: 1
+    )
+      @light_id = id
+      @type = type
+
+      @ambient  = ambient
+      @diffuse  = diffuse
+      @specular = specular
+      @position = position
+      @direction = direction
+
+      @intensity = intensity
+    end
+
+    def draw
+      glLightfv(@light_id, GL_AMBIENT, convert(@ambient).pack("f*"))
+      glLightfv(@light_id, GL_DIFFUSE, convert(@diffuse, true).pack("f*"))
+      glLightfv(@light_id, GL_SPECULAR, convert(@specular, true).pack("f*"))
+      glLightfv(@light_id, GL_POSITION, convert(@position).pack("f*"))
+      glLightModeli(GL_LIGHT_MODEL_LOCAL_VIEWER, 1)
+      glEnable(GL_LIGHTING)
+      glEnable(@light_id)
+    end
+
+    def convert(struct, apply_intensity = false)
+      if apply_intensity
+        struct.to_a.compact.map { |i| i * @intensity }
+      else
+        struct.to_a.compact
+      end
+    end
+  end
+end

lib/cyberarm_engine/opengl/orthographic_camera.rb

@@ -0,0 +1,46 @@
+module CyberarmEngine
+  class OrthographicCamera
+    attr_accessor :position, :orientation, :zoom, :left, :right, :bottom, :top,
+                  :min_view_distance, :max_view_distance
+
+    def initialize(
+      position:, right:, top:, orientation: Vector.new(0, 0, 0),
+      zoom: 1, left: 0, bottom: 0,
+      min_view_distance: 0.1, max_view_distance: 200.0
+    )
+      @position = position
+      @orientation = orientation
+
+      @zoom = zoom
+
+      @left = left
+      @right = right
+      @bottom = bottom
+      @top = top
+
+      @min_view_distance = min_view_distance
+      @max_view_distance = max_view_distance
+    end
+
+    # Immediate mode renderering fallback
+    def draw
+      glMatrixMode(GL_PROJECTION)
+      glLoadIdentity
+      glOrtho(@left, @right, @bottom, @top, @min_view_distance, @max_view_distance)
+      glHint(GL_PERSPECTIVE_CORRECTION_HINT, GL_NICEST)
+      glRotatef(@orientation.x, 1, 0, 0)
+      glRotatef(@orientation.y, 0, 1, 0)
+      glTranslatef(-@position.x, -@position.y, -@position.z)
+      glMatrixMode(GL_MODELVIEW)
+      glLoadIdentity
+    end
+
+    def projection_matrix
+      Transform.orthographic(@left, @right, @bottom, @top, @min_view_distance, @max_view_distance)
+    end
+
+    def view_matrix
+      Transform.translate_3d(@position * -1) * Transform.rotate_3d(@orientation)
+    end
+  end
+end

lib/cyberarm_engine/opengl/perspective_camera.rb

@@ -0,0 +1,38 @@
+module CyberarmEngine
+  class PerspectiveCamera
+    attr_accessor :position, :orientation, :aspect_ratio, :field_of_view,
+                  :min_view_distance, :max_view_distance
+
+    def initialize(position:, aspect_ratio:, orientation: Vector.new(0, 0, 0),
+                   field_of_view: 70.0, min_view_distance: 0.1, max_view_distance: 1024.0)
+      @position = position
+      @orientation = orientation
+
+      @aspect_ratio = aspect_ratio
+      @field_of_view = field_of_view
+
+      @min_view_distance = min_view_distance
+      @max_view_distance = max_view_distance
+    end
+
+    def draw
+      glMatrixMode(GL_PROJECTION)
+      glLoadIdentity
+      gluPerspective(@field_of_view, @aspect_ratio, @min_view_distance, @max_view_distance)
+      glHint(GL_PERSPECTIVE_CORRECTION_HINT, GL_NICEST)
+      glRotatef(@orientation.x, 1, 0, 0)
+      glRotatef(@orientation.y, 0, 1, 0)
+      glTranslatef(-@position.x, -@position.y, -@position.z)
+      glMatrixMode(GL_MODELVIEW)
+      glLoadIdentity
+    end
+
+    def projection_matrix
+      Transform.perspective(@field_of_view, @aspect_ratio, @min_view_distance, @max_view_distance)
+    end
+
+    def view_matrix
+      Transform.translate_3d(@position * -1) * Transform.rotate_3d(@orientation)
+    end
+  end
+end

lib/cyberarm_engine/opengl/renderer/bounding_box_renderer.rb

@@ -0,0 +1,249 @@
+module CyberarmEngine
+  class BoundingBoxRenderer
+    attr_reader :bounding_boxes, :vertex_count
+
+    def initialize
+      @bounding_boxes = {}
+      @vertex_count = 0
+    end
+
+    def render(entities)
+      entities.each do |entity|
+        create_bounding_box(entity, color = nil)
+        draw_bounding_boxes
+      end
+
+      (@bounding_boxes.keys - entities.map { |e| e.object_id }).each do |key|
+        @bounding_boxes.delete(key)
+      end
+    end
+
+    def create_bounding_box(entity, color = nil)
+      color ||= entity.debug_color
+      entity_id = entity.object_id
+
+      if @bounding_boxes[entity_id]
+        if @bounding_boxes[entity_id][:color] != color
+          @bounding_boxes[entity_id][:colors] = mesh_colors(color).pack("f*")
+          @bounding_boxes[entity_id][:color]  = color
+          return
+        else
+          return
+        end
+      end
+
+      @bounding_boxes[entity_id] = {
+        entity: entity,
+        color: color,
+        objects: []
+      }
+
+      box = entity.normalize_bounding_box
+
+      normals  = mesh_normals
+      colors   = mesh_colors(color)
+      vertices = mesh_vertices(box)
+
+      @vertex_count += vertices.size
+
+      @bounding_boxes[entity_id][:vertices_size] = vertices.size
+      @bounding_boxes[entity_id][:vertices]      = vertices.pack("f*")
+      @bounding_boxes[entity_id][:normals]       = normals.pack("f*")
+      @bounding_boxes[entity_id][:colors]        = colors.pack("f*")
+
+      entity.model.objects.each do |mesh|
+        data = {}
+        box = mesh.bounding_box.normalize(entity)
+
+        normals  = mesh_normals
+        colors   = mesh_colors(mesh.debug_color)
+        vertices = mesh_vertices(box)
+
+        @vertex_count += vertices.size
+
+        data[:vertices_size] = vertices.size
+        data[:vertices]      = vertices.pack("f*")
+        data[:normals]       = normals.pack("f*")
+        data[:colors]        = colors.pack("f*")
+
+        @bounding_boxes[entity_id][:objects] << data
+      end
+    end
+
+    def mesh_normals
+      [
+        0, 1, 0,
+        0, 1, 0,
+        0, 1, 0,
+        0, 1, 0,
+        0, 1, 0,
+        0, 1, 0,
+
+        0, -1, 0,
+        0, -1, 0,
+        0, -1, 0,
+        0, -1, 0,
+        0, -1, 0,
+        0, -1, 0,
+
+        0, 0, 1,
+        0, 0, 1,
+        0, 0, 1,
+        0, 0, 1,
+        0, 0, 1,
+        0, 0, 1,
+
+        1, 0, 0,
+        1, 0, 0,
+        1, 0, 0,
+        1, 0, 0,
+        1, 0, 0,
+        1, 0, 0,
+
+        -1, 0, 0,
+        -1, 0, 0,
+        -1, 0, 0,
+        -1, 0, 0,
+        -1, 0, 0,
+        -1, 0, 0,
+
+        -1, 0, 0,
+        -1, 0, 0,
+        -1, 0, 0,
+
+        -1, 0, 0,
+        -1, 0, 0,
+        -1, 0, 0
+      ]
+    end
+
+    def mesh_colors(color)
+      [
+        color.red, color.green, color.blue,
+        color.red, color.green, color.blue,
+        color.red, color.green, color.blue,
+        color.red, color.green, color.blue,
+        color.red, color.green, color.blue,
+        color.red, color.green, color.blue,
+        color.red, color.green, color.blue,
+        color.red, color.green, color.blue,
+        color.red, color.green, color.blue,
+        color.red, color.green, color.blue,
+        color.red, color.green, color.blue,
+        color.red, color.green, color.blue,
+        color.red, color.green, color.blue,
+        color.red, color.green, color.blue,
+        color.red, color.green, color.blue,
+        color.red, color.green, color.blue,
+        color.red, color.green, color.blue,
+        color.red, color.green, color.blue,
+        color.red, color.green, color.blue,
+        color.red, color.green, color.blue,
+        color.red, color.green, color.blue,
+        color.red, color.green, color.blue,
+        color.red, color.green, color.blue,
+        color.red, color.green, color.blue,
+        color.red, color.green, color.blue,
+        color.red, color.green, color.blue,
+        color.red, color.green, color.blue,
+        color.red, color.green, color.blue,
+        color.red, color.green, color.blue,
+        color.red, color.green, color.blue,
+        color.red, color.green, color.blue,
+        color.red, color.green, color.blue,
+        color.red, color.green, color.blue,
+        color.red, color.green, color.blue,
+        color.red, color.green, color.blue,
+        color.red, color.green, color.blue
+      ]
+    end
+
+    def mesh_vertices(box)
+      [
+        box.min.x, box.max.y, box.max.z,
+        box.min.x, box.max.y, box.min.z,
+        box.max.x, box.max.y, box.min.z,
+
+        box.min.x, box.max.y, box.max.z,
+        box.max.x, box.max.y, box.max.z,
+        box.max.x, box.max.y, box.min.z,
+
+        box.max.x, box.min.y, box.min.z,
+        box.max.x, box.min.y, box.max.z,
+        box.min.x, box.min.y, box.max.z,
+
+        box.max.x, box.min.y, box.min.z,
+        box.min.x, box.min.y, box.min.z,
+        box.min.x, box.min.y, box.max.z,
+
+        box.min.x, box.max.y, box.max.z,
+        box.min.x, box.max.y, box.min.z,
+        box.min.x, box.min.y, box.min.z,
+
+        box.min.x, box.min.y, box.max.z,
+        box.min.x, box.min.y, box.min.z,
+        box.min.x, box.max.y, box.max.z,
+
+        box.max.x, box.max.y, box.max.z,
+        box.max.x, box.max.y, box.min.z,
+        box.max.x, box.min.y, box.min.z,
+
+        box.max.x, box.min.y, box.max.z,
+        box.max.x, box.min.y, box.min.z,
+        box.max.x, box.max.y, box.max.z,
+
+        box.min.x, box.max.y, box.max.z,
+        box.max.x, box.max.y, box.max.z,
+        box.max.x, box.min.y, box.max.z,
+
+        box.min.x, box.max.y, box.max.z,
+        box.max.x, box.min.y, box.max.z,
+        box.min.x, box.min.y, box.max.z,
+
+        box.max.x, box.min.y, box.min.z,
+        box.min.x, box.min.y, box.min.z,
+        box.min.x, box.max.y, box.min.z,
+
+        box.max.x, box.min.y, box.min.z,
+        box.min.x, box.max.y, box.min.z,
+        box.max.x, box.max.y, box.min.z
+      ]
+    end
+
+    def draw_bounding_boxes
+      @bounding_boxes.each do |key, bounding_box|
+        glPushMatrix
+
+        glTranslatef(
+          bounding_box[:entity].position.x,
+          bounding_box[:entity].position.y,
+          bounding_box[:entity].position.z
+        )
+        draw_bounding_box(bounding_box)
+        @bounding_boxes[key][:objects].each { |o| draw_bounding_box(o) }
+
+        glPopMatrix
+      end
+    end
+
+    def draw_bounding_box(bounding_box)
+      glEnableClientState(GL_VERTEX_ARRAY)
+      glEnableClientState(GL_COLOR_ARRAY)
+      glEnableClientState(GL_NORMAL_ARRAY)
+
+      glVertexPointer(3, GL_FLOAT, 0, bounding_box[:vertices])
+      glColorPointer(3, GL_FLOAT, 0, bounding_box[:colors])
+      glNormalPointer(GL_FLOAT, 0, bounding_box[:normals])
+
+      glPolygonMode(GL_FRONT_AND_BACK, GL_LINE)
+      glDisable(GL_LIGHTING)
+      glDrawArrays(GL_TRIANGLES, 0, bounding_box[:vertices_size] / 3)
+      glEnable(GL_LIGHTING)
+      glPolygonMode(GL_FRONT_AND_BACK, GL_FILL)
+
+      glDisableClientState(GL_VERTEX_ARRAY)
+      glDisableClientState(GL_COLOR_ARRAY)
+      glDisableClientState(GL_NORMAL_ARRAY)
+    end
+  end
+end

lib/cyberarm_engine/opengl/renderer/g_buffer.rb

@@ -0,0 +1,165 @@
+module CyberarmEngine
+  class GBuffer
+    attr_reader :screen_vbo, :vertices, :uvs
+    attr_reader :width, :height
+
+    def initialize(width:, height:)
+      @width = width
+      @height = height
+
+      @framebuffer = nil
+      @buffers = %i[position diffuse normal texcoord]
+      @textures = {}
+      @screen_vbo = nil
+      @ready = false
+
+      @vertices = [
+        -1.0, -1.0, 0,
+        1.0,  -1.0, 0,
+        -1.0,  1.0, 0,
+
+        -1.0,  1.0, 0,
+        1.0, -1.0, 0,
+        1.0, 1.0, 0
+      ].freeze
+
+      @uvs = [
+        0, 0,
+        1, 0,
+        0, 1,
+
+        0, 1,
+        1, 0,
+        1, 1
+      ].freeze
+
+      create_framebuffer
+      create_screen_vbo
+    end
+
+    def create_framebuffer
+      buffer = " " * 4
+      glGenFramebuffers(1, buffer)
+      @framebuffer = buffer.unpack1("L2")
+
+      glBindFramebuffer(GL_DRAW_FRAMEBUFFER, @framebuffer)
+
+      create_textures
+
+      status = glCheckFramebufferStatus(GL_FRAMEBUFFER)
+
+      if status != GL_FRAMEBUFFER_COMPLETE
+        message = ""
+
+        message = case status
+                  when GL_FRAMEBUFFER_INCOMPLETE_ATTACHMENT
+                    "GL_FRAMEBUFFER_INCOMPLETE_ATTACHMENT"
+                  when GL_FRAMEBUFFER_INCOMPLETE_MISSING_ATTACHMENT
+                    "GL_FRAMEBUFFER_INCOMPLETE_MISSING_ATTACHMENT"
+                  when GL_FRAMEBUFFER_INCOMPLETE_DRAW_BUFFER
+                    "GL_FRAMEBUFFER_INCOMPLETE_DRAW_BUFFER"
+                  when GL_FRAMEBUFFER_INCOMPLETE_READ_BUFFER
+                    "GL_FRAMEBUFFER_INCOMPLETE_READ_BUFFER"
+                  when GL_FRAMEBUFFER_UNSUPPORTED
+                    "GL_FRAMEBUFFER_UNSUPPORTED"
+                  else
+                    "Unknown error!"
+                  end
+        puts "Incomplete framebuffer: #{status}\nError: #{message}"
+      else
+        @ready = true
+      end
+
+      glBindFramebuffer(GL_DRAW_FRAMEBUFFER, 0)
+    end
+
+    def create_textures
+      @buffers.size.times do |i|
+        buffer = " " * 4
+        glGenTextures(1, buffer)
+        texture_id = buffer.unpack1("L2")
+        @textures[@buffers[i]] = texture_id
+
+        glBindTexture(GL_TEXTURE_2D, texture_id)
+        glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA16F, @width, @height, 0, GL_RGBA, GL_FLOAT, nil)
+        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR)
+        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR)
+        glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0 + i, GL_TEXTURE_2D, texture_id, 0)
+      end
+
+      buffer = " " * 4
+      glGenTextures(1, buffer)
+      texture_id = buffer.unpack1("L2")
+      @textures[:depth] = texture_id
+
+      glBindTexture(GL_TEXTURE_2D, texture_id)
+      glTexImage2D(GL_TEXTURE_2D, 0, GL_DEPTH_COMPONENT32F, @width, @height, 0, GL_DEPTH_COMPONENT, GL_FLOAT, nil)
+      glFramebufferTexture2D(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, GL_TEXTURE_2D, texture_id, 0)
+
+      draw_buffers = [GL_COLOR_ATTACHMENT0, GL_COLOR_ATTACHMENT1, GL_COLOR_ATTACHMENT2, GL_COLOR_ATTACHMENT3]
+      glDrawBuffers(draw_buffers.size, draw_buffers.pack("I*"))
+    end
+
+    def create_screen_vbo
+      buffer = " " * 4
+      glGenVertexArrays(1, buffer)
+      @screen_vbo = buffer.unpack1("L2")
+
+      buffer = " " * 4
+      glGenBuffers(1, buffer)
+      @positions_buffer_id = buffer.unpack1("L2")
+
+      buffer = " " * 4
+      glGenBuffers(1, buffer)
+      @uvs_buffer_id = buffer.unpack1("L2")
+
+      glBindVertexArray(@screen_vbo)
+      glBindBuffer(GL_ARRAY_BUFFER, @positions_buffer_id)
+      glBufferData(GL_ARRAY_BUFFER, @vertices.size * Fiddle::SIZEOF_FLOAT, @vertices.pack("f*"), GL_STATIC_DRAW)
+      glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 0, nil)
+
+      glBindBuffer(GL_ARRAY_BUFFER, @uvs_buffer_id)
+      glBufferData(GL_ARRAY_BUFFER, @uvs.size * Fiddle::SIZEOF_FLOAT, @uvs.pack("f*"), GL_STATIC_DRAW)
+      glVertexAttribPointer(1, 2, GL_FLOAT, GL_FALSE, 0, nil)
+
+      glEnableVertexAttribArray(0)
+      glEnableVertexAttribArray(1)
+
+      glBindVertexArray(0)
+    end
+
+    def bind_for_writing
+      glBindFramebuffer(GL_DRAW_FRAMEBUFFER, @framebuffer)
+    end
+
+    def bind_for_reading
+      glBindFramebuffer(GL_READ_FRAMEBUFFER, @framebuffer)
+    end
+
+    def set_read_buffer(buffer)
+      glReadBuffer(GL_COLOR_ATTACHMENT0 + @textures.keys.index(buffer))
+    end
+
+    def set_read_buffer_depth
+      glReadBuffer(GL_DEPTH_ATTACHMENT)
+    end
+
+    def unbind_framebuffer
+      glBindFramebuffer(GL_FRAMEBUFFER, 0)
+    end
+
+    def texture(type)
+      @textures[type]
+    end
+
+    def clean_up
+      glDeleteFramebuffers(1, [@framebuffer].pack("L"))
+
+      glDeleteTextures(@textures.values.size, @textures.values.pack("L*"))
+
+      glDeleteBuffers(2, [@positions_buffer_id, @uvs_buffer_id].pack("L*"))
+      glDeleteVertexArrays(1, [@screen_vbo].pack("L"))
+      gl_error?
+    end
+  end
+end

