implemented background tile fetching

src/Bus.cpp

@@ -52,6 +52,15 @@ uint8_t Bus::Tick()
 	return result;
 }
 
+void Bus::PPUTick()
+{
+	if (ppuClock == 0)
+		cpu.Tick();
+
+	ppu.Tick();
+	ppuClock = (ppuClock + 1) % 3;
+}
+
 bool Bus::Instruction()
 {
 	try

src/Bus.hpp

@@ -45,6 +45,8 @@ public:
 	 */
 	uint8_t Tick();
 
+	void PPUTick();
+
 	/**
 	 * @brief Advance the emulator by one CPU instruction.
 	 */
@@ -87,4 +89,6 @@ private:
 	PPU ppu;
 	Cartridge cartridge;
 	ControllerPort controllerPort;
+
+	uint8_t ppuClock = 0;
 };

src/PPU.cpp

@@ -16,9 +16,15 @@ void PPU::Powerup()
 	ppuscroll.y		= 0x00;
 	ppuaddr.Raw		= 0x0000;
 
-	x = 0;
+	// This will cause the Tick() functioon to set both to 0 on the first tick
-	y = 0;
+	x = 400;
+	y = 400;
+	fineX = 0;
 	addressLatch = 0;
+
+	scanlineType = ScanlineType::Visible;
+	cycleType = CycleType::Idle;
+	fetchPhase = FetchingPhase::NametableByte;
 }
 
 void PPU::Reset()
@@ -28,13 +34,63 @@ void PPU::Reset()
 	ppuscroll.x = 0x00;
 	ppuscroll.y = 0x00;
 
-	x = 0;
+	// This will cause the Tick() functioon to set both to 0 on the first tick
-	y = 0;
+	x = 400;
-	addressLatch = 1;
+	y = 400;
+	fineX = 0;
+	addressLatch = 0;
+
+	scanlineType = ScanlineType::Visible;
+	cycleType = CycleType::Idle;
+	fetchPhase = FetchingPhase::NametableByte;
 }
 
 void PPU::Tick()
 {
+	// Advance pixel counters
+	x++;
+	if (x > 340)
+	{
+		x = 0;
+		y++;
+		if (y > 261)
+			y = 0;
+	}
+
+	current.CoarseX++;
+	if (current.CoarseX > 31)
+	{
+		current.CoarseX = 0;
+		current.NametableSel ^= 0x1;
+	}
+
+	if (x == 256)
+	{
+		if (current.FineY < 7)
+		{
+			current.FineY++;
+		}
+		else
+		{
+			current.FineY = 0;
+			if (current.CoarseY == 29)
+			{
+				current.CoarseY = 0;
+				current.NametableSel ^= 0x2;
+			}
+			else if (current.CoarseY == 31)
+			{
+				current.CoarseY = 0;
+			}
+			else
+			{
+				current.CoarseY++;
+			}
+		}
+	}
+
+	UpdateState();
+
 	// On this cycle the VBlankStarted bit is set in the ppustatus
 	if (y == 241 && x == 1)
 	{
@@ -50,15 +106,13 @@ void PPU::Tick()
 	if (y == 261 && x == 1)
 		ppustatus.Flag.VBlankStarted = 0;
 
-	// Advance pixel counters
+
-	x++;
+	// Need to render
-	if (x > 340)
+	if (scanlineType == ScanlineType::Visible || scanlineType == ScanlineType::PreRender)
 	{
-		x = 0;
+		PerformRenderAction();
-		y++;
-		if (y > 261)
-			y = 0;
 	}
+	
 }
 
 Byte PPU::ReadRegister(Byte id)
@@ -107,6 +161,7 @@ void PPU::WriteRegister(Byte id, Byte val)
 	{
 	case 0:
 		ppuctrl.Raw = val;
+		temporary.NametableSel = ppuctrl.Flag.BaseNametableAddr;
 		break;
 
 	case 1:
@@ -122,18 +177,37 @@ void PPU::WriteRegister(Byte id, Byte val)
 		// determines whether the hi or lo byte should be written next
 	case 5:
 		if (addressLatch == 0)
+		{
 			ppuscroll.x = val;
+			temporary.CoarseX = (val >> 3);
+			fineX = val & 0x3;
+		}
 		else
+		{
 			ppuscroll.y = val;
+			temporary.CoarseY = (val >> 3);
+			temporary.FineY = val & 0x3;
+		}
 
