Bump version

README.md

@@ -1,8 +1,13 @@
 # CyberarmEngine
 
-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 +27,32 @@ Or install it yourself as:
 
 ## Usage
 
-TODO: Write usage instructions here
+```ruby
+require "cyberarm_engine"
+
+class Hello < CyberarmEngine::GuiState
+  def setup
+    stack do
+      label "Hello World!"
+
+      button "close" do
+        window.close
+      end
+    end
+  end
+end
+
+class Window < CyberarmEngine::Window
+  def initialize
+    super
+    self.show_cursor = true
+
+    push_state(Hello)
+  end
+end
+
+Window.new.show
+```
 
 ## Development
 

cyberarm_engine.gemspec

@@ -28,9 +28,10 @@ Gem::Specification.new do |spec|
   spec.executables   = spec.files.grep(%r{^exe/}) { |f| File.basename(f) }
   spec.require_paths = ["lib"]
 
-  spec.add_dependency "gosu", "~> 0.14.0"
+  spec.add_dependency "gosu", "~> 0.15.0"
+  spec.add_dependency "gosu_more_drawables", "~> 0.3"
 
   spec.add_development_dependency "bundler", "~> 1.16"
-  spec.add_development_dependency "rake", "~> 10.0"
+  spec.add_development_dependency "rake", "~> 13.0"
   spec.add_development_dependency "minitest", "~> 5.0"
 end

lib/cyberarm_engine.rb

@@ -4,23 +4,30 @@ rescue LoadError => e
   pp e
   require "gosu"
 end
-
+require "json"
+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/lib/ray"
-require_relative "cyberarm_engine/lib/shader" if defined?(OpenGL)
+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/shader" if defined?(OpenGL)
 require_relative "cyberarm_engine/background"
+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/ui/dsl"
 
 require_relative "cyberarm_engine/ui/theme"
 require_relative "cyberarm_engine/ui/event"
@@ -28,17 +35,19 @@ require_relative "cyberarm_engine/ui/style"
 require_relative "cyberarm_engine/ui/border_canvas"
 require_relative "cyberarm_engine/ui/element"
 require_relative "cyberarm_engine/ui/elements/label"
+require_relative "cyberarm_engine/ui/elements/list_box"
 require_relative "cyberarm_engine/ui/elements/button"
 require_relative "cyberarm_engine/ui/elements/toggle_button"
 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/dsl"
+require_relative "cyberarm_engine/ui/elements/slider"
 
 require_relative "cyberarm_engine/game_state"
 require_relative "cyberarm_engine/ui/gui_state"

lib/cyberarm_engine/animator.rb

@@ -0,0 +1,54 @@
+module CyberarmEngine
+  class Animator
+    DEFAULT_TWEEN = :linear
+    def initialize(start_time:, duration:, from:, to:, &block)
+      @start_time, @duration = start_time, duration
+      @from, @to = from.dup, to.dup
+      @block = block
+    end
+
+    def update
+      @block.call(self, @from, @to) if @block
+    end
+
+    def progress
+      (@start_time.to_f + (Gosu.milliseconds - @start_time)) / (@start_time + @duration.to_f)
+    end
+
+    def complete?
+      progress >= 1.0
+    end
+
+    def transition(from, to, tween = DEFAULT_TWEEN)
+      from + (to - from) * send("tween_#{tween}", progress)
+    end
+
+    def color_transition(from, to, tween = DEFAULT_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, to, tween = DEFAULT_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
+
+    # NOTE: Use this for future reference? https://github.com/danro/easing-js/blob/master/easing.js
+
+    def tween_linear(t)
+      t
+    end
+
+    def tween_sine(t)
+      Math.sin(t) * t
+    end
+  end
+end

lib/cyberarm_engine/common.rb

@@ -54,7 +54,7 @@ module CyberarmEngine
       return 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
@@ -64,7 +64,12 @@ module CyberarmEngine
       end
 
       unless asset
-        instance = klass.new(path)
+        instance = nil
+        if klass == Gosu::Image
+          instance = klass.new(path, retro: retro, tileable: tileable)
+        else
+          instance = klass.new(path)
+        end
         hash[path] = instance
         asset = instance
       end
@@ -72,16 +77,16 @@ module CyberarmEngine
       return 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

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[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/game_state.rb

