bsnes/higan/sfc/coprocessor/icd2/interface.cpp

87 lines
1.9 KiB
C++

auto ICD2::lcdScanline() -> void {
if(GameBoy::ppu.status.ly > 143) return; //Vblank
if((GameBoy::ppu.status.ly & 7) == 0) {
writeBank = (writeBank + 1) & 3;
writeAddress = 0;
}
}
auto ICD2::lcdOutput(uint2 color) -> void {
uint y = writeAddress / 160;
uint x = writeAddress % 160;
uint addr = writeBank * 512 + y * 2 + x / 8 * 16;
output[addr + 0] = (output[addr + 0] << 1) | (bool)(color & 1);
output[addr + 1] = (output[addr + 1] << 1) | (bool)(color & 2);
writeAddress = (writeAddress + 1) % 1280;
}
auto ICD2::joypWrite(bool p15, bool p14) -> void {
//joypad handling
if(p15 == 1 && p14 == 1) {
if(joyp15Lock == 0 && joyp14Lock == 0) {
joyp15Lock = 1;
joyp14Lock = 1;
joypID = (joypID + 1) & 3;
}
}
if(p15 == 0 && p14 == 1) joyp15Lock = 0;
if(p15 == 1 && p14 == 0) joyp14Lock = 0;
//packet handling
if(p15 == 0 && p14 == 0) { //pulse
pulseLock = false;
packetOffset = 0;
bitOffset = 0;
strobeLock = true;
packetLock = false;
return;
}
if(pulseLock) return;
if(p15 == 1 && p14 == 1) {
strobeLock = false;
return;
}
if(strobeLock) {
if(p15 == 1 || p14 == 1) { //malformed packet
packetLock = false;
pulseLock = true;
bitOffset = 0;
packetOffset = 0;
} else {
return;
}
}
//p15:1, p14:0 = 0
//p15:0, p14:1 = 1
bool bit = (p15 == 0);
strobeLock = true;
if(packetLock) {
if(p15 == 1 && p14 == 0) {
if((joypPacket[0] >> 3) == 0x11) {
mltReq = joypPacket[1] & 3;
if(mltReq == 2) mltReq = 3;
joypID = 0;
}
if(packetSize < 64) packet[packetSize++] = joypPacket;
packetLock = false;
pulseLock = true;
}
return;
}
bitData = (bit << 7) | (bitData >> 1);
if(++bitOffset < 8) return;
bitOffset = 0;
joypPacket[packetOffset] = bitData;
if(++packetOffset < 16) return;
packetLock = true;
}