int32_t GBVideoProcessEvents(struct GBVideo* video, int32_t cycles) {
video->eventDiff += cycles;
if (video->nextEvent != INT_MAX) {
video->nextEvent -= cycles;
}
if (video->nextEvent <= 0) {
if (video->nextMode != INT_MAX) {
video->nextMode -= video->eventDiff;
}
if (video->nextFrame != INT_MAX) {
video->nextFrame -= video->eventDiff;
}
video->nextEvent = INT_MAX;
GBVideoProcessDots(video);
if (video->nextMode <= 0) {
int lyc = video->p->memory.io[REG_LYC];
switch (video->mode) {
case 0:
if (video->frameskipCounter <= 0) {
video->renderer->finishScanline(video->renderer, video->ly);
}
++video->ly;
video->p->memory.io[REG_LY] = video->ly;
video->stat = GBRegisterSTATSetLYC(video->stat, lyc == video->ly);
if (video->ly < GB_VIDEO_VERTICAL_PIXELS) {
video->nextMode = GB_VIDEO_MODE_2_LENGTH + (video->p->memory.io[REG_SCX] & 7);
video->mode = 2;
if (!GBRegisterSTATIsHblankIRQ(video->stat) && GBRegisterSTATIsOAMIRQ(video->stat)) {
video->p->memory.io[REG_IF] |= (1 << GB_IRQ_LCDSTAT);
}
} else {
video->nextMode = GB_VIDEO_HORIZONTAL_LENGTH;
video->mode = 1;
if (video->nextFrame != 0) {
video->nextFrame = 0;
}
if (GBRegisterSTATIsVblankIRQ(video->stat) || GBRegisterSTATIsOAMIRQ(video->stat)) {
video->p->memory.io[REG_IF] |= (1 << GB_IRQ_LCDSTAT);
}
video->p->memory.io[REG_IF] |= (1 << GB_IRQ_VBLANK);
struct mCoreThread* thread = mCoreThreadGet();
mCoreThreadFrameEnded(thread);
}
if (GBRegisterSTATIsLYCIRQ(video->stat) && lyc == video->ly) {
video->p->memory.io[REG_IF] |= (1 << GB_IRQ_LCDSTAT);
}
GBUpdateIRQs(video->p);
break;
case 1:
// TODO: One M-cycle delay
++video->ly;
if (video->ly == GB_VIDEO_VERTICAL_TOTAL_PIXELS + 1) {
video->ly = 0;
video->p->memory.io[REG_LY] = video->ly;
// TODO: Cache SCX & 7 in case it changes during mode 2
video->nextMode = GB_VIDEO_MODE_2_LENGTH + (video->p->memory.io[REG_SCX] & 7);
video->mode = 2;
if (GBRegisterSTATIsOAMIRQ(video->stat)) {
video->p->memory.io[REG_IF] |= (1 << GB_IRQ_LCDSTAT);
GBUpdateIRQs(video->p);
}
video->renderer->finishFrame(video->renderer);
if (video->p->memory.mbcType == GB_MBC7 && video->p->memory.rotation && video->p->memory.rotation->sample) {
video->p->memory.rotation->sample(video->p->memory.rotation);
}
break;
} else if (video->ly == GB_VIDEO_VERTICAL_TOTAL_PIXELS) {
video->p->memory.io[REG_LY] = 0;
video->nextMode = GB_VIDEO_HORIZONTAL_LENGTH - 8;
} else if (video->ly == GB_VIDEO_VERTICAL_TOTAL_PIXELS - 1) {
video->p->memory.io[REG_LY] = video->ly;
video->nextMode = 8;
} else {
video->p->memory.io[REG_LY] = video->ly;
video->nextMode = GB_VIDEO_HORIZONTAL_LENGTH;
}
video->stat = GBRegisterSTATSetLYC(video->stat, lyc == video->p->memory.io[REG_LY]);
if (GBRegisterSTATIsLYCIRQ(video->stat) && lyc == video->p->memory.io[REG_LY]) {
video->p->memory.io[REG_IF] |= (1 << GB_IRQ_LCDSTAT);
GBUpdateIRQs(video->p);
}
break;
case 2:
_cleanOAM(video, video->ly);
video->dotCounter = 0;
video->nextEvent = GB_VIDEO_HORIZONTAL_LENGTH;
video->x = 0;
// TODO: Estimate sprite timings better
video->nextMode = GB_VIDEO_MODE_3_LENGTH_BASE + video->objMax * 11 - (video->p->memory.io[REG_SCX] & 7);
video->mode = 3;
break;
case 3:
video->nextMode = GB_VIDEO_MODE_0_LENGTH_BASE - video->objMax * 11;
video->mode = 0;
if (GBRegisterSTATIsHblankIRQ(video->stat)) {
video->p->memory.io[REG_IF] |= (1 << GB_IRQ_LCDSTAT);