@@ -3,7 +3,7 @@ module CyberarmEngine
     include Common
 
     attr_accessor :options, :global_pause
-    attr_reader :game_objects, :containers
+    attr_reader :game_objects
 
     def initialize(options={})
       @options = options

lib/cyberarm_engine/lib/shader.rb

@@ -1,205 +0,0 @@
-module CyberarmEngine
-  # Ref: https://github.com/vaiorabbit/ruby-opengl/blob/master/sample/OrangeBook/brick.rb
-  class Shader
-    include OpenGL
-    @@shaders = {}
-
-    def self.add(name, instance)
-      @@shaders[name] = instance
-    end
-
-    def self.use(name, &block)
-      shader = @@shaders.dig(name)
-      if shader
-        shader.use(&block)
-      else
-        raise ArgumentError, "Shader '#{name}' not found!"
-      end
-    end
-
-    def self.available?(name)
-      @@shaders.dig(name).is_a?(Shader)
-    end
-
-    def self.get(name)
-      @@shaders.dig(name)
-    end
-
-    def self.active_shader
-      @active_shader
-    end
-
-    def self.active_shader=(instance)
-      @active_shader = instance
-    end
-
-    def self.stop
-      shader = Shader.active_shader
-
-      if shader
-        shader.stop
-      else
-        raise ArgumentError, "No active shader to stop!"
-      end
-    end
-
-    def self.attribute_location(variable)
-      raise RuntimeError, "No active shader!" unless Shader.active_shader
-      Shader.active_shader.attribute_location(variable)
-    end
-
-    def self.set_uniform(variable, value)
-      raise RuntimeError, "No active shader!" unless Shader.active_shader
-      Shader.active_shader.set_uniform(variable, value)
-    end
-
-    attr_reader :name, :program
-    def initialize(name:, vertex: "shaders/default.vert", fragment:)
-      @name = name
-      @vertex_file   = vertex
-      @fragment_file = fragment
-      @compiled = false
-
-      @program = nil
-
-      @error_buffer_size = 1024
-      @variable_missing = {}
-
-      raise ArgumentError, "Shader files not found: #{@vertex_file} or #{@fragment_file}" unless shader_files_exist?
-
-      create_shaders
-      compile_shaders
-
-      # Only add shader if it successfully compiles
-      if @compiled
-        Shader.add(@name, self)
-      else
-        puts "FAILED to compile shader: #{@name}", ""
-      end
-    end
-
-    def shader_files_exist?
-      File.exist?(@vertex_file) && File.exist?(@fragment_file)
-    end
-
-    def create_shaders
-      @vertex   = glCreateShader(GL_VERTEX_SHADER)
-      @fragment = glCreateShader(GL_FRAGMENT_SHADER)
-
-      source = [File.read(@vertex_file)].pack('p')
-      size   = [File.size(@vertex_file)].pack('I')
-      glShaderSource(@vertex, 1, source, size)
-
-      source = [File.read(@fragment_file)].pack('p')
-      size   = [File.size(@fragment_file)].pack('I')
-      glShaderSource(@fragment, 1, source, size)
-    end
-
-    def compile_shaders
-      return unless shader_files_exist?
-
-      glCompileShader(@vertex)
-      buffer = '    '
-      glGetShaderiv(@vertex, GL_COMPILE_STATUS, buffer)
-      compiled = buffer.unpack('L')[0]
-
-      if compiled == 0
-        log = ' ' * @error_buffer_size
-        glGetShaderInfoLog(@vertex, @error_buffer_size, nil, log)
-        puts "Shader Error: Program \"#{@name}\""
-        puts "  Vectex 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
-        return
-      end
-
-      glCompileShader(@fragment)
-      buffer = '    '
-      glGetShaderiv(@fragment, GL_COMPILE_STATUS, buffer)
-      compiled = buffer.unpack('L')[0]
-
-      if compiled == 0
-        log = ' ' * @error_buffer_size
-        glGetShaderInfoLog(@fragment, @error_buffer_size, nil, log)
-        puts "Shader Error: Program \"#{@name}\""
-        puts "  Fragment Shader InfoLog:", "  #{log.strip.split("\n").join("\n  ")}\n\n"
-        puts "  Shader Compiled status: #{compiled}"
-        puts "    NOTE: assignment of uniforms in shader is illegal!"
-        puts
-        return
-      end
-
-      @program = glCreateProgram
-      glAttachShader(@program, @vertex)
-      glAttachShader(@program, @fragment)
-      glLinkProgram(@program)
-
-      buffer = '    '
-      glGetProgramiv(@program, GL_LINK_STATUS, buffer)
-      linked = buffer.unpack('L')[0]
-
-      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 ? false : true
-    end
-
-    # Returns the location of a uniform variable
-    def variable(variable)
-      loc = glGetUniformLocation(@program, variable)
-      if (loc == -1)
-        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?" unless @variable_missing[variable]
-        @variable_missing[variable] = true
-      end
-      return loc
-    end
-
-    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
-
-    def stop
-      Shader.active_shader = nil if Shader.active_shader == self
-      glUseProgram(0)
-    end
-
-    def compiled?
-      @compiled
-    end
-
-    def attribute_location(variable)
-      glGetUniformLocation(@program, variable)
-    end
-
-    def set_uniform(variable, value, location = nil)
-      attr_loc = location ? location : attribute_location(variable)
-
-      case value.class.to_s.downcase.to_sym
-      when :integer
-        glUniform1i(attr_loc, value)
-      when :float
-        glUniform1f(attr_loc, value)
-      when :string
-      when :array
-      else
-        raise NotImplementedError, "Shader support for #{value.class.inspect} not implemented."
-      end
-
-      Window.handle_gl_error
-    end
-  end
-end

