Extracted movement and turret into 'components' that entity get add to its self when defined

i-mic-rts.rb

@@ -29,6 +29,7 @@ require_relative "lib/states/menus/solo_lobby_menu"
 require_relative "lib/states/menus/multiplayer_lobby_menu"
 
 require_relative "lib/zorder"
+require_relative "lib/component"
 require_relative "lib/entity"
 require_relative "lib/map"
 require_relative "lib/tiled_map"

lib/component.rb

@@ -0,0 +1,23 @@
+class IMICRTS
+  class Component
+    @@components = {}
+
+    def self.get(name)
+      @@components.dig(name)
+    end
+
+    def self.inherited(klass)
+      name = klass.to_s.split("::").last.downcase.to_sym
+
+      if get(name)
+        raise "#{klass.inspect} is already defined!"
+      else
+        @@components[name] = klass
+      end
+    end
+  end
+end
+
+Dir.glob("#{IMICRTS::GAME_ROOT_PATH}/lib/components/**/*.rb").each do |component|
+  require_relative component
+end

lib/components/movement.rb

@@ -0,0 +1,31 @@
+class IMICRTS
+  class Movement < Component
+    attr_accessor :pathfinder
+    def initialize(parent:)
+      @parent = parent
+    end
+
+    def rotate_towards(vector)
+      _angle = Gosu.angle(@parent.position.x, @parent.position.y, vector.x, vector.y)
+      a = (360.0 + (_angle - @parent.angle)) % 360.0
+
+      # FIXME: Fails if vector is directly behind entity
+      if @parent.angle.between?(_angle - 3, _angle + 3)
+        @parent.angle = _angle
+      elsif a < 180
+        @parent.angle -= 1.0
+      else
+        @parent.angle += 1.0
+      end
+
+      @parent.angle %= 360.0
+    end
+
+    def follow_path
+      if @pathfinder && node = @pathfinder.path_current_node
+        @pathfinder.path_next_node if @pathfinder.at_current_path_node?(@parent)
+        @parent.position -= (@parent.position.xy - node.tile.position.xy).normalized * @parent.speed
+      end
+    end
+  end
+end

lib/components/turret.rb

@@ -0,0 +1,37 @@
+class IMICRTS
+  class Turret < Component
+    attr_accessor :angle, :center
+    def initialize(parent:)
+      @parent = parent
+
+      @angle = 0
+      @center = CyberarmEngine::Vector.new(0.5, 0.5)
+    end
+
+    def body_image=(image)
+      @body_image = Gosu::Image.new("#{IMICRTS::ASSETS_PATH}/#{image}", retro: true)
+    end
+
+    def shell_image=(image)
+      @shell_image = Gosu::Image.new("#{IMICRTS::ASSETS_PATH}/#{image}", retro: true)
+    end
+
+    def overlay_image=(image)
+      @overlay_image = Gosu::Image.new("#{IMICRTS::ASSETS_PATH}/#{image}", retro: true)
+    end
+
+    def render
+      @render = Gosu.render(32, 32, retro: true) do
+        @body_image.draw(0, 0, 0) if @body_image
+        @shell_image.draw_rot(0, 0, 0, 0, 0, 0, 1, 1, @parent.player.color) if @shell_image
+        @overlay_image.draw(0, 0, 0) if @overlay_image
+      end
+    end
+
+    def draw
+      render unless @render
+      @angle += 0.1
+      @render.draw_rot(@parent.position.x + @center.x, @parent.position.y + @center.y, @parent.position.z, @angle)
+    end
+  end
+end

lib/entities/units/construction_worker.rb

@@ -1,4 +1,6 @@
 IMICRTS::Entity.define_entity(:construction_worker, :unit, 1000, "Constructs buildings") do |entity|
+  entity.has(:movement)
+
   entity.radius = 14
   entity.movement = :ground
   entity.max_health = 100.0

lib/entities/units/harvester.rb

@@ -1,4 +1,6 @@
 IMICRTS::Entity.define_entity(:harvester, :unit, 1400, "Harvests ore") do |entity, director|
+  entity.has(:movement)
+
   entity.radius = 10
   entity.movement = :ground
   entity.max_health = 100.0
@@ -28,7 +30,7 @@ IMICRTS::Entity.define_entity(:harvester, :unit, 1400, "Harvests ore") do |entit
   entity.define_singleton_method(:seek_refinery) do
   end
 
