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PPU: Fixed sprite draw order/priority and implemented priority activation bit

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This commit is contained in:
Sour 2019-03-02 13:51:42 -05:00
parent b46ef705f8
commit 37c9996e7b
2 changed files with 60 additions and 44 deletions
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103
Core/Ppu.cpp
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@ -131,14 +131,15 @@ void Ppu::EvaluateNextLineSprites()
memset(_spritePixels, 0xFF, sizeof(_spritePixels));
memset(_spritePalette, 0, sizeof(_spritePalette));
_spriteCount = 0;
uint16_t totalWidth = 0;
uint16_t screenY = _objInterlace ? ((_frameCount & 0x01) ? ((_scanline << 1) + 1) : (_scanline << 1)) : _scanline;
uint16_t baseAddr = _enableOamPriority ? (_internalOamAddress & 0x1FC) : 0;
for(int i = 0; i < 512; i += 4) {
uint8_t y = _oamRam[i + 1];
uint16_t addr = (baseAddr + i) & 0x1FF;
uint8_t y = _oamRam[addr + 1];
uint8_t highTableOffset = i >> 4;
uint8_t shift = ((i >> 2) & 0x03) << 1;
uint8_t highTableOffset = addr >> 4;
uint8_t shift = ((addr >> 2) & 0x03) << 1;
uint8_t highTableValue = _oamRam[0x200 | highTableOffset] >> shift;
uint8_t largeSprite = (highTableValue & 0x02) >> 1;
uint8_t height = _oamSizes[_oamMode][largeSprite][1] << 3;
@ -152,73 +153,87 @@ void Ppu::EvaluateNextLineSprites()
info.LargeSprite = largeSprite;
uint8_t width = _oamSizes[_oamMode][info.LargeSprite][0] << 3;
uint16_t sign = (highTableValue & 0x01) << 8;
info.X = (int16_t)((sign | _oamRam[i]) << 7) >> 7;
if(info.X != -256 && info.X + width <= 0 || info.X > 255) {
info.X = (int16_t)((sign | _oamRam[addr]) << 7) >> 7;
info.Y = y;
if(info.X != -256 && (info.X + width <= 0 || info.X > 255)) {
//Sprite is not visible (and must be ignored for time/range flag calculations)
//Sprites at X=-256 are always used when considering Time/Range flag calculations, but not actually drawn.
continue;
}
info.TileRow = (_oamRam[i + 2] & 0xF0) >> 4;
info.TileColumn = _oamRam[i + 2] & 0x0F;
info.TileRow = (_oamRam[addr + 2] & 0xF0) >> 4;
info.TileColumn = _oamRam[addr + 2] & 0x0F;
uint8_t flags = _oamRam[i + 3];
uint8_t flags = _oamRam[addr + 3];
info.UseSecondTable = (flags & 0x01) != 0;
info.Palette = (flags >> 1) & 0x07;
info.Priority = (flags >> 4) & 0x03;
info.HorizontalMirror = (flags & 0x40) != 0;
info.VerticalMirror = (flags & 0x80) != 0;
if(_spriteCount < 32) {
_spriteCount++;
} else {
_rangeOver = true;
break;
}
}
uint16_t spriteTileCount = 0;
for(int i = (int16_t)_spriteCount - 1; i >= 0; i--) {
SpriteInfo &info = _sprites[i];
uint8_t height = _oamSizes[_oamMode][info.LargeSprite][1] << 3;
uint8_t width = _oamSizes[_oamMode][info.LargeSprite][0] << 3;
uint8_t yOffset;
int rowOffset;
if(info.VerticalMirror) {
yOffset = (height - 1 - (screenY - y)) & 0x07;
rowOffset = (height - 1 - (screenY - y)) >> 3;
yOffset = (height - 1 - (screenY - info.Y)) & 0x07;
rowOffset = (height - 1 - (screenY - info.Y)) >> 3;
} else {
yOffset = (screenY - y) & 0x07;
rowOffset = (screenY - y) >> 3;
yOffset = (screenY - info.Y) & 0x07;
rowOffset = (screenY - info.Y) >> 3;
}
uint8_t row = (info.TileRow + rowOffset) & 0x0F;
int prevColumnOffset = -1;
for(int x = std::max<int16_t>(info.X, 0); x < info.X + width && x < 256; x++) {
if(_spritePixels[x] == 0xFFFF) {
uint8_t xOffset;
int columnOffset;
if(info.HorizontalMirror) {
xOffset = (width - (x - info.X) - 1) & 0x07;
columnOffset = (width - (x - info.X) - 1) >> 3;
} else {
xOffset = (x - info.X) & 0x07;
columnOffset = (x - info.X) >> 3;
uint8_t xOffset;
int columnOffset;
if(info.HorizontalMirror) {
xOffset = (width - (x - info.X) - 1) & 0x07;
columnOffset = (width - (x - info.X) - 1) >> 3;
} else {
xOffset = (x - info.X) & 0x07;
columnOffset = (x - info.X) >> 3;
}
if(prevColumnOffset != columnOffset) {
spriteTileCount++;
if(spriteTileCount > 34) {
_timeOver = true;
return;
}
prevColumnOffset = columnOffset;
}
uint8_t column = (info.TileColumn + columnOffset) & 0x0F;
uint8_t tileIndex = (row << 4) | column;
uint16_t tileStart = ((_oamBaseAddress + (tileIndex << 4) + (info.UseSecondTable ? _oamAddressOffset : 0)) & 0x7FFF) << 1;
uint8_t column = (info.TileColumn + columnOffset) & 0x0F;
uint8_t tileIndex = (row << 4) | column;
uint16_t tileStart = ((_oamBaseAddress + (tileIndex << 4) + (info.UseSecondTable ? _oamAddressOffset : 0)) & 0x7FFF) << 1;
uint16_t color = GetTilePixelColor<4>(tileStart + yOffset * 2, 7 - xOffset);
uint16_t color = GetTilePixelColor<4>(tileStart + yOffset * 2, 7 - xOffset);
if(color != 0) {
uint16_t paletteRamOffset = 256 + (((info.Palette << 4) + color) << 1);
_spritePixels[x] = _cgram[paletteRamOffset] | (_cgram[paletteRamOffset + 1] << 8);
_spritePriority[x] = info.Priority;
_spritePalette[x] = info.Palette;
}
if(color != 0) {
uint16_t paletteRamOffset = 256 + (((info.Palette << 4) + color) << 1);
_spritePixels[x] = _cgram[paletteRamOffset] | (_cgram[paletteRamOffset + 1] << 8);
_spritePriority[x] = info.Priority;
_spritePalette[x] = info.Palette;
}
}
totalWidth += width;
if(totalWidth > 34 * 8) {
_timeOver = true;
}
_spriteCount++;
if(_spriteCount > 32) {
_rangeOver = true;
}
if(_timeOver || _rangeOver) {
if(_timeOver) {
break;
}
}

1
Core/Ppu.h
View file

@ -8,6 +8,7 @@ class InternalRegisters;
struct SpriteInfo
{
int16_t X;
uint8_t Y;
bool HorizontalMirror;
bool VerticalMirror;
uint8_t Priority;