From b832731fa0c86453d81d75f6778d233ee3c876ca Mon Sep 17 00:00:00 2001
From: Donald Ball <donald.ball@gmail.com>
Date: Sat, 15 Nov 2025 21:43:10 -0500
Subject: [PATCH] introduce actor trait

---
 asteroids/main.lua | 37 ++++++++++++++++++++++++++++---------
 1 file changed, 28 insertions(+), 9 deletions(-)

diff --git a/asteroids/main.lua b/asteroids/main.lua
index 61c1a0b..a0ad3ee 100644
--- a/asteroids/main.lua
+++ b/asteroids/main.lua
@@ -13,7 +13,6 @@ local function initGame()
                 time = 4,
                 sound = love.sound.newSoundData('resources/bullet.mp3'),
             },
-            -- 99x75
             sprite = love.graphics.newImage('resources/ship.png'),
         },
         asteroids = {
@@ -53,6 +52,9 @@ local function initState()
     for _, asteroid in ipairs(asteroids) do
         asteroid.angle = love.math.random() * (2 * math.pi)
         asteroid.stage = #game.asteroids.stages
+        local stage = game.asteroids.stages[asteroid.stage]
+        asteroid.speed = stage.speed
+        asteroid.radius = stage.radius
     end
     local joystick = nil
     if love.joystick.getJoystickCount() == 1 then
@@ -86,6 +88,19 @@ function love.load()
     reset()
 end
 
+-- updates the actor's location by applying the passage of time
+-- TODO ship
+-- TODO spin
+local function update(actor, dt)
+    local dv = actor.speed * dt
+    actor.x = (actor.x + math.cos(actor.angle) * dv) % game.width
+    actor.y = (actor.y + math.sin(actor.angle) * dv) % game.height
+end
+
+local function intersects(actor1, actor2)
+    return (actor1.x - actor2.x) ^ 2 + (actor1.y - actor2.y) ^ 2 <= (actor1.radius + actor2.radius) ^ 2
+end
+
 function love.update(dt)
     if state.controls.joystick ~= nil then
         local thrust = state.controls.joystick:getGamepadAxis('triggerright') * game.controls.ship.maxThrust
@@ -108,27 +123,32 @@ function love.update(dt)
         if bullet.timeLeft <= 0 then
             table.remove(state.bullets, bulletIndex)
         else
-            bullet.x = (bullet.x + math.cos(bullet.angle) * game.ship.bullet.speed * dt) % game.width
-            bullet.y = (bullet.y + math.sin(bullet.angle) * game.ship.bullet.speed * dt) % game.height
+            update(bullet, dt)
         end
         for asteroidIndex = #state.asteroids, 1, -1 do
             local asteroid = state.asteroids[asteroidIndex]
-            if areCirclesIntersecting(bullet.x, bullet.y, game.ship.bullet.radius, asteroid.x, asteroid.y, game.asteroids.stages[asteroid.stage].radius) then
+            if intersects(bullet, asteroid) then
                 table.remove(state.bullets, bulletIndex)
                 if asteroid.stage > 1 then
                     local angle1 = love.math.random() * (2 * math.pi)
                     local angle2 = (angle1 - math.pi) % (2 * math.pi)
+                    local radius = game.asteroids.stages[asteroid.stage - 1].radius
+                    local speed = game.asteroids.stages[asteroid.stage - 1].speed
                     table.insert(state.asteroids, {
                         x = asteroid.x,
                         y = asteroid.y,
                         angle = angle1,
                         stage = asteroid.stage - 1,
+                        radius = radius,
+                        speed = speed,
                     })
                     table.insert(state.asteroids, {
                         x = asteroid.x,
                         y = asteroid.y,
                         angle = angle2,
                         stage = asteroid.stage - 1,
+                        radius = radius,
+                        speed = speed,
                     })
                 end
                 table.remove(state.asteroids, asteroidIndex)
@@ -138,12 +158,9 @@ function love.update(dt)
     end
 
     for _, asteroid in ipairs(state.asteroids) do
-        asteroid.x = (asteroid.x + math.cos(asteroid.angle) * game.asteroids.stages[asteroid.stage].speed * dt) %
-            game.width
-        asteroid.y = (asteroid.y + math.sin(asteroid.angle) * game.asteroids.stages[asteroid.stage].speed * dt) %
-            game.height
+        update(asteroid, dt)
 
-        if areCirclesIntersecting(state.ship.x, state.ship.y, game.ship.radius, asteroid.x, asteroid.y, game.asteroids.stages[asteroid.stage].radius) then
+        if areCirclesIntersecting(state.ship.x, state.ship.y, game.ship.radius, asteroid.x, asteroid.y, asteroid.radius) then
             reset()
             break
         end
@@ -164,6 +181,8 @@ function love.gamepadpressed(joystick, button)
             x = state.ship.x + math.cos(state.ship.angle) * game.ship.radius,
             y = state.ship.y + math.sin(state.ship.angle) * game.ship.radius,
             angle = state.ship.angle,
+            speed = game.ship.bullet.speed,
+            radius = game.ship.bullet.radius,
             timeLeft = game.ship.bullet.time,
             sound = love.audio.newSource(game.ship.bullet.sound),
         }