lib/cyberarm_engine/opengl/renderer/opengl_renderer.rb

@@ -0,0 +1,304 @@
+module CyberarmEngine
+  class OpenGLRenderer
+    @@immediate_mode_warning = false
+
+    attr_accessor :show_wireframe
+    attr_reader :number_of_vertices
+
+    def initialize(width:, height:, show_wireframe: false)
+      @width = width
+      @height = height
+      @show_wireframe = show_wireframe
+
+      @number_of_vertices = 0
+
+      @g_buffer = GBuffer.new(width: @width, height: @height)
+    end
+
+    def canvas_size_changed
+      @g_buffer.unbind_framebuffer
+      @g_buffer.clean_up
+
+      @g_buffer = GBuffer.new(width: @width, height: @height)
+    end
+
+    def render(camera, lights, entities)
+      @number_of_vertices = 0
+
+      glViewport(0, 0, @width, @height)
+      glEnable(GL_DEPTH_TEST)
+
+      if Shader.available?("g_buffer") && Shader.available?("lighting")
+        @g_buffer.bind_for_writing
+        gl_error?
+
+        glClearColor(0.0, 0.0, 0.0, 0.0)
+        glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT)
+
+        Shader.use("g_buffer") do |shader|
+          gl_error?
+
+          entities.each do |entity|
+            next unless entity.visible && entity.renderable
+
+            shader.uniform_transform("projection", camera.projection_matrix)
+            shader.uniform_transform("view", camera.view_matrix)
+            shader.uniform_transform("model", entity.model_matrix)
+            shader.uniform_vector3("camera_position", camera.position)
+
+            gl_error?
+            draw_model(entity.model, shader)
+            entity.draw
+
+            @number_of_vertices += entity.model.vertices_count
+          end
+        end
+
+        @g_buffer.unbind_framebuffer
+        gl_error?
+
+        @g_buffer.bind_for_reading
+        glBindFramebuffer(GL_DRAW_FRAMEBUFFER, 0)
+
+        lighting(lights)
+        gl_error?
+
+        post_processing
+        gl_error?
+
+        # render_framebuffer
+        gl_error?
+
+        @g_buffer.unbind_framebuffer
+        gl_error?
+      else
+        unless @@immediate_mode_warning
+          puts "Shaders are disabled or failed to compile, using immediate mode for rendering..."
+        end
+        @@immediate_mode_warning = true
+
+        gl_error?
+        lights.each(&:draw)
+        camera.draw
+
+        glEnable(GL_NORMALIZE)
+        entities.each do |entity|
+          next unless entity.visible && entity.renderable
+
+          glPushMatrix
+
+          glTranslatef(entity.position.x, entity.position.y, entity.position.z)
+          glScalef(entity.scale.x, entity.scale.y, entity.scale.z)
+          glRotatef(entity.orientation.x, 1.0, 0, 0)
+          glRotatef(entity.orientation.y, 0, 1.0, 0)
+          glRotatef(entity.orientation.z, 0, 0, 1.0)
+
+          gl_error?
+          draw_mesh(entity.model)
+          entity.draw
+          glPopMatrix
+
+          @number_of_vertices += entity.model.vertices_count
+        end
+      end
+
+      gl_error?
+    end
+
+    def copy_g_buffer_to_screen
+      @g_buffer.set_read_buffer(:position)
+      glBlitFramebuffer(0, 0, @g_buffer.width, @g_buffer.height,
+                        0, 0, @g_buffer.width / 2, @g_buffer.height / 2,
+                        GL_COLOR_BUFFER_BIT, GL_LINEAR)
+
+      @g_buffer.set_read_buffer(:diffuse)
+      glBlitFramebuffer(0, 0, @g_buffer.width, @g_buffer.height,
+                        0, @g_buffer.height / 2, @g_buffer.width / 2, @g_buffer.height,
+                        GL_COLOR_BUFFER_BIT, GL_LINEAR)
+
+      @g_buffer.set_read_buffer(:normal)
+      glBlitFramebuffer(0, 0, @g_buffer.width, @g_buffer.height,
+                        @g_buffer.width / 2, @g_buffer.height / 2, @g_buffer.width, @g_buffer.height,
+                        GL_COLOR_BUFFER_BIT, GL_LINEAR)
+
+      @g_buffer.set_read_buffer(:texcoord)
+      glBlitFramebuffer(0, 0, @g_buffer.width, @g_buffer.height,
+                        @g_buffer.width / 2, 0, @g_buffer.width, @g_buffer.height / 2,
+                        GL_COLOR_BUFFER_BIT, GL_LINEAR)
+    end
+
+    def lighting(lights)
+      Shader.use("lighting") do |shader|
+        glBindVertexArray(@g_buffer.screen_vbo)
+
+        glDisable(GL_DEPTH_TEST)
+        glEnable(GL_BLEND)
+
+        glActiveTexture(GL_TEXTURE0)
+        glBindTexture(GL_TEXTURE_2D, @g_buffer.texture(:diffuse))
+        shader.uniform_integer("diffuse", 0)
+
+        glActiveTexture(GL_TEXTURE1)
+        glBindTexture(GL_TEXTURE_2D, @g_buffer.texture(:position))
+        shader.uniform_integer("position", 1)
+
+        glActiveTexture(GL_TEXTURE2)
+        glBindTexture(GL_TEXTURE_2D, @g_buffer.texture(:texcoord))
+        shader.uniform_integer("texcoord", 2)
+
+        glActiveTexture(GL_TEXTURE3)
+        glBindTexture(GL_TEXTURE_2D, @g_buffer.texture(:normal))
+        shader.uniform_integer("normal", 3)
+
+        glActiveTexture(GL_TEXTURE4)
+        glBindTexture(GL_TEXTURE_2D, @g_buffer.texture(:depth))
+        shader.uniform_integer("depth", 4)
+
+        # FIXME: Try to figure out how to up this to 32 and/or beyond
+        #        (currently fails with more then 7 lights passed in to shader)
+        lights.each_slice(7).each do |light_group|
+          light_group.each_with_index do |light, _i|
+            shader.uniform_integer("light_count", light_group.size)
+
+            shader.uniform_integer("lights[#{_i}].type",      light.type)
+            shader.uniform_vector3("lights[#{_i}].direction", light.direction)
+            shader.uniform_vector3("lights[#{_i}].position",  light.position)
+            shader.uniform_vector3("lights[#{_i}].diffuse",   light.diffuse)
+            shader.uniform_vector3("lights[#{_i}].ambient",   light.ambient)
+            shader.uniform_vector3("lights[#{_i}].specular",  light.specular)
+
+            glDrawArrays(GL_TRIANGLES, 0, @g_buffer.vertices.size)
+          end
+        end
+
+        glBindVertexArray(0)
+      end
+    end
+
+    def post_processing
+    end
+
+    def render_framebuffer
+      if Shader.available?("lighting")
+        Shader.use("lighting") do |shader|
+          glBindVertexArray(@g_buffer.screen_vbo)
+
+          glDisable(GL_DEPTH_TEST)
+          glEnable(GL_BLEND)
+
+          glActiveTexture(GL_TEXTURE0)
+          glBindTexture(GL_TEXTURE_2D, @g_buffer.texture(:diffuse))
+          shader.uniform_integer("diffuse_texture", 0)
+
+          glDrawArrays(GL_TRIANGLES, 0, @g_buffer.vertices.size)
+
+          glBindVertexArray(0)
+        end
+      end
+    end
+
+    def draw_model(model, shader)
+      glBindVertexArray(model.vertex_array_id)
+      glEnableVertexAttribArray(0)
+      glEnableVertexAttribArray(1)
+      glEnableVertexAttribArray(2)
+      if model.has_texture?
+        glEnableVertexAttribArray(3)
+        glEnableVertexAttribArray(4)
+      end
+
+      if @show_wireframe
+        glLineWidth(2)
+        glPolygonMode(GL_FRONT_AND_BACK, GL_LINE)
+        Shader.active_shader.uniform_boolean("disableLighting", true)
+
+        glDrawArrays(GL_TRIANGLES, 0, model.faces.count * 3)
+
+        Shader.active_shader.uniform_boolean("disableLighting", false)
+        glPolygonMode(GL_FRONT_AND_BACK, GL_FILL)
+        glLineWidth(1)
+      end
+
+      offset = 0
+      model.objects.each do |object|
+        shader.uniform_boolean("has_texture", object.has_texture?)
+
+        if object.has_texture?
+          glBindTexture(GL_TEXTURE_2D, object.materials.find { |mat| mat.texture_id }.texture_id)
+        else
+          glBindTexture(GL_TEXTURE_2D, 0)
+        end
+
+        glDrawArrays(GL_TRIANGLES, offset, object.faces.count * 3)
+        offset += object.faces.count * 3
+      end
+
+      if model.has_texture?
+        glDisableVertexAttribArray(4)
+        glDisableVertexAttribArray(3)
+
+        glBindTexture(GL_TEXTURE_2D, 0)
+      end
+      glDisableVertexAttribArray(2)
+      glDisableVertexAttribArray(1)
+      glDisableVertexAttribArray(0)
+
+      glBindBuffer(GL_ARRAY_BUFFER, 0)
+      glBindVertexArray(0)
+    end
+
+    def draw_mesh(model)
+      model.objects.each_with_index do |o, _i|
+        glEnable(GL_COLOR_MATERIAL)
+        glColorMaterial(GL_FRONT_AND_BACK, GL_AMBIENT_AND_DIFFUSE)
+        glShadeModel(GL_FLAT) unless o.faces.first[4]
+        glShadeModel(GL_SMOOTH) if o.faces.first[4]
+        glEnableClientState(GL_VERTEX_ARRAY)
+        glEnableClientState(GL_COLOR_ARRAY)
+        glEnableClientState(GL_NORMAL_ARRAY)
+
+        if o.has_texture?
+          glEnable(GL_TEXTURE_2D)
+          glBindTexture(GL_TEXTURE_2D, o.materials.find { |mat| mat.texture_id }.texture_id)
+          glEnableClientState(GL_TEXTURE_COORD_ARRAY)
+          glTexCoordPointer(3, GL_FLOAT, 0, o.flattened_uvs)
+        end
+
+        glVertexPointer(4, GL_FLOAT, 0, o.flattened_vertices)
+        glColorPointer(3, GL_FLOAT, 0, o.flattened_materials)
+        glNormalPointer(GL_FLOAT, 0, o.flattened_normals)
+
+        if @show_wireframe # This is kinda expensive
+          glDisable(GL_LIGHTING)
+          glPolygonMode(GL_FRONT_AND_BACK, GL_LINE)
+          glPolygonOffset(2, 0.5)
+          glLineWidth(3)
+
+          glDrawArrays(GL_TRIANGLES, 0, o.flattened_vertices_size / 4)
+
+          glLineWidth(1)
+          glPolygonOffset(0, 0)
+          glPolygonMode(GL_FRONT_AND_BACK, GL_FILL)
+          glEnable(GL_LIGHTING)
+
+          glDrawArrays(GL_TRIANGLES, 0, o.flattened_vertices_size / 4)
+        else
+          glDrawArrays(GL_TRIANGLES, 0, o.flattened_vertices_size / 4)
+        end
+
+        # glBindBuffer(GL_ARRAY_BUFFER, 0)
+
+        glDisableClientState(GL_VERTEX_ARRAY)
+        glDisableClientState(GL_COLOR_ARRAY)
+        glDisableClientState(GL_NORMAL_ARRAY)
+
+        if o.has_texture?
+          glDisableClientState(GL_TEXTURE_COORD_ARRAY)
+          glDisable(GL_TEXTURE_2D)
+        end
+
+        glDisable(GL_COLOR_MATERIAL)
+      end
+    end
+  end
+end

lib/cyberarm_engine/opengl/renderer/renderer.rb

@@ -0,0 +1,33 @@
+module CyberarmEngine
+  class Renderer
+    attr_reader :opengl_renderer, :bounding_box_renderer
+
+    def initialize
+      @bounding_box_renderer = BoundingBoxRenderer.new
+      @opengl_renderer = OpenGLRenderer.new(width: CyberarmEngine::Window.instance.width, height: CyberarmEngine::Window.instance.height)
+    end
+
+    def draw(camera, lights, entities)
+      Stats.frame.start_timing(:opengl_renderer)
+
+      Stats.frame.start_timing(:opengl_model_renderer)
+      @opengl_renderer.render(camera, lights, entities)
+      Stats.frame.end_timing(:opengl_model_renderer)
+
+      if @show_bounding_boxes
+        Stats.frame.start_timing(:opengl_boundingbox_renderer)
+        @bounding_box_renderer.render(entities)
+        Stats.frame.end_timing(:opengl_boundingbox_renderer)
+      end
+
+      Stats.frame.end_timing(:opengl_renderer)
+    end
+
+    def canvas_size_changed
+      @opengl_renderer.canvas_size_changed
+    end
+
+    def finalize # cleanup
+    end
+  end
+end

lib/cyberarm_engine/opengl/shader.rb

@@ -0,0 +1,406 @@
+module CyberarmEngine
+  # Ref: https://github.com/vaiorabbit/ruby-opengl/blob/master/sample/OrangeBook/brick.rb
+  class Shader
+    include OpenGL
+    @@shaders = {} # Cache for {Shader} instances
+    PREPROCESSOR_CHARACTER = "@".freeze # magic character for preprocessor phase of {Shader} compilation
+
+    # add instance of {Shader} to cache
+    #
+    # @param name [String]
+    # @param instance [Shader]
+    def self.add(name, instance)
+      @@shaders[name] = instance
+    end
+
+    # removes {Shader} from cache and cleans up
+    #
+    # @param name [String]
+    def self.delete(name)
+      shader = @@shaders.dig(name)
+
+      if shader
+        @@shaders.delete(name)
+
+        glDeleteProgram(shader.program) if shader.compiled?
+      end
+    end
+
+    ##
+    # runs _block_ using {Shader} with _name_
+    #
+    # @example
+    #
+    #   CyberarmEngine::Shader.use("blur") do |shader|
+    #     shader.uniform_float("radius", 20.0)
+    #     # OpenGL Code that uses shader
+    #   end
+    #
+    # @param name [String] name of {Shader} to use
+    # @return [void]
+    def self.use(name, &block)
+      shader = @@shaders.dig(name)
+      if shader
+        shader.use(&block)
+      else
+        raise ArgumentError, "Shader '#{name}' not found!"
+      end
+    end
+
+    # returns whether {Shader} with _name_ is in cache
+    #
+    # @param name [String]
+    # @return [Boolean]
+    def self.available?(name)
+      @@shaders.dig(name).is_a?(Shader)
+    end
+
+    # returns instance of {Shader}, if it exists
+    #
+    # @param name [String]
+    # @return [Shader?]
+    def self.get(name)
+      @@shaders.dig(name)
+    end
+
+    # returns currently active {Shader}, if one is active
+    #
+    # @return [Shader?]
+    class << self
+      attr_reader :active_shader
+    end
+
+    # sets currently active {Shader}
+    #
+    # @param instance [Shader] instance of {Shader} to set as active
+    class << self
+      attr_writer :active_shader
+    end
+
+    # stops using currently active {Shader}
+    def self.stop
+      shader = Shader.active_shader
+
+      if shader
+        shader.stop
+      else
+        raise ArgumentError, "No active shader to stop!"
+      end
+    end
+
+    # returns location of OpenGL Shader uniform
+    #
+    # @param variable [String]
+    def self.attribute_location(variable)
+      raise "No active shader!" unless Shader.active_shader
+
+      Shader.active_shader.attribute_location(variable)
+    end
+
+    # sets _variable_ to _value_
+    #
+    # @param variable [String]
+    # @param value
+    def self.set_uniform(variable, value)
+      raise "No active shader!" unless Shader.active_shader
+
+      Shader.active_shader.set_uniform(variable, value)
+    end
+
+    attr_reader :name, :program
+
+    def initialize(name:, fragment:, includes_dir: nil, vertex: "shaders/default.vert")
+      raise "Shader name can not be blank" if name.length == 0
+
+      @name = name
+      @includes_dir = includes_dir
+      @compiled = false
+
+      @program = nil
+
+      @error_buffer_size = 1024 * 8
+      @variable_missing = {}
+
+      @data = { shaders: {} }
+
+      unless shader_files_exist?(vertex: vertex, fragment: fragment)
+        raise ArgumentError, "Shader files not found: #{vertex} or #{fragment}"
+      end
+
+      create_shader(type: :vertex, source: File.read(vertex))
+      create_shader(type: :fragment, source: File.read(fragment))
+
+      compile_shader(type: :vertex)
+      compile_shader(type: :fragment)
+      link_shaders
+
+      @data[:shaders].each { |_key, id| glDeleteShader(id) }
+
+      # Only add shader if it successfully compiles
+      if @compiled
+        puts "compiled!"
+        puts "Compiled shader: #{@name}"
+        Shader.add(@name, self)
+      else
+        glDeleteProgram(@program)
+        warn "FAILED to compile shader: #{@name}", ""
+      end
+    end
+
+    # whether vertex and fragment files exist on disk
+    #
+    # @return [Boolean]
+    def shader_files_exist?(vertex:, fragment:)
+      File.exist?(vertex) && File.exist?(fragment)
+    end
+
+    # creates an OpenGL Shader of _type_ using _source_
+    #
+    # @param type [Symbol] valid values are: :vertex, :fragment
+    # @param source [String] source code for shader
+    def create_shader(type:, source:)
+      _shader = nil
+
+      case type
+      when :vertex
+        _shader = glCreateShader(GL_VERTEX_SHADER)
+      when :fragment
+        _shader = glCreateShader(GL_FRAGMENT_SHADER)
+      else
+        raise ArgumentError, "Unsupported shader type: #{type.inspect}"
+      end
+
+      processed_source = preprocess_source(source: source)
+
+      _source = [processed_source].pack("p")
+      _size = [processed_source.length].pack("I")
+      glShaderSource(_shader, 1, _source, _size)
+
+      @data[:shaders][type] = _shader
+    end
+
+    # evaluates shader preprocessors
+    #
+    # currently supported preprocessors:
+    #
+    #   @include "file/path" "another/file/path" # => Replace line with contents of file; Shader includes_dir must be specified in constructor
+    #
+    # @example
+    #   # Example Vertex Shader #
+    #   # #version 330 core
+    #   # @include "material_struct"
+    #   # void main() {
+    #   #   gl_Position = vec4(1, 1, 1, 1);
+    #   # }
+    #
+    #   Shader.new(name: "model_renderer", includes_dir: "path/to/includes", vertex: "path/to/vertex_shader.glsl")
+    #
+    # @param source shader source code
+    def preprocess_source(source:)
+      lines = source.lines
+
+      lines.each_with_index do |line, i|
+        next unless line.start_with?(PREPROCESSOR_CHARACTER)
+
+        preprocessor = line.strip.split(" ")
+        lines.delete(line)
+
+        case preprocessor.first
+        when "@include"
+          unless @includes_dir
+            raise ArgumentError,
+                  "Shader preprocessor include directory was not given for shader #{@name}"
+          end
+
+          preprocessor[1..preprocessor.length - 1].join.scan(/"([^"]*)"/).flatten.each do |file|
+            source = File.read("#{@includes_dir}/#{file}.glsl")
+
+            lines.insert(i, source)
+          end
+        else
+          warn "Unsupported preprocessor #{preprocessor.first} for #{@name}"
+        end
+      end
+
+      lines.join
+    end
+
+    # compile OpenGL Shader of _type_
+    #
+    # @return [Boolean] whether compilation succeeded
+    def compile_shader(type:)
+      _compiled = false
+      _shader = @data[:shaders][type]
+      raise ArgumentError, "No shader for #{type.inspect}" unless _shader
+
+      glCompileShader(_shader)
+      buffer = "    "
+      glGetShaderiv(_shader, GL_COMPILE_STATUS, buffer)
+      compiled = buffer.unpack1("L")
+
+      if compiled == 0
+        log = " " * @error_buffer_size
+        glGetShaderInfoLog(_shader, @error_buffer_size, nil, log)
+        puts "Shader Error: Program \"#{@name}\""
+        puts "  #{type.to_s.capitalize} Shader InfoLog:", "  #{log.strip.split("\n").join("\n  ")}\n\n"
+        puts "  Shader Compiled status: #{compiled}"
+        puts "    NOTE: assignment of uniforms in shaders is illegal!"
+        puts
+      else
+        _compiled = true
+      end
+
+      _compiled
+    end
+
+    # link compiled OpenGL Shaders in to a OpenGL Program
+    #
+    # @note linking must succeed or shader cannot be used
+    #
+    # @return [Boolean] whether linking succeeded
+    def link_shaders
+      @program = glCreateProgram
+      @data[:shaders].values.each do |_shader|
+        glAttachShader(@program, _shader)
+      end
+      glLinkProgram(@program)
+
+      buffer = "    "
+      glGetProgramiv(@program, GL_LINK_STATUS, buffer)
+      linked = buffer.unpack1("L")
+
+      if linked == 0
+        log = " " * @error_buffer_size
+        glGetProgramInfoLog(@program, @error_buffer_size, nil, log)
+        puts "Shader Error: Program \"#{@name}\""
+        puts "  Program InfoLog:", "  #{log.strip.split("\n").join("\n  ")}\n\n"
+      end
+
+      @compiled = !(linked == 0)
+    end
+
+    # Returns the location of a uniform _variable_
+    #
+    # @param variable [String]
+    # @return [Integer] location of uniform
+    def variable(variable)
+      loc = glGetUniformLocation(@program, variable)
+      if loc == -1
+        unless @variable_missing[variable]
+          puts "Shader Error: Program \"#{@name}\" has no such uniform named \"#{variable}\"",
+               "  Is it used in the shader? GLSL may have optimized it out.", "  Is it miss spelled?"
+        end
+        @variable_missing[variable] = true
+      end
+      loc
+    end
+
+    # @see Shader.use Shader.use
+    def use(&block)
+      return unless compiled?
+      raise "Another shader is already in use! #{Shader.active_shader.name.inspect}" if Shader.active_shader
+
+      Shader.active_shader = self
+
+      glUseProgram(@program)
+
+      if block
+        block.call(self)
+        stop
+      end
+    end
+
+    # stop using shader, if shader is active
+    def stop
+      Shader.active_shader = nil if Shader.active_shader == self
+      glUseProgram(0)
+    end
+
+    # @return [Boolean] whether {Shader} successfully compiled
+    def compiled?
+      @compiled
+    end
+
+    # returns location of a uniform _variable_
+    #
+    # @note Use {#variable} for friendly error handling
+    # @see #variable Shader#variable
+    #
+    # @param variable [String]
+    # @return [Integer]
+    def attribute_location(variable)
+      glGetUniformLocation(@program, variable)
+    end
+
+    # send {Transform} to {Shader}
+    #
+    # @param variable [String]
+    # @param value [Transform]
+    # @param location [Integer]
+    # @return [void]
+    def uniform_transform(variable, value, location = nil)
+      attr_loc = location || attribute_location(variable)
+
+      glUniformMatrix4fv(attr_loc, 1, GL_FALSE, value.to_gl.pack("F16"))
+    end
+
+    # send Boolean to {Shader}
+    #
+    # @param variable [String]
+    # @param value [Boolean]
+    # @param location [Integer]
+    # @return [void]
+    def uniform_boolean(variable, value, location = nil)
+      attr_loc = location || attribute_location(variable)
+
+      glUniform1i(attr_loc, value ? 1 : 0)
+    end
+
+    # send Integer to {Shader}
+    # @param variable [String]
+    # @param value [Integer]
+    # @param location [Integer]
+    # @return [void]
+    def uniform_integer(variable, value, location = nil)
+      attr_loc = location || attribute_location(variable)
+
+      glUniform1i(attr_loc, value)
+    end
+
+    # send Float to {Shader}
+    #
+    # @param variable [String]
+    # @param value [Float]
+    # @param location [Integer]
+    # @return [void]
+    def uniform_float(variable, value, location = nil)
+      attr_loc = location || attribute_location(variable)
+
+      glUniform1f(attr_loc, value)
+    end
+
+    # send {Vector} (x, y, z) to {Shader}
+    #
+    # @param variable [String]
+    # @param value [Vector]
+    # @param location [Integer]
+    # @return [void]
+    def uniform_vector3(variable, value, location = nil)
+      attr_loc = location || attribute_location(variable)
+
+      glUniform3f(attr_loc, *value.to_a[0..2])
+    end
+
+    # send {Vector} to {Shader}
+    #
+    # @param variable [String]
+    # @param value [Vector]
+    # @param location [Integer]
+    # @return [void]
+    def uniform_vector4(variable, value, location = nil)
+      attr_loc = location || attribute_location(variable)
+
+      glUniform4f(attr_loc, *value.to_a)
+    end
+  end
+end

lib/cyberarm_engine/opengl/texture.rb

@@ -0,0 +1,69 @@
+module CyberarmEngine
+  class Texture
+    DEFAULT_TEXTURE = "#{CYBERARM_ENGINE_ROOT_PATH}/assets/textures/default.png".freeze
+
+    CACHE = {}
+
+    def self.release_textures
+      CACHE.values.each do |id|
+        glDeleteTextures(id)
+      end
+    end
+
+    def self.from_cache(path, retro)
+      CACHE.dig("#{path}?retro=#{retro}")
+    end
+
+    attr_reader :id
+
+    def initialize(path: nil, image: nil, retro: false)
+      raise "keyword :path or :image must be provided!" if path.nil? && image.nil?
+
+      @retro = retro
+      @path = path
+
+      if @path
+        unless File.exist?(@path)
+          warn "Missing texture at: #{@path}"
+          @retro = true # override retro setting
+          @path = DEFAULT_TEXTURE
+        end
+
+        if texture = Texture.from_cache(@path, @retro)
+          @id = texture.id
+          return
+        end
+
+        image = load_image(@path)
+        @id = create_from_image(image)
+      else
+        @id = create_from_image(image)
+      end
+    end
+
+    def load_image(path)
+      CACHE["#{path}?retro=#{@retro}"] = self
+      Gosu::Image.new(path, retro: @retro)
+    end
+
+    def create_from_image(image)
+      array_of_pixels = image.to_blob
+
+      tex_names_buf = " " * 4
+      glGenTextures(1, tex_names_buf)
+      texture_id = tex_names_buf.unpack1("L2")
+
+      glBindTexture(GL_TEXTURE_2D, texture_id)
+      glTexImage2D(GL_TEXTURE_2D, 0, GL_SRGB_ALPHA, image.width, image.height, 0, GL_RGBA, GL_UNSIGNED_BYTE, array_of_pixels)
+      glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT)
+      glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT)
+      glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST) if @retro
+      glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR) unless @retro
+      glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_LINEAR)
+      glGenerateMipmap(GL_TEXTURE_2D)
+      gl_error?
+
+      texture_id
+    end
+  end
+end

lib/cyberarm_engine/ray.rb

@@ -0,0 +1,56 @@
+module CyberarmEngine
+  class Ray
+    def initialize(origin, direction, range = Float::INFINITY)
+      raise "Origin must be a Vector!" unless origin.is_a?(Vector)
+      raise "Direction must be a Vector!" unless direction.is_a?(Vector)
+
+      @origin = origin
+      @direction = direction
+      @range = range
+
+      @inverse_direction = @direction.inverse
+    end
+
+    def intersect?(intersectable)
+      if intersectable.is_a?(BoundingBox)
+        intersect_bounding_box?(intersectable)
+      else
+        raise NotImplementedError, "Ray intersection test for #{intersectable.class} not implemented."
+      end
+    end
+
+    # Based on: https://tavianator.com/fast-branchless-raybounding-box-intersections/
+    def intersect_bounding_box?(box)
+      tmin = -@range
+      tmax = @range
+
+      tx1 = (box.min.x - @origin.x) * @inverse_direction.x
+      tx2 = (box.max.x - @origin.x) * @inverse_direction.x
+
+      tmin = max(tmin, min(tx1, tx2))
+      tmax = min(tmax, max(tx1, tx2))
+
+      ty1 = (box.min.y - @origin.y) * @inverse_direction.y
+      ty2 = (box.max.y - @origin.y) * @inverse_direction.y
+
+      tmin = max(tmin, min(ty1, ty2))
+      tmax = min(tmax, max(ty1, ty2))
+
+      tz1 = (box.min.z - @origin.z) * @inverse_direction.z
+      tz2 = (box.max.z - @origin.z) * @inverse_direction.z
+
+      tmin = max(tmin, min(tz1, tz2))
+      tmax = min(tmax, max(tz1, tz2))
+
+      tmax >= max(tmin, 0.0)
+    end
+
+    def min(x, y)
+      ((x) < (y) ? x : y)
+    end
+
+    def max(x, y)
+      ((x) > (y) ? x : y)
+    end
+  end
+end