 		addressLatch = !addressLatch;
 		break;
 
 	case 6:
 		if (addressLatch == 0)
+		{
 			ppuaddr.Bytes.hi = val;
+			temporary.Raw &= 0xFF;
+			temporary.Raw |= ((Word)(val & 0x3F) << 8);
+			temporary.FineY &= 0x3;
+		}
 		else
+		{
 			ppuaddr.Bytes.lo = val;
+			temporary.Raw &= ((Word)0xFF << 8);
+			temporary.Raw |= val;
+
+			current.Raw = temporary.Raw;
+		}
 
 		addressLatch = !addressLatch;
 		break;
@@ -160,3 +234,84 @@ void PPU::Write(Word addr, Byte val)
 {
 	bus->WritePPU(addr, val);
 }
+
+void PPU::UpdateState()
+{
+	switch (y)
+	{
+	case 0:
+		scanlineType = ScanlineType::Visible;
+		break;
+
+	case 240:
+		scanlineType = ScanlineType::PostRender;
+		break;
+
+	case 241:
+		scanlineType = ScanlineType::VBlank;
+		break;
+
+	case 261:
+		scanlineType = ScanlineType::PreRender;
+		break;
+	}
+
+	switch (x)
+	{
+	case 0:
+		cycleType = CycleType::Idle;
+		break;
+
+	case 1:
+		cycleType = CycleType::Fetching;
+		break;
+
+	case 257:
+		cycleType = CycleType::SpriteFetching;
+		break;
+
+	case 321:
+		cycleType = CycleType::PreFetching;
+		break;
+
+	case 337:
+		cycleType = CycleType::UnknownFetching;
+		break;
+	}
+}
+
+void PPU::PerformRenderAction()
+{
+	if (cycleType == CycleType::Idle)
+		return;
+
+	if (memoryAccessLatch == 1)
+	{
+		switch (fetchPhase)
+		{
+		case FetchingPhase::NametableByte:
+			nametableByte = Read(0x2000 | (current.Raw & 0x0FFF));
+
+			if(cycleType != CycleType::UnknownFetching)
+				fetchPhase = FetchingPhase::AttributeTableByte;
+			break;
+
+		case FetchingPhase::AttributeTableByte:
+			attributeTableByte = Read(0x23C0 | (current.Raw & 0x0FFF) | ((current.Raw >> 4) & 0x38) | ((current.Raw >> 2) & 0x07));
+			fetchPhase = FetchingPhase::PatternTableLo;
+			break;
+
+		case FetchingPhase::PatternTableLo:
+			patternTableLo = Read(ppuctrl.Flag.BackgrPatternTableAddr | nametableByte);
+			fetchPhase = FetchingPhase::PatternTableHi;
+			break;
+
+		case FetchingPhase::PatternTableHi:
+			patternTableLo = Read((ppuctrl.Flag.BackgrPatternTableAddr | nametableByte) + 8);
+			fetchPhase = FetchingPhase::NametableByte;
+			break;
+		}
+	}
+
+	memoryAccessLatch = 1 - memoryAccessLatch;
+}

src/PPU.hpp

@@ -4,6 +4,44 @@
 
 class Bus;
 
+enum class ScanlineType
+{
+	PreRender,
+	Visible,
+	PostRender,
+	VBlank
+};
+
+enum class CycleType
+{
+	Idle,
+	Fetching,
+	SpriteFetching,
+	PreFetching,
+	UnknownFetching
+};
+
+enum class FetchingPhase
+{
+	NametableByte,
+	AttributeTableByte,
+	PatternTableLo,
+	PatternTableHi
+};
+
+union VRAMAddress
+{
+	struct
+	{
+		Byte CoarseX : 5;
+		Byte CoarseY : 5;
+		Byte NametableSel : 2;
+		Byte FineY : 3;
+	};
+
+	Word Raw;
+};
+
 /**
  * @brief The PPU of the NES.
  */
@@ -59,6 +97,9 @@ private:
 	 */
 	void Write(Word addr, Byte val);
 
