nes_crsfml.cr

require "crsfml"
require "./src/nes"

def color(x)
  r = (x >> 16) & 0xFF
  g = (x >> 8) & 0xFF
  b = x & 0xFF
  SF.color(r, g, b, 0xFF)
end

def handle_events(window, nes)
  while event = window.poll_event()
    case event.type
    when SF::Event::Closed
      window.close()
    when SF::Event::KeyPressed
      case event.key.code
      when SF::Keyboard::Z
        nes.control_pad.press(ControlPad::Button::A)
      when SF::Keyboard::X
        nes.control_pad.press(ControlPad::Button::B)
      when SF::Keyboard::Up
        nes.control_pad.press(ControlPad::Button::Up)
      when SF::Keyboard::Down
        nes.control_pad.press(ControlPad::Button::Down)
      when SF::Keyboard::Left
        nes.control_pad.press(ControlPad::Button::Left)
      when SF::Keyboard::Right
        nes.control_pad.press(ControlPad::Button::Right)
      when SF::Keyboard::O
        nes.control_pad.press(ControlPad::Button::Start)
      when SF::Keyboard::P
        nes.control_pad.press(ControlPad::Button::Select)
      end
    when SF::Event::KeyReleased
      case event.key.code
      when SF::Keyboard::Z
        nes.control_pad.release(ControlPad::Button::A)
      when SF::Keyboard::X
        nes.control_pad.release(ControlPad::Button::B)
      when SF::Keyboard::Up
        nes.control_pad.release(ControlPad::Button::Up)
      when SF::Keyboard::Down
        nes.control_pad.release(ControlPad::Button::Down)
      when SF::Keyboard::Left
        nes.control_pad.release(ControlPad::Button::Left)
      when SF::Keyboard::Right
        nes.control_pad.release(ControlPad::Button::Right)
      when SF::Keyboard::O
        nes.control_pad.release(ControlPad::Button::Start)
      when SF::Keyboard::P
        nes.control_pad.release(ControlPad::Button::Select)
      end
    end
  end
end

filename = ARGV.first? || abort("error: missing rom filename")
nes = Nes.new filename

p "PRG banks: #{nes.rom.prg_banks}"
p "CHR banks: #{nes.rom.chr_banks}"
p "MAPPER: #{nes.rom.mapper_number}"

window = SF::RenderWindow.new(
  SF.video_mode(256, 240), "NES",
  settings: SF.context_settings(depth: 32, antialiasing: 8)
)
window.vertical_sync_enabled = true
window.framerate_limit = 60

image = SF::Image.new 256, 240
texture = SF::Texture.new 256, 240

count = 0

while window.open?
  count += 1

  nes.step

  if count % 100_000 == 0
    count = 0

    handle_events window, nes

    256.times do |x|
      240.times do |y|
        image.set_pixel(x, y, color(nes.ppu.shown[x][y]))
      end
    end

    texture.update image, 0, 0
    sprite = SF::Sprite.new(texture)
    window.draw sprite
    window.display
  end
end