lib/cyberarm_engine/stats.rb

@@ -0,0 +1,192 @@
+module CyberarmEngine
+  class Stats
+    @frames = []
+    @frame_index = -1
+    @max_frame_history = 1024
+
+    def self.new_frame
+      if @frames.size < @max_frame_history
+        @frames << Frame.new
+      else
+        @frames[@frame_index] = Frame.new
+      end
+    end
+
+    def self.frame
+      @frames[@frame_index]
+    end
+
+    def self.end_frame
+      frame&.complete
+
+      @frame_index += 1
+      @frame_index %= @max_frame_history
+    end
+
+    def self.frames
+      if @frames.size < @max_frame_history
+        @frames
+      else
+        @frames.rotate(@frame_index - (@max_frame_history - (@frames.size - 1)))
+      end
+    end
+
+    def self.frame_index
+      @frame_index
+    end
+
+    def self.max_frame_history
+      @max_frame_history
+    end
+
+    class Frame
+      Timing = Struct.new(:start_time, :end_time, :duration)
+
+      attr_reader :frame_timing, :counters, :timings, :multitimings
+      def initialize
+        @frame_timing = Timing.new(Gosu.milliseconds, -1, -1)
+        @attempted_multitiming = false
+
+        @counters = {
+          gui_recalculations: 0
+        }
+
+        @timings = {}
+        @multitimings = {}
+      end
+
+      def increment(key, number = 1)
+        @counters[key] ||= 0
+        @counters[key] += number
+      end
+
+      def start_timing(key)
+        raise "key must be a symbol!" unless key.is_a?(Symbol)
+        if @timings[key]
+          # FIXME: Make it not spammy...
+          # warn "Only one timing per key per frame. (Timing for #{key.inspect} already exists!)"
+          @attempted_multitiming = true
+          @multitimings[key] = true
+
+          return
+        end
+
+        @timings[key] = Timing.new(Gosu.milliseconds, -1, -1)
+      end
+
+      def end_timing(key)
+        timing = @timings[key]
+
+        # FIXME: Make it not spammy...
+        # warn "Timing #{key.inspect} already ended!" if timing.end_time != -1
+
+        timing.end_time = Gosu.milliseconds
+        timing.duration = timing.end_time - timing.start_time
+      end
+
+      def complete
+        @frame_timing.end_time = Gosu.milliseconds
+        @frame_timing.duration = @frame_timing.end_time - @frame_timing.start_time
+
+        # Lock data structures
+        @frame_timing.freeze
+        @counters.freeze
+        @timings.freeze
+        @multitimings.freeze
+      end
+
+      def complete?
+        @frame_timing.duration != -1
+      end
+
+      def attempted_multitiming?
+        @attempted_multitiming
+      end
+    end
+
+    class StatsPlotter
+      attr_reader :position
+
+      def initialize(x, y, z = Float::INFINITY, width = 128, height = 128)
+        @position = Vector.new(x, y, z)
+        @width = width
+        @height = height
+
+        @padding = 2
+        @text_size = 16
+
+        @max_timing_label = CyberarmEngine::Text.new("", x: x + @padding + 1, y: y + @padding, z: z, size: @text_size, border: true)
+        @avg_timing_label = CyberarmEngine::Text.new("", x: x + @padding + 1, y: y + @padding + @height / 2 - @text_size / 2, z: z, size: @text_size, border: true)
+        @min_timing_label = CyberarmEngine::Text.new("", x: x + @padding + 1, y: y + @height - (@text_size + @padding / 2), z: z, size: @text_size, border: true)
+
+        @timings_label = CyberarmEngine::Text.new("", x: x + @padding + @width + @padding, y: y + @padding, z: z, size: @text_size, border: true)
+
+        @frame_stats = []
+        @graphs = {
+          frame_timings: []
+        }
+      end
+
+      def calculate_graphs
+        calculate_frame_timings_graph
+      end
+
+      def calculate_frame_timings_graph
+        @graphs[:frame_timings].clear
+
+        samples = @width - @padding
+        nodes = Array.new(samples.ceil) { [] }
+
+        slice = 0
+        @frame_stats.each_slice((CyberarmEngine::Stats.max_frame_history / samples.to_f).ceil) do |bucket|
+          bucket.each do |frame|
+            nodes[slice] << frame.frame_timing.duration
+          end
+
+          slice += 1
+        end
+
+        nodes.each_with_index do |cluster, i|
+          break if cluster.empty?
+
+          @graphs[:frame_timings] << CyberarmEngine::Vector.new(@position.x + @padding + 1 * i, (@position.y + @height - @padding) - cluster.max)
+        end
+      end
+
+      def draw
+        @frame_stats = CyberarmEngine::Stats.frames.select(&:complete?)
+        return if @frame_stats.empty?
+
+        calculate_graphs
+
+        @max_timing_label.text = "Max: #{@frame_stats.map { |f| f.frame_timing.duration }.max.to_s.rjust(3, " ")}ms"
+        @avg_timing_label.text = "Avg: #{(@frame_stats.map { |f| f.frame_timing.duration }.sum / @frame_stats.size).to_s.rjust(3, " ")}ms"
+        @min_timing_label.text = "Min: #{@frame_stats.map { |f| f.frame_timing.duration }.min.to_s.rjust(3, " ")}ms"
+
+        Gosu.draw_rect(@position.x, @position.y, @width, @height, 0xaa_222222, @position.z)
+        Gosu.draw_rect(@position.x + @padding, @position.y + @padding, @width - @padding * 2, @height - @padding * 2, 0xaa_222222, @position.z)
+
+        draw_graphs
+
+        @max_timing_label.draw
+        @avg_timing_label.draw
+        @min_timing_label.draw
+
+        # TODO: Make this optional
+        draw_timings
+      end
+
+      def draw_graphs
+        Gosu.draw_path(@graphs[:frame_timings], Gosu::Color::WHITE, Float::INFINITY)
+      end
+
+      def draw_timings
+        frame = @frame_stats.last
+
+        @timings_label.text = "#{frame.attempted_multitiming? ? "<c=d00>Attempted Multitiming!\nTimings may be inaccurate for:\n#{frame.multitimings.map { |m, _| m}.join("\n") }</c>\n\n" : ''}#{frame.timings.map { |t, v| "#{t}: #{v.duration}ms" }.join("\n")}"
+        Gosu.draw_rect(@timings_label.x - @padding, @timings_label.y - @padding, @timings_label.width + @padding * 2, @timings_label.height + @padding * 2, 0xdd_222222, @position.z)
+        @timings_label.draw
+      end
+    end
+  end
+end

lib/cyberarm_engine/text.rb

@@ -0,0 +1,260 @@
+module CyberarmEngine
+  class Text
+    CACHE = {}
+
+    attr_accessor :x, :y, :z, :size, :options
+    attr_reader :text, :textobject, :factor_x, :factor_y, :color,
+                :border, :border_size, :border_alpha, :border_color,
+                :shadow, :shadow_size, :shadow_alpha, :shadow_color
+
+    def initialize(text, options = {})
+      @text = text.to_s || ""
+      @options = options
+      @size = options[:size] || 18
+      @font = options[:font] || Gosu.default_font_name
+      @x = options[:x] || 0
+      @y = options[:y] || 0
+      @z = options[:z] || 1025
+      @factor_x = options[:factor_x]  || 1
+      @factor_y = options[:factor_y]  || 1
+      if options[:color]
+        @color = options[:color].is_a?(Gosu::Color) ? options[:color] : Gosu::Color.new(options[:color])
+      else
+        @color = Gosu::Color::WHITE
+      end
+      @mode      = options[:mode]      || :default
+      @alignment = options[:alignment] || nil
+
+      @border   = options[:border]
+      @border   = true if options[:border].nil?
+      @border_size = options[:border_size] || 1
+      @border_alpha = options[:border_alpha] || 30
+      @border_color = options[:border_color] || Gosu::Color::BLACK
+
+      @shadow = options[:shadow]
+      @shadow_size = options[:shadow_size] || 2
+      @shadow_alpha = options[:shadow_alpha] || 30
+      @shadow_color = options[:shadow_color] || Gosu::Color::BLACK
+
+      @static = options[:static] || (options[:static].nil? || options[:static] == false ? false : true)
+
+      @textobject = check_cache(@size, @font)
+
+      if @alignment
+        case @alignment
+        when :left
+          @x = 0 + BUTTON_PADDING
+        when :center
+          @x = (CyberarmEngine::Window.instance.width / 2) - (@textobject.text_width(@text) / 2)
+        when :right
+          @x = CyberarmEngine::Window.instance.width - BUTTON_PADDING - @textobject.text_width(@text)
+        end
+      end
+    end
+
+    def check_cache(size, font_name)
+      available = false
+      font      = nil
+
+      if CACHE[size]
+        if CACHE[size][font_name]
+          font = CACHE[size][font_name]
+          available = true
+        else
+          available = false
+        end
+      else
+        available = false
+      end
+
+      unless available
+        font = Gosu::Font.new(@size, name: @font)
+        CACHE[@size] = {} unless CACHE[@size].is_a?(Hash)
+        CACHE[@size][@font] = font
+      end
+
+      font
+    end
+
+    def swap_font(size, font_name = @font)
+      if @size != size || @font != font_name
+        @size = size
+        @font = font_name
+
+        invalidate_cache!
+        @textobject = check_cache(size, font_name)
+      end
+    end
+
+    def text=(string)
+      invalidate_cache! if @text != string
+      @text = string
+    end
+
+    def factor_x=(n)
+      invalidate_cache! if @factor_x != n
+      @factor_x = n
+    end
+
+    def factor_y=(n)
+      invalidate_cache! if @factor_y != n
+      @factor_y = n
+    end
+
+    def color=(color)
+      old_color = @color
+
+      if color
+        @color = color.is_a?(Gosu::Color) ? color : Gosu::Color.new(color)
+      else
+        raise "color cannot be nil"
+      end
+
+      invalidate_cache! if old_color != color
+    end
+
+    def border=(boolean)
+      invalidate_cache! if @border != boolean
+      @border = boolean
+    end
+
+    def border_size=(n)
+      invalidate_cache! if @border_size != n
+      @border_size = n
+    end
+
+    def border_alpha=(n)
+      invalidate_cache! if @border_alpha != n
+      @border_alpha = n
+    end
+
+    def border_color=(n)
+      invalidate_cache! if @border_color != n
+      @border_color = n
+    end
+
+    def width(text = @text)
+      markup_width(text)
+    end
+
+    def text_width(text = @text)
+      spacing = 0
+      spacing += @border_size if @border
+      spacing += @shadow_size if @shadow
+
+      if text == @text && @static && @gosu_cached_text_image
+        @gosu_cached_text_image&.width + spacing
+      else
+        textobject.text_width(text) + spacing
+      end
+    end
+
+    def markup_width(text = @text)
+      text = text.to_s
+
+      spacing = 0
+      spacing += @border_size if @border
+      spacing += @shadow_size if @shadow
+
+      if text == @text && @static && @gosu_cached_text_image
+        @gosu_cached_text_image&.width + spacing
+      else
+        textobject.markup_width(text) + spacing
+      end
+    end
+
+    def height(text = @text)
+      if text.lines.count > 0
+        text.lines.count * textobject.height + @border_size + @shadow_size
+      else
+        @textobject.height + @border_size + @shadow_size
+      end
+    end
+
+    def draw(method = :draw_markup)
+      if @static
+        if @border && !@cached_text_border_image
+          _x = @border_size
+          _y = @border_size
+          _width = method == :draw_markup ? text_width : markup_width
+          img = Gosu::Image.send(:"from_#{method.to_s.split("_").last}", @text, @size, font: @font)
+
+          @cached_text_border_image = Gosu.render((_width + (@border_size * 2)).ceil, (height + (@border_size * 2)).ceil) do
+            img.draw(-_x, 0, @z, @factor_x, @factor_y, @border_color, @mode)
+            img.draw(-_x, -_y, @z, @factor_x, @factor_y, @border_color, @mode)
+
+            img.draw(0, -_y, @z, @factor_x, @factor_y, @border_color, @mode)
+            img.draw(_x, -_y, @z, @factor_x, @factor_y, @border_color, @mode)
+
+            img.draw(_x, 0, @z, @factor_x, @factor_y, @border_color, @mode)
+            img.draw(_x, _y, @z, @factor_x, @factor_y, @border_color, @mode)
+
+            img.draw(0, _y, @z, @factor_x, @factor_y, @border_color, @mode)
+            img.draw(-_x, _y, @z, @factor_x, @factor_y, @border_color, @mode)
+          end
+        end
+
+        @cached_text_shadow_image ||= Gosu::Image.send(:"from_#{method.to_s.split("_").last}", @text, @size, font: @font) if @shadow
+
+        @gosu_cached_text_image ||= Gosu::Image.send(:"from_#{method.to_s.split("_").last}", @text, @size, font: @font)
+
+        @cached_text_border_image.draw(@x, @y, @z, @factor_x, @factor_y, @border_color, @mode) if @border
+
+        @cached_text_shadow_image.draw(@x + @shadow_size, @y + @shadow_size, @z, @factor_x, @factor_y, @shadow_color, @mode) if @shadow
+
+        @gosu_cached_text_image.draw(@x, @y, @z, @factor_x, @factor_y, @color, @mode)
+      else
+        if @border && !ARGV.join.include?("--no-border")
+          border_alpha = @color.alpha <= 30 ? @color.alpha : @border_alpha
+          border_color = @border_color || Gosu::Color.rgba(@color.red, @color.green, @color.blue,
+                                                          border_alpha)
+          white = Gosu::Color::WHITE
+
+          _x = @border_size
+          _y = @border_size
+          _width = method == :draw_markup ? text_width : markup_width
+
+          @cached_text_border_image ||= Gosu.render((_width + (border_size * 2)).ceil, (height + (@border_size * 2)).ceil) do
+            @textobject.send(method, @text, _x - @border_size, _y, @z, @factor_x, @factor_y, white, @mode)
+            @textobject.send(method, @text, _x - @border_size, _y - @border_size, @z, @factor_x, @factor_y, white, @mode)
+
+            @textobject.send(method, @text, _x, _y - @border_size, @z, @factor_x, @factor_y, white, @mode)
+            @textobject.send(method, @text, _x + @border_size, _y - @border_size, @z, @factor_x, @factor_y, white, @mode)
+
+            @textobject.send(method, @text, _x, _y + @border_size, @z, @factor_x, @factor_y, white, @mode)
+            @textobject.send(method, @text, _x - @border_size, _y + @border_size, @z, @factor_x, @factor_y, white, @mode)
+
+            @textobject.send(method, @text, _x + @border_size, _y, @z, @factor_x, @factor_y, white, @mode)
+            @textobject.send(method, @text, _x + @border_size, _y + @border_size, @z, @factor_x, @factor_y, white, @mode)
+          end
+
+          @cached_text_border_image.draw(@x - @border_size, @y - @border_size, @z, @factor_x, @factor_y, border_color)
+        end
+
+        if @shadow
+          shadow_color = @shadow_color || Gosu::Color.rgba(@color.red, @color.green, @color.blue, @shadow_alpha)
+          @textobject.send(method, @text, @x + @shadow_size, @y + @shadow_size, @z, @factor_x, @factor_y, shadow_color, @mode)
+        end
+
+        @textobject.send(method, @text, @x, @y, @z, @factor_x, @factor_y, @color, @mode)
+      end
+    end
+
+    def alpha=(n)
+      @color = Gosu::Color.rgba(@color.red, @color.green, @color.blue, n)
+    end
+
+    def alpha
+      @color.alpha
+    end
+
+    def update
+    end
+
+    def invalidate_cache!
+      @cached_text_border_image = nil
+      @cached_text_shadow_image = nil
+      @gosu_cached_text_image = nil
+    end
+  end
+end

lib/cyberarm_engine/timer.rb

@@ -20,4 +20,4 @@ module CyberarmEngine
       end
     end
   end
-end
+end

lib/cyberarm_engine/transform.rb

@@ -0,0 +1,296 @@
+module CyberarmEngine
+  # Basic 4x4 matrix operations
+  class Transform
+    attr_reader :elements
+
+    def initialize(matrix)
+      @elements = matrix
+
+      raise "Transform is wrong size! Got #{@elements.size}, expected 16" if 16 != @elements.size
+      raise "Invalid value for matrix, must all be numeric!" if @elements.any? { |e| e.nil? || !e.is_a?(Numeric) }
+    end
+
+    def self.identity
+      Transform.new(
+        [
+          1, 0, 0, 0,
+          0, 1, 0, 0,
+          0, 0, 1, 0,
+          0, 0, 0, 1
+        ]
+      )
+    end
+
+    ### 2D Operations meant for interacting with Gosu ###
+
+    # 2d rotate operation, replicates Gosu's Gosu.rotate function
+    def self.rotate(angle, rotate_around = nil)
+      double c = Math.cos(angle).degrees_to_radians
+      double s = Math.sin(angle).degrees_to_radians
+      matrix = [
+        +c, +s, 0, 0,
+        -s, +c, 0, 0,
+        0,  0,  1, 0,
+        0,  0,  0, 1
+      ]
+
+      rotate_matrix = Transform.new(matrix, rows: 4, columns: 4)
+
+      if rotate_around && (rotate_around.x != 0.0 || rotate_around.y != 0.0)
+        negative_rotate_around = Vector.new(-rotate_around.x, -rotate_around.y, -rotate_around.z)
+
+        rotate_matrix = concat(
+          concat(translate(negative_rotate_around), rotate_matrix),
+          translate(rotate_around)
+        )
+      end
+
+      rotate_matrix
+    end
+
+    # 2d translate operation, replicates Gosu's Gosu.translate function
+    def self.translate(vector)
+      x, y, z = vector.to_a[0..2]
+      matrix = [
+        1, 0, 0, 0,
+        0, 1, 0, 0,
+        0, 0, 1, 0,
+        x, y, z, 1
+      ]
+
+      Transform.new(matrix)
+    end
+
+    # 2d scale operation, replicates Gosu's Gosu.rotate function
+    def self.scale(vector, center_around = nil)
+      scale_x, scale_y, scale_z = vector.to_a[0..2]
+      matrix = [
+        scale_x, 0,       0,       0,
+        0,       scale_y, 0,       0,
+        0,       0,       scale_z, 0,
+        0,       0,       0,       1
+      ]
+
+      scale_matrix = Transform.new(matrix)
+
+      if center_around && (center_around.x != 0.0 || center_around.y != 0.0)
+        negative_center_around = Vector.new(-center_around.x, -center_around.y, -center_around.z)
+
+        scale_matrix = concat(
+          concat(translate(negative_center_around), scale_matrix),
+          translate(center_around)
+        )
+      end
+
+      scale_matrix
+    end
+
+    def self.concat(left, right)
+      matrix = Array.new(left.elements.size)
+      rows = 4
+
+      matrix.size.times do |i|
+        matrix[i] = 0
+
+        rows.times do |j|
+          matrix[i] += left.elements[i / rows * rows + j] * right.elements[i % rows + j * rows]
+        end
+      end
+
+      Transform.new(matrix)
+    end
+
+    #### 3D Operations meant for OpenGL ###
+
+    def self.translate_3d(vector)
+      x, y, z = vector.to_a[0..2]
+      matrix = [
+        1, 0, 0, x,
+        0, 1, 0, y,
+        0, 0, 1, z,
+        0, 0, 0, 1
+      ]
+
+      Transform.new(matrix)
+    end
+
+    def self.rotate_3d(vector, _order = "zyx")
+      x, y, z = vector.to_a[0..2].map { |axis| axis * Math::PI / 180.0 }
+
+      rotation_x = Transform.new(
+        [
+          1, 0,           0,            0,
+          0, Math.cos(x), -Math.sin(x), 0,
+          0, Math.sin(x), Math.cos(x),  0,
+          0, 0,           0,            1
+        ]
+      )
+
+      rotation_y = Transform.new(
+        [
+          Math.cos(y),  0, Math.sin(y), 0,
+          0,            1, 0,           0,
+          -Math.sin(y), 0, Math.cos(y), 0,
+          0,            0, 0,           1
+        ]
+      )
+
+      rotation_z = Transform.new(
+        [
+          Math.cos(z), -Math.sin(z), 0, 0,
+          Math.sin(z), Math.cos(z),  0, 0,
+          0,           0,            1, 0,
+          0,           0,            0, 1
+        ]
+      )
+
+      rotation_z * rotation_y * rotation_x
+    end
+
+    # Implements glRotatef
+    # https://www.khronos.org/registry/OpenGL-Refpages/gl2.1/xhtml/glRotate.xml
+    def self.rotate_gl(angle, axis)
+      radians = angle * Math::PI / 180.0
+      s = Math.sin(radians)
+      c = Math.cos(radians)
+
+      axis = axis.normalized
+      x, y, z = axis.to_a[0..2]
+
+      n = (1.0 - c)
+
+      Transform.new(
+        [
+          x * x * n + c,     x * y * n - z * s, x * z * n + y * s, 0,
+          y * x * n + z * s, y * y * n + c,     y * z * n - x * s, 0,
+          x * z * n - y * s, y * z * n + x * s, z * z * n + c,     0,
+          0,                 0,                 0, 1.0
+        ]
+      )
+    end
+
+    def self.scale_3d(vector)
+      x, y, z = vector.to_a[0..2]
+
+      Transform.new(
+        [
+          x, 0, 0, 0,
+          0, y, 0, 0,
+          0, 0, z, 0,
+          0, 0, 0, 1
+        ]
+      )
+    end
+
+    def self.perspective(fov_y, aspect_ratio, near, far)
+      f = 1.0 / Math.tan(fov_y.degrees_to_radians / 2.0) # cotangent
+      zn = (far + near.to_f) / (near - far.to_f)
+      zf = (2.0 * far * near.to_f) / (near - far.to_f)
+
+      Transform.new(
+        [
+          f / aspect_ratio, 0.0,    0.0, 0.0,
+          0.0,                f,    0.0, 0.0,
+          0.0,                0.0, zn, zf,
+          0.0,                0.0, -1.0, 0.0
+        ]
+      )
+    end
+
+    def self.orthographic(left, right, bottom, top, near, far)
+      s = Vector.new(
+        2 / (right - left.to_f),
+        2 / (top - bottom.to_f),
+        -2 / (far - near.to_f)
+      )
+
+      t = Vector.new(
+        (right + left.to_f)   / (right - left.to_f),
+        (top   + bottom.to_f) / (top   - bottom.to_f),
+        (far   + near.to_f)   / (far   - near.to_f)
+      )
+
+      Transform.new(
+        [
+          s.x, 0.0, 0.0, t.x,
+          0.0, s.y, 0.0, t.y,
+          0.0, 0.0, s.z, t.z,
+          0.0, 0.0, 0.0, 1.0
+        ]
+      )
+    end
+
+    def self.view(eye, orientation)
+      # https://www.3dgep.com/understanding-the-view-matrix/#The_View_Matrix
+      cosPitch = Math.cos(orientation.z * Math::PI / 180.0)
+      sinPitch = Math.sin(orientation.z * Math::PI / 180.0)
+      cosYaw = Math.cos(orientation.y * Math::PI / 180.0)
+      sinYaw = Math.sin(orientation.y * Math::PI / 180.0)
+
+      x_axis = Vector.new(cosYaw, 0, -sinYaw)
+      y_axis = Vector.new(sinYaw * sinPitch, cosPitch, cosYaw * sinPitch)
+      z_axis = Vector.new(sinYaw * cosPitch, -sinPitch, cosPitch * cosYaw)
+
+      Transform.new(
+        [
+          x_axis.x, y_axis.y, z_axis.z, 0,
+          x_axis.x,         y_axis.y,         z_axis.z, 0,
+          x_axis.x,         y_axis.y,         z_axis.z, 0,
+          -x_axis.dot(eye), -y_axis.dot(eye), -z_axis.dot(eye), 1
+        ]
+      )
+    end
+
+    def *(other)
+      case other
+      when CyberarmEngine::Vector
+        matrix = @elements.clone
+        list = other.to_a
+
+        @elements.each_with_index do |e, i|
+          matrix[i] = e + list[i % 4]
+        end
+
+        Transform.new(matrix)
+
+      when CyberarmEngine::Transform
+        multiply_matrices(other)
+      else
+        p other.class
+        raise TypeError, "Expected CyberarmEngine::Vector or CyberarmEngine::Transform got #{other.class}"
+      end
+    end
+
+    def get(x, y)
+      width = 4
+
+      # puts "Transform|#{self.object_id} -> #{@elements[width * y + x].inspect} (index: #{width * y + x})"
+      @elements[width * y + x]
+    end
+
+    def multiply_matrices(other)
+      matrix = Array.new(16, 0)
+
+      4.times do |x|
+        4.times do |y|
+          4.times do |k|
+            matrix[4 * y + x] += get(x, k) * other.get(k, y)
+          end
+        end
+      end
+
+      Transform.new(matrix)
+    end
+
+    # arranges Matrix in column major form
+    def to_gl
+      e = @elements
+      [
+        e[0], e[4], e[8],  e[12],
+        e[1], e[5], e[9],  e[13],
+        e[2], e[6], e[10], e[14],
+        e[3], e[7], e[11], e[15]
+      ]
+    end
+  end
+end

lib/cyberarm_engine/ui/border_canvas.rb

@@ -1,6 +1,7 @@
 module CyberarmEngine
   class BorderCanvas
     attr_reader :element, :top, :right, :bottom, :left
+
     def initialize(element:)
       @element = element
 