-  entity.define_singleton_method(:rotate_towards) do |target|
+  entity.component(:movement).define_singleton_method(:rotate_towards) do |target|
     entity.angle = Gosu.angle(target.x, target.y, entity.position.x, entity.position.y)
   end
 end

lib/entities/units/tank.rb

@@ -1,11 +1,15 @@
 IMICRTS::Entity.define_entity(:tank, :unit, 800, "Attacks ground targets") do |entity|
+  entity.has(:movement)
+  entity.has(:turret)
+
   entity.radius = 14
   entity.movement = :ground
   entity.max_health = 100.0
 
   entity.shell_image = "vehicles/tank/tank_shell.png"
 
-  entity.turret_shell_image = "vehicles/tank/tank_turret_shell.png"
+  entity.component(:turret).shell_image = "vehicles/tank/tank_turret_shell.png"
+  entity.component(:turret).center.y = 0.4
 
   entity.on_tick do
   end

lib/entity.rb

@@ -15,7 +15,7 @@ class IMICRTS
       end
     end
 
-    attr_reader :player, :id, :name, :type
+    attr_reader :player, :id, :name, :type, :speed
     attr_accessor :position, :angle, :radius, :target, :state,
                   :movement, :health, :max_health,
                   :turret
@@ -31,6 +31,8 @@ class IMICRTS
       @target = nil
       @state  = :idle
 
+      @components = {}
+
       if entity = Entity.get(name)
         @name = entity.name
         @type = entity.type
@@ -40,6 +42,8 @@ class IMICRTS
         raise "Failed to find entity #{name.inspect} definition"
       end
 
+      component(:turret).angle = @angle if component(:turret)
+
       @goal_color   = Gosu::Color.argb(175, 25, 200, 25)
       @target_color = Gosu::Color.argb(175, 200, 25, 25)
 
@@ -52,6 +56,20 @@ class IMICRTS
     def deserialize
     end
 
+    def has(symbol)
+      component = Component.get(symbol)
+
+      if component
+        @components[symbol] = component.new(parent: self)
+      else
+        raise "Unknown component: #{component.inspect}"
+      end
+    end
+
+    def component(symbol)
+      @components.dig(symbol)
+    end
+
     def body_image=(image)
       @body_image = Gosu::Image.new("#{IMICRTS::ASSETS_PATH}/#{image}", retro: true)
     end
@@ -60,17 +78,13 @@ class IMICRTS
       @shell_image = Gosu::Image.new("#{IMICRTS::ASSETS_PATH}/#{image}", retro: true)
     end
 
-    def turret_body_image=(image)
-      @turret_body_image = Gosu::Image.new("#{IMICRTS::ASSETS_PATH}/#{image}", retro: true)
-    end
-
-    def turret_shell_image=(image)
-      @turret_shell_image = Gosu::Image.new("#{IMICRTS::ASSETS_PATH}/#{image}", retro: true)
+    def overlay_image=(image)
+      @overlay_image = Gosu::Image.new("#{IMICRTS::ASSETS_PATH}/#{image}", retro: true)
     end
 
     def target=(entity)
       @target = entity
-      @pathfinder = @director.find_path(player: @player, entity: self, goal: @target)
+      component(:movement).pathfinder = @director.find_path(player: @player, entity: self, goal: @target) if component(:movement)
     end
 
     def hit?(x_or_vector, y = nil)
@@ -85,24 +99,28 @@ class IMICRTS
       @position.distance(vector) < @radius + 1
     end
 
-    def draw
-      @body_image.draw_rot(@position.x, @position.y, @position.z, @angle) if @body_image
-      @shell_image.draw_rot(@position.x, @position.y, @position.z, @angle, 0.5, 0.5, 1, 1, @player.color)
-      @overlay_image.draw_rot(@position.x, @position.y, @position.z, @angle, 0.5, 0.5, 1, 1) if @overlay_image
+    def render
+      @render = Gosu.render(32, 32, retro: true) do
+        @body_image.draw(0, 0, 0) if @body_image
+        @shell_image.draw(0, 0, 0, 1, 1, @player.color)
+        @overlay_image.draw(0, 0, 0) if @overlay_image
+      end
+    end
 
