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Fixed PPU glitches

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This commit is contained in:
Souryo 2014-06-18 23:59:10 -04:00
parent 0262e8c53c
commit b947be23bc
2 changed files with 19 additions and 17 deletions
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35
Core/PPU.cpp
View file

@ -230,10 +230,6 @@ void PPU::UpdateScrolling()
_state.VideoRamAddr = (_state.VideoRamAddr & ~0x041F) | (_state.TmpVideoRamAddr & 0x041F);
} else if((_cycle % 8 == 0 && _cycle > 0 && _cycle < 256) || _cycle == 328 || _cycle == 336) {
IncHorizontalScrolling();
} else if((_cycle - 1) % 8 == 0 && _cycle < 250) {
LoadTileInfo();
} else if(_cycle == 321 || _cycle == 329) {
LoadTileInfo();
}
}
@ -258,6 +254,7 @@ void PPU::ProcessPrerenderScanline()
_scanline = 0;
} else if(_cycle == 321 || _cycle == 329) {
LoadTileInfo();
LoadShiftRegisters();
}
}
@ -268,12 +265,14 @@ void PPU::LoadTileInfo()
uint16_t tileIndex = _memoryManager->ReadVRAM(GetTileAddr());
uint16_t tileAddr = (tileIndex << 4) | (_state.VideoRamAddr >> 12) | _flags.BackgroundPatternAddr;
//std::cout << std::hex << GetAttributeAddr() << " ";
uint16_t shift = _state.VideoRamAddr&0x3FF;
_nextTile.Attributes = ((_memoryManager->ReadVRAM(GetAttributeAddr()) >> shift) & 0x03) << 2;
_nextTile.LowByte = _memoryManager->ReadVRAM(tileAddr);
_nextTile.HighByte = _memoryManager->ReadVRAM(tileAddr + 8);
}
void PPU::LoadShiftRegisters()
{
_state.LowBitShift = (_state.LowBitShift << 8) | _nextTile.LowByte;
_state.HighBitShift = (_state.HighBitShift << 8) | _nextTile.HighByte;
}
@ -282,7 +281,7 @@ void PPU::DrawPixel()
{
uint8_t palette = 0;
uint8_t tileXPixel = _cycle % 8;
uint8_t tileXPixel = (_cycle - 1) % 8;
uint32_t bufferPosition = _scanline * 256 + _cycle;
uint8_t fineXScroll = _state.XScroll;
@ -291,14 +290,7 @@ void PPU::DrawPixel()
uint8_t pixelColor = ((_state.LowBitShift >> offset) & 0x01) | (((_state.HighBitShift >> offset) & 0x01) << 1);
// If we're grabbing the pixel from the high
// part of the shift register, use the buffered
// palette, not the current one
if(pixelColor != 0 && _frameCount > 1000) {
//std::cout << std::hex << (short)pixelColor << std::endl;
}
// If we're grabbing the pixel from the high part of the shift register, use the buffered palette, not the current one
if(offset < 8) {
palette = GetBGPaletteEntry(_nextTile.Attributes, pixelColor);
} else {
@ -319,14 +311,23 @@ void PPU::DrawPixel()
void PPU::ProcessVisibleScanline()
{
if(IsRenderingEnabled()) {
UpdateScrolling();
if((_cycle - 1) % 8 == 0 && _cycle <= 250) {
LoadShiftRegisters();
LoadTileInfo();
} else if(_cycle == 321 || _cycle == 329) {
LoadShiftRegisters();
LoadTileInfo();
}
if(_cycle <= 254) {
if(_cycle > 0 && _cycle <= 255) {
DrawPixel();
}
if(IsRenderingEnabled()) {
UpdateScrolling();
}
if(_cycle == 254) {
//DrawScanline();
if(_scanline == 239) {

1
Core/PPU.h
View file

@ -112,6 +112,7 @@ class PPU : public IMemoryHandler
void DrawScanline();
void LoadTileInfo();
void LoadShiftRegisters();
void DrawPixel();
void CopyFrame();