@@ -25,7 +26,7 @@ module CyberarmEngine
 
       elsif color.is_a?(Array)
         if color.size == 1
-          color=color.first
+          color = color.first
 
         elsif color.size == 2
           @top.background    = color.first
@@ -61,36 +62,36 @@ module CyberarmEngine
 
     def update
       # TOP
-      @top.x = @element.x# + @element.border_thickness_left
+      @top.x = @element.x + @element.style.border_thickness_left
       @top.y = @element.y
       @top.z = @element.z
 
-      @top.width  = @element.width
-      @top.height = @element.border_thickness_top
+      @top.width  = @element.width - @element.style.border_thickness_left
+      @top.height = @element.style.border_thickness_top
 
       # RIGHT
       @right.x = @element.x + @element.width
-      @right.y = @element.y + @element.border_thickness_top
+      @right.y = @element.y + @element.style.border_thickness_top
       @right.z = @element.z
 
-      @right.width  = -@element.border_thickness_right
-      @right.height = @element.height - @element.border_thickness_top
+      @right.width  = -@element.style.border_thickness_right
+      @right.height = @element.height - @element.style.border_thickness_top
 
       # BOTTOM
       @bottom.x = @element.x
       @bottom.y = @element.y + @element.height
       @bottom.z = @element.z
 
-      @bottom.width  = @element.width - @element.border_thickness_right
-      @bottom.height = -@element.border_thickness_bottom
+      @bottom.width  = @element.width - @element.style.border_thickness_right
+      @bottom.height = -@element.style.border_thickness_bottom
 
       # LEFT
       @left.x = @element.x
       @left.y = @element.y
       @left.z = @element.z
 
-      @left.width  = @element.border_thickness_left
-      @left.height = @element.height - @element.border_thickness_bottom
+      @left.width  = @element.style.border_thickness_left
+      @left.height = @element.height - @element.style.border_thickness_bottom
 
       @top.update
       @right.update
@@ -98,4 +99,4 @@ module CyberarmEngine
       @left.update
     end
   end
-end
+end

lib/cyberarm_engine/ui/button.rb

@@ -1,53 +0,0 @@
-module CyberarmEngine
-  class Button < Label
-    def initialize(text, options = {}, block = nil)
-      super(text, options, block)
-
-      @background_canvas.background = default(:background)
-    end
-
-    def render
-      draw_text
-    end
-
-    def draw_text
-      @text.draw
-    end
-
-    def enter(sender)
-      @focus = false unless window.button_down?(Gosu::MsLeft)
-
-      if @focus
-        @background_canvas.background = default(:active, :background)
-        @text.color = default(:active, :color)
-      else
-        @background_canvas.background = default(:hover, :background)
-        @text.color = default(:hover, :color)
-      end
-    end
-
-    def left_mouse_button(sender, x, y)
-      @focus = true
-      @background_canvas.background = default(:active, :background)
-      window.current_state.focus = self
-      @text.color = default(:active, :color)
-    end
-
-    def released_left_mouse_button(sender,x, y)
-      enter(sender)
-    end
-
-    def clicked_left_mouse_button(sender, x, y)
-      @block.call(self) if @block
-    end
-
-    def leave(sender)
-      @background_canvas.background = default(:background)
-      @text.color = default(:color)
-    end
-
-    def blur(sender)
-      @focus = false
-    end
-  end
-end

lib/cyberarm_engine/ui/check_box.rb

@@ -1,52 +0,0 @@
-module CyberarmEngine
-  class CheckBox < Flow
-    def initialize(text, options, block = nil)
-      super({}, block = nil)
-      options[:toggled] = options[:checked]
-
-      @toggle_button = ToggleButton.new(options)
-      @label         = Label.new(text, options)
-
-      define_label_singletons
-
-      add(@toggle_button)
-      add(@label)
-
-      @width  = @toggle_button.width + @label.width
-      @height = @toggle_button.height + @label.height
-    end
-
-    def text=(text)
-      @label.text = text
-      recalculate
-    end
-
-    def define_label_singletons
-      @label.define_singleton_method(:_toggle_button) do |button|
-        @_toggle_button = button
-      end
-
-      @label._toggle_button(@toggle_button)
-
-      @label.define_singleton_method(:holding_left_mouse_button) do |sender, x, y|
-        @_toggle_button.left_mouse_button(sender, x, y)
-      end
-
-      @label.define_singleton_method(:released_left_mouse_button) do |sender, x, y|
-        @_toggle_button.released_left_mouse_button(sender, x, y)
-      end
-
-      @label.define_singleton_method(:clicked_left_mouse_button) do |sender, x, y|
-        @_toggle_button.clicked_left_mouse_button(sender, x, y)
-      end
-
-      @label.define_singleton_method(:enter) do |sender|
-        @_toggle_button.enter(sender)
-      end
-
-      @label.define_singleton_method(:leave) do |sender|
-        @_toggle_button.leave(sender)
-      end
-    end
-  end
-end

lib/cyberarm_engine/ui/container.rb

@@ -1,154 +0,0 @@
-module CyberarmEngine
-  class Container < Element
-    include Common
-
-    attr_accessor :stroke_color, :fill_color
-    attr_reader :children
-    attr_reader :scroll_x, :scroll_y
-
-    def initialize(options = {}, block = nil)
-      super
-
-      @scroll_x, @scroll_y = 0, 0
-      @scroll_speed = 10
-
-      @text_color = options[:color]
-
-      @children = []
-
-      @theme = {}
-    end
-
-    def build
-      @theme.merge(@parent.theme) if @parent
-      @block.call(self) if @block
-
-      recalculate
-    end
-
-    def add(element)
-      @children << element
-
-      recalculate
-    end
-
-    def render
-        @children.each(&:draw)
-    end
-
-    def update
-      @children.each(&:update)
-    end
-
-    def theme
-      @theme
-    end
-
-    def color(color)
-      @theme[:color] = color
-    end
-
-    def hit_element?(x, y)
-      @children.reverse_each do |child|
-        case child
-        when Container
-          if element = child.hit_element?(x, y)
-            return element
-          end
-        else
-          return child if child.hit?(x, y)
-        end
-      end
-
-      self if hit?(x, y)
-    end
-
-    def recalculate
-      @current_position = Vector.new(@margin_left, @margin_top)
-
-      layout
-
-      @width  = @max_width  ? @max_width  : (@children.map {|c| c.x + c.width  + c.margin_right }.max || 0).round
-      @height = @max_height ? @max_height : (@children.map {|c| c.y + c.height + c.margin_bottom}.max || 0).round
-
-      # Move child to parent after positioning
-      @children.each do |child|
-        child.x += @x
-        child.y += @y
-
-        # Fix child being displaced
-        child.recalculate
-      end
-
-      update_background
-    end
-
-    def layout
-      raise "Not overridden"
-    end
-
-    def max_width
-      @max_width ? @max_width : window.width - (@parent ? @parent.margin_right + @margin_right : @margin_right)
-    end
-
-    def fits_on_line?(element) # Flow
-      @current_position.x + element.outer_width <= max_width &&
-      @current_position.x + element.outer_width <= window.width
-    end
-
-    def position_on_current_line(element) # Flow
-      element.x = element.margin_left + @current_position.x
-      element.y = element.margin_top  + @current_position.y
-
-      element.recalculate
-
-      @current_position.x += element.outer_width
-      @current_position.x = @margin_left if @current_position.x >= max_width
-    end
-
-    def tallest_neighbor(querier, y_position) # Flow
-      response = querier
-      @children.each do |child|
-        response = child if child.outer_height > response.outer_height
-        break if child == querier
-      end
-
-      return response
-    end
-
-    def position_on_next_line(child) # Flow
-      @current_position.x = @margin_left
-      @current_position.y += tallest_neighbor(child, @current_position.y).outer_height
-
-      child.x = child.margin_left + @current_position.x
-      child.y = child.margin_top  + @current_position.y
-
-      child.recalculate
-
-      @current_position.x += child.outer_width
-    end
-
-    def move_to_next_line(element) # Stack
-      element.x = element.margin_left + @current_position.x
-      element.y = element.margin_top  + @current_position.y
-
-      element.recalculate
-
-      @current_position.y += element.outer_height
-    end
-
-    # def mouse_wheel_up(sender, x, y)
-    #   @children.each {|c| c.y -= @scroll_speed}
-    #   @children.each {|c| c.recalculate}
-    # end
-
-    # def mouse_wheel_down(sender, x, y)
-    #   @children.each {|c| c.y += @scroll_speed}
-    #   @children.each {|c| c.recalculate}
-    # end
-
-    def value
-      @children.map {|c| c.class}.join(", ")
-    end
-  end
-end

lib/cyberarm_engine/ui/dsl.rb

@@ -1,94 +1,139 @@
 module CyberarmEngine
   module DSL
     def flow(options = {}, &block)
-      options[:parent] = @containers.last
-      options[:theme] = @current_theme
-      _container = Flow.new(options, block)
-      @containers << _container
-      _container.build
-      options[:parent].add(_container)
-      @containers.pop
-
-      return _container
+      container(CyberarmEngine::Element::Flow, options, &block)
     end
 
     def stack(options = {}, &block)
-      options[:parent] = @containers.last
-      options[:theme] = @current_theme
-      _container = Stack.new(options, block)
-      @containers << _container
-      _container.build
-      options[:parent].add(_container)
-      @containers.pop
-
-      return _container
+      container(CyberarmEngine::Element::Stack, options, &block)
     end
 
+    # TODO: Remove in version 0.16.0+
     def label(text, options = {}, &block)
-      options[:parent] = @containers.last
-      options[:theme] = @current_theme
-      _element = Label.new(text, options, block)
-      @containers.last.add(_element)
+      options[:parent] = element_parent
+      options[:theme] = current_theme
 
-      return _element
+      add_element(Element::TextBlock.new(text, options, block))
+    end
+
+    [
+      "Banner",
+      "Title",
+      "Subtitle",
+      "Tagline",
+      "Caption",
+      "Para",
+      "Inscription",
+      "Link"
+    ].each do |const|
+      define_method(:"#{const.downcase}") do |text, options = {}, &block|
+        options[:parent] = element_parent
+        options[:theme] = current_theme
+
+        add_element(Element.const_get(const).new(text, options, block))
+      end
     end
 
     def button(text, options = {}, &block)
-      options[:parent] = @containers.last
-      options[:theme] = @current_theme
-      _element = Button.new(text, options, block) { if block.is_a?(Proc); block.call; end }
-      @containers.last.add(_element)
+      options[:parent] = element_parent
+      options[:theme] = current_theme
 
-      return _element
+      add_element(Element::Button.new(text, options, block) { block.call if block.is_a?(Proc) })
+    end
+
+    def list_box(options = {}, &block)
+      options[:parent] = element_parent
+      options[:theme] = current_theme
+
+      add_element(Element::ListBox.new(options, block) { block.call if block.is_a?(Proc) })
     end
 
     def edit_line(text, options = {}, &block)
-      options[:parent] = @containers.last
-      options[:theme] = @current_theme
-      _element = EditLine.new(text, options, block)
-      @containers.last.add(_element)
+      options[:parent] = element_parent
+      options[:theme] = current_theme
 
-      return _element
+      add_element(Element::EditLine.new(text, options, block))
+    end
+
+    def edit_box(text, options = {}, &block)
+      options[:parent] = element_parent
+      options[:theme] = current_theme
+
+      add_element(Element::EditBox.new(text, options, block))
     end
 
     def toggle_button(options = {}, &block)
-      options[:parent] = @containers.last
-      options[:theme] = @current_theme
-      _element = ToggleButton.new(options, block)
-      @containers.last.add(_element)
+      options[:parent] = element_parent
+      options[:theme] = current_theme
 
-      return _element
+      add_element(Element::ToggleButton.new(options, block))
     end
 
     def check_box(text, options = {}, &block)
-      options[:parent] = @containers.last
-      options[:theme] = @current_theme
-      _element = CheckBox.new(text, options, block)
-      @containers.last.add(_element)
+      options[:parent] = element_parent
+      options[:theme] = current_theme
 
-      return _element
+      add_element(Element::CheckBox.new(text, options, block))
     end
 
     def image(path, options = {}, &block)
-      options[:parent] = @containers.last
-      options[:theme] = @current_theme
-      _element = Image.new(path, options, block)
-      @containers.last.add(_element)
+      options[:parent] = element_parent
+      options[:theme] = current_theme
 
-      return _element
+      add_element(Element::Image.new(path, options, block))
+    end
+
+    def progress(options = {}, &block)
+      options[:parent] = element_parent
+      options[:theme] = current_theme
+
+      add_element(Element::Progress.new(options, block))
+    end
+
+    def slider(options = {}, &block)
+      options[:parent] = element_parent
+      options[:theme] = current_theme
+
+      add_element(Element::Slider.new(options, block))
     end
 
     def background(color = Gosu::Color::NONE)
-      @containers.last.background = color
+      element_parent.style.default[:background] = color
     end
 
-    # Foreground color, e.g. Text
-    def color(color)
-      @containers.last.color(color)
+    def theme(theme)
+      element_parent.options[:theme] = theme
     end
 
-    def set_theme(theme)
-      @current_theme = theme
+    def current_theme
+      element_parent.options[:theme]
+    end
+
+    private def add_element(element)
+      element_parent.add(element)
+
+      element
+    end
+
+    private def element_parent
+      CyberarmEngine::Element::Container.current_container
+    end
+
+    private def container(klass, options = {}, &block)
+      options[:parent] = element_parent
+      options[:theme] = current_theme
+
+      _container = klass.new(options, block)
+
+      old_parent = element_parent
+      CyberarmEngine::Element::Container.current_container = _container
+
+      _container.build
+      _container.parent.add(_container)
+
+      CyberarmEngine::Element::Container.current_container = old_parent
+
+      _container
     end
   end
-end
+end

lib/cyberarm_engine/ui/edit_line.rb

@@ -1,88 +0,0 @@
-module CyberarmEngine
-  class EditLine < Button
-    def initialize(text, options = {}, block = nil)
-      super(text, options, block)
-
-      @type = default(:type)
-
-
-      @caret_width = default(:caret_width)
-      @caret_height= @text.height
-      @caret_color = default(:caret_color)
-      @caret_interval = default(:caret_interval)
-      @caret_last_interval = Gosu.milliseconds
-      @show_caret  = true
-
-      @text_input = Gosu::TextInput.new
-      @text_input.text = text
-
-      return self
-    end
-
-    def render
-      Gosu.clip_to(@text.x, @text.y, @width, @text.height) do
-        draw_text
-        Gosu.draw_rect(caret_position, @text.y, @caret_width, @caret_height, @caret_color, @z + 40) if @focus && @show_caret
-      end
-    end
-
-    def update
-      if @type == :password
-        @text.text = default(:password_character) * @text_input.text.length
-      else
-        @text.text = @text_input.text
-      end
-
-      if Gosu.milliseconds >= @caret_last_interval + @caret_interval
-        @caret_last_interval = Gosu.milliseconds
-
-        @show_caret = !@show_caret
-      end
-    end
-
-    def left_mouse_button(sender, x, y)
-      super
-      window.text_input = @text_input
-    end
-
-    def enter(sender)
-      if @focus
-        @background_canvas.background = default(:active, :background)
-        @text.color = default(:active, :color)
-      else
-        @background_canvas.background = default(:hover, :background)
-        @text.color = default(:hover, :color)
-      end
-    end
-
-    def leave(sender)
-    end
-
-    def blur(sender)
-      @focus = false
-      @background_canvas.background = default(:background)
-      @text.color = default(:color)
-      window.text_input = nil
-    end
-
-    # TODO: Fix caret rendering in wrong position unless caret_pos is at end of text
-    def caret_position
-      if @type == :password
-        @text.x + @text.textobject.text_width(default(:password_character) * @text_input.text[0..@text_input.caret_pos-1].length)
-      else
-        @text.x + @text.textobject.text_width(@text_input.text[0..@text_input.caret_pos-1])
-      end
-    end
-
-    def recalculate
-      super
-
-      @width = default(:width)
-      update_background
-    end
-
-    def value
-      @text_input.text
-    end
-  end
-end

lib/cyberarm_engine/ui/element.rb

@@ -4,104 +4,178 @@ module CyberarmEngine
     include Event
     include Common
 
-    attr_accessor :x, :y, :z, :enabled
-    attr_reader :width, :height, :parent, :options, :event_handler, :background_canvas, :border_canvas
-
-    attr_reader :border_thickness, :border_thickness_left, :border_thickness_right, :border_thickness_top, :border_thickness_bottom
-    attr_reader :border_color, :border_color_left, :border_color_right, :border_color_top, :border_color_bottom
-
-    attr_reader :padding, :padding_left, :padding_right, :padding_top, :padding_bottom
-    attr_reader :margin, :margin_left, :margin_right, :margin_top, :margin_bottom
+    attr_accessor :x, :y, :z, :tip, :element_visible
+    attr_reader :parent, :options, :style, :event_handler, :background_canvas, :border_canvas
 
     def initialize(options = {}, block = nil)
-      @parent = options[:parent] # parent Container (i.e. flow/stack)
+      @parent = options.delete(:parent) # parent Container (i.e. flow/stack)
       options = theme_defaults(options)
       @options = options
       @block = block
 
-      @style             = Style.new(options)
-      @focus             = false
-      @background_canvas = Background.new
-      @border_canvas     = BorderCanvas.new(element: self)
+      @focus   = !@options.key?(:focus)   ? false : @options[:focus]
+      @enabled = !@options.key?(:enabled) ? true  : @options[:enabled]
+      @visible = !@options.key?(:visible) ? true  : @options[:visible]
+      @tip     = @options[:tip] || ""
 
-      @x = default(:x)
-      @y = default(:y)
-      @z = default(:z)
+      @debug_color = @options[:debug_color].nil? ? Gosu::Color::RED : @options[:debug_color]
 
-      @fixed_x = @x if @x != 0
-      @fixed_y = @y if @y != 0
+      @style = Style.new(options)
 
-      @width  = default(:width)  || $window.width
-      @height = default(:height) || $window.height
+      @root ||= nil
+      @gui_state ||= nil
+      @element_visible = true
 
-      set_border_thickness(default(:border_thickness))
+      @x = @style.x
+      @y = @style.y
+      @z = @style.z
 
-      set_padding(default(:padding))
+      @width  = 0
+      @height = 0
 
-      set_margin(default(:margin))
+      @style.width  = default(:width)  || nil
+      @style.height = default(:height) || nil
 
-      set_background(default(:background))
-      set_border_color(default(:border_color))
+      @style.background_canvas = Background.new
+      @style.background_nine_slice_canvas = BackgroundNineSlice.new
+      @style.background_image_canvas = BackgroundImage.new
+      @style.border_canvas = BorderCanvas.new(element: self)
 
-      raise "#{self.class} 'x' must be a number" unless @x.is_a?(Numeric)
-      raise "#{self.class} 'y' must be a number" unless @y.is_a?(Numeric)
-      raise "#{self.class} 'z' must be a number" unless @z.is_a?(Numeric)
-      raise "#{self.class} 'width' must be a number"  unless @width.is_a?(Numeric)  || @width.nil?
-      raise "#{self.class} 'height' must be a number" unless @height.is_a?(Numeric) || @height.nil?
-      raise "#{self.class} 'options' must be a Hash" unless @options.is_a?(Hash)
+      @style_event = :default
 
-      # raise "#{self.class} 'padding' must be a number" unless @padding.is_a?(Numeric)
-
-      @enabled = true
+      stylize
 
       default_events
+
+      root.gui_state.request_focus(self) if @options[:autofocus]
     end
 
-    def set_background(background)
-      @background = background
-      @background_canvas.background = background
+    def stylize
+      set_static_position
+
+      set_color
+      set_font
+
+      set_padding
+      set_margin
+
+      set_background
+      set_background_nine_slice
+      set_background_image
+
+      set_border_thickness
+      set_border_color
+
+      root.gui_state.request_repaint
     end
 
-    def set_border_thickness(border_thickness)
-      @border_thickness = border_thickness
-
-      @border_thickness_left   = default(:border_thickness_left)   || @border_thickness
-      @border_thickness_right  = default(:border_thickness_right)  || @border_thickness
-      @border_thickness_top    = default(:border_thickness_top)    || @border_thickness
-      @border_thickness_bottom = default(:border_thickness_bottom) || @border_thickness
+    def safe_style_fetch(*args)
+      @style.hash.dig(@style_event, *args) || @style.hash.dig(:default, *args) || default(*args)
     end
 
-    def set_border_color(color)
-      @border_color = color
-
-      @border_color_left   = default(:border_color_left)   || @border_color
-      @border_color_right  = default(:border_color_right)  || @border_color
-      @border_color_top    = default(:border_color_top)    || @border_color
-      @border_color_bottom = default(:border_color_bottom) || @border_color
-
-      @border_canvas.color = color
+    def set_static_position
+      @x = @style.x if @style.x != 0
+      @y = @style.y if @style.y != 0
     end
 
-    def set_padding(padding)
-      @padding = padding
-
-      @padding_left   = default(:padding_left)   || @padding
-      @padding_right  = default(:padding_right)  || @padding
-      @padding_top    = default(:padding_top)    || @padding
-      @padding_bottom = default(:padding_bottom) || @padding
+    def set_color
+      @style.color = safe_style_fetch(:color)
+      @text&.color = @style.color
     end
 
-    def set_margin(margin)
-      @margin = margin
+    def set_font
+      @text&.swap_font(safe_style_fetch(:text_size), safe_style_fetch(:font))
+    end
 
-      @margin_left   = default(:margin_left)   || @margin
-      @margin_right  = default(:margin_right)  || @margin
-      @margin_top    = default(:margin_top)    || @margin
-      @margin_bottom = default(:margin_bottom) || @margin
+    def set_background
+      @style.background = safe_style_fetch(:background)
+
+      @style.background_canvas.background = @style.background
+    end
+
+    def set_background_nine_slice
+      @style.background_nine_slice = safe_style_fetch(:background_nine_slice)
+
+      @style.background_nine_slice_mode = safe_style_fetch(:background_nine_slice_mode) || :stretch
+      @style.background_nine_slice_color = safe_style_fetch(:background_nine_slice_color) || Gosu::Color::WHITE
+      @style.background_nine_slice_canvas.color = @style.background_nine_slice_color
+
+      @style.background_nine_slice_from_edge = safe_style_fetch(:background_nine_slice_from_edge)
+
+      @style.background_nine_slice_left      = safe_style_fetch(:background_nine_slice_left)   || @style.background_nine_slice_from_edge
+      @style.background_nine_slice_top       = safe_style_fetch(:background_nine_slice_top)    || @style.background_nine_slice_from_edge
+      @style.background_nine_slice_right     = safe_style_fetch(:background_nine_slice_right)  || @style.background_nine_slice_from_edge
+      @style.background_nine_slice_bottom    = safe_style_fetch(:background_nine_slice_bottom) || @style.background_nine_slice_from_edge
+    end
+
+    def set_background_image
+      @style.background_image = safe_style_fetch(:background_image)
+      @style.background_image_mode = safe_style_fetch(:background_image_mode) || :stretch
+      @style.background_image_color = safe_style_fetch(:background_image_color) || Gosu::Color::WHITE
+      @style.background_image_canvas.mode = @style.background_image_mode
+      @style.background_image_canvas.color = @style.background_image_color
+    end
+
+    def set_border_thickness
+      @style.border_thickness = safe_style_fetch(:border_thickness)
+
+      @style.border_thickness_left   = safe_style_fetch(:border_thickness_left)   || @style.border_thickness
+      @style.border_thickness_right  = safe_style_fetch(:border_thickness_right)  || @style.border_thickness
+      @style.border_thickness_top    = safe_style_fetch(:border_thickness_top)    || @style.border_thickness
+      @style.border_thickness_bottom = safe_style_fetch(:border_thickness_bottom) || @style.border_thickness
+    end
+
+    def set_border_color
+      @style.border_color = safe_style_fetch(:border_color)
+
+      @style.border_color_left   = safe_style_fetch(:border_color_left)   || @style.border_color
+      @style.border_color_right  = safe_style_fetch(:border_color_right)  || @style.border_color
+      @style.border_color_top    = safe_style_fetch(:border_color_top)    || @style.border_color
+      @style.border_color_bottom = safe_style_fetch(:border_color_bottom) || @style.border_color
+
+      @style.border_canvas.color = [
+        @style.border_color_top,
+        @style.border_color_right,
+        @style.border_color_bottom,
+        @style.border_color_left
+      ]
+    end
+
+    def set_padding
+      @style.padding = safe_style_fetch(:padding)
+
+      @style.padding_left   = safe_style_fetch(:padding_left)   || @style.padding
+      @style.padding_right  = safe_style_fetch(:padding_right)  || @style.padding
+      @style.padding_top    = safe_style_fetch(:padding_top)    || @style.padding
+      @style.padding_bottom = safe_style_fetch(:padding_bottom) || @style.padding
+    end
+
+    def set_margin
+      @style.margin = safe_style_fetch(:margin)
+
+      @style.margin_left   = safe_style_fetch(:margin_left)   || @style.margin
+      @style.margin_right  = safe_style_fetch(:margin_right)  || @style.margin
+      @style.margin_top    = safe_style_fetch(:margin_top)    || @style.margin
+      @style.margin_bottom = safe_style_fetch(:margin_bottom) || @style.margin
+    end
+
+    def update_styles(event = :default)
+      old_width = width
+      old_height = height
+
+      @style_event = event
+
+      return if self.is_a?(ToolTip)
+
+      if old_width != width || old_height != height
+        root.gui_state.request_recalculate
+      end
+
+      stylize
     end
 
     def default_events
-      [:left, :middle, :right].each do |button|
+      %i[left middle right].each do |button|
         event(:"#{button}_mouse_button")
         event(:"released_#{button}_mouse_button")
         event(:"clicked_#{button}_mouse_button")
@@ -115,19 +189,158 @@ module CyberarmEngine
       event(:hover)
       event(:leave)
 
