Add astroids

src/asteroid.cr

@@ -0,0 +1,12 @@
+class Asteroid < VectorSprite
+  def initialize
+    super
+    @frame = VectorSprite.generate_circle(12, size: 10.0, jitter: 3.0)
+  end
+
+  def draw(renderer)
+    frame = project_points(@frame)
+    renderer.draw_color = SDL::Color[128, 128, 128, 255]
+    draw_frame(renderer, frame)
+  end
+end

src/asteroids.cr

@@ -4,10 +4,12 @@ include CrystalEdge
 require "./lx_game/*"
 include LxGame
 require "./ship"
+require "./asteroid"
 require "./bullet"
 
 class Asteroids < Game
   @ship : Ship
+  @asteroids = [] of Asteroid
   @controller : Controller(LibSDL::Keycode)
 
   def initialize(*args)
@@ -17,6 +19,13 @@ class Asteroids < Game
       ship.position = Vector2.new(x: width / 2.0, y: height / 2.0)
     end
 
+    4.times do
+      @asteroids << Asteroid.build do |a|
+        a.position = Vector2.new(x: rand(0.0..width.to_f), y: rand(0.0..height.to_f))
+        a.velocity = Vector2.new(x: rand(-20.0..20.0), y: rand(-20.0..20.0))
+      end
+    end
+
     @controller = Controller(LibSDL::Keycode).new({
       LibSDL::Keycode::UP    => "Thrust",
       LibSDL::Keycode::RIGHT => "Rotate Right",
@@ -54,6 +63,10 @@ class Asteroids < Game
     end
 
     @bullets = @bullets.reject { |b| b.age >= 4.0 }
+    @asteroids.each do |a|
+      a.update(dt)
+      a.position = wrap(a.position)
+    end
   end
 
   def draw
@@ -61,6 +74,7 @@ class Asteroids < Game
     @renderer.clear
     @ship.draw(@renderer)
     @bullets.each { |b| b.draw(@renderer) }
+    @asteroids.each { |a| a.draw(@renderer) }
   end
 end
 

src/lx_game/game.cr

@@ -13,8 +13,6 @@ module LxGame
 
     def initialize(@width, @height, @scale = 1)
       SDL.init(SDL::Init::VIDEO)
-      at_exit { SDL.quit }
-
       @window = SDL::Window.new("SDL test", @width * @scale, @height * @scale)
       @renderer = SDL::Renderer.new(@window, flags: SDL::Renderer::Flags::SOFTWARE)
       @renderer.scale = {@scale, @scale}
@@ -63,6 +61,8 @@ module LxGame
         engine_update
         engine_draw
       end
+    ensure
+      SDL.quit
     end
   end
 end

src/lx_game/graphics.cr

@@ -1,6 +1,6 @@
 module LxGame
   # Draw a line using Bresenham’s Algorithm
-  def draw_line(renderer : SDL::Renderer, p1 : Vector2, p2 : Vector2, draw_points = false)
+  def draw_line(renderer : SDL::Renderer, p1 : Vector2, p2 : Vector2, draw_points = false, thickness = 1)
     return draw_line(renderer, p2, p1) if p1.x > p2.x
     x1, y1, x2, y2 = p1.x.to_i, p1.y.to_i, p2.x.to_i, p2.y.to_i
 

src/lx_game/vector_sprite.cr

@@ -1,5 +1,19 @@
 module LxGame
   abstract class VectorSprite < Sprite
+    getter frame = [] of Vector2
+
+    def self.generate_circle(num_points : Int, size = 1.0, jitter = 0.0) : Array(Vector2)
+      0.upto(num_points).map do |n|
+        angle = (2 * Math::PI) * (n / 12)
+
+        x = size + rand(-jitter..jitter)
+
+        rc = Math.cos(angle)
+        rs = Math.sin(angle)
+        Vector2.new(0.0 * rc - x * rs, x * rc + 0.0 * rs)
+      end.to_a
+    end
+
     def project_points(points : Array(Vector2), rotation = @rotation, translate : Vector2? = nil, scale : Vector2? = nil)
       rc = Math.cos(rotation)
       rs = Math.sin(rotation)
@@ -21,5 +35,15 @@ module LxGame
         translation + rotated
       end
     end
+
+    def update(dt : Float64)
+      update_position(dt)
+    end
+
+    def draw_frame(renderer : SDL::Renderer, frame = @frame)
+      0.upto(frame.size - 1) do |n|
+        draw_line(renderer, frame[n], frame[(n + 1) % frame.size])
+      end
+    end
   end
 end

src/ship.cr

@@ -1,5 +1,4 @@
 class Ship < VectorSprite
-  getter frame : Array(Vector2)
   @fire_cooldown : Float64 = 0.0
   @fire_rate : Float64 = 0.2
   @emitter : Emitter
@@ -74,8 +73,9 @@ class Ship < VectorSprite
   end
 
   def update(dt : Float64)
+    super
+
     @fire_cooldown -= dt unless can_fire?
-    update_position(dt)
 
     @emitter.update(dt)
     @emitter.position = project_points([Vector2.new(-3.0, 0.0)]).first
@@ -100,13 +100,9 @@ class Ship < VectorSprite
     @l_emitter.emitting = false
     @r_emitter.draw(renderer)
     @r_emitter.emitting = false
+
     frame = project_points(@frame)
-
-    renderer.draw_color = SDL::Color[128, 128, 128, 255]
     renderer.draw_color = SDL::Color[255, 255, 255, 255]
-
-    draw_line(renderer, frame[0], frame[1])
-    draw_line(renderer, frame[1], frame[2])
-    draw_line(renderer, frame[2], frame[0])
+    draw_frame(renderer, frame)
   end
 end