mirror of https://github.com/bsnes-emu/bsnes.git
104 lines
3.4 KiB
C++
104 lines
3.4 KiB
C++
auto PPU::Line::renderBackground(PPU::IO::Background& self, uint source) -> void {
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if(io.displayDisable) return;
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if(self.tileMode == TileMode::Inactive) return;
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if(self.tileMode == TileMode::Mode7) return; //todo
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if(!self.aboveEnable && !self.belowEnable) return;
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bool hires = io.bgMode == 5 || io.bgMode == 6;
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bool offsetPerTile = io.bgMode == 2 || io.bgMode == 4 || io.bgMode == 6;
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bool directColor = io.col.directColor && source == Source::BG1 && (io.bgMode == 3 || io.bgMode == 4);
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uint width = !hires ? 256 : 512;
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uint tileHeight = self.tileSize ? 4 : 3;
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uint tileWidth = hires ? 4 : tileHeight;
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uint tileMask = 0x0fff >> self.tileMode;
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uint tiledataIndex = self.tiledataAddress >> 4 + self.tileMode;
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uint maskX = width << (tileHeight == 4);
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uint maskY = maskX;
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if(self.screenSize.bit(0)) maskX <<= 1;
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if(self.screenSize.bit(1)) maskY <<= 1;
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maskX--;
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maskY--;
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uint screenX = self.screenSize.bit(0) ? 32 << 5 : 0;
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uint screenY = self.screenSize.bit(1) ? 32 << 5 : 0;
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if(self.screenSize == 3) screenY <<= 1;
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uint paletteBase = io.bgMode == 0 ? source << 5 : 0;
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uint paletteShift = 2 << self.tileMode;
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uint hscroll = self.hoffset;
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uint vscroll = self.voffset;
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uint y = this->y; //todo: vmosaic
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if(hires) {
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hscroll <<= 1;
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if(io.interlace) y = y << 1 | ppu.PPUcounter::field();
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}
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uint mosaicCounter = 1;
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uint mosaicPalette = 0;
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uint mosaicPriority = 0;
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uint mosaicColor = 0;
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auto getTile = [&](uint hoffset, uint voffset) -> uint {
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uint tileX = (hoffset & maskX) >> tileWidth;
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uint tileY = (voffset & maskY) >> tileHeight;
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uint tilePosition = (tileY & 0x1f) << 5 | (tileX & 0x1f);
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if(tileX & 0x20) tilePosition += screenX;
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if(tileY & 0x20) tilePosition += screenY;
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uint15 tiledataAddress = self.screenAddress + tilePosition;
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return ppu.vram[tiledataAddress];
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};
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int x = 0 - (hscroll & 7);
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while(x < width) {
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uint hoffset = x + hscroll;
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uint voffset = y + vscroll;
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if(offsetPerTile); //todo
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hoffset &= maskX;
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voffset &= maskY;
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uint tileNumber = getTile(hoffset, voffset);
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uint mirrorY = tileNumber & 0x8000 ? 7 : 0;
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uint mirrorX = tileNumber & 0x4000 ? 7 : 0;
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uint tilePriority = tileNumber & 0x2000 ? self.priority[1] : self.priority[0];
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uint paletteNumber = tileNumber >> 10 & 7;
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uint paletteIndex = (paletteBase + (paletteNumber << paletteShift)) & 0xff;
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if(tileWidth == 4 && (hoffset & 8) - 1 != mirrorX) tileNumber += 1;
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if(tileHeight == 4 && (voffset & 8) - 1 != mirrorY) tileNumber += 16;
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tileNumber = ((tileNumber & 0x03ff) + tiledataIndex) & tileMask;
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auto tiledata = ppu.tilecache[self.tileMode] + (tileNumber << 6);
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tiledata += ((voffset & 7) ^ mirrorY) << 3;
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for(uint tileX = 0; tileX < 8; tileX++, x++) {
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if(x & width) continue; //x < 0 || x >= width
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if(--mosaicCounter == 0) {
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mosaicCounter = 1 + io.mosaicSize;
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mosaicPalette = tiledata[tileX ^ mirrorX];
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mosaicPriority = tilePriority;
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if(directColor) {
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//todo
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} else {
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mosaicColor = cgram[paletteIndex + mosaicPalette];
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}
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}
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if(!mosaicPalette) continue;
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if(!hires) {
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if(self.aboveEnable) { //todo: window
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plotAbove(x, source, mosaicPriority, mosaicColor);
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}
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if(self.belowEnable) { //todo: window
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plotBelow(x, source, mosaicPriority, mosaicColor);
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}
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} else {
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//todo
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}
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}
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}
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}
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