+      event(:focus)
       event(:blur)
+
+      event(:changed)
+    end
+
+    def enter(_sender)
+      @focus = false unless Gosu.button_down?(Gosu::MS_LEFT)
+
+      if !@enabled
+        update_styles(:disabled)
+      elsif @focus
+        update_styles(:active)
+      else
+        update_styles(:hover)
+      end
+
+      :handled
+    end
+
+    def left_mouse_button(_sender, _x, _y)
+      @focus = true
+
+      unless @enabled
+        update_styles(:disabled)
+      else
+        update_styles(:active)
+      end
+
+      window.current_state.focus = self
+
+      :handled
+    end
+
+    def released_left_mouse_button(sender, _x, _y)
+      enter(sender)
+
+      :handled
+    end
+
+    def clicked_left_mouse_button(_sender, _x, _y)
+      @block&.call(self) if @enabled && !self.is_a?(Container)
+
+      :handled
+    end
+
+    def leave(_sender)
+      if @enabled
+        update_styles
+      else
+        update_styles(:disabled)
+      end
+
+      :handled
+    end
+
+    def blur(_sender)
+      @focus = false
+
+      if @enabled
+        update_styles
+      else
+        update_styles(:disabled)
+      end
+
+      :handled
+    end
+
+    def enabled=(boolean)
+      root.gui_state.request_repaint if @enabled != boolean
+
+      @enabled = boolean
+
+      recalculate
+
+      @enabled
     end
 
     def enabled?
       @enabled
     end
 
+    def focused?
+      @focus
+    end
+
+    def visible?
+      @visible
+    end
+
+    def element_visible?
+      @element_visible
+    end
+
+    def toggle
+      @visible = !@visible
+      root.gui_state.request_recalculate
+      root.gui_state.request_repaint
+    end
+
+    def show
+      bool = visible?
+      @visible = true
+      root.gui_state.request_recalculate unless bool
+      root.gui_state.request_repaint unless bool
+    end
+
+    def hide
+      bool = visible?
+      @visible = false
+      root.gui_state.request_recalculate if bool
+      root.gui_state.request_repaint if bool
+    end
+
     def draw
-      @background_canvas.draw
-      @border_canvas.draw
+      return unless visible?
+      return unless element_visible?
+
+      @style.background_canvas.draw
+      @style.background_nine_slice_canvas.draw
+      @style.background_image_canvas.draw
+      @style.border_canvas.draw
+
       render
     end
 
+    def debug_draw
+      # FIXME
+      return# if const_defined?(GUI_DEBUG_ONLY_ELEMENT) && self.class == GUI_DEBUG_ONLY_ELEMENT
+
+      Gosu.draw_line(
+        x, y, @debug_color,
+        x + outer_width, y, @debug_color,
+        Float::INFINITY
+      )
+      Gosu.draw_line(
+        x + outer_width, y, @debug_color,
+        x + outer_width, y + outer_height, @debug_color,
+        Float::INFINITY
+      )
+      Gosu.draw_line(
+        x + outer_width, y + outer_height, @debug_color,
+        x, y + outer_height, @debug_color,
+        Float::INFINITY
+      )
+      Gosu.draw_line(
+        x, outer_height, @debug_color,
+        x, y, @debug_color,
+        Float::INFINITY
+      )
+    end
+
     def update
     end
 
@@ -137,85 +350,275 @@ module CyberarmEngine
     def button_up(id)
     end
 
+    def draggable?(_button)
+      false
+    end
+
     def render
     end
 
     def hit?(x, y)
       x.between?(@x, @x + width) &&
-      y.between?(@y, @y + height)
+        y.between?(@y, @y + height)
     end
 
     def width
-      (@border_thickness_left + @padding_left) + @width + (@padding_right + @border_thickness_right)
-    end
-
-    def outer_width
-      @margin_left + width + @margin_right
-    end
-
-    def height
-      (@border_thickness_top + @padding_top) + @height + (@padding_bottom + @border_thickness_bottom)
-    end
-
-    def outer_height
-      @margin_top + height + @margin_bottom
-    end
-
-    def style(hash)
-      if hash
-        @style.set(hash)
+      if visible?
+        inner_width + @width
       else
-        @style.hash
+        0
       end
     end
 
+    def content_width
+      @width
+    end
+
+    def noncontent_width
+      (inner_width + outer_width) - width
+    end
+
+    def outer_width
+      @style.margin_left + width + @style.margin_right
+    end
+
+    def inner_width
+      (@style.border_thickness_left + @style.padding_left) + (@style.padding_right + @style.border_thickness_right)
+    end
+
+    def height
+      if visible?
+        inner_height + @height
+      else
+        0
+      end
+    end
+
+    def content_height
+      @height
+    end
+
+    def noncontent_height
+      (inner_height + outer_height) - height
+    end
+
+    def outer_height
+      @style.margin_top + height + @style.margin_bottom
+    end
+
+    def inner_height
+      (@style.border_thickness_top + @style.padding_top) + (@style.padding_bottom + @style.border_thickness_bottom)
+    end
+
+    def scroll_width
+      return @cached_scroll_width if @cached_scroll_width && is_a?(Container)
+
+      @cached_scroll_width = @children.sum(&:outer_width)
+    end
+
+    def scroll_height
+      return @cached_scroll_height if @cached_scroll_height && is_a?(Container)
+
+      if is_a?(CyberarmEngine::Element::Flow)
+        return 0 if @children.size.zero?
+
+        pairs_ = []
+        sorted_children_ = @children.sort_by(&:y)
+        a_ = []
+        y_position_ = sorted_children_.first.y
+
+        sorted_children_.each do |child|
+          unless child.y == y_position_
+            y_position_ = child.y
+            pairs_ << a_
+            a_ = []
+          end
+
+          a_ << child
+        end
+
+        pairs_ << a_ unless pairs_.last == a_
+
+        @cached_scroll_height = pairs_.sum { |pair|  + @style.padding_top + @style.border_thickness_top + pair.map(&:outer_height).max } + @style.padding_bottom + @style.border_thickness_bottom
+      else
+        @cached_scroll_height = @style.padding_top + @style.border_thickness_top + @children.sum(&:outer_height) + @style.padding_bottom + @style.border_thickness_bottom
+      end
+    end
+
+    def max_scroll_width
+      (scroll_width - outer_width).positive? ? scroll_width - outer_width : scroll_width
+    end
+
+    def max_scroll_height
+      (scroll_height - outer_height).positive? ? scroll_height - outer_height : scroll_height
+    end
+
+    def dimensional_size(size, dimension)
+      raise "dimension must be either :width or :height" unless %i[width height].include?(dimension)
+
+      new_size = if size.is_a?(Float) && size.between?(0.0, 1.0)
+                   (@parent.send(:"content_#{dimension}") * size).floor - send(:"noncontent_#{dimension}").floor
+                 else
+                   size
+                 end
+
+      # Handle fill behavior
+      if @parent && @style.fill &&
+         (dimension == :width && @parent.is_a?(Flow) ||
+          dimension == :height && @parent.is_a?(Stack))
+        new_size = space_available_width - noncontent_width if dimension == :width && @parent.is_a?(Flow)
+        new_size = space_available_height - noncontent_height if dimension == :height && @parent.is_a?(Stack)
+      end
+
+      return @style.send(:"min_#{dimension}") if @style.send(:"min_#{dimension}") && new_size.to_f < @style.send(:"min_#{dimension}")
+      return @style.send(:"max_#{dimension}") if @style.send(:"max_#{dimension}") && new_size.to_f > @style.send(:"max_#{dimension}")
+
+      new_size
+    end
+
+    def space_available_width
+      # TODO: This may get expensive if there are a lot of children, probably should cache it somehow
+      fill_siblings = @parent.children.select { |c| c.style.fill }.count.to_f # include self since we're dividing
+
+      available_space = ((@parent.content_width - (@parent.children.reject { |c| c.style.fill }).map(&:outer_width).sum) / fill_siblings)
+      (available_space.nan? || available_space.infinite?) ? 0 : available_space.floor # The parent element might not have its dimensions, yet.
+    end
+
+    def space_available_height
+      # TODO: This may get expensive if there are a lot of children, probably should cache it somehow
+      fill_siblings = @parent.children.select { |c| c.style.fill }.count.to_f # include self since we're dividing
+
+      available_space = ((@parent.content_height - (@parent.children.reject { |c| c.style.fill }).map(&:outer_height).sum) / fill_siblings)
+      (available_space.nan? || available_space.infinite?) ? 0 : available_space.floor # The parent element might not have its dimensions, yet.
+    end
+
     def background=(_background)
-      @background_canvas.background=(_background)
+      root.gui_state.request_repaint
+
+      @style.background_canvas.background = _background
       update_background
     end
 
     def update_background
-      @background_canvas.x = @x
-      @background_canvas.y = @y
-      @background_canvas.z = @z
-      @background_canvas.width  = width
-      @background_canvas.height = height
+      @style.background_canvas.x = @x
+      @style.background_canvas.y = @y
+      @style.background_canvas.z = @z
+      @style.background_canvas.width  = width
+      @style.background_canvas.height = height
 
-      @background_canvas.update
+      @style.background_canvas.update
+      update_background_nine_slice
+      update_background_image
+      @style.border_canvas.update
+    end
 
-      @border_canvas.update
+    def background_nine_slice=(_image_path)
+      root.gui_state.request_repaint
+
+      @style.background_nine_slice_canvas.image = _image_path
+      update_background_nine_slice
+    end
+
+    def update_background_nine_slice
+      @style.background_nine_slice_canvas.x = @x
+      @style.background_nine_slice_canvas.y = @y
+      @style.background_nine_slice_canvas.z = @z
+      @style.background_nine_slice_canvas.width = width
+      @style.background_nine_slice_canvas.height = height
+
+      @style.background_nine_slice_canvas.mode = @style.background_nine_slice_mode
+
+      @style.background_nine_slice_canvas.color = @style.background_nine_slice_color
+
+      @style.background_nine_slice_canvas.left   = @style.background_nine_slice_left
+      @style.background_nine_slice_canvas.top    = @style.background_nine_slice_top
+      @style.background_nine_slice_canvas.right  = @style.background_nine_slice_right
+      @style.background_nine_slice_canvas.bottom = @style.background_nine_slice_bottom
+
+      @style.background_nine_slice_canvas.image = @style.background_nine_slice
+    end
+
+    def background_image=(image_path)
+      root.gui_state.request_repaint
+
+      @style.background_image = image_path.is_a?(Gosu::Image) ? image_path : get_image(image_path)
+      update_background_image
+    end
+
+    def update_background_image
+      @style.background_image_canvas.x = @x
+      @style.background_image_canvas.y = @y
+      @style.background_image_canvas.z = @z
+      @style.background_image_canvas.width = width
+      @style.background_image_canvas.height = height
+
+      @style.background_image_canvas.mode = @style.background_image_mode
+      @style.background_image_canvas.color = @style.background_image_color
+
+      @style.background_image_canvas.image = @style.background_image
     end
 
     def root
+      return self if is_root?
+
       unless @root && @root.parent.nil?
         @root = parent
 
         loop do
-          if @root.parent.nil?
-            break
-          else
-            @root = @root.parent
-          end
+          break unless @root&.parent
+
+          @root = @root.parent
         end
       end
 
       @root
     end
 
+    def is_root?
+      @gui_state != nil
+    end
+
+    def child_of?(element)
+      return element == self if is_root?
+      return false unless element.is_a?(Container)
+      return true if element.children.find { |child| child == self }
+
+      element.children.find { |child| child.child_of?(element) if child.is_a?(Container) }
+    end
+
+    # def parent_of?(element)
+    #   return true if element.children.find { |child| child == self }
+
+    #   element.children.find { |child| child.parent}
+    # end
+
+    def focus(_)
+      warn "#{self.class}#focus was not overridden!"
+
+      :handled
+    end
+
     def recalculate
       raise "#{self.class}#recalculate was not overridden!"
     end
 
     def reposition
-      raise "#{self.class}#reposition was not overridden!"
     end
 
     def value
       raise "#{self.class}#value was not overridden!"
     end
 
-    def value=(value)
+    def value=(_value)
       raise "#{self.class}#value= was not overridden!"
     end
+
+    def to_s
+      "#{self.class} x=#{x} y=#{y} width=#{width} height=#{height} value=#{value.is_a?(String) ? "\"#{value}\"" : value}"
+    end
+
+    def inspect
+      to_s
+    end
   end
-end
+end

lib/cyberarm_engine/ui/elements/button.rb

@@ -0,0 +1,100 @@
+module CyberarmEngine
+  class Element
+    class Button < TextBlock
+      def initialize(text_or_image, options = {}, block = nil)
+        @image = nil
+        @scale_x = 1
+        @scale_y = 1
+
+        @image = text_or_image if text_or_image.is_a?(Gosu::Image)
+
+        super(text_or_image, options, block)
+
+        @style.background_canvas.background = @style.background
+      end
+
+      def render
+        if @image
+          draw_image
+        else
+          draw_text
+        end
+      end
+
+      def draw_image
+        @image.draw(
+          @style.border_thickness_left + @style.padding_left + @x,
+          @style.border_thickness_top + @style.padding_top + @y,
+          @z + 2,
+          @scale_x, @scale_y, @text.color
+        )
+      end
+
+      def draw_text
+        @text.draw
+      end
+
+      def recalculate
+        unless @enabled
+          @style.background_canvas.background = @style.disabled[:background]
+          @text.color = @style.disabled[:color]
+        else
+          @style.background_canvas.background = @style.background
+          @text.color = @style.color
+        end
+
+        if @image
+          @width = 0
+          @height = 0
+
+          _width = dimensional_size(@style.image_width, :width)
+          _height = dimensional_size(@style.image_height, :height)
+
+          if _width && _height
+            @scale_x = _width.to_f / @image.width
+            @scale_y = _height.to_f / @image.height
+          elsif _width
+            @scale_x = _width.to_f / @image.width
+            @scale_y = @scale_x
+          elsif _height
+            @scale_y = _height.to_f / @image.height
+            @scale_x = @scale_y
+          else
+            @scale_x = 1
+            @scale_y = 1
+          end
+
+          @width = _width || @image.width.floor * @scale_x
+          @height = _height || @image.height.floor * @scale_y
+
+          update_background
+        else
+          super
+        end
+      end
+
+      def value
+        @image || super
+      end
+
+      def value=(value)
+        if value.is_a?(Gosu::Image)
+          @image = value
+        else
+          super
+        end
+
+        old_width = width
+        old_height = height
+
+        if old_width != width || old_height != height
+          root.gui_state.request_recalculate
+        else
+          recalculate
+        end
+
+        publish(:changed, self.value)
+      end
+    end
+  end
+end

lib/cyberarm_engine/ui/elements/check_box.rb

@@ -0,0 +1,54 @@
+module CyberarmEngine
+  class Element
+    class CheckBox < Flow
+      def initialize(text, options, block = nil)
+        super(options, block)
+        options[:toggled] = options[:checked]
+
+        options[:parent] = self
+        @toggle_button = ToggleButton.new(options)
+
+        options[:parent] = self
+        @label = TextBlock.new(text, options)
+
+        @label.subscribe(:holding_left_mouse_button) do |sender, x, y|
+          @toggle_button.left_mouse_button(sender, x, y)
+        end
+
+        @label.subscribe(:released_left_mouse_button) do |sender, x, y|
+          @toggle_button.released_left_mouse_button(sender, x, y)
+        end
+
+        @label.subscribe(:clicked_left_mouse_button) do |sender, x, y|
+          @toggle_button.clicked_left_mouse_button(sender, x, y)
+          publish(:changed, @toggle_button.value)
+        end
+
+        @label.subscribe(:enter) do |sender|
+          @toggle_button.enter(sender)
+        end
+
+        @label.subscribe(:leave) do |sender|
+          @toggle_button.leave(sender)
+        end
+
+        add(@toggle_button)
+        add(@label)
+      end
+
+      def text=(text)
+        @label.text = text
+        recalculate
+      end
+
+      def value
+        @toggle_button.value
+      end
+
+      def value=(bool)
+        @toggle_button.value = bool
+        publish(:changed, @toggle_button.value)
+      end
+    end
+  end
+end

lib/cyberarm_engine/ui/elements/container.rb

@@ -0,0 +1,373 @@
+module CyberarmEngine
+  class Element
+    class Container < Element
+      include Common
+
+      attr_accessor :stroke_color, :fill_color
+      attr_reader :children, :gui_state, :scroll_position
+
+      def self.current_container
+        @@current_container
+      end
+
+      def self.current_container=(container)
+        raise ArgumentError, "Expected container to an an instance of CyberarmEngine::Element::Container, got #{container.class}" unless container.is_a?(CyberarmEngine::Element::Container)
+
+        @@current_container = container
+      end
+
+      def initialize(options = {}, block = nil)
+        @gui_state = options.delete(:gui_state)
+        super
+
+        @last_scroll_position = Vector.new(0, 0)
+        @scroll_position = Vector.new(0, 0)
+        @scroll_target_position = Vector.new(0, 0)
+        @scroll_chunk = 120
+        @scroll_speed = 40
+
+        @text_color = options[:color]
+
+        @children = []
+
+        event(:window_size_changed)
+      end
+
+      def build
+        @block.call(self) if @block
+
+        root.gui_state.request_recalculate_for(self)
+      end
+
+      def add(element)
+        @children << element
+
+        root.gui_state.request_recalculate_for(self)
+      end
+
+      def remove(element)
+        root.gui_state.request_recalculate_for(self) if @children.delete(element)
+      end
+
+      def clear(&block)
+        @children.clear
+
+        old_container = CyberarmEngine::Element::Container.current_container
+
+        CyberarmEngine::Element::Container.current_container = self
+        block.call(self) if block
+
+        CyberarmEngine::Element::Container.current_container = old_container
+
+        root.gui_state.request_recalculate_for(self)
+      end
+
+      def append(&block)
+        old_container = CyberarmEngine::Element::Container.current_container
+
+        CyberarmEngine::Element::Container.current_container = self
+        block.call(self) if block
+
+        CyberarmEngine::Element::Container.current_container = old_container
+
+        root.gui_state.request_recalculate_for(self)
+      end
+
+      def render
+        Gosu.clip_to(
+          @x + @style.border_thickness_left + @style.padding_left,
+          @y + @style.border_thickness_top + @style.padding_top,
+          content_width + 1,
+          content_height + 1
+        ) do
+          Gosu.translate(@scroll_position.x, @scroll_position.y) do
+            @children.each(&:draw)
+          end
+        end
+      end
+
+      def debug_draw
+        super
+
+        @children.each do |child|
+          child.debug_draw
+        end
+      end
+
+      def update
+        update_scroll
+        @children.each(&:update)
+      end
+
+      def hit_element?(x, y)
+        return unless hit?(x, y)
+
+        # Offset child hit point by scroll position/offset
+        child_x = x - @scroll_position.x
+        child_y = y - @scroll_position.y
+
+        @children.reverse_each do |child|
+          next unless child.visible?
+
+          case child
+          when Container
+            if element = child.hit_element?(child_x, child_y)
+              return element
+            end
+          else
+            return child if child.hit?(child_x, child_y)
+          end
+        end
+
+        self if hit?(x, y)
+      end
+
+      def update_child_element_visibity(child)
+        child.element_visible = child.x >= (@x - @scroll_position.x) - child.width && child.x <= (@x - @scroll_position.x) + width &&
+                                child.y >= (@y - @scroll_position.y) - child.height && child.y <= (@y - @scroll_position.y) + height
+      end
+
+      def update_scroll
+        dt = window.dt > 1 ? 1.0 : window.dt
+
+        scroll_x_diff = (@scroll_target_position.x - @scroll_position.x)
+        scroll_y_diff = (@scroll_target_position.y - @scroll_position.y)
+
+        @scroll_position.x += (scroll_x_diff * @scroll_speed * 0.25 * dt).round
+        @scroll_position.y += (scroll_y_diff * @scroll_speed * 0.25 * dt).round
+
+        @scroll_position.x = @scroll_target_position.x if scroll_x_diff.abs < 1.0
+        @scroll_position.y = @scroll_target_position.y if scroll_y_diff.abs < 1.0
+
+        # Scrolled PAST top
+        if @scroll_position.y > 0
+          @scroll_target_position.y = 0
+
+        # Scrolled PAST bottom
+        elsif @scroll_position.y.abs > max_scroll_height
+          @scroll_target_position.y = -max_scroll_height
+        end
+
+        if @last_scroll_position != @scroll_position
+          @children.each { |child| update_child_element_visibity(child) }
+          root.gui_state.request_repaint
+        end
+
+        @last_scroll_position.x = @scroll_position.x
+        @last_scroll_position.y = @scroll_position.y
+      end
+
+      def recalculate
+        @current_position = Vector.new(@style.margin_left + @style.padding_left, @style.margin_top + @style.padding_top)
+
+        return unless visible?
+
+        Stats.frame.increment(:gui_recalculations)
+
+        stylize
+
+        # s = Gosu.milliseconds
+
+        layout
+
+        old_width  = @width
+        old_height = @height
+
+        @cached_scroll_width = nil
+        @cached_scroll_height = nil
+
+        if is_root?
+          @width  = @style.width  = window.width
+          @height = @style.height = window.height
+        else
+          @width = 0
+          @height = 0
+
+          _width = dimensional_size(@style.width, :width)
+          _height = dimensional_size(@style.height, :height)
+
+          @width  = _width  || (@children.map { |c| c.x + c.outer_width }.max || 0).floor
+          @height = _height || (@children.map { |c| c.y + c.outer_height }.max || 0).floor
+        end
+
+        # FIXME: Correctly handle alignment when element has siblings
+        # FIXME: Enable alignment for any element, not just containers
+        if @style.v_align
+          space = space_available_height
+
+          case @style.v_align
+          when :center
+            @y = parent.height / 2 - height / 2
+          when :bottom
+            @y = parent.height - height
+          end
+        end
+
+        if @style.h_align
+          space = space_available_width
+
+          case @style.h_align
+          when :center
+            @x = parent.width / 2 - width / 2
+          when :right
+            @x = parent.width - width
+          end
+        end
+
+        # Move children to parent after positioning
+        @children.each do |child|
+          child.x += (@x + @style.border_thickness_left) - style.margin_left
+          child.y += (@y + @style.border_thickness_top) - style.margin_top
+
+          child.stylize
+          child.recalculate
+          child.reposition # TODO: Implement top,bottom,left,center, and right positioning
+
+          Stats.frame.increment(:gui_recalculations)
+
+          update_child_element_visibity(child)
+        end
+
+        # puts "TOOK: #{Gosu.milliseconds - s}ms to recalculate #{self.class}:0x#{self.object_id.to_s(16)}"
+
+        update_background
+
+        # Fixes resized container scrolled past bottom
+        self.scroll_top = -@scroll_position.y
+        @scroll_target_position.y = @scroll_position.y
+
+        # NOTE: Experiment for removing need to explicitly call gui_state#recalculate at least 3 times for layout to layout...
+        if old_width != @width || old_height != @height
+          if @parent
+            root.gui_state.request_recalculate_for(@parent)
+          else
+            root.gui_state.request_recalculate
+          end
+        end
+
+        root.gui_state.request_repaint if @width != old_width || @height != old_height
+      end
+
+      def layout
+        raise "Not overridden"
+      end
+
+      def max_width
+        # _width = dimensional_size(@style.width, :width)
+        # if _width
+        #   outer_width
+        # else
+        #   window.width - (@parent ? @parent.style.margin_right + @style.margin_right : @style.margin_right)
+        # end
+
+        outer_width
+      end
+
+      def fits_on_line?(element) # Flow
+        @current_position.x + element.outer_width <= max_width &&
+          @current_position.x + element.outer_width <= window.width
+      end
+
+      def position_on_current_line(element) # Flow
+        element.x = element.style.margin_left + @current_position.x
+        element.y = element.style.margin_top  + @current_position.y
+
+        @current_position.x += element.outer_width
+      end
+
+      def tallest_neighbor(querier, _y_position) # Flow
+        response = querier
+        @children.each do |child|
+          response = child if child.outer_height > response.outer_height
+          break if child == querier
+        end
+
+        response
+      end
+
+      def position_on_next_line(element) # Flow
+        @current_position.x = @style.margin_left + @style.padding_left
+        @current_position.y += tallest_neighbor(element, @current_position.y).outer_height
+
+        element.x = element.style.margin_left + @current_position.x
+        element.y = element.style.margin_top  + @current_position.y
+
+        @current_position.x += element.outer_width
+      end
+
+      def move_to_next_line(element) # Stack
+        element.x = element.style.margin_left + @current_position.x
+        element.y = element.style.margin_top  + @current_position.y
+
+        @current_position.y += element.outer_height
+      end
+
+      def mouse_wheel_up(sender, x, y)
+        return unless @style.scroll
+
+        # Allow overscrolling UP, only if one can scroll DOWN
+        if height < scroll_height
+          if @scroll_target_position.y > 0
+            @scroll_target_position.y = @scroll_chunk
+          else
+            @scroll_target_position.y += @scroll_chunk
+          end
+
+          return :handled
+        end
+      end
+
+      def mouse_wheel_down(sender, x, y)
+        return unless @style.scroll
+
+        return unless height < scroll_height
+
+        if @scroll_target_position.y > 0
+          @scroll_target_position.y = -@scroll_chunk
+        else
+          @scroll_target_position.y -= @scroll_chunk
+        end
+
+        return :handled
+      end
+
+      def scroll_top
+        @scroll_position.y
+      end
+
+      def scroll_top=(n)
+        n = 0 if n <= 0
+        @scroll_position.y = -n
+
+        if max_scroll_height.positive?
+          @scroll_position.y = -max_scroll_height if @scroll_position.y.abs > max_scroll_height
+        else
+          @scroll_position.y = 0
+        end
+      end
+
+      def value
+        @children.map(&:class).join(", ")
+      end
+
+      def to_s
+        "#{self.class} x=#{x} y=#{y} width=#{width} height=#{height} children=#{@children.size}"
+      end
+
+      def write_tree(indent = "", _index = 0)
+        puts self
+
+        indent += "  "
+        @children.each_with_index do |child, i|
+          print "#{indent}#{i}: "
+
+          if child.is_a?(Container)
+            child.write_tree(indent)
+          else
+            puts child
+          end
+        end
+      end
+    end
+  end
+end

