bsnes/higan/gba/ppu/object.cpp

96 lines
2.9 KiB
C++

auto PPU::Objects::scanline(uint y) -> void {
mosaicOffset = 0;
for(auto& pixel : buffer) pixel = {};
if(ppu.blank() || !io.enable) return;
for(auto& object : ppu.object) {
uint8 py = y - object.y;
if(object.affine == 0 && object.affineSize == 1) continue; //hidden
if(py >= object.height << object.affineSize) continue; //offscreen
uint rowSize = io.mapping == 0 ? 32 >> object.colors : object.width >> 3;
uint baseAddress = object.character << 5;
if(object.mosaic && io.mosaicHeight) {
int mosaicY = (y / (1 + io.mosaicHeight)) * (1 + io.mosaicHeight);
py = object.y >= 160 || mosaicY - object.y >= 0 ? mosaicY - object.y : 0;
}
int16 pa = ppu.objectParam[object.affineParam].pa;
int16 pb = ppu.objectParam[object.affineParam].pb;
int16 pc = ppu.objectParam[object.affineParam].pc;
int16 pd = ppu.objectParam[object.affineParam].pd;
//center-of-sprite coordinates
int16 centerX = object.width >> 1;
int16 centerY = object.height >> 1;
//origin coordinates (top-left of sprite)
int28 originX = -(centerX << object.affineSize);
int28 originY = -(centerY << object.affineSize) + py;
//fractional pixel coordinates
int28 fx = originX * pa + originY * pb;
int28 fy = originX * pc + originY * pd;
for(uint px : range(object.width << object.affineSize)) {
uint sx, sy;
if(!object.affine) {
sx = px ^ (object.hflip ? object.width - 1 : 0);
sy = py ^ (object.vflip ? object.height - 1 : 0);
} else {
sx = (fx >> 8) + centerX;
sy = (fy >> 8) + centerY;
}
uint9 bx = object.x + px;
if(bx < 240 && sx < object.width && sy < object.height) {
uint offset = (sy >> 3) * rowSize + (sx >> 3);
offset = offset * 64 + (sy & 7) * 8 + (sx & 7);
uint8 color = ppu.readObjectVRAM(baseAddress + (offset >> !object.colors));
if(object.colors == 0) color = sx & 1 ? color >> 4 : color & 15;
if(color) {
if(object.mode & 2) {
buffer[bx].window = true;
} else if(!buffer[bx].enable || object.priority < buffer[bx].priority) {
if(object.colors == 0) color = object.palette * 16 + color;
buffer[bx].enable = true;
buffer[bx].priority = object.priority;
buffer[bx].color = ppu.pram[256 + color];
buffer[bx].translucent = object.mode == 1;
buffer[bx].mosaic = object.mosaic;
}
}
}
fx += pa;
fy += pc;
}
}
}
auto PPU::Objects::run(uint x, uint y) -> void {
output = {};
if(ppu.blank() || !io.enable) {
mosaic = {};
return;
}
output = buffer[x];
//horizontal mosaic
if(!output.mosaic || ++mosaicOffset >= 1 + io.mosaicWidth) {
mosaicOffset = 0;
mosaic = output;
}
}
auto PPU::Objects::power() -> void {
memory::fill(&io, sizeof(IO));
for(auto& pixel : buffer) pixel = {};
output = {};
mosaic = {};
mosaicOffset = 0;
}