+	void UpdateState();
+	void PerformRenderAction();
+
 private: // Registers
 
 	union
@@ -115,12 +156,25 @@ private: // Registers
 
 	Address ppuaddr;
 
-	// Current x, y position the PPU operates on
+	VRAMAddress current{ 0 };
-	uint16_t x, y;
+	VRAMAddress temporary{ 0 };
-	Byte latch = 0;
+	uint16_t fineX;
 	bool addressLatch = false;
 
+	Byte latch = 0;
+
+	Word x, y;
+	Byte nametableByte = 0x00;
+	Byte attributeTableByte = 0x00;
+	Byte patternTableLo = 0x00;
+	Byte patternTableHi = 0x00;
+
 private:
+	ScanlineType scanlineType;
+	CycleType cycleType;
+	FetchingPhase fetchPhase;
+
+	uint8_t memoryAccessLatch = 0;
 	bool isFrameDone = false;
 	Bus* bus;
 };

src/debugger/Debugger.cpp

@@ -16,9 +16,13 @@ Debugger::Debugger(Bus* bus) :
 	bus(bus)
 {
 	windows.push_back(new CPUWatcher(this, &bus->cpu));
-	windows.push_back(new PPUWatcher(this, &bus->ppu));
+
+	ppuWatcher = new PPUWatcher(this, &bus->ppu);
+	windows.push_back(ppuWatcher);
+
 	disassembler = new Disassembler(this, &bus->cpu);
 	windows.push_back(disassembler);
+
 	windows.push_back(new MemoryViewer(this, bus));
 	windows.push_back(new NametableViewer(this, bus));
 	windows.push_back(new ControllerPortViewer(this, &bus->controllerPort));
@@ -37,7 +41,7 @@ bool Debugger::Frame()
 		while (!bus->ppu.IsFrameDone())
 		{
 			bus->Tick();
-			if (disassembler->BreakpointHit())
+			if (disassembler->BreakpointHit() || ppuWatcher->BreakpointHit())
 			{
 				running = false;
 				break;
@@ -92,13 +96,18 @@ void Debugger::Render()
 		if (running)
 			ImGui::PushStyleColor(ImGuiCol_Button, ImVec4{ 0.7f, 0.7f, 0.7f, 0.7f });
 
+		if (ImGui::Button("PPU Tick"))
+			bus->PPUTick();
+
+		ImGui::SameLine();
+
 		if (ImGui::Button("Single Step"))
 			bus->Instruction();
 
 		ImGui::SameLine();
 
 		if (ImGui::Button("Single Frame"))
-			bus->Frame();
+			Frame();
 
 		if (running)
 			ImGui::PopStyleColor();

src/debugger/Debugger.hpp

@@ -5,6 +5,7 @@
 
 class Bus;
 class Disassembler;
+class PPUWatcher;
 
 class Debugger
 {
@@ -27,4 +28,5 @@ private:
 
 	std::vector<DebugWindow*> windows;
 	Disassembler* disassembler;
+	PPUWatcher* ppuWatcher;
 };

src/debugger/NametableViewer.cpp

@@ -98,7 +98,7 @@ void NametableViewer::DisplayNametable(uint8_t index)
 
 		for (Word hi = 0x0; hi <= 0x3F; hi++)
 		{
-			Byte hiOffset = hi << 4;
+			Word hiOffset = hi << 4;
 			ImGui::TableNextColumn();
 
 			ImGui::PushStyleColor(ImGuiCol_Text, ImVec4(0.7f, 0.7f, 0.7f, 1.0f));

src/debugger/PPUWatcher.cpp

@@ -1,11 +1,38 @@
 #include "PPUWatcher.hpp"
 
+#include <map>
 #include <imgui/imgui.h>
 #include "../PPU.hpp"
 