lib/cyberarm_engine/ui/elements/edit_box.rb

@@ -0,0 +1,179 @@
+module CyberarmEngine
+  class Element
+    class EditBox < EditLine
+      def initialize(*args)
+        super(*args)
+
+        @active_line = 0
+
+        @repeatable_keys = [
+          {
+            key: Gosu::KB_UP,
+            down: false,
+            repeat_delay: 50,
+            last_repeat: 0,
+            action: proc { move(:up) }
+          },
+          {
+            key: Gosu::KB_DOWN,
+            down: false,
+            repeat_delay: 50,
+            last_repeat: 0,
+            action: proc { move(:down) }
+          }
+        ]
+      end
+
+      def update
+        super
+
+        caret_stay_left_of_last_newline
+        calculate_active_line
+
+        @repeatable_keys.each do |key|
+          if key[:down] && (Gosu.milliseconds > key[:last_repeat] + key[:repeat_delay])
+            key[:action].call
+            key[:last_repeat] = Gosu.milliseconds
+          end
+        end
+      end
+
+      def draw_caret
+        Gosu.draw_rect(caret_position, @text.y + @active_line * @text.textobject.height, @caret_width, @caret_height,
+                       @caret_color, @z)
+      end
+
+      def draw_selection
+        selection_width = caret_position - selection_start_position
+
+        Gosu.draw_rect(selection_start_position, @text.y, selection_width, @text.textobject.height,
+                       default(:selection_color), @z)
+      end
+
+      def text_input_position_for(_method)
+        line = @text_input.text[0...@text_input.caret_pos].lines.last
+        _x = @text.x + @offset_x
+
+        if @type == :password
+          _x + @text.width(default(:password_character) * line.length)
+        else
+          _x + @text.width(line)
+        end
+      end
+
+      def set_position(int)
+        int = 0 if int < 0
+        @text_input.selection_start = @text_input.caret_pos = int
+      end
+
+      def calculate_active_line
+        sub_text = @text_input.text[0...@text_input.caret_pos]
+        @active_line = sub_text.lines.size - 1
+      end
+
+      def caret_stay_left_of_last_newline
+        @text_input.text += "\n" unless @text_input.text.end_with?("\n")
+
+        eof = @text_input.text.chomp.length
+        set_position(eof) if @text_input.caret_pos > eof
+      end
+
+      def caret_position_under_mouse(mouse_x, mouse_y)
+        active_line = row_at(mouse_y)
+        right_offset = column_at(mouse_x, mouse_y)
+
+        buffer = @text_input.text.lines[0..active_line].join if active_line != 0
+        buffer = @text_input.text.lines.first if active_line == 0
+        line = buffer.lines.last
+
+        if buffer.chars.last == "\n"
+          (buffer.length - line.length) + right_offset - 1
+        else
+          (buffer.length - line.length) + right_offset
+        end
+      end
+
+      def move_caret_to_mouse(mouse_x, mouse_y)
+        set_position(caret_position_under_mouse(mouse_x, mouse_y))
+      end
+
+      def row_at(y)
+        ((y - @text.y) / @text.textobject.height).floor
+      end
+
+      def column_at(x, y)
+        row = row_at(y)
+
+        buffer = @text_input.text.lines[0..row].join if row != 0
+        buffer = @text_input.text.lines.first if row == 0
+
+        line = @text_input.text.lines[row]
+        line ||= ""
+        column = 0
+
+        line.length.times do |_i|
+          break if @text.textobject.text_width(line[0...column]) >= (x - @text.x).clamp(0.0, Float::INFINITY)
+
+          column += 1
+        end
+
+        column
+      end
+
+      def button_down(id)
+        super
+
+        @repeatable_keys.detect do |key|
+          next unless key[:key] == id
+
+          key[:down] = true
+          key[:last_repeat] = Gosu.milliseconds + key[:repeat_delay]
+          return true
+        end
+
+        case id
+        when Gosu::KB_ENTER, Gosu::KB_RETURN
+          caret_pos = @text_input.caret_pos
+          @text_input.text = @text_input.text.insert(@text_input.caret_pos, "\n")
+          @text_input.caret_pos = @text_input.selection_start = caret_pos + 1
+        end
+      end
+
+      def button_up(id)
+        super
+
+        @repeatable_keys.detect do |key|
+          if key[:key] == id
+            key[:down] = false
+            return true
+          end
+        end
+      end
+
+      def move(direction)
+        pos = @text_input.caret_pos
+        line = nil
+
+        case direction
+        when :up
+          return if @active_line == 0
+        when :down
+          return if @active_line == @text_input.text.chomp.lines
+
+          text = @text_input.text.chomp.lines[0..@active_line].join("\n")
+          pos = text.length
+        end
+
+        set_position(pos)
+      end
+
+      def drag_update(_sender, x, y, _button)
+        int = caret_position_under_mouse(x, y)
+        int = 0 if int < 0
+        @text_input.caret_pos = int
+
+        :handled
+      end
+    end
+  end
+end

lib/cyberarm_engine/ui/elements/edit_line.rb

@@ -0,0 +1,297 @@
+module CyberarmEngine
+  class Element
+    class EditLine < Button
+      class TextInput < Gosu::TextInput
+        def filter=(filter)
+          @filter = filter
+        end
+
+        def filter(text_in)
+          if @filter
+            @filter.call(text_in)
+          else
+            text_in
+          end
+        end
+      end
+
+      def initialize(text, options = {}, block = nil)
+        @filter = options.delete(:filter)
+        super(text, options, block)
+
+        @type = default(:type)
+
+        @caret_width = default(:caret_width)
+        @caret_height = @text.textobject.height
+        @caret_color = default(:caret_color)
+        @caret_interval = default(:caret_interval)
+        @caret_last_interval = Gosu.milliseconds
+        @show_caret = true
+
+        @text_input = TextInput.new
+        @text_input.filter = @filter
+        @text_input.text = text
+        @last_text_value = text
+        @last_caret_position = @text_input.caret_pos
+
+        @offset_x = 0
+        @offset_y = 0
+
+        event(:begin_drag)
+        event(:drag_update)
+        event(:end_drag)
+      end
+
+      def render
+        Gosu.clip_to(@text.x, @text.y, @width, @height) do
+          Gosu.translate(-@offset_x, -@offset_y) do
+            draw_selection
+            draw_caret if @focus && @show_caret
+            draw_text
+          end
+        end
+      end
+
+      def draw_text
+        @text.draw(:draw_text)
+      end
+
+      def draw_caret
+        Gosu.draw_rect(caret_position, @text.y, @caret_width, @caret_height, @caret_color, @z)
+      end
+
+      def draw_selection
+        selection_width = caret_position - selection_start_position
+
+        Gosu.draw_rect(selection_start_position, @text.y, selection_width, @text.height, default(:selection_color), @z)
+      end
+
+      def update
+        @style_event = :active if @focus
+
+        @text.text = if @type == :password
+                       default(:password_character) * @text_input.text.length
+                     else
+                       @text_input.text
+                     end
+
+        if @last_text_value != value
+          @last_text_value = value
+          @show_caret = true
+          @caret_last_interval = Gosu.milliseconds
+
+          root.gui_state.request_repaint
+
+          publish(:changed, value)
+        end
+
+        if @last_caret_position != @text_input.caret_pos
+          @last_caret_position = @text_input.caret_pos
+          root.gui_state.request_repaint
+
+          @show_caret = true
+          @caret_last_interval = Gosu.milliseconds
+        end
+
+        if Gosu.milliseconds >= @caret_last_interval + @caret_interval
+          root.gui_state.request_repaint
+
+          @caret_last_interval = Gosu.milliseconds
+
+          @show_caret = !@show_caret
+        end
+
+        keep_caret_visible
+      end
+
+      def button_down(id)
+        handle_keyboard_shortcuts(id)
+      end
+
+      def handle_keyboard_shortcuts(id)
+        return unless @focus && @enabled
+
+        if Gosu.button_down?(Gosu::KB_LEFT_CONTROL) || Gosu.button_down?(Gosu::KB_RIGHT_CONTROL)
+          case id
+          when Gosu::KB_A
+            @text_input.selection_start = 0
+            @text_input.caret_pos = @text_input.text.length
+
+          when Gosu::KB_C
+            Gosu.clipboard = if @text_input.selection_start < @text_input.caret_pos
+                               @text_input.text[@text_input.selection_start...@text_input.caret_pos]
+                             else
+                               @text_input.text[@text_input.caret_pos...@text_input.selection_start]
+                             end
+
+          when Gosu::KB_X
+            chars = @text_input.text.chars
+
+            if @text_input.selection_start < @text_input.caret_pos
+              Gosu.clipboard = @text_input.text[@text_input.selection_start...@text_input.caret_pos]
+              chars.slice!(@text_input.selection_start, @text_input.caret_pos)
+            else
+              Gosu.clipboard = @text_input.text[@text_input.caret_pos...@text_input.selection_start]
+              chars.slice!(@text_input.caret_pos, @text_input.selection_start)
+            end
+
+            @text_input.text = chars.join
+
+          when Gosu::KB_V
+            if instance_of?(EditLine) # EditLine assumes a single line of text
+              @text_input.insert_text(Gosu.clipboard.gsub("\n", ""))
+            else
+              @text_input.insert_text(Gosu.clipboard)
+            end
+          end
+        end
+      end
+
+      def caret_position_under_mouse(mouse_x)
+        1.upto(@text.text.length) do |i|
+          return i - 1 if mouse_x < @text.x - @offset_x + @text.width(@text.text[0...i])
+        end
+
+        @text_input.text.length
+      end
+
+      def move_caret_to_mouse(mouse_x, _mouse_y)
+        @text_input.caret_pos = @text_input.selection_start = caret_position_under_mouse(mouse_x)
+      end
+
+      def keep_caret_visible
+        caret_pos = (caret_position - @text.x) + @caret_width
+
+        @last_text ||= "/\\"
+        @last_pos ||= -1
+
+        @last_text = @text.text
+        @last_pos = caret_pos
+
+        if caret_pos.between?(@offset_x, @width + @offset_x)
+          # Do nothing
+
+        elsif caret_pos < @offset_x
+          @offset_x = if caret_pos > @width
+                        caret_pos + @width
+                      else
+                        0
+                      end
+
+        elsif caret_pos > @width
+          @offset_x = caret_pos - @width
+
+        else
+          # Reset to Zero
+          @offset_x = 0
+        end
+      end
+
+      def caret_position
+        text_input_position_for(:caret_pos)
+      end
+
+      def selection_start_position
+        text_input_position_for(:selection_start)
+      end
+
+      def text_input_position_for(method)
+        if @type == :password
+          @text.x + @text.width(default(:password_character) * @text_input.text[0...@text_input.send(method)].length)
+        else
+          @text.x + @text.width(@text_input.text[0...@text_input.send(method)]) - @style.border_thickness_left
+        end
+      end
+
+      def left_mouse_button(sender, x, y)
+        super
+        window.text_input = @text_input
+
+        @caret_last_interval = Gosu.milliseconds
+        @show_caret = true
+
+        move_caret_to_mouse(x, y)
+
+        :handled
+      end
+
+      def focus(sender)
+        @focus = true
+        window.text_input = @text_input
+        @text_input.caret_pos = @text_input.selection_start = @text_input.text.length
+
+        update_styles(:active)
+
+        :handled
+      end
+
+      def enter(sender)
+        if @enabled && @focus
+          update_styles(:active)
+        elsif @enabled && !@focus
+          update_styles(:hover)
+        else
+          update_styles(:disabled)
+        end
+
+        :handled
+      end
+
+      def leave(sender)
+        if @enabled && @focus
+          update_styles(:active)
+        elsif @enabled && !@focus
+          update_styles
+        else
+          update_styles(:disabled)
+        end
+
+        :handled
+      end
+
+      def blur(_sender)
+        super
+        window.text_input = nil
+
+        :handled
+      end
+
+      def draggable?(button)
+        button == :left
+      end
+
+      def begin_drag(_sender, x, _y, _button)
+        @drag_start = x
+        @offset_drag_start = @offset_x
+        @drag_caret_position = @text_input.caret_pos
+
+        :handled
+      end
+
+      def drag_update(_sender, x, _y, _button)
+        @text_input.caret_pos = caret_position_under_mouse(x)
+
+        :handled
+      end
+
+      def end_drag(_sender, _x, _y, _button)
+        :handled
+      end
+
+      def recalculate
+        super
+
+        @width = dimensional_size(@style.width, :width) || default(:width)
+        update_background
+      end
+
+      def value
+        @text_input.text
+      end
+
+      def value=(string)
+        @text_input.text = string
+      end
+    end
+  end
+end

lib/cyberarm_engine/ui/elements/flow.rb

@@ -0,0 +1,15 @@
+module CyberarmEngine
+  class Element
+    class Flow < Container
+      def layout
+        @children.each do |child|
+          if fits_on_line?(child)
+            position_on_current_line(child)
+          else
+            position_on_next_line(child)
+          end
+        end
+      end
+    end
+  end
+end

lib/cyberarm_engine/ui/elements/image.rb

@@ -0,0 +1,72 @@
+module CyberarmEngine
+  class Element
+    class Image < Element
+      def initialize(path_or_image, options = {}, block = nil)
+        super(options, block)
+        @path = path_or_image if path_or_image.is_a?(String)
+
+        @image = Gosu::Image.new(path_or_image, retro: @options[:retro], tileable: @options[:tileable]) if @path
+        @image = path_or_image unless @path
+
+        @scale_x = 1
+        @scale_y = 1
+      end
+
+      def render
+        @image.draw(
+          @style.border_thickness_left + @style.padding_left + @x,
+          @style.border_thickness_top + @style.padding_top + @y,
+          @z + 2,
+          @scale_x, @scale_y, @style.color
+        )
+      end
+
+      def clicked_left_mouse_button(_sender, _x, _y)
+        @block.call(self) if @block
+
+        :handled
+      end
+
+      def recalculate
+        _width = dimensional_size(@style.width, :width)
+        _height = dimensional_size(@style.height, :height)
+
+        if _width && _height
+          @scale_x = _width.to_f / @image.width
+          @scale_y = _height.to_f / @image.height
+        elsif _width
+          @scale_x = _width.to_f / @image.width
+          @scale_y = @scale_x
+        elsif _height
+          @scale_y = _height.to_f / @image.height
+          @scale_x = @scale_y
+        else
+          @scale_x = 1
+          @scale_y = 1
+        end
+
+        @width = _width || (@image.width * @scale_x).floor
+        @height = _height || (@image.height * @scale_y).floor
+
+        update_background
+      end
+
+      def value
+        @image
+      end
+
+      def value=(path_or_image, retro: false, tileable: false)
+        @path = path_or_image if path_or_image.is_a?(String)
+
+        @image = Gosu::Image.new(path_or_image, retro: retro, tileable: tileable) if @path
+        @image = path_or_image unless @path
+
+        recalculate
+      end
+
+      def path
+        @path
+      end
+    end
+  end
+end

lib/cyberarm_engine/ui/elements/list_box.rb

@@ -0,0 +1,101 @@
+module CyberarmEngine
+  class Element
+    class ListBox < Button
+      attr_accessor :items
+      attr_reader :choose
+
+      def initialize(options = {}, block = nil)
+        @items = options[:items] || []
+        @choose = options[:choose] || @items.first
+
+        super(@choose, options, block)
+
+        @style.background_canvas.background = default(:background)
+
+        # TODO: "Clean Up" into own class?
+        @menu = Stack.new(parent: self, theme: @options[:theme])
+        @menu.define_singleton_method(:recalculate_menu) do
+          @x = @__list_box.x
+          @y = @__list_box.y + @__list_box.height
+
+          @y = @__list_box.y - height if @y + height > window.height
+        end
+        @menu.instance_variable_set(:"@__list_box", self)
+
+        def @menu.recalculate
+          super
+
+          recalculate_menu
+        end
+
+        self.choose = @choose
+      end
+
+      def render
+        super
+
+        w = @text.textobject.text_width("▼")
+        @text.textobject.draw_text("▼", @x + content_width - w, @y + @style.padding_top, @z, 1, 1, @text.color)
+      end
+
+      def choose=(item)
+        valid = @items.detect { |i| i == item }
+        raise "Invalid value '#{item}' for choose, valid options were: #{@items.map { |i| "#{i.inspect}" }.join(", ")}" unless valid
+
+        @choose = item
+
+        self.value = item.to_s
+
+        recalculate
+      end
+
+      def released_left_mouse_button(_sender, _x, _y)
+        show_menu
+
+        :handled
+      end
+
+      def clicked_left_mouse_button(_sender, _x, _y)
+        # @block&.call(self.value) if @enabled
+
+        :handled
+      end
+
+      def show_menu
+        @menu.clear
+
+        @menu.style.width = width
+
+        @items.each do |item|
+          next if item == self.value
+
+          btn = Button.new(
+            item,
+            {
+              parent: @menu,
+              width: 1.0,
+              theme: @options[:theme],
+              margin: 0,
+              border_color: 0x00ffffff
+            },
+            proc do
+              self.choose = item
+              @block&.call(self.value)
+            end
+          )
+
+          @menu.add(btn)
+        end
+        recalculate
+
+        root.gui_state.show_menu(@menu)
+      end
+
+      def recalculate
+        super
+
+        @menu.recalculate
+      end
+    end
+  end
+end

lib/cyberarm_engine/ui/elements/progress.rb

@@ -0,0 +1,93 @@
+module CyberarmEngine
+  class Element
+    class Progress < Element
+      attr_reader :type
+
+      def initialize(options = {}, block = nil)
+        super(options, block)
+
+        @animation_speed = options[:animation_speed] || 3_000
+        @marquee_width = options[:marquee_width] || 0.25
+        @marquee_offset = 0
+        @marquee_animation_time = Gosu.milliseconds
+        @type = options[:type] || :linear
+        @fraction_background = Background.new(background: @style.fraction_background)
+        self.value = options[:fraction] || 0.0
+      end
+
+      def render
+        @fraction_background.draw
+      end
+
+      def recalculate
+        _width = dimensional_size(@style.width, :width)
+        _height = dimensional_size(@style.height, :height)
+        @width = _width
+        @height = _height
+
+        update_background
+      end
+
+      def update_background
+        super
+
+        @fraction_background.x = (@style.border_thickness_left + @style.padding_left + @x) + @marquee_offset
+        @fraction_background.y = @style.border_thickness_top + @style.padding_top + @y
+        @fraction_background.z = @z
+        @fraction_background.width = @width * (@type == :marquee ? @marquee_width : @fraction)
+        @fraction_background.height = @height
+
+        @fraction_background.background = @style.fraction_background
+      end
+
+      def update
+        super
+
+        return unless @type == :marquee
+
+        marquee_width = @width * @marquee_width
+        range = @width + marquee_width
+
+        @marquee_offset = (@width * (Gosu.milliseconds - @marquee_animation_time) / @animation_speed) - marquee_width
+        @marquee_animation_time = Gosu.milliseconds if @marquee_offset > range
+
+        update_background
+        root.gui_state.request_repaint
+      end
+
+      def type=(type)
+        @type = type
+
+        case type
+        when :linear
+          @marquee_offset = 0
+        when :marquee
+          @marquee_offset = 0
+          @marquee_animation_time = Gosu.milliseconds
+        else
+          raise ArgumentError, "Only types :linear and :marquee are supported"
+        end
+
+        update_background
+      end
+
+      def value
+        @fraction
+      end
+
+      def value=(decimal)
+        raise "value must be number" unless decimal.is_a?(Numeric)
+
+        old_value = @fraction
+
+        @fraction = decimal.clamp(0.0, 1.0)
+        update_background
+
+        root.gui_state.request_repaint if @fraction != old_value
+
+        publish(:changed, @fraction)
+        @fraction
+      end
+    end
+  end
+end

lib/cyberarm_engine/ui/elements/radio.rb

@@ -0,0 +1,6 @@
+module CyberarmEngine
+  class Element
+    class Radio < Element
+    end
+  end
+end

