Refactor starting phase

Author: Gumball2415

Core/BaseVideoFilter.cpp

@@ -52,17 +52,11 @@ bool BaseVideoFilter::IsOddFrame()
 	return _isOddFrame;
 }
 
-uint8_t BaseVideoFilter::GetFieldPhase()
-{
-	return _fieldPhase;
-}
-
 void BaseVideoFilter::SendFrame(uint16_t *ppuOutputBuffer, uint32_t frameNumber)
 {
 	_frameLock.Acquire();
 	_overscan = _console->GetSettings()->GetOverscanDimensions();
 	_isOddFrame = frameNumber & 0x01;
-	_fieldPhase = frameNumber % 3;
 	UpdateBufferSize();
 	OnBeforeApplyFilter();
 	ApplyFilter(ppuOutputBuffer);

Core/BaseVideoFilter.h

@@ -15,8 +15,6 @@ class BaseVideoFilter
 	SimpleLock _frameLock;
 	OverscanDimensions _overscan;
 	bool _isOddFrame;
-	// https://forums.nesdev.org/viewtopic.php?p=30625#p30625
-	uint8_t _fieldPhase;
 
 	void UpdateBufferSize();
 
@@ -25,7 +23,6 @@ class BaseVideoFilter
 
 	virtual void ApplyFilter(uint16_t *ppuOutputBuffer) = 0;
 	virtual void OnBeforeApplyFilter();
-	uint8_t GetFieldPhase();
 
 public:
 	BaseVideoFilter(shared_ptr<Console> console);

Core/BisqwitNtscFilter.cpp

@@ -50,7 +50,7 @@ BisqwitNtscFilter::BisqwitNtscFilter(shared_ptr<Console> console, int resDivider
 			} else {
 				outputBuffer += GetOverscan().GetScreenWidth() * 64 / _resDivider / _resDivider * (120 - GetOverscan().Top);
 			}
-			DecodeFrame(120, 239 - GetOverscan().Bottom, _ppuOutputBuffer, outputBuffer, (_console->IsDotBypassed() ? (GetFieldPhase() * 4) : (IsOddFrame() ? 0 : 8)) + 327360);
+			DecodeFrame(120, 239 - GetOverscan().Bottom, _ppuOutputBuffer, outputBuffer, (_console->GetStartingPhase() * 4) + 327360);
 
 			_workDone = true;
 		}
@@ -70,7 +70,7 @@ void BisqwitNtscFilter::ApplyFilter(uint16_t *ppuOutputBuffer)
 
 	_workDone = false;
 	_waitWork.Signal();
-	DecodeFrame(GetOverscan().Top, 120, ppuOutputBuffer, GetOutputBuffer(), (_console->IsDotBypassed() ? (GetFieldPhase() * 4) : (IsOddFrame() ? 0 : 8)) + GetOverscan().Top * 341 * 8);
+	DecodeFrame(GetOverscan().Top, 120, ppuOutputBuffer, GetOutputBuffer(), (_console->GetStartingPhase() * 4) + GetOverscan().Top * 341 * 8);
 	while(!_workDone) {}
 }
 

Core/Console.cpp

@@ -568,9 +568,9 @@ uint32_t Console::GetFrameCount()
 	return _ppu ? _ppu->GetFrameCount() : 0;
 }
 
-bool Console::IsDotBypassed()
+uint8_t Console::GetStartingPhase()
 {
-	return _ppu ? _ppu->IsDotBypassed() : false;
+	return _ppu ? _ppu->GetStartingPhase() : 0;
 }
 
 NesModel Console::GetModel()

Core/Console.h

@@ -205,7 +205,7 @@ class Console : public std::enable_shared_from_this<Console>
 	RomInfo GetRomInfo();
 	uint32_t GetFrameCount();
 	// https://forums.nesdev.org/viewtopic.php?p=30625#p30625
-	bool IsDotBypassed();
+	uint8_t GetStartingPhase();
 	NesModel GetModel();
 
 	uint32_t GetLagCounter();