GBUpdateIRQs(video->p);
}
if (video->ly < GB_VIDEO_VERTICAL_PIXELS && video->p->memory.isHdma && video->p->memory.io[REG_HDMA5] != 0xFF) {
video->p->memory.hdmaRemaining = 0x10;
video->p->memory.hdmaNext = video->p->cpu->cycles;
}
break;
}
video->stat = GBRegisterSTATSetMode(video->stat, video->mode);
video->p->memory.io[REG_STAT] = video->stat;
}
if (video->nextFrame <= 0) {
if (video->p->cpu->executionState == LR35902_CORE_FETCH) {
GBFrameEnded(video->p);
video->nextFrame = GB_VIDEO_TOTAL_LENGTH;
video->nextEvent = GB_VIDEO_TOTAL_LENGTH;
--video->frameskipCounter;
if (video->frameskipCounter < 0) {
mCoreSyncPostFrame(video->p->sync);
video->frameskipCounter = video->frameskip;
}
++video->frameCounter;
if (video->p->stream && video->p->stream->postVideoFrame) {
const color_t* pixels;
size_t stride;
video->renderer->getPixels(video->renderer, &stride, (const void**) &pixels);
video->p->stream->postVideoFrame(video->p->stream, pixels, stride);
}
struct mCoreThread* thread = mCoreThreadGet();
mCoreThreadFrameStarted(thread);
} else {
video->nextFrame = 4 - ((video->p->cpu->executionState + 1) & 3);
if (video->nextFrame < video->nextEvent) {
video->nextEvent = video->nextFrame;
}
}
}
if (video->nextMode < video->nextEvent) {
video->nextEvent = video->nextMode;
}
video->eventDiff = 0;
}
return video->nextEvent;
}
void GBIOWrite(struct GB* gb, unsigned address, uint8_t value) {
switch (address) {
case REG_DIV:
GBTimerDivReset(&gb->timer);
return;
case REG_NR10:
if (gb->audio.enable) {
GBAudioWriteNR10(&gb->audio, value);
} else {
value = 0;
}
break;
case REG_NR11:
if (gb->audio.enable) {
GBAudioWriteNR11(&gb->audio, value);
} else {
if (gb->audio.style == GB_AUDIO_DMG) {
GBAudioWriteNR11(&gb->audio, value & _registerMask[REG_NR11]);
}
value = 0;
}
break;
case REG_NR12:
if (gb->audio.enable) {
GBAudioWriteNR12(&gb->audio, value);
} else {
value = 0;
}
break;
case REG_NR13:
if (gb->audio.enable) {
GBAudioWriteNR13(&gb->audio, value);
} else {
value = 0;
}
break;
case REG_NR14:
if (gb->audio.enable) {
GBAudioWriteNR14(&gb->audio, value);
} else {
value = 0;
}
break;
case REG_NR21:
if (gb->audio.enable) {
GBAudioWriteNR21(&gb->audio, value);
} else {
if (gb->audio.style == GB_AUDIO_DMG) {
GBAudioWriteNR21(&gb->audio, value & _registerMask[REG_NR21]);
}
value = 0;
}
break;
case REG_NR22:
if (gb->audio.enable) {
GBAudioWriteNR22(&gb->audio, value);
} else {
value = 0;
}
break;
case REG_NR23:
if (gb->audio.enable) {
GBAudioWriteNR23(&gb->audio, value);
} else {
value = 0;
}
break;
case REG_NR24:
if (gb->audio.enable) {
GBAudioWriteNR24(&gb->audio, value);
} else {
value = 0;
}
break;
case REG_NR30:
if (gb->audio.enable) {
GBAudioWriteNR30(&gb->audio, value);
} else {
value = 0;
}
break;
case REG_NR31:
if (gb->audio.enable || gb->audio.style == GB_AUDIO_DMG) {
GBAudioWriteNR31(&gb->audio, value);
} else {
value = 0;
}
break;
case REG_NR32:
if (gb->audio.enable) {
GBAudioWriteNR32(&gb->audio, value);
} else {
value = 0;
}
break;
case REG_NR33:
if (gb->audio.enable) {
GBAudioWriteNR33(&gb->audio, value);
} else {
value = 0;
}
break;
case REG_NR34:
if (gb->audio.enable) {
GBAudioWriteNR34(&gb->audio, value);
} else {
value = 0;
}
break;
case REG_NR41:
if (gb->audio.enable || gb->audio.style == GB_AUDIO_DMG) {
GBAudioWriteNR41(&gb->audio, value);
} else {
value = 0;
}
break;