lib/cyberarm_engine/ui/elements/slider.rb

@@ -0,0 +1,107 @@
+module CyberarmEngine
+  class Element
+    class Slider < Container
+      class Handle < Button
+        def initialize(*args)
+          super(*args)
+
+          event(:begin_drag)
+          event(:drag_update)
+          event(:end_drag)
+
+          subscribe :begin_drag do |_sender, x, y, _button|
+            @drag_start_pos = Vector.new(x, y)
+
+            :handled
+          end
+
+          subscribe :drag_update do |_sender, x, y, _button|
+            @parent.handle_dragged_to(x, y)
+
+            :handled
+          end
+
+          subscribe :end_drag do
+            @drag_start_pos = nil
+
+            :handled
+          end
+        end
+
+        def draggable?(button)
+          button == :left
+        end
+      end
+
+      attr_reader :step_size, :value
+      attr_accessor :range, :step_size
+
+      def initialize(options = {}, block = nil)
+        super(options, block)
+
+        @range     = @options[:range] || (0.0..1.0)
+        @step_size = @options[:step] || 0.1
+        @value     = @options[:value] || (@range.first + @range.last) / 2
+
+        @handle = Handle.new("", parent: self, theme: options[:theme], width: 8, height: 1.0) { close }
+        add(@handle)
+      end
+
+      def recalculate
+        _width = dimensional_size(@style.width, :width)
+        _height = dimensional_size(@style.height, :height)
+
+        @width  = _width
+        @height = _height
+
+        position_handle
+        @handle.recalculate
+        @handle.update_background
+
+        update_background
+      end
+
+      def position_handle
+        @handle.x = @x + @handle.style.margin_left + @style.padding_left + @style.border_thickness_left +
+                    ((content_width - @handle.outer_width) * (@value - @range.min) / (@range.max - @range.min).to_f)
+
+        @handle.y = @y + @handle.style.margin_top + @style.border_thickness_top + @style.padding_top
+      end
+
+      def draw
+        super
+
+        @handle.draw
+      end
+
+      def update
+        super
+
+        @tip = format("%.2f", value.to_f)
+        @handle.tip = @tip
+      end
+
+      def holding_left_mouse_button(_sender, x, y)
+        handle_dragged_to(x, y)
+
+        :handled
+      end
+
+      def handle_dragged_to(x, _y)
+        @ratio = ((x - @handle.width / 2.0) - @x) / (content_width - @handle.outer_width.to_f)
+
+        self.value = @ratio.clamp(0.0, 1.0) * (@range.max - @range.min) + @range.min
+      end
+
+      def value=(n)
+        @value = n
+        position_handle
+        @handle.recalculate
+
+        root.gui_state.request_repaint
+
+        publish(:changed, @value)
+      end
+    end
+  end
+end

lib/cyberarm_engine/ui/elements/stack.rb

@@ -0,0 +1,11 @@
+module CyberarmEngine
+  class Element
+    class Stack < Container
+      def layout
+        @children.each do |child|
+          move_to_next_line(child)
+        end
+      end
+    end
+  end
+end

lib/cyberarm_engine/ui/elements/text_block.rb

@@ -0,0 +1,221 @@
+module CyberarmEngine
+  class Element
+    class TextBlock < Element
+      def initialize(text, options = {}, block = nil)
+        super(options, block)
+
+        @text = Text.new(
+          text, font: @options[:font], z: @z, color: @options[:color],
+                size: @options[:text_size], shadow: @options[:text_shadow],
+                static: @options[:text_static],
+                shadow_size: @options[:text_shadow_size],
+                shadow_color: @options[:text_shadow_color],
+                border: @options[:text_border],
+                border_size: @options[:text_border_size],
+                border_color: @options[:text_border_color]
+        )
+
+        @raw_text = text
+      end
+
+      def update
+        super
+
+        if @text.textobject.name != safe_style_fetch(:font)
+          set_font
+          root.gui_state.request_recalculate
+        end
+      end
+
+      def render
+        # Gosu.clip_to is too expensive to always use so check if we actually need it.
+        if @text.width > width || @text.height > height
+          Gosu.clip_to(@x, @y, width, height) do
+            @text.draw
+          end
+        else
+          @text.draw
+        end
+      end
+
+      def recalculate
+        unless @enabled
+          @text.color = @style.disabled[:color]
+        else
+          @text.color = @style.color
+        end
+
+        old_width  = @width
+        old_height = @height
+
+        @width  = 0
+        @height = 0
+
+        _width  = dimensional_size(@style.width,  :width)
+        _height = dimensional_size(@style.height, :height)
+
+        handle_text_wrapping(_width)
+
+        @width  = _width  || @text.width.floor
+        @height = _height || @text.height.floor
+
+        @text.y = @style.border_thickness_top + @style.padding_top + @y
+        @text.z = @z + 3
+
+        if (text_alignment = @options[:text_align] || @options[:text_h_align])
+          case text_alignment
+          when :left
+            @text.x = @style.border_thickness_left + @style.padding_left + @x
+          when :center
+            @text.x = if @text.width <= width
+                        @x + width / 2 - @text.width / 2
+                      else # Act as left aligned
+                        @style.border_thickness_left + @style.padding_left + @x
+                      end
+          when :right
+            @text.x = @x + outer_width - (@text.width + @style.border_thickness_right + @style.padding_right)
+          end
+        end
+
+        if (vertical_alignment = @options[:text_v_align])
+          case vertical_alignment
+          when :center
+            @text.y = if @text.height <= height
+                        @y + height / 2 - @text.height / 2
+                      else
+                        @style.border_thickness_top + @style.padding_top + @y
+                      end
+          when :bottom
+            @text.y = @y + outer_height - (@text.height + @style.border_thickness_bottom + @style.padding_bottom)
+          end
+        end
+
+        update_background
+
+        root.gui_state.request_repaint if @width != old_width || @height != old_height
+      end
+
+      def handle_text_wrapping(max_width)
+        max_width ||= @parent&.content_width
+        max_width ||= @x - (window.width + noncontent_width)
+        wrap_behavior = style.text_wrap
+        copy = @raw_text.to_s.dup
+
+        # Only perform text wrapping: if it is enabled, is possible to wrap, and text is too long to fit on one line
+        if wrap_behavior != :none && line_width(copy[0]) <= max_width && line_width(copy) > max_width
+          breaks = [] # list of indexes to insert a line break
+          line_start = 0
+          line_end = copy.length
+
+          stalled = false
+          stalled_interations = 0
+          max_stalled_iterations = 10
+          checked_copy_length = line_width(copy[line_start..line_end])
+
+          # find length of lines
+          while line_width(copy[line_start..line_end]) > max_width && stalled_interations < max_stalled_iterations
+            search_start = line_start
+            search_end = line_end
+
+            # Perform a binary search to find length of line
+            while search_start < search_end
+              midpoint = ((search_start.to_f + search_end) / 2.0).floor
+
+              if line_width(copy[line_start..midpoint]) > max_width
+                search_end = midpoint
+              else
+                search_start = midpoint + 1
+              end
+            end
+
+            if wrap_behavior == :word_wrap
+              word_search_end = search_end
+              failed = false
+
+              until(copy[word_search_end].to_s.match(/[[:punct:]]| /))
+                word_search_end -= 1
+
+                if word_search_end <= 1 || word_search_end < line_start
+                  failed = true
+                  break
+                end
+              end
+
+              line_start = failed ? search_end : word_search_end + 1 # walk in front of punctuation
+            else
+              line_start = search_end
+            end
+
+            breaks << line_start
+
+            # Prevent locking up due to outer while loop text width < max_width check not being satisfied.
+            stalled = checked_copy_length == line_width(copy[line_start..line_end])
+            checked_copy_length = line_width(copy[line_start..line_end])
+
+            stalled_interations += 1 if stalled
+            stalled_interations = 0 unless stalled
+          end
+
+          breaks.each_with_index do |pos, index|
+            copy.insert(pos + index, "\n") if pos + index >= 0 && pos + index < copy.length
+          end
+        end
+
+        @text.text = copy
+      end
+
+      def line_width(text)
+        (@text.textobject.markup_width(text.to_s) + noncontent_width)
+      end
+
+      def value
+        @raw_text
+      end
+
+      def value=(value)
+        old_value = @raw_text
+        @raw_text = value.to_s.chomp
+
+        old_width = width
+        old_height = height
+
+        if old_width != width || old_height != height
+          root.gui_state.request_recalculate
+        else
+          recalculate
+        end
+
+        root.gui_state.request_repaint if old_value != @raw_text
+
+        publish(:changed, self.value)
+      end
+    end
+
+    class Banner < TextBlock
+    end
+
+    class Title < TextBlock
+    end
+
+    class Subtitle < TextBlock
+    end
+
+    class Tagline < TextBlock
+    end
+
+    class Caption < TextBlock
+    end
+
+    class Para < TextBlock
+    end
+
+    class Inscription < TextBlock
+    end
+
+    class ToolTip < TextBlock
+    end
+
+    class Link < TextBlock
+    end
+  end
+end

lib/cyberarm_engine/ui/elements/toggle_button.rb

@@ -0,0 +1,65 @@
+module CyberarmEngine
+  class Element
+    class ToggleButton < Button
+      attr_reader :toggled, :value
+
+      def initialize(options, block = nil)
+        if options.dig(:theme, :ToggleButton, :checkmark_image)
+          options[:theme][:ToggleButton][:image_width] ||= options[:theme][:TextBlock][:text_size]
+          super(get_image(options.dig(:theme, :ToggleButton, :checkmark_image)), options, block)
+
+          @_image = @image
+        else
+          super(options[:checkmark], options, block)
+        end
+
+        @value = options[:checked] || false
+
+        if @value
+          @image = @_image if @_image
+          @raw_text = @options[:checkmark]
+        else
+          @image = nil
+          @raw_text = ""
+        end
+      end
+
+      def clicked_left_mouse_button(_sender, _x, _y)
+        self.value = !@value
+
+        @block.call(self) if @block
+
+        :handled
+      end
+
+      def recalculate
+        super
+        return if @image
+
+        _width  = dimensional_size(@style.width,  :width)
+        _height = dimensional_size(@style.height, :height)
+
+        @width  = _width  || @text.textobject.text_width(@options[:checkmark])
+        @height = _height || @text.height
+
+        update_background
+      end
+
+      def value=(boolean)
+        @value = boolean
+
+        if boolean
+          @image = @_image if @_image
+          @raw_text = @options[:checkmark]
+        else
+          @image = nil
+          @raw_text = ""
+        end
+
+        recalculate
+
+        publish(:changed, @value)
+      end
+    end
+  end
+end

lib/cyberarm_engine/ui/event.rb

@@ -15,19 +15,25 @@ module CyberarmEngine
 
       return unless enabled?
 
-      if respond_to?(event)
-        return :handled if send(event, self, *args) == :handled
-      end
+      was_handled = false
+
+      was_handled = true if respond_to?(event) && (send(event, self, *args) == :handled)
 
       @event_handler[event].reverse_each do |handler|
-        return :handled if handler.call(self, *args) == :handled
+        if handler.call(self, *args) == :handled
+          was_handled = true
+          break
+        end
       end
 
-      return nil
+      return :handled if was_handled
+
+      parent.publish(event, *args) if parent
+      nil
     end
 
     def event(event)
-      @event_handler ||= Hash.new
+      @event_handler ||= {}
       @event_handler[event] ||= []
     end
   end
@@ -36,11 +42,13 @@ module CyberarmEngine
     attr_reader :publisher, :event, :handler
 
     def initialize(publisher, event, handler)
-      @publisher, @event, @handler = publisher, event, handler
+      @publisher = publisher
+      @event = event
+      @handler = handler
     end
 
     def unsubscribe
       @publisher.unsubscribe(self)
     end
   end
-end
+end

lib/cyberarm_engine/ui/flow.rb

@@ -1,15 +0,0 @@
-module CyberarmEngine
-  class Flow < Container
-    include Common
-
-    def layout
-      @children.each do |child|
-        if fits_on_line?(child)
-          position_on_current_line(child)
-        else
-          position_on_next_line(child)
-        end
-      end
-    end
-  end
-end

lib/cyberarm_engine/ui/gui_state.rb

@@ -10,23 +10,38 @@ module CyberarmEngine
 
       @down_keys = {}
 
-      @root_container = Stack.new
+      @root_container = Element::Stack.new(gui_state: self)
       @game_objects << @root_container
-      @containers     = [@root_container]
+      CyberarmEngine::Element::Container.current_container = @root_container
 
+      @active_width  = window.width
+      @active_height = window.height
+
+      @menu = nil
       @focus = nil
       @mouse_over = nil
       @mouse_down_on = {}
       @mouse_down_position = {}
+      @last_mouse_pos = nil
+      @dragging_element = nil
+      @pending_recalculate_request = false
+      @pending_element_recalculate_requests = []
 
+      @needs_repaint = false
 
-      setup
+      @menu = nil
+      @min_drag_distance = 0
+      @mouse_pos = Vector.new
+    end
+
+    def post_setup
+      @tip = Element::ToolTip.new("", parent: @root_container, z: Float::INFINITY, theme: current_theme)
     end
 
     # throws :blur event to focused element and sets GuiState focused element
     # Does NOT throw :focus event at element or set element as focused
     def focus=(element)
-      @focus.publish(:blur) if @focus and element && @focus != element
+      @focus.publish(:blur) if @focus && element && @focus != element
       @focus = element
     end
 
@@ -34,10 +49,77 @@ module CyberarmEngine
       @focus
     end
 
-    def update
+    def draw
       super
 
-      new_mouse_over = @root_container.hit_element?(window.mouse_x, window.mouse_y)
+      if @menu
+        Gosu.flush
+        @menu.draw
+      end
+
+      if @tip && @tip.value.length.positive?
+        Gosu.flush
+
+        @tip.draw
+      end
+
+      # FIXME
+      if false# defined?(GUI_DEBUG)
+        Gosu.flush
+
+        @root_container.debug_draw
+      end
+
+      @needs_repaint = false
+    end
+
+    def needs_repaint?
+      @needs_repaint
+    end
+
+    def update
+      if @pending_recalculate_request
+        Stats.frame.start_timing(:gui_recalculate)
+        @root_container.recalculate
+
+        @pending_recalculate_request = false
+
+        Stats.frame.end_timing(:gui_recalculate)
+      end
+
+      Stats.frame.start_timing(:gui_element_recalculate_requests)
+
+      # puts "PENDING REQUESTS: #{@pending_element_recalculate_requests.size}" if @pending_element_recalculate_requests.size.positive?
+      @pending_element_recalculate_requests.each(&:recalculate)
+      @pending_element_recalculate_requests.clear
+
+      Stats.frame.end_timing(:gui_element_recalculate_requests)
+
+      if @pending_focus_request
+        @pending_focus_request = false
+
+        self.focus = @pending_focus_element
+        @pending_focus_element.publish(:focus)
+      end
+
+      @menu&.update
+
+      super
+
+      if @active_width != window.width || @active_height != window.height
+        request_recalculate
+        @root_container.publish(:window_size_changed)
+      end
+
+      @active_width  = window.width
+      @active_height = window.height
+
+      return unless window.has_focus?
+      return unless window.current_state == self
+
+      new_mouse_over = @menu.hit_element?(window.mouse_x, window.mouse_y) if @menu
+      new_mouse_over ||= @root_container.hit_element?(window.mouse_x, window.mouse_y)
+
       if new_mouse_over
         new_mouse_over.publish(:enter) if new_mouse_over != @mouse_over
         new_mouse_over.publish(:hover)
@@ -46,48 +128,84 @@ module CyberarmEngine
       @mouse_over.publish(:leave) if @mouse_over && new_mouse_over != @mouse_over
       @mouse_over = new_mouse_over
 
-      redirect_holding_mouse_button(:left) if @mouse_over && Gosu.button_down?(Gosu::MsLeft)
-      redirect_holding_mouse_button(:middle) if @mouse_over && Gosu.button_down?(Gosu::MsMiddle)
-      redirect_holding_mouse_button(:right) if @mouse_over && Gosu.button_down?(Gosu::MsRight)
+      redirect_holding_mouse_button(:left) if @mouse_over && Gosu.button_down?(Gosu::MS_LEFT)
+      redirect_holding_mouse_button(:middle) if @mouse_over && Gosu.button_down?(Gosu::MS_MIDDLE)
+      redirect_holding_mouse_button(:right) if @mouse_over && Gosu.button_down?(Gosu::MS_RIGHT)
+
+      if Vector.new(window.mouse_x, window.mouse_y) == @last_mouse_pos
+        if @mouse_over && (Gosu.milliseconds - @mouse_moved_at) > tool_tip_delay
+          @tip.value = @mouse_over.tip if @mouse_over
+          @tip.x = window.mouse_x
+          @tip.x = 0 if @tip.x < 0
+          @tip.x = window.width - @tip.width if @tip.x + @tip.width > window.width
+          @tip.y = window.mouse_y - (@tip.height + 5)
+          @tip.y = 0 if @tip.y < 0
+          @tip.y = window.height - @tip.height if @tip.y + @tip.height > window.height
+          @tip.update
+          @tip.recalculate
+        else
+          @tip.value = ""
+        end
+      else
+        @mouse_moved_at = Gosu.milliseconds
+      end
+
+      @last_mouse_pos = Vector.new(window.mouse_x, window.mouse_y)
+      @mouse_pos = @last_mouse_pos.clone
     end
 
     def button_down(id)
       super
 
       case id
-      when Gosu::MsLeft
+      when Gosu::MS_LEFT
         redirect_mouse_button(:left)
-      when Gosu::MsMiddle
+      when Gosu::MS_MIDDLE
         redirect_mouse_button(:middle)
-      when Gosu::MsRight
+      when Gosu::MS_RIGHT
         redirect_mouse_button(:right)
+      when Gosu::KB_F5
+        request_recalculate
       end
+
+      @focus.button_down(id) if @focus.respond_to?(:button_down)
     end
 
     def button_up(id)
       super
 
       case id
-      when Gosu::MsLeft
+      when Gosu::MS_LEFT
         redirect_released_mouse_button(:left)
-      when Gosu::MsMiddle
+      when Gosu::MS_MIDDLE
         redirect_released_mouse_button(:middle)
-      when Gosu::MsRight
+      when Gosu::MS_RIGHT
         redirect_released_mouse_button(:right)
-      when Gosu::MsWheelUp
+      when Gosu::MS_WHEEL_UP
         redirect_mouse_wheel(:up)
-      when Gosu::MsWheelDown
+      when Gosu::MS_WHEEL_DOWN
         redirect_mouse_wheel(:down)
       end
+
+      @focus.button_up(id) if @focus.respond_to?(:button_up)
+
+      # Prevents menu from popping back up if the listbox is clicked to hide it.
+      @hid_menu_for = nil
+    end
+
+    def tool_tip_delay
+      @tip.style.delay || 250 # ms
     end
 
     def redirect_mouse_button(button)
+      hide_menu unless @menu && (@menu == @mouse_over) || (@mouse_over&.parent == @menu)
+
       if @focus && @mouse_over != @focus
         @focus.publish(:blur)
         @focus = nil
       end
 
-      if @mouse_over
+      if @mouse_over && @hid_menu_for != @mouse_over
         @mouse_down_position[button] = Vector.new(window.mouse_x, window.mouse_y)
         @mouse_down_on[button]       = @mouse_over
 
@@ -99,9 +217,19 @@ module CyberarmEngine
     end
 
     def redirect_released_mouse_button(button)
-      if @mouse_over
+      hide_menu if @menu && (@menu == @mouse_over) || (@mouse_over&.parent == @menu)
+
+      if @mouse_over && @hid_menu_for != @mouse_over
         @mouse_over.publish(:"released_#{button}_mouse_button", window.mouse_x, window.mouse_y)
-        @mouse_over.publish(:"clicked_#{button}_mouse_button", window.mouse_x, window.mouse_y) if @mouse_over == @mouse_down_on[button]
+        if @mouse_over == @mouse_down_on[button]
+          @mouse_over.publish(:"clicked_#{button}_mouse_button", window.mouse_x,
+                              window.mouse_y)
+        end
+      end
+
+      if @dragging_element
+        @dragging_element.publish(:end_drag, window.mouse_x, window.mouse_y, button)
+        @dragging_element = nil
       end
 
       @mouse_down_position[button] = nil
@@ -109,11 +237,65 @@ module CyberarmEngine
     end
 
     def redirect_holding_mouse_button(button)
-      @mouse_over.publish(:"holding_#{button}_mouse_button", window.mouse_x, window.mouse_y) if @mouse_over
+      if !@dragging_element && @mouse_down_on[button] && @mouse_down_on[button].draggable?(button) && @mouse_pos.distance(@mouse_down_position[button]) > @min_drag_distance
+        @dragging_element = @mouse_down_on[button]
+        @dragging_element.publish(:begin_drag, window.mouse_x, window.mouse_y, button)
+      end
+
+      if @dragging_element
+        @dragging_element.publish(:drag_update, window.mouse_x, window.mouse_y, button) if @dragging_element
+      elsif @mouse_over
+        @mouse_over.publish(:"holding_#{button}_mouse_button", window.mouse_x, window.mouse_y)
+      end
     end
 
     def redirect_mouse_wheel(button)
       @mouse_over.publish(:"mouse_wheel_#{button}", window.mouse_x, window.mouse_y) if @mouse_over
     end
+
+    # Schedule a full GUI recalculation on next update
+    def request_recalculate
+      @pending_recalculate_request = true
+    end
+
+    def request_recalculate_for(element)
+      # element is already queued
+      return if @pending_element_recalculate_requests.detect { |e| e == element }
+
+      @pending_element_recalculate_requests << element
+    end
+
+    def request_focus(element)
+      @pending_focus_request = true
+      @pending_focus_element = element
+    end
+
+    def request_repaint
+      # puts caller[0..4]
+      # puts
+      @needs_repaint = true
+    end
+
+    def show_menu(list_box)
+      @menu = list_box
+    end
+
+    def hide_menu
+      return unless @menu
+
+      request_repaint
+
+      @hid_menu_for = @menu.parent
+      @menu = nil
+    end
+
+    def to_s
+      # "#{self.class} children=#{@children.map { |c| c.to_s }}"
+      @root_container.to_s
+    end
+
+    def inspect
+      to_s
+    end
   end
-end
+end

lib/cyberarm_engine/ui/image.rb

@@ -1,42 +0,0 @@
-module CyberarmEngine
-  class Image < Element
-    def initialize(path, options = {}, block = nil)
-      super(options, block)
-      @path = path
-
-      @image = Gosu::Image.new(path, retro: @options[:image_retro])
-      if @options[:width] && @options[:height]
-        @scale_x = @options[:width].to_f / @image.width
-        @scale_y = @options[:height].to_f / @image.height
-      elsif @options[:width]
-        @scale_x = @options[:width].to_f / @image.width
-        @scale_y = @scale_x
-      elsif @options[:height]
-        @scale_y = @options[:height].to_f / @image.height
-        @scale_x = @scale_y
-      else
-        @scale_x, @scale_y = 1, 1
-      end
-
-      raise "Scale X" unless @scale_x.is_a?(Numeric)
-      raise "Scale Y" unless @scale_y.is_a?(Numeric)
-    end
-
-    def render
-      @image.draw(@border_thickness_left + @padding_left + @x, @border_thickness_top + @padding_top + @y, @z + 2, @scale_x, @scale_y) # TODO: Add color support?
-    end
-
-    def clicked_left_mouse_button(sender, x, y)
-      @block.call(self) if @block
-    end
-
-    def recalculate
-      @width  = @image.width * @scale_x
-      @height = @image.height * @scale_y
-    end
-
-    def value
-      @path
-    end
-  end
-end

lib/cyberarm_engine/ui/label.rb

@@ -1,43 +0,0 @@
-module CyberarmEngine
-  class Label < Element
-    def initialize(text, options = {}, block = nil)
-      super(options, block)
-
-      @text = Text.new(text, font: @options[:font], z: @z, color: @options[:color], size: @options[:text_size], shadow: @options[:text_shadow])
-
-      return self
-    end
-
-    def render
-      @text.draw
-    end
-
-    def clicked_left_mouse_button(sender, x, y)
-      @block.call(self) if @block
-    end
-
-    def recalculate
-      @width = @text.width.round
-      @height= @text.height.round
-
-      @text.x = @border_thickness_left + @padding_left + @x
-      @text.y = @border_thickness_top + @padding_top  + @y
-      @text.z = @z + 3
-
-      update_background
-    end
-
-    def value
-      @text.text
-    end
-
-    def value=(value)
-      @text.text = value
-
-      old_width, old_height = width, height
-      recalculate
-
-      root.recalculate if old_width != width || old_height != height
-    end
-  end
-end

lib/cyberarm_engine/ui/stack.rb

@@ -1,11 +0,0 @@
-module CyberarmEngine
-  class Stack < Container
-    include Common
-
-    def layout
-      @children.each do |child|
-        move_to_next_line(child)
-      end
-    end
-  end
-end

lib/cyberarm_engine/ui/style.rb

@@ -1,15 +1,50 @@
-module CyberarmEngine
-  class Style
-    def initialize(hash)
-      @hash = hash
+module Gosu
+  class Color
+    def _dump(_level)
+      [
+        "%02X" % alpha,
+        "%02X" % red,
+        "%02X" % green,
+        "%02X" % blue
+      ].join
     end
 
