GBC: Fixed issues with read/writing palette register

Fixes "CRAM readable" and "CRAM access blocking" tests
SourMesen · May 13, 2023 · ff032b3 · ff032b3
1 parent d9ae147
commit ff032b3
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Showing 4 changed files with 17 additions and 8 deletions.
diff --git a/Core/Gameboy/Debugger/GbPpuTools.cpp b/Core/Gameboy/Debugger/GbPpuTools.cpp
@@ -266,11 +266,11 @@ DebugPaletteInfo GbPpuTools::GetPaletteInfo(GetPaletteInfoOptions options)
 
 		for(int i = 0; i < 8 * 4; i++) {
 			info.RawPalette[i] = state.CgbBgPalettes[i];
-			info.RgbPalette[i] = SnesDefaultVideoFilter::ToArgb(state.CgbBgPalettes[i]);
+			info.RgbPalette[i] = SnesDefaultVideoFilter::ToArgb(state.CgbBgPalettes[i] & 0x7FFF);
 		}
 		for(int i = 0; i < 8 * 4; i++) {
 			info.RawPalette[i+32] = state.CgbObjPalettes[i];
-			info.RgbPalette[i+32] = SnesDefaultVideoFilter::ToArgb(state.CgbObjPalettes[i]);
+			info.RgbPalette[i+32] = SnesDefaultVideoFilter::ToArgb(state.CgbObjPalettes[i] & 0x7FFF);
 		}
 	} else {
 		info.RawFormat = RawPaletteFormat::Indexed;

diff --git a/Core/Gameboy/GbPpu.cpp b/Core/Gameboy/GbPpu.cpp
@@ -411,7 +411,7 @@ void GbPpu::RunDrawCycle()
 void GbPpu::WriteBgPixel(uint8_t colorIndex)
 {
 	uint16_t outOffset = _state.Scanline * GbConstants::ScreenWidth + _drawnPixels;
-	_currentBuffer[outOffset] = _state.CgbBgPalettes[colorIndex];
+	_currentBuffer[outOffset] = _state.CgbBgPalettes[colorIndex] & 0x7FFF;
 	if(_gameboy->IsSgb()) {
 		_gameboy->GetSgb()->WriteLcdColor(_state.Scanline, (uint8_t)_drawnPixels, colorIndex & 0x03);
 	}
@@ -420,7 +420,7 @@ void GbPpu::WriteBgPixel(uint8_t colorIndex)
 void GbPpu::WriteObjPixel(uint8_t colorIndex)
 {
 	uint16_t outOffset = _state.Scanline * GbConstants::ScreenWidth + _drawnPixels;
-	_currentBuffer[outOffset] = _state.CgbObjPalettes[colorIndex];
+	_currentBuffer[outOffset] = _state.CgbObjPalettes[colorIndex] & 0x7FFF;
 	if(_gameboy->IsSgb()) {
 		_gameboy->GetSgb()->WriteLcdColor(_state.Scanline, (uint8_t)_drawnPixels, colorIndex & 0x03);
 	}
@@ -1026,9 +1026,9 @@ uint8_t GbPpu::ReadCgbRegister(uint16_t addr)
 	switch(addr) {
 		case 0xFF4F: return _state.CgbVramBank | 0xFE;
 		case 0xFF68: return _state.CgbBgPalPosition | (_state.CgbBgPalAutoInc ? 0x80 : 0) | 0x40;
-		case 0xFF69: return (_state.CgbBgPalettes[_state.CgbBgPalPosition >> 1] >> ((_state.CgbBgPalPosition & 0x01) ? 8 : 0) & 0xFF);
+		case 0xFF69: return ReadCgbPalette(_state.CgbBgPalPosition, _state.CgbBgPalettes);
 		case 0xFF6A: return _state.CgbObjPalPosition | (_state.CgbObjPalAutoInc ? 0x80 : 0) | 0x40;
-		case 0xFF6B: return (_state.CgbObjPalettes[_state.CgbObjPalPosition >> 1] >> ((_state.CgbObjPalPosition & 0x01) ? 8 : 0) & 0xFF);
+		case 0xFF6B: return ReadCgbPalette(_state.CgbObjPalPosition, _state.CgbObjPalettes);
 	}
 	LogDebug("[Debug] GBC - Missing read handler: $" + HexUtilities::ToHex(addr));
 	return 0xFF;
@@ -1073,11 +1073,19 @@ void GbPpu::WriteCgbRegister(uint16_t addr, uint8_t value)
 	}
 }
 
+uint8_t GbPpu::ReadCgbPalette(uint8_t& pos, uint16_t* pal)
+{
+	if(_state.Mode <= PpuMode::OamEvaluation) {
+		return (pal[pos >> 1] >> ((pos & 0x01) ? 8 : 0)) & 0xFF;
+	}
+	return 0xFF;
+}
+
 void GbPpu::WriteCgbPalette(uint8_t& pos, uint16_t* pal, bool autoInc, uint8_t value)
 {
 	if(_state.Mode <= PpuMode::OamEvaluation) {
 		if(pos & 0x01) {
-			pal[pos >> 1] = (pal[pos >> 1] & 0xFF) | ((value & 0x7F) << 8);
+			pal[pos >> 1] = (pal[pos >> 1] & 0xFF) | (value << 8);
 		} else {
 			pal[pos >> 1] = (pal[pos >> 1] & 0xFF00) | value;
 		}

diff --git a/Core/Gameboy/GbPpu.h b/Core/Gameboy/GbPpu.h
@@ -75,6 +75,7 @@ class GbPpu : public ISerializable
 	void SendFrame();
 	void UpdatePalette();
 
+	uint8_t ReadCgbPalette(uint8_t& pos, uint16_t* pal);
 	void WriteCgbPalette(uint8_t& pos, uint16_t* pal, bool autoInc, uint8_t value);
 
 public:

diff --git a/UI/Debugger/Utilities/PaletteHelper.cs b/UI/Debugger/Utilities/PaletteHelper.cs
@@ -26,7 +26,7 @@ public static DynamicTooltip GetPreviewPanel(UInt32[] rgbPalette, UInt32[] rawPa
 				entries.AddEntry("Value", "$" + rawPalette[index].ToString("X4"));
 				entries.AddEntry("R", "$" + (rawPalette[index] & 0x1F).ToString("X2"));
 				entries.AddEntry("G", "$" + ((rawPalette[index] >> 5) & 0x1F).ToString("X2"));
-				entries.AddEntry("B", "$" + (rawPalette[index] >> 10).ToString("X2"));
+				entries.AddEntry("B", "$" + ((rawPalette[index] >> 10) & 0x1F).ToString("X2"));
 			} else if(format == RawPaletteFormat.Rgb333) {
 				entries.AddEntry("Value", "$" + rawPalette[index].ToString("X3"));
 				entries.AddEntry("R", "$" + ((rawPalette[index] >> 3) & 0x07).ToString("X2"));