-Fixed timing issues (with sprite DMA) + a bit of refactoring

-PPU is now run AFTER a read/write, instead of before.  (And the CPU class is in charge of running it, instead of the MemoryManager class)

Core/CPU.cpp

@@ -118,24 +118,28 @@ void CPU::EndFrame()
 	_cycleCount = 0;
 }
 
+void CPU::IncCycleCount()
+{
+	PPU::ExecStatic();
+	_cycleCount++;
+}
+
 void CPU::RunDMATransfer(uint8_t* spriteRAM, uint32_t &spriteRamAddr, uint8_t offsetValue)
 {
 	//"the DMA procedure takes 513 CPU cycles (+1 on odd CPU cycles)"
 	if((CPU::GetRelativeCycleCount() + Instance->_cycleCount) % 2 != 0) {
-		Instance->_cycleCount++;
+		Instance->IncCycleCount();
 	}
-	Instance->_cycleCount++;
+	Instance->IncCycleCount();
 
 	//DMA transfer starts at SpriteRamAddr and wraps around
 	for(int i = 0; i < 0x100; i++) {
 		//Read value
-		uint8_t readValue = Instance->_memoryManager->Read(offsetValue*0x100 + i);		
-		Instance->_cycleCount++;
+		uint8_t readValue = Instance->MemoryRead(offsetValue * 0x100 + i);
 
 		//Write to ram
 		spriteRAM[(spriteRamAddr+i) & 0xFF] = readValue;
-		PPU::ExecStatic();
-		Instance->_cycleCount++;
+		Instance->IncCycleCount();
 	}
 }
 

Core/CPU.h

@@ -2,6 +2,7 @@
 
 #include "stdafx.h"
 #include "MemoryManager.h"
+#include "PPU.h"
 #include "Snapshotable.h"
 
 namespace PSFlags
@@ -74,18 +75,16 @@ private:
 	bool _runNMI = false;
 	bool _runIRQ = false;
 
+	void IncCycleCount();
+
 	uint8_t GetOPCode()
 	{
-		uint8_t value = _memoryManager->Read(_state.PC, true);
-		_cycleCount++;
-		_state.PC++;
-		return value;
+		return MemoryRead(_state.PC++, true);
 	}
 
 	void DummyRead()
 	{
-		_memoryManager->Read(_state.PC, false);
-		_cycleCount++;
+		MemoryRead(_state.PC);
 	}
 
 	uint8_t ReadByte()
@@ -139,19 +138,19 @@ private:
 	void MemoryWrite(uint16_t addr, uint8_t value)
 	{
 		_memoryManager->Write(addr, value);
-		_cycleCount++;
+		IncCycleCount();
 	}
 
-	uint8_t MemoryRead(uint16_t addr) {
+	uint8_t MemoryRead(uint16_t addr, bool forExecute = false) {
 		uint8_t value = _memoryManager->Read(addr);
-		_cycleCount++;
+		IncCycleCount();
 		return value;
 	}
 
 	uint16_t MemoryReadWord(uint16_t addr) {
-		uint16_t value = _memoryManager->ReadWord(addr);
-		_cycleCount+=2;
-		return value;
+		uint8_t lo = MemoryRead(addr);
+		uint8_t hi = MemoryRead(addr + 1);
+		return lo | hi << 8;
 	}
 
 	void SetRegister(uint8_t &reg, uint8_t value) {

Core/MemoryManager.cpp

@@ -1,7 +1,6 @@
 #include "stdafx.h"
 #include "MemoryManager.h"
 #include "BaseMapper.h"
-#include "PPU.h"
 #include "Debugger.h"
 
 MemoryManager::MemoryManager(shared_ptr<BaseMapper> mapper)
@@ -109,12 +108,12 @@ uint8_t MemoryManager::Read(uint16_t addr, bool forExecution)
 	Debugger::CheckBreakpoint(forExecution ? BreakpointType::Execute : BreakpointType::Read, addr);
 
 	uint8_t value;
-	PPU::ExecStatic();
 	if(addr <= 0x1FFF) {
 		value = _internalRAM[addr & 0x07FF];
 	} else {
 		value = ReadRegister(addr);
 	}
+
 	return value;
 }
 
@@ -122,7 +121,6 @@ void MemoryManager::Write(uint16_t addr, uint8_t value)
 {
 	Debugger::CheckBreakpoint(BreakpointType::Write, addr);
 
-	PPU::ExecStatic();
 	if(addr <= 0x1FFF) {
 		_internalRAM[addr & 0x07FF] = value;
 	} else {
@@ -130,13 +128,6 @@ void MemoryManager::Write(uint16_t addr, uint8_t value)
 	}
 }
 
-uint16_t MemoryManager::ReadWord(uint16_t addr) 
-{
-	uint8_t lo = Read(addr);
-	uint8_t hi = Read(addr+1);
-	return lo | hi << 8;
-}
-
 uint8_t MemoryManager::ReadVRAM(uint16_t addr)
 {	
 	addr &= 0x3FFF;

Core/MemoryManager.h

@@ -48,7 +48,6 @@ class MemoryManager: public Snapshotable
 		uint8_t* GetInternalRAM();
 
 		uint8_t Read(uint16_t addr, bool forExecution = false);
-		uint16_t ReadWord(uint16_t addr);
 		void Write(uint16_t addr, uint8_t value);
 
 		uint8_t ReadVRAM(uint16_t addr);

Core/PPU.cpp

@@ -459,7 +459,7 @@ void PPU::ProcessPrerenderScanline()
 {
 	ProcessPreVBlankScanline();
 
-	if(_cycle == 1) {
+	if(_cycle == 0) {
 		_statusFlags.SpriteOverflow = false;
 		_statusFlags.Sprite0Hit = false;
 		_statusFlags.VerticalBlank = false;
@@ -601,7 +601,7 @@ void PPU::CopyOAMData()
 
 void PPU::BeginVBlank()
 {
-	if(_cycle == 1) {
+	if(_cycle == 0) {
 		if(!_doNotSetVBFlag) {
 			_statusFlags.VerticalBlank = true;
 			if(_flags.VBlank) {

Core/PPU.h

@@ -95,7 +95,6 @@ class PPU : public IMemoryHandler, public Snapshotable
 		int32_t _scanline = 0;
 		uint32_t _cycle = 0;
 		uint32_t _frameCount = 0;
-		int32_t _cycleCount = 0;
 		uint8_t _memoryReadBuffer = 0;
 		
 		uint8_t _paletteRAM[0x100];