lib/cyberarm_engine/shader.rb

@@ -0,0 +1,398 @@
+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)
+
+        if shader.compiled?
+          glDeleteProgram(shader.program)
+        end
+      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?]
+    def self.active_shader
+      @active_shader
+    end
+
+    # sets currently active {Shader}
+    #
+    # @param instance [Shader] instance of {Shader} to set as active
+    def self.active_shader=(instance)
+      @active_shader = instance
+    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 RuntimeError, "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 RuntimeError, "No active shader!" unless Shader.active_shader
+      Shader.active_shader.set_uniform(variable, value)
+    end
+
+    attr_reader :name, :program
+    def initialize(name:, includes_dir: nil, vertex: "shaders/default.vert", fragment:)
+      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|
+        if line.start_with?(PREPROCESSOR_CHARACTER)
+          preprocessor = line.strip.split(" ")
+          lines.delete(line)
+
+          case preprocessor.first
+          when "@include"
+            raise ArgumentError, "Shader preprocessor include directory was not given for shader #{@name}" unless @includes_dir
+
+            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
+      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.unpack('L')[0]
+
+      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
+
+      return _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.unpack('L')[0]
+
+      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 ? false : true
+    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)
+        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?" unless @variable_missing[variable]
+        @variable_missing[variable] = true
+      end
+      return 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 ? 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 ? 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 ? 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 ? 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_vec3(variable, value, location = nil)
+      attr_loc = location ? 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_vec4(variable, value, location = nil)
+      attr_loc = location ? location : attribute_location(variable)
+
+      glUniform4f(attr_loc, *value.to_a)
+    end
+  end
+end

lib/cyberarm_engine/stats.rb

@@ -0,0 +1,21 @@
+module CyberarmEngine
+  class Stats
+    @@hash = {
+      gui_recalculations_last_frame: 0
+    }
+
+    def self.get(key)
+      @@hash.dig(key)
+    end
+
+    def self.increment(key, n)
+      @@hash[key] += n
+    end
+
+    def self.clear
+      @@hash.each do |key, value|
+        @@hash[key] = 0
+      end
+    end
+  end
+end

lib/cyberarm_engine/text.rb

@@ -9,7 +9,7 @@ module CyberarmEngine
       @text = text.to_s || ""
       @options = options
       @size = options[:size] || 18
-      @font = options[:font] || "sans-serif"#Gosu.default_font_name
+      @font = options[:font] || Gosu.default_font_name
       @x = options[:x] || 0
       @y = options[:y] || 0
       @z = options[:z] || 1025
@@ -98,12 +98,12 @@ module CyberarmEngine
       @shadow_color = n
     end
 
-    def width
-      textobject.text_width(@text)
+    def width(text = @text)
+      textobject.text_width(text)
     end
 
-    def height
-      @text.lines.count > 0 ? (@text.lines.count) * textobject.height : @textobject.height
+    def height(text = @text)
+      text.lines.count > 0 ? (text.lines.count) * textobject.height : @textobject.height
     end
 
     def draw

lib/cyberarm_engine/transform.rb

@@ -0,0 +1,273 @@
+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
+
+      return 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
+
+      return 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.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
+        return 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
+
+      return 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/dsl.rb

