bsnes/higan/sfc/coprocessor/superfx/core.cpp

105 lines
3.2 KiB
C++

auto SuperFX::stop() -> void {
cpu.r.irq = 1;
}
auto SuperFX::color(uint8 source) -> uint8 {
if(regs.por.highnibble) return (regs.colr & 0xf0) | (source >> 4);
if(regs.por.freezehigh) return (regs.colr & 0xf0) | (source & 0x0f);
return source;
}
auto SuperFX::plot(uint8 x, uint8 y) -> void {
uint8 color = regs.colr;
if(regs.por.dither && regs.scmr.md != 3) {
if((x ^ y) & 1) color >>= 4;
color &= 0x0f;
}
if(!regs.por.transparent) {
if(regs.scmr.md == 3) {
if(regs.por.freezehigh) {
if((color & 0x0f) == 0) return;
} else {
if(color == 0) return;
}
} else {
if((color & 0x0f) == 0) return;
}
}
uint16 offset = (y << 5) + (x >> 3);
if(offset != pixelcache[0].offset) {
flushPixelCache(pixelcache[1]);
pixelcache[1] = pixelcache[0];
pixelcache[0].bitpend = 0x00;
pixelcache[0].offset = offset;
}
x = (x & 7) ^ 7;
pixelcache[0].data[x] = color;
pixelcache[0].bitpend |= 1 << x;
if(pixelcache[0].bitpend == 0xff) {
flushPixelCache(pixelcache[1]);
pixelcache[1] = pixelcache[0];
pixelcache[0].bitpend = 0x00;
}
}
auto SuperFX::rpix(uint8 x, uint8 y) -> uint8 {
flushPixelCache(pixelcache[1]);
flushPixelCache(pixelcache[0]);
uint cn; //character number
switch(regs.por.obj ? 3 : regs.scmr.ht) {
case 0: cn = ((x & 0xf8) << 1) + ((y & 0xf8) >> 3); break;
case 1: cn = ((x & 0xf8) << 1) + ((x & 0xf8) >> 1) + ((y & 0xf8) >> 3); break;
case 2: cn = ((x & 0xf8) << 1) + ((x & 0xf8) << 0) + ((y & 0xf8) >> 3); break;
case 3: cn = ((y & 0x80) << 2) + ((x & 0x80) << 1) + ((y & 0x78) << 1) + ((x & 0x78) >> 3); break;
}
uint bpp = 2 << (regs.scmr.md - (regs.scmr.md >> 1)); // = [regs.scmr.md]{ 2, 4, 4, 8 };
uint addr = 0x700000 + (cn * (bpp << 3)) + (regs.scbr << 10) + ((y & 0x07) * 2);
uint8 data = 0x00;
x = (x & 7) ^ 7;
for(uint n : range(bpp)) {
uint byte = ((n >> 1) << 4) + (n & 1); // = [n]{ 0, 1, 16, 17, 32, 33, 48, 49 };
step(regs.clsr ? 5 : 6);
data |= ((read(addr + byte) >> x) & 1) << n;
}
return data;
}
auto SuperFX::flushPixelCache(PixelCache& cache) -> void {
if(cache.bitpend == 0x00) return;
uint8 x = cache.offset << 3;
uint8 y = cache.offset >> 5;
uint cn; //character number
switch(regs.por.obj ? 3 : regs.scmr.ht) {
case 0: cn = ((x & 0xf8) << 1) + ((y & 0xf8) >> 3); break;
case 1: cn = ((x & 0xf8) << 1) + ((x & 0xf8) >> 1) + ((y & 0xf8) >> 3); break;
case 2: cn = ((x & 0xf8) << 1) + ((x & 0xf8) << 0) + ((y & 0xf8) >> 3); break;
case 3: cn = ((y & 0x80) << 2) + ((x & 0x80) << 1) + ((y & 0x78) << 1) + ((x & 0x78) >> 3); break;
}
uint bpp = 2 << (regs.scmr.md - (regs.scmr.md >> 1)); // = [regs.scmr.md]{ 2, 4, 4, 8 };
uint addr = 0x700000 + (cn * (bpp << 3)) + (regs.scbr << 10) + ((y & 0x07) * 2);
for(uint n : range(bpp)) {
uint byte = ((n >> 1) << 4) + (n & 1); // = [n]{ 0, 1, 16, 17, 32, 33, 48, 49 };
uint8 data = 0x00;
for(uint x : range(8)) data |= ((cache.data[x] >> n) & 1) << x;
if(cache.bitpend != 0xff) {
step(regs.clsr ? 5 : 6);
data &= cache.bitpend;
data |= read(addr + byte) & ~cache.bitpend;
}
step(regs.clsr ? 5 : 6);
write(addr + byte, data);
}
cache.bitpend = 0x00;
}