colored circles program

main.lua

@@ -12,9 +12,13 @@ Baton = require 'lib/baton/baton'
 ---@type Timer
 Timer = require 'lib/hump/timer'
 
--- objects --
+-- generic objects --
 Room = require 'obj/Room'
 Area = require 'obj/Area'
+GameObject = require 'obj/GameObject'
+
+-- game objects --
+Circle = require 'obj/game/Circle'
 
 function love.load()
     ---@type Room|nil
@@ -46,6 +50,7 @@ end
 function love.update(dt)
     input:update(dt)
     if current_room then current_room:update(dt) end
+    if input:pressed('f1') then gotoRoom('Stage') end
 end
 
 function love.draw()

obj/Area.lua

@@ -2,6 +2,7 @@
 
 ---@class Area:Object
 ---@field room Room
+---@field game_objects GameObject[]
 local Area = Object:extend()
 
 ---Instantiates area
@@ -13,7 +14,10 @@ end
 ---Updates area
 ---@param dt number
 function Area:update(dt)
-    for _, game_object in ipairs(self.game_objects) do game_object:update(dt) end
+    for i, game_object in ipairs(self.game_objects) do
+        if game_object:isDead() then table.remove(self.game_objects, i) end
+        game_object:update(dt)
+    end
 end
 
 ---Draws area

obj/GameObject.lua

@@ -1,10 +1,11 @@
 ---@module 'obj/GameObject'
 
 ---@class GameObject:Object
----@field area number 
+---@field area Area 
 ---@field x number
 ---@field y number
 ---@field opts table|nil
+---@field super GameObject
 local GameObject = Object:extend()
 
 ---Instantiates game object
@@ -28,4 +29,25 @@ end
 ---Draw game object
 function GameObject:draw() end
 
+---Mark object for destruction
+function GameObject:destroy()
+    if self.timer then
+        self.timer:clear()  -- cancel all tweens/after/every
+        self.timer = nil
+    end
+    self.dead = true
+end
+
+---Returns whether object is marked for destruction
+---@return boolean
+function GameObject:isDead()
+    return self.dead == true
+end
+
+---Kill object (meant to be overridden)
+---**default behavior:** self:destroy()
+function GameObject:kill()
+    self:destroy()
+end
+
 return GameObject

obj/Room.lua

@@ -1,16 +1,26 @@
 ---@module 'obj/Room'
 
 ---@class Room:Object
+---@field area Area room area
+---@field id string room id
+---@field super Room
 local Room = Object:extend()
 
 ---Instantiates room.
-function Room:new() end
+function Room:new()
+    self.area = Area(self)
+    self.id = UUID()
+end
 
 ---Updates room (see [love.update()](lua://love.update))
 ---@param dt number delta time
-function Room:update(dt) end
+function Room:update(dt)
+    self.area:update(dt)
+end
 
 ---Draws graphics (see [love.draw()](lua://love.draw))
-function Room:draw() end
+function Room:draw()
+    self.area:draw()
+end
 
 return Room

obj/game/Circle.lua

@@ -0,0 +1,36 @@
+---@class Circle:GameObject circle object
+---@field area Area area of circle
+---@field x number horizontal position of circle
+---@field y number vertical position of circle
+---@field radius number radius of circle
+---@field mode string drawing mode of circle
+local Circle = GameObject:extend()
+
+function Circle:new(area, x, y, config)
+    Circle.super.new(self, area, x or 400, y or 300)
+    self.tweened = false
+    self.current_radius = 0
+    self.radius = config.radius or 50
+    self.mode = config.mode or "fill"
+    self._r, self._g, self._b = love.math.random(0.1, 1.0), love.math.random(0.1, 1.0), love.math.random(0.1, 1.0)
+end
+
+function Circle:update(dt)
+    Circle.super.update(self, dt)
+    if not self.tweened then
+        self.tweened = true
+        self.timer:tween(0.4, self, {current_radius = self.radius}, 'in-out-cubic')
+    end
+end
+
+function Circle:draw()
+    Circle.super.draw(self)
+    love.graphics.setColor(self._r, self._g, self._b)
+    love.graphics.circle(self.mode, self.x, self.y, self.current_radius)
+end
+
+function Circle:kill()
+    self.timer:tween(0.4, self, {current_radius = 0}, 'in-out-cubic', function() self:destroy() end)
+end
+
+return Circle

rooms/Stage.lua

@@ -0,0 +1,27 @@
+---@class Stage:Room
+local Stage = Room:extend()
+
+function Stage:new()
+    Stage.super.new(self)
+    self.timer = Timer()
+end
+
+function Stage:update(dt)
+    Stage.super.update(self, dt)
+
+    if input:pressed('action') then
+        local latest_object = self.area:addGameObject('Circle', love.math.random(1, 800), love.math.random(1, 600))
+    end
+
+    if input:pressed('right') then
+        for _, game_object in ipairs(self.area.game_objects) do
+            game_object:kill()
+        end
+    end
+end
+
+function Stage:draw()
+    Stage.super.draw(self)
+end
+
+return Stage