@@ -1,102 +1,106 @@
 module CyberarmEngine
   module DSL
     def flow(options = {}, &block)
-      options[:parent] = @containers.last
-      options[:theme] = current_theme
-      _container = Element::Flow.new(options, block)
-      @containers << _container
-      _container.build
-      _container.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 = Element::Stack.new(options, block)
-      @containers << _container
-      _container.build
-      _container.parent.add(_container)
-      @containers.pop
-
-      return _container
+      container(CyberarmEngine::Element::Stack, options, &block)
     end
 
     def label(text, options = {}, &block)
-      options[:parent] = @containers.last
+      options[:parent] = element_parent
       options[:theme] = current_theme
-      _element = Element::Label.new(text, options, block)
-      @containers.last.add(_element)
 
-      return _element
+      add_element( Element::Label.new(text, options, block) )
     end
 
     def button(text, options = {}, &block)
-      options[:parent] = @containers.last
+      options[:parent] = element_parent
       options[:theme] = current_theme
-      _element = Element::Button.new(text, options, block) { if block.is_a?(Proc); block.call; end }
-      @containers.last.add(_element)
 
-      return _element
+      add_element( Element::Button.new(text, options, block) { if block.is_a?(Proc); block.call; end } )
     end
 
     def edit_line(text, options = {}, &block)
-      options[:parent] = @containers.last
+      options[:parent] = element_parent
       options[:theme] = current_theme
-      _element = Element::EditLine.new(text, options, block)
-      @containers.last.add(_element)
 
-      return _element
+      add_element( Element::EditLine.new(text, options, block) )
     end
 
     def toggle_button(options = {}, &block)
-      options[:parent] = @containers.last
+      options[:parent] = element_parent
       options[:theme] = current_theme
-      _element = Element::ToggleButton.new(options, block)
-      @containers.last.add(_element)
 
-      return _element
+      add_element( Element::ToggleButton.new(options, block) )
     end
 
     def check_box(text, options = {}, &block)
-      options[:parent] = @containers.last
+      options[:parent] = element_parent
       options[:theme] = current_theme
-      _element = Element::CheckBox.new(text, options, block)
-      @containers.last.add(_element)
 
-      return _element
+      add_element( Element::CheckBox.new(text, options, block) )
     end
 
     def image(path, options = {}, &block)
-      options[:parent] = @containers.last
+      options[:parent] = element_parent
       options[:theme] = current_theme
-      _element = Element::Image.new(path, options, block)
-      @containers.last.add(_element)
 
-      return _element
+      add_element( Element::Image.new(path, options, block) )
     end
 
     def progress(options = {}, &block)
-      options[:parent] = @containers.last
+      options[:parent] = element_parent
       options[:theme] = current_theme
-      _element = Element::Progress.new(options, block)
-      @containers.last.add(_element)
 
-      return _element
+      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.style.background = color
+      element_parent.style.background = color
     end
 
     def theme(theme)
-      @containers.last.options[:theme] = theme
+      element_parent.options[:theme] = theme
     end
 
     def current_theme
-      @containers.last.options[:theme]
+      element_parent.options[:theme]
+    end
+
+    private def add_element(element)
+      element_parent.add(element)
+
+      return element
+    end
+
+    private def element_parent
+      $__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
+      $__current_container__ = _container
+
+      _container.build
+      _container.parent.add(_container)
+
+      $__current_container__ = old_parent
+
+      return _container
     end
   end
 end

lib/cyberarm_engine/ui/element.rb

@@ -4,7 +4,7 @@ module CyberarmEngine
     include Event
     include Common
 
-    attr_accessor :x, :y, :z, :enabled
+    attr_accessor :x, :y, :z, :enabled, :tip
     attr_reader :parent, :options, :style, :event_handler, :background_canvas, :border_canvas
 
     def initialize(options = {}, block = nil)
@@ -16,6 +16,7 @@ module CyberarmEngine
       @focus   = false
       @enabled = true
       @visible = true
+      @tip = @options[:tip] ? @options[:tip] : ""
 
       @style = Style.new(options)
 
@@ -110,6 +111,8 @@ module CyberarmEngine
       event(:leave)
 
       event(:blur)
+
+      event(:changed)
     end
 
     def enabled?
@@ -152,6 +155,10 @@ module CyberarmEngine
     def button_up(id)
     end
 
