empathicqubit/Mesen-SX
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

GB: Stat IRQ logic improvements

Browse source
This commit is contained in:
Sour 2020-05-22 00:47:55 -04:00
parent 713d18c2d4
commit 2f511530bd
4 changed files with 42 additions and 28 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

62
Core/GbPpu.cpp
View file

@ -21,7 +21,7 @@ void GbPpu::Init(Console* console, Gameboy* gameboy, GbMemoryManager* memoryMana
_oam = oam;
_state = {};
_state.Mode = PpuMode::HBlank;
_state.Mode = PpuMode::OamEvaluation;
_lastFrameTime = 0;
_outputBuffers[0] = new uint16_t[256 * 240];
@ -99,13 +99,9 @@ void GbPpu::ExecCycle()
_spriteCount = 0;
if(_state.Scanline == 144) {
_state.Mode = PpuMode::VBlank;
ChangeMode(PpuMode::VBlank);
_memoryManager->RequestIrq(GbIrqSource::VerticalBlank);
if(_state.Status & GbPpuStatusFlags::VBlankIrq) {
_memoryManager->RequestIrq(GbIrqSource::LcdStat);
}
SendFrame();
} else if(_state.Scanline == 154) {
_state.Scanline = 0;
@ -119,11 +115,7 @@ void GbPpu::ExecCycle()
}
if(_state.Scanline < 144) {
_state.Mode = PpuMode::OamEvaluation;
if(_state.Status & GbPpuStatusFlags::OamIrq) {
_memoryManager->RequestIrq(GbIrqSource::LcdStat);
}
ChangeMode(PpuMode::OamEvaluation);
}
if(_state.LyCompare == _state.Scanline && (_state.Status & GbPpuStatusFlags::CoincidenceIrq)) {
@ -189,10 +181,7 @@ void GbPpu::ExecCycle()
}
if(_drawnPixels >= 160) {
_state.Mode = PpuMode::HBlank;
if(_state.Status & GbPpuStatusFlags::HBlankIrq) {
_memoryManager->RequestIrq(GbIrqSource::LcdStat);
}
ChangeMode(PpuMode::HBlank);
}
}
}
@ -212,7 +201,7 @@ void GbPpu::RunSpriteEvaluation()
}
if(_state.Cycle == 79) {
_state.Mode = PpuMode::Drawing;
ChangeMode(PpuMode::Drawing);
//Reset fetcher & pixel FIFO
_fetcherStep = 0;
@ -229,11 +218,6 @@ void GbPpu::RunSpriteEvaluation()
}
}
void GbPpu::ResetTileFetcher()
{
_fetcherStep = 0;
}
void GbPpu::ClockTileFetcher()
{
if(_fetchSprite < 0 && _fifoSize >= 8) {
@ -242,7 +226,7 @@ void GbPpu::ClockTileFetcher()
_fetchSprite = _spriteIndexes[i];
_fetchSpriteOffset = _spriteX[i] < 8 ? (8 - _spriteX[i]) : 0;
_spriteX[i] = 0xFF; //prevent processing this sprite again
ResetTileFetcher();
_fetcherStep = 0;
break;
}
}
@ -320,7 +304,7 @@ void GbPpu::ClockTileFetcher()
void GbPpu::PushSpriteToPixelFifo()
{
_fetchSprite = -1;
ResetTileFetcher();
_fetcherStep = 0;
if(!_state.SpritesEnabled) {
return;
@ -363,7 +347,29 @@ void GbPpu::PushTileToPixelFifo()
_fetchColumn = (_fetchColumn + 1) & 0x1F;
_fifoSize += 8;
ResetTileFetcher();
_fetcherStep = 0;
}
void GbPpu::ChangeMode(PpuMode mode)
{
_state.Mode = mode;
UpdateStatIrq();
}
void GbPpu::UpdateStatIrq()
{
bool irqFlag = (
_state.LcdEnabled &&
((_state.Scanline == _state.LyCompare && (_state.Status & GbPpuStatusFlags::CoincidenceIrq)) ||
(_state.Mode == PpuMode::HBlank && (_state.Status & GbPpuStatusFlags::HBlankIrq)) ||
(_state.Mode == PpuMode::OamEvaluation && (_state.Status & GbPpuStatusFlags::OamIrq)) ||
(_state.Mode == PpuMode::VBlank && ((_state.Status & GbPpuStatusFlags::VBlankIrq) || (_state.Status & GbPpuStatusFlags::OamIrq))))
);
if(irqFlag && !_state.StatIrqFlag) {
_memoryManager->RequestIrq(GbIrqSource::LcdStat);
}
_state.StatIrqFlag = irqFlag;
}
void GbPpu::GetPalette(uint16_t out[4], uint8_t palCfg)
@ -441,7 +447,7 @@ void GbPpu::Write(uint16_t addr, uint8_t value)
//Reset LCD to top of screen when it gets turned on
_state.Cycle = 0;
_state.Scanline = 0;
_state.Mode = PpuMode::HBlank;
ChangeMode(PpuMode::HBlank);
//Send a blank (white) frame
_lastFrameTime = _gameboy->GetCycleCount();
@ -459,7 +465,11 @@ void GbPpu::Write(uint16_t addr, uint8_t value)
_state.BgEnabled = (value & 0x01) != 0;
break;
case 0xFF41: _state.Status = value & 0xF8; break;
case 0xFF41:
_state.Status = value & 0xF8;
UpdateStatIrq();
break;
case 0xFF42: _state.ScrollY = value; break;
case 0xFF43: _state.ScrollX = value; break;
case 0xFF45: _state.LyCompare = value; break;

6
Core/GbPpu.h
View file

@ -28,7 +28,7 @@ private:
uint8_t* _vram = nullptr;
uint8_t* _oam = nullptr;
uint64_t _lastFrameTime = 0;
uint8_t _fifoPosition = 0;
@ -53,11 +53,13 @@ private:
void ExecCycle();
void RunSpriteEvaluation();
void ResetTileFetcher();
void ClockTileFetcher();
void PushSpriteToPixelFifo();
void PushTileToPixelFifo();
void ChangeMode(PpuMode mode);
void UpdateStatIrq();
void WriteCgbPalette(uint8_t& pos, uint16_t* pal, bool autoInc, uint8_t value);
public:

1
Core/GbTypes.h
View file

@ -106,6 +106,7 @@ struct GbPpuState
uint8_t Scanline;
uint16_t Cycle;
PpuMode Mode;
bool StatIrqFlag;
uint8_t LyCompare;
uint8_t BgPalette;

1
UI/Interop/DebugState.cs
View file

@ -710,6 +710,7 @@ namespace Mesen.GUI
public byte Scanline;
public UInt16 Cycle;
public PpuMode Mode;
[MarshalAs(UnmanagedType.I1)] public bool StatIrqFlag;
public byte LyCompare;
public byte BgPalette;