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PPU: Fixed regression where sprites at X=-256 were shown in some scenarios

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This commit is contained in:
Sour 2019-08-06 22:22:04 -04:00
parent 973a59a027
commit a387d5db4c
1 changed files with 6 additions and 11 deletions
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17
Core/Ppu.cpp
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@ -684,10 +684,6 @@ void Ppu::FetchSpriteAttributes(uint16_t oamAddress)
_currentSprite.ColumnOffset--;
int16_t x = _currentSprite.X == -256 ? 0 : _currentSprite.X;
uint8_t columnCount = (_currentSprite.Width / 8);
_currentSprite.DrawX = x + ((columnCount - _currentSprite.ColumnOffset - 1) << 3);
uint8_t yOffset;
int rowOffset;
int yGap = (_scanline - _currentSprite.Y);
@ -705,6 +701,7 @@ void Ppu::FetchSpriteAttributes(uint16_t oamAddress)
rowOffset = yGap >> 3;
}
uint8_t columnCount = (_currentSprite.Width / 8);
uint8_t tileRow = (_oamRam[oamAddress] & 0xF0) >> 4;
uint8_t tileColumn = _oamRam[oamAddress] & 0x0F;
uint8_t row = (tileRow + rowOffset) & 0x0F;
@ -713,7 +710,11 @@ void Ppu::FetchSpriteAttributes(uint16_t oamAddress)
uint16_t tileStart = (_oamBaseAddress + (tileIndex << 4) + (useSecondTable ? _oamAddressOffset : 0)) & 0x7FFF;
_currentSprite.FetchAddress = tileStart + yOffset;
if(_currentSprite.ColumnOffset == 0 || _currentSprite.DrawX + 8 >= 256) {
int16_t x = _currentSprite.X == -256 ? 0 : _currentSprite.X;
int16_t endTileX = x + ((columnCount - _currentSprite.ColumnOffset - 1) << 3) + 8;
_currentSprite.DrawX = _currentSprite.X + ((columnCount - _currentSprite.ColumnOffset - 1) << 3);
if(_currentSprite.ColumnOffset == 0 || endTileX >= 256) {
//Last tile of the sprite, or skip the remaining tiles (because the tiles are hidden to the right of the screen)
_spriteCount--;
_currentSprite.ColumnOffset = 0;
@ -729,10 +730,6 @@ void Ppu::FetchSpriteTile(bool secondCycle)
if(!secondCycle) {
_currentSprite.FetchAddress += 8;
} else {
if(_currentSprite.X == -256) {
return;
}
int16_t xPos = _currentSprite.DrawX;
for(int x = 0; x < 8; x++) {
if(xPos + x < 0 || xPos + x > 255) {
@ -749,8 +746,6 @@ void Ppu::FetchSpriteTile(bool secondCycle)
}
}
}
//Dummy fetches to VRAM when no sprite to load?
//This might be observable by reading from VMDATAxREAD?
}
void Ppu::RenderMode0()