+    def draggable?(button)
+      false
+    end
+
     def render
     end
 
@@ -168,6 +175,14 @@ module CyberarmEngine
       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
@@ -184,6 +199,14 @@ module CyberarmEngine
       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
@@ -196,7 +219,7 @@ module CyberarmEngine
       raise "dimension must be either :width or :height" unless dimension == :width || dimension == :height
       if size && size.is_a?(Numeric)
         if size.between?(0.0, 1.0)
-          @parent.send(:"#{dimension}") * size
+          ((@parent.send(:"content_#{dimension}") - self.send(:"noncontent_#{dimension}")) * size).round
         else
           size
         end
@@ -223,6 +246,8 @@ module CyberarmEngine
     end
 
     def root
+      return self if is_root?
+
       unless @root && @root.parent.nil?
         @root = parent
 
@@ -256,5 +281,9 @@ module CyberarmEngine
     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
   end
 end

lib/cyberarm_engine/ui/elements/check_box.rb

@@ -2,13 +2,32 @@ module CyberarmEngine
   class Element
     class CheckBox < Flow
       def initialize(text, options, block = nil)
-        super({}, block = nil)
+        super(options, block)
         options[:toggled] = options[:checked]
 
         @toggle_button = ToggleButton.new(options)
         @label         = Label.new(text, options)
 
-        define_label_singletons
+        @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)
@@ -24,35 +43,8 @@ module CyberarmEngine
       end
 
       def value=(bool)
-        @toggle_button.vlaue = bool
-      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
+        @toggle_button.value = bool
+        publish(:changed, @toggle_button.value)
       end
     end
   end

lib/cyberarm_engine/ui/elements/container.rb

@@ -22,13 +22,26 @@ module CyberarmEngine
       def build
         @block.call(self) if @block
 
-        recalculate
+        root.gui_state.request_recalculate
       end
 
       def add(element)
         @children << element
 
-        recalculate
+        root.gui_state.request_recalculate
+      end
+
+      def clear(&block)
+        @children.clear
+
+        old_container = $__current_container__
+
+        $__current_container__ = self
+        block.call(self) if block
+
+        $__current_container__ = old_container
+
+        root.gui_state.request_recalculate
       end
 
       def render
@@ -43,6 +56,8 @@ module CyberarmEngine
 
       def hit_element?(x, y)
         @children.reverse_each do |child|
+          next unless child.visible?
+
           case child
           when Container
             if element = child.hit_element?(x, y)
@@ -59,6 +74,9 @@ module CyberarmEngine
       def recalculate
         @current_position = Vector.new(@style.margin_left + @style.padding_left, @style.margin_top + @style.padding_top)
         return unless visible?
+
+        Stats.increment(:gui_recalculations_last_frame, 1)
+
         stylize
 
         layout
@@ -76,15 +94,16 @@ module CyberarmEngine
           @height = _height ? _height : (@children.map {|c| c.y + c.outer_height}.max || 0).round
         end
 
-
         # Move child to parent after positioning
         @children.each do |child|
-          child.x += @x
-          child.y += @y
+          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.increment(:gui_recalculations_last_frame, 1)
         end
 
         update_background
@@ -95,10 +114,12 @@ module CyberarmEngine
       end
 
       def max_width
-        @max_width ? @max_width : window.width - (@parent ? @parent.style.margin_right + @style.margin_right : @style.margin_right)
+        _width = dimensional_size(@style.width, :width)
+        _width ? outer_width : window.width - (@parent ? @parent.style.margin_right + @style.margin_right : @style.margin_right)
       end
 
       def fits_on_line?(element) # Flow
+        p [@options[:id], @width] if @options[:id]
         @current_position.x + element.outer_width <= max_width &&
         @current_position.x + element.outer_width <= window.width
       end
@@ -157,6 +178,25 @@ module CyberarmEngine
       def value
         @children.map {|c| c.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 = 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
+end

lib/cyberarm_engine/ui/elements/edit_box.rb

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

lib/cyberarm_engine/ui/elements/edit_line.rb

@@ -16,16 +16,31 @@ module CyberarmEngine
         @text_input = Gosu::TextInput.new
         @text_input.text = text
 