-      @turret_body_image.draw_rot(@position.x, @position.y, @position.z, @angle, 0.5, 0.5, 1, 1) if @turret_body_image
-      @turret_shell_image.draw_rot(@position.x, @position.y, @position.z, @angle, 0.5, 0.5, 1, 1, @player.color) if @turret_shell_image
-      @turret_overlay_image.draw_rot(@position.x, @position.y, @position.z, @angle, 0.5, 0.5, 1, 1) if @turret_overlay_image
+    def draw
+      render unless @render
+      @render.draw_rot(@position.x, @position.y, @position.z, @angle)
+
+      component(:turret).draw if component(:turret)
     end
 
     def update
-      if @movement
-        # rotate_towards(@target) if @target
-        rotate_towards(@pathfinder.path_current_node.tile.position) if @pathfinder && @pathfinder.path_current_node
-      end
+      if component(:movement)
+        if component(:movement).pathfinder && component(:movement).pathfinder.path_current_node
+          component(:movement).rotate_towards(component(:movement).pathfinder.path_current_node.tile.position)
+        end
 
-      if @movement
-        follow_path
+        component(:movement).follow_path
       end
     end
 
@@ -114,13 +132,6 @@ class IMICRTS
       @on_tick = block
     end
 
-    def follow_path
-      if @pathfinder && node = @pathfinder.path_current_node
-        @pathfinder.path_next_node if @pathfinder.at_current_path_node?(self)
-        @position -= (@position.xy - node.tile.position.xy).normalized * @speed
-      end
-    end
-
     def selected_draw
       draw_radius
       draw_gizmos
@@ -133,15 +144,15 @@ class IMICRTS
     def draw_gizmos
       Gosu.draw_rect(@position.x - @radius, @position.y - (@radius + 2), @radius * 2, 2, Gosu::Color::GREEN, ZOrder::ENTITY_GIZMOS)
 
-      if Setting.enabled?(:debug_pathfinding) && @pathfinder && @pathfinder.path_current_node
+      if Setting.enabled?(:debug_pathfinding) && component(:movement) && component(:movement).pathfinder && component(:movement).pathfinder.path_current_node
         Gosu.draw_line(
           @position.x, @position.y, Gosu::Color::RED,
-          @pathfinder.path_current_node.tile.position.x, @pathfinder.path_current_node.tile.position.y, Gosu::Color::RED,
+          component(:movement).pathfinder.path_current_node.tile.position.x, component(:movement).pathfinder.path_current_node.tile.position.y, Gosu::Color::RED,
           ZOrder::ENTITY_GIZMOS
         )
 
-        node = @pathfinder.path_current_node
-        @pathfinder.path[@pathfinder.path_current_node_index..@pathfinder.path.size - 1].each do |next_node|
+        node = component(:movement).pathfinder.path_current_node
+        component(:movement).pathfinder.path[component(:movement).pathfinder.path_current_node_index..component(:movement).pathfinder.path.size - 1].each do |next_node|
           if node
             Gosu.draw_line(
               node.tile.position.x, node.tile.position.y, Gosu::Color::RED,
@@ -160,22 +171,6 @@ class IMICRTS
         Gosu.draw_line(@position.x, @position.y, @goal_color, @target.x, @target.y, @goal_color, ZOrder::ENTITY_GIZMOS) if @target
       end
     end
-
-    def rotate_towards(vector)
-      _angle = Gosu.angle(@position.x, @position.y, vector.x, vector.y)
-      a = (360.0 + (_angle - @angle)) % 360.0
-
-      # Fails if vector is directly behind entity
-      if @angle.between?(_angle - 3, _angle + 3)
-        @angle = _angle
-      elsif a < 180
-        @angle -= 1.0
-      else
-        @angle += 1.0
-      end
-
-      @angle %= 360.0
-    end
   end
 end