+static const std::map<ScanlineType, std::string> scanlineTypeNames = {
+	{ScanlineType::PreRender,	"Pre-render"},
+	{ScanlineType::Visible,		"Visible"},
+	{ScanlineType::PostRender,	"Post-render"},
+	{ScanlineType::VBlank,		"VBlank"}
+};
+
+static const std::map<CycleType, std::string> cycleTypeNames = {
+	{CycleType::Idle,				"Idle"},
+	{CycleType::Fetching,			"Fetching BG Tiles"},
+	{CycleType::SpriteFetching,		"Sprite Fetching"},
+	{CycleType::PreFetching,		"Pre-Fetching"},
+	{CycleType::UnknownFetching,	"Random Fetches"}
+};
+
+static const std::map<FetchingPhase, std::string> fetchingPhaseNames = {
+	{FetchingPhase::NametableByte,		"Nametable"},
+	{FetchingPhase::AttributeTableByte,	"Attribute Table"},
+	{FetchingPhase::PatternTableLo,		"Pattern Table (lo)"},
+	{FetchingPhase::PatternTableHi,		"Pattern Table (hi)"},
+};
+
 PPUWatcher::PPUWatcher(Debugger* debugger, PPU* ppu) :
 	DebugWindow("PPU Watch", debugger), ppu(ppu)
 {
+	breakpoints.emplace_back(ScanlineType::PreRender,	"Pre-Render");
+	breakpoints.emplace_back(ScanlineType::Visible,		"Visible");
+	breakpoints.emplace_back(ScanlineType::PostRender,	"Post-Render");
+	breakpoints.emplace_back(ScanlineType::VBlank,		"VBlank");
 }
 
 void PPUWatcher::OnRender()
@@ -18,135 +45,205 @@ void PPUWatcher::OnRender()
 	}
 
 	ImGui::Text("On Pixel (%d, %d)", ppu->x, ppu->y);
+	ImGui::Text("Scanline      : %s", scanlineTypeNames.find(ppu->scanlineType)->second.c_str());
+	ImGui::Text("Cycle         : %s", cycleTypeNames.find(ppu->cycleType)->second.c_str());
+	ImGui::Text("Fetching Phase: %s", fetchingPhaseNames.find(ppu->fetchPhase)->second.c_str());
 
 	ImGui::Separator();
 
-	if (ImGui::CollapsingHeader("PPUCTRL"))
+	if (ImGui::CollapsingHeader("Internal Registers"))
 	{
-		if (ImGui::BeginTable("ppuctrl", 2))
+		ImGui::Text("Current VRAM Address (v)  : %02X ($%04X)", ppu->current.Raw, 0x2000 | (ppu->current.Raw & 0x0FFF));
+		if (ImGui::TreeNode("Breakdown (v)"))
 		{
-			ImGui::TableNextColumn();
+			ImGui::Text("Coarse X : %02X", ppu->current.CoarseX);
-			ImGui::Text("Base Nametable Addr");
+			ImGui::Text("Coarse Y : %02X", ppu->current.CoarseY);
-			ImGui::TableNextColumn();
+			ImGui::Text("Nametable: %02X", ppu->current.NametableSel);
-			ImGui::Text("$%04X", 0x2000 + 0x400 * ppu->ppuctrl.Flag.BaseNametableAddr);
+			ImGui::Text("Fine Y   : %02X", ppu->current.FineY);
 
-			ImGui::TableNextColumn();
+			ImGui::TreePop();
-			ImGui::Text("VRAM Addr Increment");
+		}
-			ImGui::TableNextColumn();
-			ImGui::Text("%d", ppu->ppuctrl.Flag.VRAMAddrIncrement ? 32 : 1);
 
-			ImGui::TableNextColumn();
+		ImGui::Text("Temporary VRAM Address (t): %02X ($%04X)", ppu->temporary.Raw, 0x2000 | (ppu->current.Raw & 0x0FFF));
-			ImGui::Text("Sprite Pattern Table Addr");
+		if (ImGui::TreeNode("Breakdown (t)"))
-			ImGui::TableNextColumn();
+		{
-			ImGui::Text("$%04X", ppu->ppuctrl.Flag.SpritePatternTableAddr ? 0x1000 : 0x0000);
+			ImGui::Text("Coarse X : %02X", ppu->temporary.CoarseX);
+			ImGui::Text("Coarse Y : %02X", ppu->temporary.CoarseY);
+			ImGui::Text("Nametable: %02X", ppu->temporary.NametableSel);
+			ImGui::Text("Fine Y   : %02X", ppu->temporary.FineY);
 
