mirror of https://github.com/bsnes-emu/bsnes.git
33 lines
921 B
C++
33 lines
921 B
C++
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auto VDP::Background::scanline() -> void {
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}
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auto VDP::Background::run(uint x, uint y) -> void {
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output.priority = 0;
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output.color = 0;
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uint tileX = x >> 3;
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uint tileY = y >> 3;
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uint15 nametableAddress = io.nametableAddress;
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nametableAddress += (tileY << io.nametableWidth) + tileX;
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uint16 tileAttributes = vdp.vram[nametableAddress];
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uint15 tileAddress = tileAttributes.bits(0,10) << 4;
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uint pixelX = (x & 7) ^ (tileAttributes.bit(11) ? 7 : 0);
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uint pixelY = (y & 7) ^ (tileAttributes.bit(12) ? 7 : 0);
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tileAddress += pixelY << 1 | pixelX >> 2;
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uint16 tileData = vdp.vram[tileAddress];
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uint4 palette = tileData >> (((pixelX & 3) ^ 3) << 2);
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if(palette) {
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output.color = tileAttributes.bits(13,14) << 4 | palette;
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output.priority = tileAttributes.bit(15);
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}
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}
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auto VDP::Background::power() -> void {
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}
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auto VDP::Background::reset() -> void {
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memory::fill(&io, sizeof(IO));
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}
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