very basic ppu, passing tonc first.gba

shard.yml

@@ -14,5 +14,7 @@ dependencies:
   bitfield:
     github: mattrberry/bitfield
     version: 0.1.0
+  sdl:
+    git: git@github.com:ysbaddaden/sdl.cr.git
 
 license: MIT

src/crab.cr

@@ -1,4 +1,5 @@
 require "bitfield"
+require "sdl"
 
 require "./crab/gba"
 

src/crab/display.cr

@@ -0,0 +1,23 @@
+class Display
+  WIDTH  = 240
+  HEIGHT = 160
+  SCALE  =   4
+
+  PIXELFORMAT_RGB24       = (1 << 28) | (7 << 24) | (1 << 20) | (0 << 16) | (24 << 8) | (3 << 0)
+  PIXELFORMAT_BGR555      = (1 << 28) | (5 << 24) | (5 << 20) | (3 << 16) | (15 << 8) | (2 << 0)
+  TEXTUREACCESS_STREAMING = 1
+
+  def initialize
+    @window = SDL::Window.new("crab", WIDTH * SCALE, HEIGHT * SCALE)
+    @renderer = SDL::Renderer.new @window
+    @renderer.logical_size = {WIDTH, HEIGHT}
+    @texture = LibSDL.create_texture @renderer, PIXELFORMAT_BGR555, TEXTUREACCESS_STREAMING, WIDTH, HEIGHT
+  end
+
+  def draw(framebuffer : Bytes) : Nil
+    LibSDL.update_texture @texture, nil, framebuffer, WIDTH * 2
+    @renderer.clear
+    @renderer.copy @texture
+    @renderer.present
+  end
+end

src/crab/gba.cr

@@ -3,22 +3,44 @@ require "./util"
 require "./cartridge"
 require "./bus"
 require "./cpu"
+require "./display"
 require "./ppu"
 
 class GBA
   getter cartridge : Cartridge
   getter bus : Bus { Bus.new self }
   getter cpu : CPU { CPU.new self }
+  getter display : Display { Display.new }
   getter ppu : PPU { PPU.new self }
 
   def initialize(rom_path : String)
     @cartridge = Cartridge.new rom_path
+
+    SDL.init(SDL::Init::VIDEO | SDL::Init::AUDIO | SDL::Init::JOYSTICK)
+    LibSDL.joystick_open 0
+    at_exit { SDL.quit }
+  end
+
+  def handle_events : Nil
+    while event = SDL::Event.poll
+      case event
+      when SDL::Event::Quit then exit 0
+      when SDL::Event::Keyboard,
+           SDL::Event::JoyHat,
+           SDL::Event::JoyButton
+      else nil
+      end
+    end
   end
 
   def run : Nil
     # puts @cartridge.title
     loop do
-      cpu.tick
+      280896.times do
+        cpu.tick
+      end
+      ppu.tick 280896
+      handle_events
     end
   end
 end

src/crab/ppu.cr

@@ -28,6 +28,10 @@ class PPU
   def initialize(@gba : GBA)
   end
 
+  def tick(cycles : Int) : Nil
+    @gba.display.draw @vram
+  end
+
   def [](index : Int) : Byte
     case index
     when 0x04000000 then (@dispcnt.value >> 8).to_u8