-			ImGui::TableNextColumn();
+			ImGui::TreePop();
-			ImGui::Text("Backgr Pattern Table Addr");
+		}
-			ImGui::TableNextColumn();
-			ImGui::Text("$%04X", ppu->ppuctrl.Flag.BackgrPatternTableAddr ? 0x1000 : 0x0000);
 
-			ImGui::TableNextColumn();
+		ImGui::Text("Fine X Scroll             : %02X", ppu->fineX);
-			ImGui::Text("Master/Slave");
+		ImGui::Text("Write Toggle Bit          : %02X", ppu->addressLatch);
-			ImGui::TableNextColumn();
+	}
-			ImGui::Text(ppu->ppuctrl.Flag.MasterSlaveSelect ? "Output to EXT" : "Read from EXT");
 
-			ImGui::TableNextColumn();
+	if (ImGui::CollapsingHeader("Latches"))
-			ImGui::Text("VBlank NMI Generation");
+	{
-			ImGui::TableNextColumn();
+		ImGui::Text("Nametable Byte : %02X", ppu->nametableByte);
-			ImGui::Text(ppu->ppuctrl.Flag.VBlankNMI ? "On" : "Off");
+		ImGui::Text("Attribute Byte : %02X", ppu->attributeTableByte);
+		ImGui::Text("Pattern Tile Lo: %02X", ppu->patternTableLo);
+		ImGui::Text("Pattern Tile Hi: %02X", ppu->patternTableHi);
+	}
+	
+	if (ImGui::CollapsingHeader("Registers"))
+	{
+		if (ImGui::TreeNode("PPUCTRL"))
+		{
+			if (ImGui::BeginTable("ppuctrl", 2))
+			{
+				ImGui::TableNextColumn();
+				ImGui::Text("Base Nametable Addr");
+				ImGui::TableNextColumn();
+				ImGui::Text("$%04X", 0x2000 + 0x400 * ppu->ppuctrl.Flag.BaseNametableAddr);
 