+        @offset_x = 0
+
         return self
       end
 
       def render
         Gosu.clip_to(@text.x, @text.y, @style.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
+          Gosu.translate(-@offset_x, 0) do
+            draw_selection
+            draw_caret if @focus && @show_caret
+            draw_text
+          end
         end
       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
         if @type == :password
           @text.text = default(:password_character) * @text_input.text.length
@@ -38,6 +53,67 @@ module CyberarmEngine
 
           @show_caret = !@show_caret
         end
+
+        keep_caret_visible
+      end
+
+      def move_caret_to_mouse(mouse_x)
+        1.upto(@text.text.length) do |i|
+          if mouse_x < @text.x + @text.textobject.text_width(@text.text[0...i])
+            @text_input.caret_pos = @text_input.selection_start = i - 1;
+            return
+          end
+        end
+
+        @text_input.caret_pos = @text_input.selection_start = @text_input.text.length
+      end
+
+      def keep_caret_visible
+        caret_pos = (caret_position - @text.x) + @caret_width
+
+        @last_text ||= "/\\"
+        @last_pos ||= -1
+
+        puts "caret pos: #{caret_pos}, width: #{@width}, offset: #{@offset_x}" if (@last_text != @text.text) || (@last_pos != caret_pos)
+
+        @last_text = @text.text
+        @last_pos = caret_pos
+
+
+        if caret_pos.between?(@offset_x, @width + @offset_x)
+          # Do nothing
+
+        elsif caret_pos < @offset_x
+          if caret_pos > @width
+            @offset_x = caret_pos + @width
+          else
+            @offset_x = 0
+          end
+
+        elsif caret_pos > @width
+          @offset_x = caret_pos - @width
+          puts "triggered"
+
+        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)])
+        end
       end
 
       def left_mouse_button(sender, x, y)
@@ -47,6 +123,8 @@ module CyberarmEngine
         @caret_last_interval = Gosu.milliseconds
         @show_caret = true
 
+        move_caret_to_mouse(x)
+
         return :handled
       end
 
@@ -79,15 +157,6 @@ module CyberarmEngine
         return :handled
       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
 

lib/cyberarm_engine/ui/elements/flow.rb

@@ -1,8 +1,6 @@
 module CyberarmEngine
   class Element
     class Flow < Container
-      include Common
-
       def layout
         @children.each do |child|
           if fits_on_line?(child)

lib/cyberarm_engine/ui/elements/label.rb

@@ -14,7 +14,7 @@ module CyberarmEngine
       def clicked_left_mouse_button(sender, x, y)
         @block.call(self) if @block
 
-        return :handled
+        # return :handled
       end
 
       def recalculate
@@ -44,6 +44,8 @@ module CyberarmEngine
         recalculate
 
         root.gui_state.request_recalculate if old_width != width || old_height != height
+
+        publish(:changed, self.value)
       end
     end
   end

lib/cyberarm_engine/ui/elements/list_box.rb

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

lib/cyberarm_engine/ui/elements/progress.rb

@@ -43,6 +43,7 @@ module CyberarmEngine
         @fraction = decimal.clamp(0.0, 1.0)
         update_background
 
+        publish(:changed, @fraction)
         return @fraction
       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 :range, :step_size
+      def initialize(options = {}, block = nil)
+        super(options, block)
+
+        @range     = @options[:range] ? @options[:range] : 0.0..1.0
+        @step_size = @options[:step] ? @options[:step] : 0.1
+        @value     = @options[:value] ? @options[:value] : (@range.first + @range.last) / 2
+
+        @handle = Handle.new("", parent: self, width: 8, height: 1.0) { close }
+        self.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 + @style.padding_left + @style.border_thickness_left +
+          ((content_width - @handle.outer_width) * (@value - @range.min) / (@range.max - @range.min).to_f)
+
+        @handle.y = @y + @style.border_thickness_top + @style.padding_top
+      end
+
+      def draw
+        super
+
+        @handle.draw
+      end
+
+      def update
+        super
+
+        @tip = value.to_s
+        @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) - @x) / (content_width - @handle.outer_width)
+
+        self.value = @ratio.clamp(0.0, 1.0) * (@range.max - @range.min) + @range.min
+      end
+
+      def value
+        @value
+      end
+
+      def value=(n)
+        @value = n
+        position_handle
+        @handle.recalculate
+
+        publish(:changed, @value)
+      end
+    end
+  end
+end

