public void UpdateCGB(MMU mmu, int value)
{
int register = mmu.ReadByte(PaletteIndexAddress);
bool increment = Bitwise.IsBitOn(register, 7);
int index = register & 0x3F;
int colorToModify = (index % 8) / 2;
if ((index % 8) % 2 == 0)
{
red[colorToModify] = value & 0x1F;
green[colorToModify] = (green[colorToModify] & 0x18) | (value >> 5);
}
else
{
green[colorToModify] = (green[colorToModify] & 0x07) | ((value & 0x03) << 3);
blue[colorToModify] = (value >> 2) & 0x1F;
}
Colors[colorToModify].R = (int)((red[colorToModify] / 31.0) * 255);
Colors[colorToModify].G = (int)((green[colorToModify] / 31.0) * 255);
Colors[colorToModify].B = (int)((blue[colorToModify] / 31.0) * 255);
if (increment)
{
index = (index + 1) % 64;
mmu.WriteByte(index | (0x80), PaletteIndexAddress);
}
}
protected override void Draw(GameTime gameTime)
{
byte stat = 0;
_mmu[Registers.LY] = 0;
for (int i = 0; i < 154; i++)
{
//Per ogni scanline
for (int j = 0; j < 114; j++)
{
stat = _mmu[Registers.STAT];
if (j < 20)
{
//Mode 2 10
stat.SetBit(1, true);
stat.SetBit(0, false);
}
if (j > 20)
{
//Mode 3 11
stat.SetBit(1, true);
stat.SetBit(0, true);
}
if (j > 63)
{
//Mode 0 00
stat.SetBit(1, false);
stat.SetBit(0, false);
}
if (i > 143)
{
//Mode 1 01
stat.SetBit(1, false);
stat.SetBit(0, true);
}
_mmu[Registers.STAT] = stat;
}
_mmu[Registers.LY]++;
}
if (_mmu[Registers.LY] == _mmu[Registers.LYC])
{
/*
* The Game Boy permanently compares the value of the LYC and LY registers.
* When both values are identical, the “LYC=LY” flag in the STAT register is set, and (if enabled) a STAT interrupt is requested.
*/
}
_dmgTilemap.Draw(gameTime);
_dmgBackground.Draw(gameTime);
_spriteBatch.Begin(samplerState: SamplerState.PointClamp);
GraphicsDevice.SetRenderTarget(null);
////////////////////
_spriteBatch.Draw(_dmgTilemap.TileMap, new Rectangle(2, 2, 128 * 2, 128 * 2), Color.White);
_spriteBatch.Draw(_dmgBackground.Background, new Rectangle(260, 2, 256 * 2, 256 * 2), Color.White);
_spriteBatch.Draw(_dmgBackgroundDisplayOverlay.BackgroundDisplayOverlay, new Rectangle(260, 2 + _mmu[Registers.SCY] * 2, DMG_SCREEN_WIDTH * 2, DMG_SCREEN_HEIGHT * 2), Color.White);
_spriteBatch.End();
//////////////////////////////////////////////
//Trigghera l'interrupt V-Blank
byte oldif = _mmu.ReadByte(0xFF0F);
oldif.SetBit(0, true);
//Trigghera l'interrupt STAT
byte oldstat = _mmu[Registers.STAT];
if (oldstat.CheckBit(6))
{
if (_mmu[Registers.LY] == _mmu[Registers.LYC])
{
oldif.SetBit(1, true);
}
}
_mmu.WriteByte(0xFF0F, oldif);
base.Draw(gameTime);
_spriteBatch.Begin();
GraphicsDevice.SetRenderTarget(null);
int b = 100;
//8 bit registers
_spriteBatch.DrawString(debugFont, $"A: (0x{_cpu.A:X2}) {_cpu.A}", new Vector2(2, b + 300), Color.White);
_spriteBatch.DrawString(debugFont, $"F: (0x{_cpu.F:X2}) {_cpu.F}", new Vector2(2, b + 320), Color.White);
_spriteBatch.DrawString(debugFont, $"B: (0x{_cpu.B:X2}) {_cpu.B}", new Vector2(2, b + 340), Color.White);
_spriteBatch.DrawString(debugFont, $"C: (0x{_cpu.C:X2}) {_cpu.C}", new Vector2(2, b + 360), Color.White);
_spriteBatch.DrawString(debugFont, $"D: (0x{_cpu.D:X2}) {_cpu.D}", new Vector2(2, b + 380), Color.White);
_spriteBatch.DrawString(debugFont, $"E: (0x{_cpu.E:X2}) {_cpu.E}", new Vector2(2, b + 400), Color.White);
_spriteBatch.DrawString(debugFont, $"H: (0x{_cpu.H:X2}) {_cpu.H}", new Vector2(2, b + 420), Color.White);
_spriteBatch.DrawString(debugFont, $"H: (0x{_cpu.H:X2}) {_cpu.H}", new Vector2(2, b + 440), Color.White);
//16 bit registers
_spriteBatch.DrawString(debugFont, $"BC: (0x{_cpu.BC:X4}) {_cpu.BC}", new Vector2(2, b + 480), Color.White);
_spriteBatch.DrawString(debugFont, $"DE: (0x{_cpu.DE:X4}) {_cpu.DE}", new Vector2(2, b + 500), Color.White);
_spriteBatch.DrawString(debugFont, $"HL: (0x{_cpu.HL:X4}) {_cpu.HL}", new Vector2(2, b + 520), Color.White);
//PC e SP
_spriteBatch.DrawString(debugFont, $"SP: (0x{_cpu.SP:X4}) {_cpu.SP:X4}", new Vector2(2, b + 560), Color.White);
_spriteBatch.DrawString(debugFont, $"PC: (0x{_cpu.PC:X4}) {_cpu.PC:X4}", new Vector2(2, b + 580), Color.White);
//Current instruction
_spriteBatch.DrawString(debugFont, $"{_cpu.PC:X4} (3F)(5E)(C2) PUSH HL", new Vector2(1420, 2), Color.White);
_spriteBatch.End();
}