-			ImGui::EndTable();
+				ImGui::TableNextColumn();
+				ImGui::Text("VRAM Addr Increment");
+				ImGui::TableNextColumn();
+				ImGui::Text("%d", ppu->ppuctrl.Flag.VRAMAddrIncrement ? 32 : 1);
+
+				ImGui::TableNextColumn();
+				ImGui::Text("Sprite Pattern Table Addr");
+				ImGui::TableNextColumn();
+				ImGui::Text("$%04X", ppu->ppuctrl.Flag.SpritePatternTableAddr ? 0x1000 : 0x0000);
+
+				ImGui::TableNextColumn();
+				ImGui::Text("Backgr Pattern Table Addr");
+				ImGui::TableNextColumn();
+				ImGui::Text("$%04X", ppu->ppuctrl.Flag.BackgrPatternTableAddr ? 0x1000 : 0x0000);
+
+				ImGui::TableNextColumn();
+				ImGui::Text("Master/Slave");
+				ImGui::TableNextColumn();
+				ImGui::Text(ppu->ppuctrl.Flag.MasterSlaveSelect ? "Output to EXT" : "Read from EXT");
+
+				ImGui::TableNextColumn();
+				ImGui::Text("VBlank NMI Generation");
+				ImGui::TableNextColumn();
+				ImGui::Text(ppu->ppuctrl.Flag.VBlankNMI ? "On" : "Off");
+
+				ImGui::EndTable();
+				ImGui::TreePop();
+			}
+		}
+
+		if (ImGui::TreeNode("PPUMASK"))
+		{
+			if (ImGui::BeginTable("ppumask", 2))
+			{
+				ImGui::TableNextColumn();
+				ImGui::Text("Greyscale");
+				ImGui::TableNextColumn();
+				ImGui::Text(ppu->ppumask.Flag.Greyscale ? "On" : "Off");
+
+				ImGui::TableNextColumn();
+				ImGui::Text("Left Col Background");
+				ImGui::TableNextColumn();
+				ImGui::Text(ppu->ppumask.Flag.BackgroundOnLeft ? "Show" : "Hide");
+
+				ImGui::TableNextColumn();
+				ImGui::Text("Left Col Sprites");
+				ImGui::TableNextColumn();
+				ImGui::Text(ppu->ppumask.Flag.SpriteOnLeft ? "Show" : "Hide");
+
+				ImGui::TableNextColumn();
+				ImGui::Text("Show Background");
+				ImGui::TableNextColumn();
+				ImGui::Text(ppu->ppumask.Flag.ShowBackground ? "On" : "Off");
+
+				ImGui::TableNextColumn();
+				ImGui::Text("Show Sprites");
+				ImGui::TableNextColumn();
+				ImGui::Text(ppu->ppumask.Flag.ShowSprites ? "On" : "Off");
+
+				ImGui::TableNextColumn();
+				ImGui::Text("Emphasized Colors");
+				ImGui::TableNextColumn();
+				ImGui::Text("%s%s%s", ppu->ppumask.Flag.EmphasizeRed ? "R" : "-", ppu->ppumask.Flag.EmphasizeGreen ? "G" : "-", ppu->ppumask.Flag.EmphasizeBlue ? "B" : "-");
+
+				ImGui::EndTable();
+				ImGui::TreePop();
+			}
+		}
+
+		if (ImGui::TreeNode("PPUSTATUS"))
+		{
+			if (ImGui::BeginTable("ppustatus", 2))
+			{
+				ImGui::TableNextColumn();
+				ImGui::Text("Lower 5 Bits");
+				ImGui::TableNextColumn();
+				ImGui::Text("%02X", ppu->ppustatus.Flag.Unused);
+
+				ImGui::TableNextColumn();
+				ImGui::Text("Sprite Overflow");
+				ImGui::TableNextColumn();
+				ImGui::Text(ppu->ppustatus.Flag.SpriteOverflow ? "Yes" : "No");
+
+				ImGui::TableNextColumn();
+				ImGui::Text("Sprite 0 Hit");
+				ImGui::TableNextColumn();
+				ImGui::Text(ppu->ppustatus.Flag.SpriteZeroHit ? "Yes" : "No");
+
+				ImGui::TableNextColumn();
+				ImGui::Text("VBlank Started");
+				ImGui::TableNextColumn();
+				ImGui::Text(ppu->ppustatus.Flag.VBlankStarted ? "Yes" : "No");
+
+				ImGui::EndTable();
+				ImGui::TreePop();
+			}
+		}
+
+		if (ImGui::TreeNode("PPUSCROLL & PPUADDR"))
+		{
+			if (ImGui::BeginTable("ppuscrolladdr", 2))
+			{
+				ImGui::TableNextColumn();
+				ImGui::Text("Scroll X");
+				ImGui::TableNextColumn();
+				ImGui::Text("%d", ppu->ppuscroll.x);
+
+				ImGui::TableNextColumn();
+				ImGui::Text("Scroll Y");
+				ImGui::TableNextColumn();
+				ImGui::Text("%d", ppu->ppuscroll.x);
+
+				ImGui::TableNextColumn();
+				ImGui::Text("Address");
+				ImGui::TableNextColumn();
+				ImGui::Text("$%04X", ppu->ppuaddr.Raw);
+
+				ImGui::EndTable();
+				ImGui::TreePop();
+			}
 		}
 	}
 