lib/cyberarm_engine/ui/elements/stack.rb

@@ -1,8 +1,6 @@
 module CyberarmEngine
   class Element
     class Stack < Container
-      include Common
-
       def layout
         @children.each do |child|
           move_to_next_line(child)

lib/cyberarm_engine/ui/elements/toggle_button.rb

@@ -5,8 +5,8 @@ module CyberarmEngine
 
       def initialize(options, block = nil)
         super(options[:checkmark], options, block)
-        @toggled = options[:toggled] || false
-        if @toggled
+        @value = options[:checked] || false
+        if @value
           @text.text = @options[:checkmark]
         else
           @text.text = ""
@@ -15,41 +15,42 @@ module CyberarmEngine
         return self
       end
 
-      def toggled=(boolean)
-        @toggled = !boolean
-        toggle
-      end
-
       def clicked_left_mouse_button(sender, x, y)
-        toggle
+        self.value = !@value
 
         @block.call(self) if @block
 
         return :handled
       end
 
-      def toggle
-        if @toggled
-          @toggled = false
-          @text.text = ""
-        else
-          @toggled = true
-          @text.text = @options[:checkmark]
-        end
-      end
-
       def recalculate
         super
 
         _width = dimensional_size(@style.width, :width)
         _height= dimensional_size(@style.height,:height)
+
         @width  = _width  ? _width  : @text.textobject.text_width(@options[:checkmark])
         @height = _height ? _height : @text.height
+
         update_background
       end
 
       def value
-        @toggled
+        @value
+      end
+
+      def value=(boolean)
+        @value = boolean
+
+        if boolean
+          @text.text = @options[:checkmark]
+        else
+          @text.text = ""
+        end
+
+        recalculate
+
+        publish(:changed, @value)
       end
     end
   end

lib/cyberarm_engine/ui/event.rb

@@ -23,6 +23,7 @@ module CyberarmEngine
         return :handled if handler.call(self, *args) == :handled
       end
 
+      parent.publish(event, *args) if parent
       return nil
     end
 

lib/cyberarm_engine/ui/gui_state.rb

@@ -12,7 +12,7 @@ module CyberarmEngine
 
       @root_container = Element::Stack.new(gui_state: self)
       @game_objects << @root_container
-      @containers     = [@root_container]
+      $__current_container__ = @root_container
 
       @active_width  = window.width
       @active_height = window.height
@@ -22,6 +22,11 @@ module CyberarmEngine
       @mouse_down_on = {}
       @mouse_down_position = {}
       @pending_recalculate_request = false
+
+      @tip = CyberarmEngine::Text.new("", size: 22, z: Float::INFINITY)
+      @menu = nil
+      @min_drag_distance = 0
+      @mouse_pos = Vector.new
     end
 
     # throws :blur event to focused element and sets GuiState focused element
@@ -35,8 +40,18 @@ module CyberarmEngine
       @focus
     end
 
+    def draw
+      super
+
+      if @tip.text.length > 0
+        Gosu.draw_rect(@tip.x - 2, @tip.y - 2, @tip.width + 4, @tip.height + 4, 0xff020202, Float::INFINITY)
+        @tip.draw
+      end
+    end
+
     def update
       if @pending_recalculate_request
+        @root_container.recalculate
         @root_container.recalculate
         @pending_recalculate_request = false
       end
@@ -56,12 +71,30 @@ module CyberarmEngine
       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)
 
+      if Vector.new(window.mouse_x, window.mouse_y) == @last_mouse_pos
+        if @mouse_over && (Gosu.milliseconds - @mouse_moved_at) > tool_tip_delay
+          @tip.text = @mouse_over.tip if @mouse_over
+          @tip.x, @tip.y = window.mouse_x - @tip.width / 2, window.mouse_y - @tip.height - 4
+        else
+          @tip.text = ""
+        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
+
       request_recalculate if @active_width != window.width || @active_height != window.height
 
       @active_width  = window.width
       @active_height = window.height
     end
 
+    def tool_tip_delay
+      500 # ms
+    end
+
     def button_down(id)
       super
 
@@ -72,6 +105,8 @@ module CyberarmEngine
         redirect_mouse_button(:middle)
       when Gosu::MsRight
         redirect_mouse_button(:right)
+      when Gosu::KbF5
+        request_recalculate
       end
     end
 
