bsnes/higan/pce/vdc/background.cpp

30 lines
814 B
C++

auto VDC::Background::scanline(uint y) -> void {
}
auto VDC::Background::run(uint x, uint y) -> void {
color = nothing;
//if(blank) return;
uint10 hoffset = x + hscroll;
uint9 voffset = y + vscroll;
uint16 batAddress = (voffset >> 3) * width + (hoffset >> 3);
uint16 tiledata = vdc.vramRead(batAddress);
uint16 patternAddress = tiledata.bits(0,11) << 4;
patternAddress += (voffset & 7);
uint4 palette = tiledata.bits(12,15);
uint16 d0 = vdc.vramRead(patternAddress + 0);
uint16 d1 = vdc.vramRead(patternAddress + 8);
uint3 index = 7 - (hoffset & 7);
uint4 output;
output.bit(0) = d0.bit(0 + index);
output.bit(1) = d0.bit(8 + index);
output.bit(2) = d1.bit(0 + index);
output.bit(3) = d1.bit(8 + index);
if(output == 0) return;
color = vdc.cram[palette << 4 | output];
}