-	if (ImGui::CollapsingHeader("PPUMASK"))
+	if (ImGui::CollapsingHeader("Breakpoints"))
 	{
-		if (ImGui::BeginTable("ppumask", 2))
+		ImGui::Text("Break at beginning of");
+
+		for (FrameStateBreakpoint& breakpoint : breakpoints)
 		{
-			ImGui::TableNextColumn();
+			ImGui::Checkbox(breakpoint.name.c_str(), &breakpoint.enabled);
-			ImGui::Text("Greyscale");
-			ImGui::TableNextColumn();
-			ImGui::Text(ppu->ppumask.Flag.Greyscale ? "On" : "Off");
-
-			ImGui::TableNextColumn();
-			ImGui::Text("Left Col Background");
-			ImGui::TableNextColumn();
-			ImGui::Text(ppu->ppumask.Flag.BackgroundOnLeft ? "Show" : "Hide");
-
-			ImGui::TableNextColumn();
-			ImGui::Text("Left Col Sprites");
-			ImGui::TableNextColumn();
-			ImGui::Text(ppu->ppumask.Flag.SpriteOnLeft ? "Show" : "Hide");
-
-			ImGui::TableNextColumn();
-			ImGui::Text("Show Background");
-			ImGui::TableNextColumn();
-			ImGui::Text(ppu->ppumask.Flag.ShowBackground ? "On" : "Off");
-
-			ImGui::TableNextColumn();
-			ImGui::Text("Show Sprites");
-			ImGui::TableNextColumn();
-			ImGui::Text(ppu->ppumask.Flag.ShowSprites ? "On" : "Off");
-
-			ImGui::TableNextColumn();
-			ImGui::Text("Emphasized Colors");
-			ImGui::TableNextColumn();
-			ImGui::Text("%s%s%s", ppu->ppumask.Flag.EmphasizeRed ? "R" : "-", ppu->ppumask.Flag.EmphasizeGreen ? "G" : "-", ppu->ppumask.Flag.EmphasizeBlue ? "B" : "-");
-
-			ImGui::EndTable();
-		}
-	}
-
-	if (ImGui::CollapsingHeader("PPUSTATUS"))
-	{
-		if (ImGui::BeginTable("ppustatus", 2))
-		{
-			ImGui::TableNextColumn();
-			ImGui::Text("Lower 5 Bits");
-			ImGui::TableNextColumn();
-			ImGui::Text("%02X", ppu->ppustatus.Flag.Unused);
-
-			ImGui::TableNextColumn();
-			ImGui::Text("Sprite Overflow");
-			ImGui::TableNextColumn();
-			ImGui::Text(ppu->ppustatus.Flag.SpriteOverflow ? "Yes" : "No");
-
-			ImGui::TableNextColumn();
-			ImGui::Text("Sprite 0 Hit");
-			ImGui::TableNextColumn();
-			ImGui::Text(ppu->ppustatus.Flag.SpriteZeroHit ? "Yes" : "No");
-
-			ImGui::TableNextColumn();
-			ImGui::Text("VBlank Started");
-			ImGui::TableNextColumn();
-			ImGui::Text(ppu->ppustatus.Flag.VBlankStarted ? "Yes" : "No");
-
-			ImGui::EndTable();
-		}
-	}
-
-	if (ImGui::CollapsingHeader("PPUSCROLL & PPUADDR"))
-	{
-		if (ImGui::BeginTable("ppuscrolladdr", 2))
-		{
-			ImGui::TableNextColumn();
-			ImGui::Text("Scroll X");
-			ImGui::TableNextColumn();
-			ImGui::Text("%d", ppu->ppuscroll.x);
-
-			ImGui::TableNextColumn();
-			ImGui::Text("Scroll Y");
-			ImGui::TableNextColumn();
-			ImGui::Text("%d", ppu->ppuscroll.x);
-
-			ImGui::TableNextColumn();
-			ImGui::Text("Address");
-			ImGui::TableNextColumn();
-			ImGui::Text("$%04X", ppu->ppuaddr.Raw);
-
-			ImGui::EndTable();
 		}
 	}
 
 	ImGui::End();
 }
+
+bool PPUWatcher::BreakpointHit()
+{
+	if (ppu->x > 2)
+		return false;
+
+	for (const FrameStateBreakpoint& breakpoint : breakpoints)
+	{
+		if (breakpoint.enabled && breakpoint.location == ppu->scanlineType)
+			return true;
+	}
+
+	return false;
+}

src/debugger/PPUWatcher.hpp

@@ -1,8 +1,19 @@
 #pragma once
 
+#include <vector>
 #include "DebugWindow.hpp"
+#include "../PPU.hpp"
 
-class PPU;
+struct FrameStateBreakpoint
+{
+	FrameStateBreakpoint(ScanlineType location, const std::string& name) :
+		location(location), name(name), enabled(false)
+	{ }
+
+	ScanlineType location;
+	std::string name;
+	bool enabled;
+};
 
 class PPUWatcher :
 	public DebugWindow
@@ -11,7 +22,9 @@ public:
 	PPUWatcher(Debugger* debugger, PPU* ppu);
 
 	virtual void OnRender() override;
+	bool BreakpointHit();
 
 private:
 	PPU* ppu;
+	std::vector<FrameStateBreakpoint> breakpoints;
 };