@@ -115,12 +150,26 @@ module CyberarmEngine
         @mouse_over.publish(:"clicked_#{button}_mouse_button", window.mouse_x, window.mouse_y) if @mouse_over == @mouse_down_on[button]
       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
       @mouse_down_on[button]       = nil
     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
+      else
+        @mouse_over.publish(:"holding_#{button}_mouse_button", window.mouse_x, window.mouse_y) if @mouse_over
+      end
     end
 
     def redirect_mouse_wheel(button)

lib/cyberarm_engine/ui/theme.rb

@@ -88,6 +88,7 @@ module CyberarmEngine
         caret_width: 2,
         caret_color: Gosu::Color::WHITE,
         caret_interval: 500,
+        selection_color: Gosu::Color.rgba(255, 128, 50, 200),
       },
 
       Image: { # < Element
@@ -111,7 +112,16 @@ module CyberarmEngine
         height: 36,
         background: 0xff111111,
         fraction_background: [0xffc75e61, 0xffe26623],
-        border_thickness: 4,
+        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

lib/cyberarm_engine/vector.rb

@@ -1,25 +1,61 @@
 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
@@ -40,21 +76,33 @@ module CyberarmEngine
     def weight; @weight; end
     def weight=(n); @weight = n; end
 
+    alias w weight
+    alias w= weight=
+
+    # @return [Boolean]
     def ==(other)
       if other.is_a?(Numeric)
         @x      == other &&
         @y      == other &&
         @z      == other &&
         @weight == other
-      else
+      elsif other.is_a?(Vector)
         @x      == other.x &&
         @y      == other.y &&
         @z      == other.z &&
         @weight == other.weight
+      else
+        other == self
       end
     end
 
-    # Performs math operation, excluding @weight
+    # Create a new vector using {x} and {y} values
+    # @return [CyberarmEngine::Vector]
+    def xy
+      Vector.new(@x, @y)
+    end
+
+    # Performs math operation, excluding {weight}
     private def operator(function, other)
       if other.is_a?(Numeric)
         Vector.new(
@@ -71,22 +119,26 @@ module CyberarmEngine
       end
     end
 
-    # Adds Vector and Numberic or Vector and Vector, excluding @weight
+    # Adds Vector and Numeric or Vector and Vector, excluding {weight}
+    # @return [CyberarmEngine::Vector]
     def +(other)
       operator("+", other)
     end
 
-    # Subtracts Vector and Numberic or Vector and Vector, excluding @weight
+    # Subtracts Vector and Numeric or Vector and Vector, excluding {weight}
+    # @return [CyberarmEngine::Vector]
     def -(other)
       operator("-", other)
     end
 
-    # Multiplies Vector and Numberic or Vector and Vector, excluding @weight
+    # Multiplies Vector and Numeric or Vector and Vector, excluding {weight}
+    # @return [CyberarmEngine::Vector]
     def *(other)
       operator("*", other)
     end
 
-    # Divides Vector and Numberic or Vector and Vector, excluding @weight
+    # 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)
@@ -104,6 +156,8 @@ module CyberarmEngine
       end
     end
 
+    # dot product of {Vector}
+    # @return [Integer|Float]
     def dot(other)
       product = 0
 
@@ -117,6 +171,8 @@ module CyberarmEngine
       return product
     end
 
+    # cross product of {Vector}
+    # @return [CyberarmEngine::Vector]
     def cross(other)
       a = self.to_a
       b = other.to_a
@@ -129,24 +185,40 @@ module CyberarmEngine
     end
 
     # returns degrees
+    # @return [Float]
     def angle(other)
       Math.acos( self.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
-      # 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)
@@ -154,41 +226,63 @@ module CyberarmEngine
       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

lib/cyberarm_engine/version.rb

@@ -1,4 +1,4 @@
 module CyberarmEngine
   NAME    = "InDev"
-  VERSION = "0.11.1"
+  VERSION = "0.14.0"
 end

lib/cyberarm_engine/window.rb

@@ -1,5 +1,5 @@
 module CyberarmEngine
-  class Engine < Gosu::Window
+  class Window < Gosu::Window
     IMAGES = {}
     SAMPLES= {}
     SONGS  = {}
@@ -34,6 +34,8 @@ module CyberarmEngine
     end
 
     def update
+      Stats.clear
+
       current_state.update if current_state
       @last_frame_time = Gosu.milliseconds-@current_frame_time
       @current_frame_time = Gosu.milliseconds