initial commit

src/PPU.hpp

@@ -0,0 +1,90 @@
+#pragma once
+
+#include "Types.hpp"
+
+class Bus;
+
+class PPU
+{
+	friend class PPUWatcher;
+
+public:
+	PPU(Bus* bus);
+
+	void Powerup();
+	void Reset();
+
+	void Tick();
+
+	Byte ReadRegister(Byte id);
+	void WriteRegister(Byte id, Byte val);
+
+	inline bool IsFrameDone() { bool returnVal = isFrameDone; isFrameDone = false; return returnVal; }
+
+private:
+	Byte Read(Word addr);
+	void Write(Word addr, Byte val);
+
+private: // Registers
+
+	union
+	{
+		struct
+		{
+			Byte BaseNametableAddr : 2;
+			Byte VRAMAddrIncrement : 1;
+			Byte SpritePatternTableAddr : 1;
+			Byte BackgrPatternTableAddr : 1;
+			Byte SpriteSize : 1;
+			Byte MasterSlaveSelect : 1;
+			Byte VBlankNMI : 1;
+		} Flag;
+
+		Byte Raw;
+	} ppuctrl;
+
+	union
+	{
+		struct
+		{
+			Byte Greyscale : 1;
+			Byte BackgroundOnLeft : 1;
+			Byte SpriteOnLeft : 1;
+			Byte ShowBackground : 1;
+			Byte ShowSprites : 1;
+			Byte EmphasizeRed : 1;
+			Byte EmphasizeGreen : 1;
+			Byte EmphasizeBlue : 1;
+		} Flag;
+
+		Byte Raw;
+	} ppumask;
+
+	union
+	{
+		struct
+		{
+			Byte Unused : 5;
+			Byte SpriteOverflow : 1;
+			Byte SpriteZeroHit : 1;
+			Byte VBlankStarted : 1;
+		} Flag;
+
+		Byte Raw;
+	} ppustatus;
+
+	struct
+	{
+		Byte x;
+		Byte y;
+	} ppuscroll;
+
+	Address ppuaddr;
+
+	uint16_t x, y;
+	Byte addressLatch = 0;
+
+private:
+	bool isFrameDone = false;
+	Bus* bus;
+};