Add wrap around rendering

src/asteroid.cr

@@ -1,11 +1,13 @@
 class Asteroid < VectorSprite
+  property size : Float64 = 1.0
+
   def initialize
     super
-    @frame = VectorSprite.generate_circle(12, size: 10.0, jitter: 3.0)
+    @frame = VectorSprite.generate_circle(15, size: 10.0, jitter: 3.0)
   end
 
   def draw(renderer)
-    frame = project_points(@frame)
+    frame = project_points(points: @frame, scale: Vector2.new(@size, @size))
     renderer.draw_color = SDL::Color[128, 128, 128, 255]
     draw_frame(renderer, frame)
   end

src/asteroids.cr

@@ -7,6 +7,22 @@ require "./ship"
 require "./asteroid"
 require "./bullet"
 
+WIDTH  = 600
+HEIGHT = 400
+SCALE  =   3
+
+module LxGame
+  def draw_point(renderer, x, y)
+    x = x % WIDTH
+    y = y % HEIGHT
+
+    x = WIDTH + x if x < 0
+    y = HEIGHT + y if y < 0
+
+    renderer.draw_point(x, y)
+  end
+end
+
 class Asteroids < Game
   @ship : Ship
   @asteroids = [] of Asteroid
@@ -23,6 +39,8 @@ class Asteroids < Game
       @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))
+        a.rotation_speed = rand(-5.0..5.0)
+        a.size = rand(0.5..4.0)
       end
     end
 
@@ -78,5 +96,5 @@ class Asteroids < Game
   end
 end
 
-game = Asteroids.new(200, 120, 4)
+game = Asteroids.new(WIDTH, HEIGHT, SCALE)
 game.run!

src/lx_game/game.cr

@@ -5,15 +5,16 @@ module LxGame
     property width : Int32
     property height : Int32
     property scale : Int32
+    property title : String
 
     @fps_lasttime : Float64 = Time.monotonic.total_milliseconds # the last recorded time.
     @fps_current : UInt32 = 0                                   # the current FPS.
     @fps_frames : UInt32 = 0                                    # frames passed since the last recorded fps.
     @last_time : Float64 = Time.monotonic.total_milliseconds
 
-    def initialize(@width, @height, @scale = 1)
+    def initialize(@width, @height, @scale = 1, @title = self.class.name)
       SDL.init(SDL::Init::VIDEO)
-      @window = SDL::Window.new("SDL test", @width * @scale, @height * @scale)
+      @window = SDL::Window.new(@title, @width * @scale, @height * @scale)
       @renderer = SDL::Renderer.new(@window, flags: SDL::Renderer::Flags::SOFTWARE)
       @renderer.scale = {@scale, @scale}
     end
@@ -33,7 +34,7 @@ module LxGame
         @fps_lasttime = et
         @fps_current = @fps_frames
         @fps_frames = 0
-        @window.title = String.build { |io| io << "SDL test - " << @fps_current << " fps" }
+        @window.title = String.build { |io| io << @title << " - " << @fps_current << " fps" }
       end
 
       update((et - @last_time) / 1000.0)

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, thickness = 1)
+  def draw_line(renderer : SDL::Renderer, p1 : Vector2, p2 : Vector2, draw_points = false, point_color = SDL::Color[255, 0, 0, 255])
     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
 
@@ -14,7 +14,7 @@ module LxGame
     x, y = x1, y1
 
     loop do
-      renderer.draw_point(x, y)
+      draw_point(renderer, x, y)
       break if x == x2 && y == y2
 
       d2 = d + d
@@ -31,9 +31,13 @@ module LxGame
     end
 
     if draw_points
-      renderer.draw_color = SDL::Color[255, 0, 0, 255]
-      renderer.draw_point(x1, y1)
-      renderer.draw_point(x2, y2)
+      renderer.draw_color = point_color
+      draw_point(renderer, x1, y1)
+      draw_point(renderer, x2, y2)
     end
   end
+
+  def draw_point(renderer, x1, y1)
+    renderer.draw_point(x1, y1)
+  end
 end

src/lx_game/vector_sprite.cr

@@ -4,7 +4,7 @@ module LxGame
 
     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)
+        angle = (2 * Math::PI) * (n / num_points)
 
         x = size + rand(-jitter..jitter)