case REG_NR42:
if (gb->audio.enable) {
GBAudioWriteNR42(&gb->audio, value);
} else {
value = 0;
}
break;
case REG_NR43:
if (gb->audio.enable) {
GBAudioWriteNR43(&gb->audio, value);
} else {
value = 0;
}
break;
case REG_NR44:
if (gb->audio.enable) {
GBAudioWriteNR44(&gb->audio, value);
} else {
value = 0;
}
break;
case REG_NR50:
if (gb->audio.enable) {
GBAudioWriteNR50(&gb->audio, value);
} else {
value = 0;
}
break;
case REG_NR51:
if (gb->audio.enable) {
GBAudioWriteNR51(&gb->audio, value);
} else {
value = 0;
}
break;
case REG_NR52:
GBAudioWriteNR52(&gb->audio, value);
value &= 0x80;
value |= gb->memory.io[REG_NR52] & 0x0F;
break;
case REG_WAVE_0:
case REG_WAVE_1:
case REG_WAVE_2:
case REG_WAVE_3:
case REG_WAVE_4:
case REG_WAVE_5:
case REG_WAVE_6:
case REG_WAVE_7:
case REG_WAVE_8:
case REG_WAVE_9:
case REG_WAVE_A:
case REG_WAVE_B:
case REG_WAVE_C:
case REG_WAVE_D:
case REG_WAVE_E:
case REG_WAVE_F:
if (!gb->audio.playingCh3 || gb->audio.style != GB_AUDIO_DMG) {
gb->audio.ch3.wavedata8[address - REG_WAVE_0] = value;
} else if(gb->audio.ch3.readable) {
gb->audio.ch3.wavedata8[gb->audio.ch3.window >> 1] = value;
}
break;
case REG_JOYP:
case REG_TIMA:
case REG_TMA:
case REG_LYC:
// Handled transparently by the registers
break;
case REG_TAC:
value = GBTimerUpdateTAC(&gb->timer, value);
break;
case REG_IF:
gb->memory.io[REG_IF] = value | 0xE0;
GBUpdateIRQs(gb);
return;
case REG_LCDC:
// TODO: handle GBC differences
value = gb->video.renderer->writeVideoRegister(gb->video.renderer, address, value);
GBVideoWriteLCDC(&gb->video, value);
break;
case REG_DMA:
GBMemoryDMA(gb, value << 8);
break;
case REG_SCY:
case REG_SCX:
case REG_WY:
case REG_WX:
GBVideoProcessDots(&gb->video);
value = gb->video.renderer->writeVideoRegister(gb->video.renderer, address, value);
break;
case REG_BGP:
case REG_OBP0:
case REG_OBP1:
GBVideoProcessDots(&gb->video);
GBVideoWritePalette(&gb->video, address, value);
break;
case REG_STAT:
GBVideoWriteSTAT(&gb->video, value);
break;
case REG_IE:
gb->memory.ie = value;
GBUpdateIRQs(gb);
return;
default:
if (gb->model >= GB_MODEL_CGB) {
switch (address) {
case REG_KEY1:
value &= 0x1;
value |= gb->memory.io[address] & 0x80;
break;
case REG_VBK:
GBVideoSwitchBank(&gb->video, value);
break;
case REG_HDMA1:
case REG_HDMA2:
case REG_HDMA3:
case REG_HDMA4:
// Handled transparently by the registers
break;
case REG_HDMA5:
GBMemoryWriteHDMA5(gb, value);
value &= 0x7F;
break;
case REG_BCPS:
gb->video.bcpIndex = value & 0x3F;
gb->video.bcpIncrement = value & 0x80;
gb->memory.io[REG_BCPD] = gb->video.palette[gb->video.bcpIndex >> 1] >> (8 * (gb->video.bcpIndex & 1));
break;
case REG_BCPD:
GBVideoProcessDots(&gb->video);
GBVideoWritePalette(&gb->video, address, value);
break;
case REG_OCPS:
gb->video.ocpIndex = value & 0x3F;
gb->video.ocpIncrement = value & 0x80;
gb->memory.io[REG_OCPD] = gb->video.palette[8 * 4 + (gb->video.ocpIndex >> 1)] >> (8 * (gb->video.ocpIndex & 1));
break;
case REG_OCPD:
GBVideoProcessDots(&gb->video);
GBVideoWritePalette(&gb->video, address, value);
break;
case REG_SVBK:
GBMemorySwitchWramBank(&gb->memory, value);
value = gb->memory.wramCurrentBank;
break;
default:
goto failed;
}
goto success;
}
failed:
mLOG(GB_IO, STUB, "Writing to unknown register FF%02X:%02X", address, value);
if (address >= GB_SIZE_IO) {
return;
}
break;
}