-    def hash
-      @hash
-    end
-
-    def set(hash)
-      @hash.merge!(hash)
+    def self._load(hex)
+      argb(hex.to_i(16))
     end
   end
-end
+end
+
+module CyberarmEngine
+  class Style
+    attr_reader :hash
+
+    def initialize(hash = {})
+      h = hash
+      # h = Marshal.load(Marshal.dump(hash))
+
+      h[:default] = {}
+
+      h.each do |key, value|
+        next if value.is_a?(Hash)
+
+        h[:default][key] = value
+      end
+
+      @hash = h
+    end
+
+    def method_missing(method, *args)
+      if method.to_s.end_with?("=")
+        raise "Did not expect more than 1 argument" if args.size > 1
+
+        @hash[method.to_s.sub("=", "").to_sym] = args.first
+
+      elsif args.empty?
+        @hash[method]
+      else
+        raise ArgumentError, "Did not expect arguments"
+      end
+    end
+  end
+end

lib/cyberarm_engine/ui/theme.rb

@@ -11,22 +11,40 @@ module CyberarmEngine
 
     def theme_defaults(options)
       raise "Error" unless self.class.ancestors.include?(CyberarmEngine::Element)
+
       _theme = THEME
-      _theme = _theme.merge(options[:theme]) if options[:theme]
-      options.delete(:theme)
+      _theme = deep_merge(_theme, options[:theme]) if options[:theme]
+      _theme.delete(:theme) if options[:theme]
 
       hash = {}
       class_names = self.class.ancestors
-      class_names = class_names[0..class_names.index(CyberarmEngine::Element)].map! {|c| c.to_s.split("::").last.to_sym}.reverse!
+      class_names = class_names[0..class_names.index(CyberarmEngine::Element)].map! do |c|
+        c.to_s.split("::").last.to_sym
+      end.reverse!
 
       class_names.each do |klass|
         next unless data = _theme.dig(klass)
-        data.each do |key, value|
+
+        data.each do |_key, _value|
           hash.merge!(data)
         end
       end
 
-      hash.merge(options)
+      deep_merge(hash, options)
+    end
+
+    # Derived from Rails Hash#deep_merge!
+    # Enables passing partial themes through Element options without issue
+    def deep_merge(original, intergrate, &block)
+      original.merge(intergrate) do |key, this_val, other_val|
+        if this_val.is_a?(Hash) && other_val.is_a?(Hash)
+          deep_merge(this_val, other_val, &block)
+        elsif block_given?
+          block.call(key, this_val, other_val)
+        else
+          other_val
+        end
+      end
     end
 
     THEME = {
@@ -35,33 +53,45 @@ module CyberarmEngine
         y: 0,
         z: 30,
 
-        width:  nil,
+        width: nil,
         height: nil,
-        color:     Gosu::Color::WHITE,
+        color: Gosu::Color::WHITE,
         background: Gosu::Color::NONE,
-        margin:   0,
-        padding:  0,
+        margin: 0,
+        padding: 0,
         border_thickness: 0,
         border_color: Gosu::Color::NONE,
-        border_radius: 0,
+        border_radius: 0
+      },
+
+      Container: { # < Element (Base class for Stack and Flow)
+        debug_color: Gosu::Color::YELLOW
       },
 
       Button: { # < Label
-        margin:   1,
-        padding:  4,
-        border_thickness: 4,
+        margin: 1,
+        padding: 4,
+        border_thickness: 1,
         border_color: ["ffd59674".hex, "ffff8746".hex],
         border_radius: 0,
         background: ["ffc75e61".to_i(16), "ffe26623".to_i(16)],
+        text_align: :center,
+        text_v_align: :center,
+        text_wrap: :none,
 
         hover: {
-          color: Gosu::Color.rgb(200,200,200),
-          background:  ["ffB23E41".to_i(16), "ffFF7C00".to_i(16)],
+          color: Gosu::Color.rgb(200, 200, 200),
+          background: ["ffB23E41".to_i(16), "ffFF7C00".to_i(16)]
         },
 
         active: {
           color: Gosu::Color::BLACK,
           background: ["ffB23E41".to_i(16)]
+        },
+
+        disabled: {
+          color: Gosu::Color::GRAY,
+          background: 0xff303030
         }
       },
 
@@ -72,23 +102,113 @@ module CyberarmEngine
         caret_width: 2,
         caret_color: Gosu::Color::WHITE,
         caret_interval: 500,
+        selection_color: Gosu::Color.rgba(255, 128, 50, 200),
+        text_align: :left,
+        text_static: false # static text causes issues correctly displaying caret position
       },
 
-      Image: {
+      EditBox: { # < EditLine
+        text_v_align: :top
+      },
+
+      Image: { # < Element
+        color: Gosu::Color::WHITE,
+        tileable: false,
         retro: false
       },
 
-      Label: { # < Element
-      text_size: 28,
-      text_shadow: false,
-      font: "Arial",
-      margin: 0,
-      padding: 2
+      TextBlock: { # < Element
+        text_size: 28,
+        text_wrap: :word_wrap, # :word_wrap, :break_word, :none
+        text_shadow: false,
+        text_border: false,
+        text_align: :left,
+        font: "Arial",
+        margin: 0,
+        padding: 2,
+        disabled: {
+          color: Gosu::Color.rgb(175, 175, 175),
+        }
+      },
+
+      Banner: { # < TextBlock
+        text_size: 48
+      },
+
+      Title: { # < TextBlock
+        text_size: 34
+      },
+
+      Subtitle: { # < TextBlock
+        text_size: 26
+      },
+
+      Tagline: { # < TextBlock
+        text_size: 24
+      },
+
+      Caption: { # < TextBlock
+        text_size: 22
+      },
+
+      Para: { # < TextBlock
+        text_size: 18
+      },
+
+      Inscription: { # < TextBlock
+        text_size: 16
+      },
+
+      ToolTip: { # < TextBlock
+        delay: 100, # ms
+        color: Gosu::Color::WHITE,
+        padding_top: 4,
+        padding_bottom: 4,
+        padding_left: 8,
+        padding_right: 8,
+        border_thickness: 1,
+        border_color: 0xffaaaaaa,
+        background: 0xff404040
+      },
+      Link: { # < TextBlock
+        color: Gosu::Color::BLUE,
+        border_thickness: 1,
+        border_bottom_color: Gosu::Color::BLUE,
+        hover: {
+          color: 0xff_ff00ff,
+          border_bottom_color: 0xff_ff00ff
+        },
+        active: {
+          color: 0xff_ff0000,
+          border_bottom_color: 0xff_ff0000
+        }
       },
 
       ToggleButton: { # < Button
         checkmark: "√"
+      },
+
+      CheckBox: { # < Flow
+        text_wrap: :none
+      },
+
+      Progress: { # < Element
+        width: 250,
+        height: 36,
+        background: 0xff111111,
+        fraction_background: [0xffc75e61, 0xffe26623],
+        border_thickness: 1,
+        border_color: [0xffd59674, 0xffff8746]
+      },
+
+      Slider: { # < Element
+        width: 250,
+        height: 36,
+        background: 0xff111111,
+        fraction_background: [0xffc75e61, 0xffe26623],
+        border_thickness: 1,
+        border_color: [0xffd59674, 0xffff8746]
       }
     }.freeze
   end
-end
+end

lib/cyberarm_engine/ui/toggle_button.rb

@@ -1,49 +0,0 @@
-module CyberarmEngine
-  class ToggleButton < Button
-    attr_reader :toggled
-
-    def initialize(options, block = nil)
-      super(options[:checkmark], options, block)
-      @toggled = options[:toggled] || false
-      if @toggled
-        @text.text = @options[:checkmark]
-      else
-        @text.text = ""
-      end
-
-      return self
-    end
-
-    def toggled=(boolean)
-      @toggled = !boolean
-      toggle
-    end
-
-    def clicked_left_mouse_button(sender, x, y)
-      toggle
-
-      @block.call(self) if @block
-    end
-
-    def toggle
-      if @toggled
-        @toggled = false
-        @text.text = ""
-      else
-        @toggled = true
-        @text.text = @options[:checkmark]
-      end
-    end
-
-    def recalculate
-      super
-
-      @width = @text.textobject.text_width(@options[:checkmark])
-      update_background
-    end
-
-    def value
-      @toggled
-    end
-  end
-end

lib/cyberarm_engine/vector.rb

@@ -0,0 +1,312 @@
+module CyberarmEngine
+  class Vector
+    ##
+    # Creates a up vector
+    #
+    #   Vector.new(0, 1, 0)
+    #
+    # @return [CyberarmEngine::Vector]
+    def self.up
+      Vector.new(0, 1, 0)
+    end
+
+    ##
+    # Creates a down vector
+    #
+    #   Vector.new(0, -1, 0)
+    #
+    # @return [CyberarmEngine::Vector]
+    def self.down
+      Vector.new(0, -1, 0)
+    end
+
+    ##
+    # Creates a left vector
+    #
+    #   Vector.new(-1, 0, 0)
+    #
+    # @return [CyberarmEngine::Vector]
+    def self.left
+      Vector.new(-1, 0, 0)
+    end
+
+    ##
+    # Creates a right vector
+    #
+    #   Vector.new(1, 0, 0)
+    #
+    # @return [CyberarmEngine::Vector]
+    def self.right
+      Vector.new(1, 0, 0)
+    end
+
+    ##
+    # Creates a forward vector
+    #
+    #   Vector.new(0, 0, 1)
+    #
+    # @return [CyberarmEngine::Vector]
+    def self.forward
+      Vector.new(0, 0, 1)
+    end
+
+    ##
+    # Creates a backward vector
+    #
+    #   Vector.new(0, 0, -1)
+    #
+    # @return [CyberarmEngine::Vector]
+    def self.backward
+      Vector.new(0, 0, -1)
+    end
+
+    attr_accessor :x, :y, :z, :weight
+
+    def initialize(x = 0, y = 0, z = 0, weight = 0)
+      @x = x
+      @y = y
+      @z = z
+      @weight = weight
+    end
+
+    alias w weight
+    alias w= weight=
+
+    # @return [Boolean]
+    def ==(other)
+      if other.is_a?(Numeric)
+        @x      == other &&
+          @y      == other &&
+          @z      == other &&
+          @weight == other
+      elsif other.is_a?(Vector)
+        @x      == other.x &&
+          @y      == other.y &&
+          @z      == other.z &&
+          @weight == other.weight
+      else
+        other == self
+      end
+    end
+
+    # Create a new vector using {x} and {y} values
+    # @return [CyberarmEngine::Vector]
+    def xy
+      Vector.new(@x, @y)
+    end
+
+    # Adds Vector and Numeric or Vector and Vector, excluding {weight}
+    # @return [CyberarmEngine::Vector]
+    def +(other)
+      if other.is_a?(Numeric)
+        Vector.new(
+          @x + other,
+          @y + other,
+          @z + other
+        )
+      else
+        Vector.new(
+          @x + other.x,
+          @y + other.y,
+          @z + other.z
+        )
+      end
+    end
+
+    # Subtracts Vector and Numeric or Vector and Vector, excluding {weight}
+    # @return [CyberarmEngine::Vector]
+    def -(other)
+      if other.is_a?(Numeric)
+        Vector.new(
+          @x - other,
+          @y - other,
+          @z - other
+        )
+      else
+        Vector.new(
+          @x - other.x,
+          @y - other.y,
+          @z - other.z
+        )
+      end
+    end
+
+    # Multiplies Vector and Numeric or Vector and Vector, excluding {weight}
+    # @return [CyberarmEngine::Vector]
+    def *(other)
+      if other.is_a?(Numeric)
+        Vector.new(
+          @x * other,
+          @y * other,
+          @z * other
+        )
+      else
+        Vector.new(
+          @x * other.x,
+          @y * other.y,
+          @z * other.z
+        )
+      end
+    end
+
+    def multiply_transform(transform)
+      e = transform.elements
+
+      x = @x * e[0]  + @y * e[1]  + @z * e[2]  + 1 * e[3]
+      y = @x * e[4]  + @y * e[5]  + @z * e[6]  + 1 * e[7]
+      z = @x * e[8]  + @y * e[9]  + @z * e[10] + 1 * e[11]
+      w = @x * e[12] + @y * e[13] + @z * e[14] + 1 * e[15]
+
+      Vector.new(x / 1, y / 1, z / 1, w / 1)
+    end
+
+    # Divides Vector and Numeric or Vector and Vector, excluding {weight}
+    # @return [CyberarmEngine::Vector]
+    def /(other)
+      # Duplicated to protect from DivideByZero
+      if other.is_a?(Numeric)
+        Vector.new(
+          (@x == 0 ? 0 : @x / other),
+          (@y == 0 ? 0 : @y / other),
+          (@z == 0 ? 0 : @z / other)
+        )
+      else
+        Vector.new(
+          (@x == 0 ? 0 : @x / other.x),
+          (@y == 0 ? 0 : @y / other.y),
+          (@z == 0 ? 0 : @z / other.z)
+        )
+      end
+    end
+
+    # dot product of {Vector}
+    # @return [Integer|Float]
+    def dot(other)
+      product = 0
+
+      a = to_a
+      b = other.to_a
+
+      3.times do |i|
+        product += (a[i] * b[i])
+      end
+
+      product
+    end
+
+    # cross product of {Vector}
+    # @return [CyberarmEngine::Vector]
+    def cross(other)
+      a = to_a
+      b = other.to_a
+
+      Vector.new(
+        b[2] * a[1] - b[1] * a[2],
+        b[0] * a[2] - b[2] * a[0],
+        b[1] * a[0] - b[0] * a[1]
+      )
+    end
+
+    # returns degrees
+    # @return [Float]
+    def angle(other)
+      Math.acos(normalized.dot(other.normalized)) * 180 / Math::PI
+    end
+
+    # returns magnitude of Vector, ignoring #weight
+    # @return [Float]
+    def magnitude
+      Math.sqrt((@x * @x) + (@y * @y) + (@z * @z))
+    end
+
+    ##
+    # returns normalized {Vector}
+    #
+    # @example
+    #   CyberarmEngine::Vector.new(50, 21.2, 45).normalized
+    #   # => <CyberarmEngine::Vector:0x001 @x=0.7089... @y=0.3005... @z=0.6380... @weight=0>
+    #
+    # @return [CyberarmEngine::Vector]
+    def normalized
+      mag = magnitude
+      self / Vector.new(mag, mag, mag)
+    end
+
+    # returns a direction {Vector}
+    #
+    # z is pitch
+    #
+    # y is yaw
+    #
+    # x is roll
+    # @return [CyberarmEngine::Vector]
+    def direction
+      _x = -Math.sin(@y.degrees_to_radians) * Math.cos(@z.degrees_to_radians)
+      _y = Math.sin(@z.degrees_to_radians)
+      _z = Math.cos(@y.degrees_to_radians) * Math.cos(@z.degrees_to_radians)
+
+      Vector.new(_x, _y, _z)
+    end
+
+    # returns an inverse {Vector}
+    # @return [CyberarmEngine::Vector]
+    def inverse
+      Vector.new(1.0 / @x, 1.0 / @y, 1.0 / @z)
+    end
+
+    # Adds up values of {x}, {y}, and {z}
+    # @return [Integer|Float]
+    def sum
+      @x + @y + @z
+    end
+
+    ##
+    # Linear interpolation: smoothly transition between two {Vector}
+    #
+    #   CyberarmEngine::Vector.new(100, 100, 100).lerp( CyberarmEngine::Vector.new(0, 0, 0), 0.75 )
+    #   # => <CyberarmEngine::Vector:0x0001 @x=75.0, @y=75.0, @z=75.0, @weight=0>
+    #
+    # @param other [CyberarmEngine::Vector | Integer | Float] value to subtract from
+    # @param factor [Float] how complete transition to _other_ is, in range [0.0..1.0]
+    # @return [CyberarmEngine::Vector]
+    def lerp(other, factor)
+      (self - other) * factor.clamp(0.0, 1.0)
+    end
+
+    # 2D distance using X and Y
+    # @return [Float]
+    def distance(other)
+      Math.sqrt((@x - other.x)**2 + (@y - other.y)**2)
+    end
+
+    # 2D distance using X and Z
+    # @return [Float]
+    def gl_distance2d(other)
+      Math.sqrt((@x - other.x)**2 + (@z - other.z)**2)
+    end
+
+    # 3D distance using X, Y, and Z
+    # @return [Float]
+    def distance3d(other)
+      Math.sqrt((@x - other.x)**2 + (@y - other.y)**2 + (@z - other.z)**2)
+    end
+
+    # Converts {Vector} to Array
+    # @return [Array]
+    def to_a
+      [@x, @y, @z, @weight]
+    end
+
+    # Converts {Vector} to String
+    # @return [String]
+    def to_s
+      "X: #{@x}, Y: #{@y}, Z: #{@z}, Weight: #{@weight}"
+    end
+
+    # Converts {Vector} to Hash
+    # @return [Hash]
+    def to_h
+      { x: @x, y: @y, z: @z, weight: @weight }
+    end
+  end
+end

lib/cyberarm_engine/version.rb

@@ -1,4 +1,4 @@
 module CyberarmEngine
-  NAME    = "InDev"
-  VERSION = "0.6.0"
+  NAME    = "InDev".freeze
+  VERSION = "0.23.0".freeze
 end

lib/cyberarm_engine/window.rb

@@ -0,0 +1,195 @@
+module CyberarmEngine
+  class Window < Gosu::Window
+    include Common
+
+    IMAGES = {}
+    SAMPLES = {}
+    SONGS = {}
+
+    attr_accessor :show_cursor, :show_stats_plotter
+    attr_writer :exit_on_opengl_error
+    attr_reader :last_frame_time, :delta_time, :states
+
+    def self.now
+      Gosu.milliseconds
+    end
+
+    def self.dt
+      instance.dt
+    end
+
+    def self.instance=(window)
+      raise ArgumentError, "Expected window to be a subclass of CyberarmEngine::Window, got: #{window.class}" unless window.is_a?(CyberarmEngine::Window)
+
+      @@instance = window
+    end
+
+    def self.instance
+      @@instance
+    end
+
+    def initialize(width: 800, height: 600, fullscreen: false, update_interval: 1000.0 / 60, resizable: false, borderless: false)
+      @show_cursor = false
+      @has_focus = false
+      @show_stats_plotter = false
+
+      super(width, height, fullscreen: fullscreen, update_interval: update_interval, resizable: resizable, borderless: borderless)
+      Window.instance = self
+
+      @last_frame_time = Gosu.milliseconds - 1
+      @current_frame_time = Gosu.milliseconds
+      @delta_time = @last_frame_time
+      self.caption = "CyberarmEngine #{CyberarmEngine::VERSION} #{Gosu.user_languages.join(', ')}"
+
+      @states = []
+      @exit_on_opengl_error = false
+      preload_default_shaders if respond_to?(:preload_default_shaders)
+      @stats_plotter = Stats::StatsPlotter.new(2, 28) # FIXME: Make positioning easy
+
+      setup
+    end
+
+    def setup
+    end
+
+    def draw
+      Stats.frame.start_timing(:draw)
+
+      current_state&.draw
+      Stats.frame.start_timing(:engine_stats_renderer)
+      @stats_plotter&.draw if @show_stats_plotter
+      Stats.frame.end_timing(:engine_stats_renderer)
+
+      Stats.frame.end_timing(:draw)
+      Stats.frame.start_timing(:interframe_sleep)
+    end
+
+    def update
+      # Gosu calls update() then (optionally) draw(),
+      # so always end last frame and start next frame when update() is called.
+      Stats.frame&.end_timing(:interframe_sleep)
+      Stats.end_frame
+
+      Stats.new_frame
+
+      @delta_time = (Gosu.milliseconds - @current_frame_time) * 0.001
+
+      @last_frame_time = Gosu.milliseconds - @current_frame_time
+      @current_frame_time = Gosu.milliseconds
+
+      Stats.frame.start_timing(:update)
+      current_state&.update
+      Stats.frame.end_timing(:update)
+
+      Stats.frame.start_timing(:interframe_sleep) unless needs_redraw?
+    end
+
+    def needs_cursor?
+      @show_cursor
+    end
+
+    def needs_redraw?
+      current_state ? current_state.needs_redraw? : true
+    end
+
+    def drop(filename)
+      current_state&.drop(filename)
+    end
+
+    def gamepad_connected(index)
+      current_state&.gamepad_connected(index)
+    end
+
+    def gamepad_disconnected(index)
+      current_state&.gamepad_disconnected(index)
+    end
+
+    def gain_focus
+      @has_focus = true
+
+      current_state&.gain_focus
+    end
+
+    def lose_focus
+      @has_focus = false
+
+      current_state&.lose_focus
+    end
+
+    def button_down(id)
+      super
+      current_state&.button_down(id)
+    end
+
+    def button_up(id)
+      super
+      current_state&.button_up(id)
+    end
+
+    def close
+      current_state ? current_state.close : super
+    end
+
+    def dt
+      @last_frame_time / 1000.0
+    end
+
+    def aspect_ratio
+      width / height.to_f
+    end
+
+    def exit_on_opengl_error?
+      @exit_on_opengl_error
+    end
+
+    def push_state(klass, options = {})
+      options = { setup: true }.merge(options)
+
+      if klass.instance_of?(klass.class) && klass.respond_to?(:options)
+        @states << klass
+        klass.setup if options[:setup]
+        klass.post_setup if options[:setup]
+      else
+        @states << klass.new(options) if child_of?(klass, GameState)
+        @states << klass.new if child_of?(klass, Element::Container)
+        current_state.setup if current_state.instance_of?(klass) && options[:setup]
+        current_state.post_setup if current_state.instance_of?(klass) && options[:setup]
+      end
+    end
+
+    private def child_of?(input, klass)
+      return false unless input
+
+      input.ancestors.detect { |c| c == klass }
+    end
+
+    def current_state
+      @states.last
+    end
+
+    def pop_state
+      @states.pop
+
+      current_state.request_repaint if current_state&.is_a?(GuiState)
+    end
+
+    def shift_state
+      @states.shift
+
+      current_state.request_repaint if current_state&.is_a?(GuiState)
+    end
+
+    def has_focus?
+      @has_focus
+    end
+
+    # Sourced from https://gist.github.com/ippa/662583
+    def draw_circle(cx, cy, r, z = 9999, color = Gosu::Color::GREEN, step = 10)
+      0.step(360, step) do |a1|
+        a2 = a1 + step
+        draw_line(cx + Gosu.offset_x(a1, r), cy + Gosu.offset_y(a1, r), color, cx + Gosu.offset_x(a2, r),
+                  cy + Gosu.offset_y(a2, r), color, z)
+      end
+    end
+  end
+end

mrbgem.rake

@@ -0,0 +1,29 @@
+MRuby::Gem::Specification.new("mruby-cyberarm_engine") do |spec|
+  spec.license = "MIT"
+  spec.authors = "cyberarm"
+  spec.summary = " Yet another framework for building games with Gosu"
+
+  lib_rbfiles = []
+  # Dir.glob("#{File.expand_path("..", __FILE__)}/lib/**/*.rb").reject do |f|
+    # File.basename(f.downcase, ".rb") == "cyberarm_engine" ||
+    # File.basename(f.downcase, ".rb") == "opengl" ||
+    # f.downcase.include?("/opengl/")
+  # end.reverse!
+
+  local_path = File.expand_path("..", __FILE__)
+  File.read("#{local_path}/lib/cyberarm_engine.rb").each_line do |line|
+    line = line.strip
+
+    next unless line.start_with?("require_relative")
+
+    file = line.split("require_relative").last.strip.gsub("\"", "")
+
+    next if file.include?(" if ")
+
+    lib_rbfiles << "#{local_path}/lib/#{file}.rb"
+  end
+
+  pp lib_rbfiles
+
+  spec.rbfiles = lib_rbfiles
+end

test/test_helper.rb

@@ -1,4 +1,4 @@
-$LOAD_PATH.unshift File.expand_path("../../lib", __FILE__)
+$LOAD_PATH.unshift File.expand_path("../lib", __dir__)
 require "cyberarm_engine"
 
 require "minitest/autorun"