Core/NtscFilter.cpp

@@ -132,7 +132,7 @@ void NtscFilter::OnBeforeApplyFilter()
 
 void NtscFilter::ApplyFilter(uint16_t *ppuOutputBuffer)
 {
-	nes_ntsc_blit(&_ntscData, ppuOutputBuffer, _ntsc_border, PPU::ScreenWidth, (_console->IsDotBypassed() ? GetFieldPhase() : (IsOddFrame() ? 0 : 2)), PPU::ScreenWidth, 240, _ntscBuffer, NES_NTSC_OUT_WIDTH(PPU::ScreenWidth)*4);
+	nes_ntsc_blit(&_ntscData, ppuOutputBuffer, _ntsc_border, PPU::ScreenWidth, _console->GetStartingPhase(), PPU::ScreenWidth, 240, _ntscBuffer, NES_NTSC_OUT_WIDTH(PPU::ScreenWidth)*4);
 	GenerateArgbFrame(_ntscBuffer);
 }
 

Core/PPU.cpp

@@ -105,7 +105,7 @@ void PPU::Reset()
 	memset(_oamDecayCycles, 0, sizeof(_oamDecayCycles));
 	_enableOamDecay = _settings->CheckFlag(EmulationFlags::EnableOamDecay);
 
-	_isDotBypassed = false;
+	_startingPhase = 0;
 
 	UpdateMinimumDrawCycles();
 }
@@ -999,21 +999,13 @@ void PPU::ProcessScanline()
 			LoadTileInfo();
 		}
 	} else if(_cycle == 337 || _cycle == 339) {
-		if(_scanline == -1 && _cycle == 339 && (_frameCount & 0x01) && _nesModel == NesModel::NTSC && _settings->GetPpuModel() == PpuModel::Ppu2C02) {
-			if (IsRenderingEnabled()) {
-			//This behavior is NTSC-specific - PAL frames are always the same number of cycles
-			//"With rendering enabled, each odd PPU frame is one PPU clock shorter than normal" (skip from 339 to 0, going over 340)
-				_cycle = 340;
-				_isDotBypassed = false;
-			}
-			else {
-				// "By keeping rendering disabled until after the time when the clock is skipped on odd frames,
-				// you can get a different color dot crawl pattern than normal."
-				_isDotBypassed = true;
-			}
-		}
 		if (IsRenderingEnabled()) {
 			ReadVram(GetNameTableAddr());
+			if (_scanline == -1 && _cycle == 339 && (_frameCount & 0x01) && _nesModel == NesModel::NTSC && _settings->GetPpuModel() == PpuModel::Ppu2C02) {
+				//This behavior is NTSC-specific - PAL frames are always the same number of cycles
+				//"With rendering enabled, each odd PPU frame is one PPU clock shorter than normal" (skip from 339 to 0, going over 340)
+				_cycle = 340;
+			}
 		}
 	}
 }
@@ -1351,6 +1343,8 @@ void PPU::Exec()
 		}
 	}
 
+	_startingPhase = _cycle % 3;
+
 	if(_needStateUpdate) {
 		UpdateState();
 	}

Core/PPU.h

@@ -110,7 +110,7 @@ class PPU : public IMemoryHandler, public Snapshotable
 		bool _corruptOamRow[32];
 
 		// https://forums.nesdev.org/viewtopic.php?p=30625#p30625
-		bool _isDotBypassed;
+		uint8_t _startingPhase;
 
 		void UpdateStatusFlag();
 
@@ -220,9 +220,9 @@ class PPU : public IMemoryHandler, public Snapshotable
 			return _frameCount;
 		}
 
-		bool IsDotBypassed()
+		uint8_t GetStartingPhase()
 		{
-			return _isDotBypassed;
+			return _startingPhase;
 		}
 
 		uint32_t GetFrameCycle()