initial commit

src/debugger/CPUWatcher.cpp

@@ -0,0 +1,101 @@
+#include "CPUWatcher.hpp"
+
+#include <iomanip>
+
+#include <imgui/imgui.h>
+#include "../CPU.hpp"
+
+CPUWatcher::CPUWatcher(CPU* cpu) :
+	DebugWindow("CPU Watch"), cpu(cpu)
+{
+}
+
+void CPUWatcher::OnRender()
+{
+	ImGui::SetNextWindowSize(ImVec2(400, 400), ImGuiCond_FirstUseEver);
+	if (!ImGui::Begin(title.c_str(), &isOpen))
+	{
+		ImGui::End();
+		return;
+	}
+
+	ImGui::Text("Registers");
+	if (ImGui::BeginTable("Registers", 6))
+	{
+		ImGui::TableNextColumn();
+		ImGui::Text("A");	
+		ImGui::TableNextColumn();
+		ImGui::Text("X");	
+		ImGui::TableNextColumn();
+		ImGui::Text("Y");	
+		ImGui::TableNextColumn();
+		ImGui::Text("PC");	
+		ImGui::TableNextColumn();
+		ImGui::Text("SP");
+		ImGui::TableNextColumn();
+		ImGui::Text("P");
+		ImGui::TableNextColumn();
+		ImGui::Text("%02X", cpu->acc);	
+		ImGui::TableNextColumn();
+		ImGui::Text("%02X", cpu->idx);	
+		ImGui::TableNextColumn();
+		ImGui::Text("%02X", cpu->idy);
+		ImGui::TableNextColumn();
+		ImGui::Text("%04X", cpu->pc);	
+		ImGui::TableNextColumn();
+		ImGui::Text("%02X", cpu->sp);
+		ImGui::TableNextColumn();
+		ImGui::Text("%02X", cpu->status.Raw);
+	
+		ImGui::EndTable();
+	}
+
+	ImGui::Separator();
+	ImGui::Text("Status Flag Breakdown");
+	if (ImGui::BeginTable("Status", 8))
+	{
+		ImGui::TableNextColumn();
+		ImGui::Text("N");
+		ImGui::TableNextColumn();
+		ImGui::Text("V");
+		ImGui::TableNextColumn();
+		ImGui::Text("U");
+		ImGui::TableNextColumn();
+		ImGui::Text("B");
+		ImGui::TableNextColumn();
+		ImGui::Text("D");
+		ImGui::TableNextColumn();
+		ImGui::Text("I");
+		ImGui::TableNextColumn();
+		ImGui::Text("Z");
+		ImGui::TableNextColumn();
+		ImGui::Text("C");
+
+
+		ImGui::TableNextColumn();
+		ImGui::Text(cpu->status.Flag.Negative ? "1" : "-");
+		ImGui::TableNextColumn();
+		ImGui::Text(cpu->status.Flag.Overflow ? "1" : "-");
+		ImGui::TableNextColumn();
+		ImGui::Text(cpu->status.Flag.NoEffect ? "1" : "-");
+		ImGui::TableNextColumn();
+		ImGui::Text(cpu->status.Flag.Break ? "1" : "-");
+		ImGui::TableNextColumn();
+		ImGui::Text(cpu->status.Flag.Decimal ? "1" : "-");
+		ImGui::TableNextColumn();
+		ImGui::Text(cpu->status.Flag.InterruptDisable ? "1" : "-");
+		ImGui::TableNextColumn();
+		ImGui::Text(cpu->status.Flag.Zero ? "1" : "-");
+		ImGui::TableNextColumn();
+		ImGui::Text(cpu->status.Flag.Carry ? "1" : "-");
+		ImGui::TableNextColumn();
+
+		ImGui::EndTable();
+	}
+
+	ImGui::Separator();
+
+	ImGui::Text("Halted: %s", cpu->halted ? "Yes" : "No");
+
+	ImGui::End();
+}

src/debugger/CPUWatcher.hpp

@@ -0,0 +1,17 @@
+#pragma once
+
+#include "DebugWindow.hpp"
+
+class CPU;
+
+class CPUWatcher :
+	public DebugWindow
+{
+public:
+	CPUWatcher(CPU* cpu);
+
+	virtual void OnRender() override;
+
+private:
+	CPU* cpu;
+};

src/debugger/DebugWindow.hpp

@@ -0,0 +1,19 @@
+#pragma once
+
+#include <string>
+
+class DebugWindow
+{
+public:
+	DebugWindow(const std::string& title) :
+		title(title)
+	{
+	}
+
+	virtual ~DebugWindow() = default;
+	virtual void OnRender() = 0;
+
+public:
+	const std::string title;
+	bool isOpen = false;
+};

src/debugger/Debugger.cpp

@@ -0,0 +1,127 @@
+#include "Debugger.hpp"
+
+#include <imgui/imgui.h>
+#include <imgui/imgui_internal.h>
+
+#include "../Bus.hpp"
+#include "CPUWatcher.hpp"
+#include "PPUWatcher.hpp"
+#include "Disassembler.hpp"
+#include "MemoryViewer.hpp"
+#include "NametableViewer.hpp"
+
+Debugger::Debugger(Bus* bus) :
+	bus(bus)
+{
+	windows.push_back(new CPUWatcher(&bus->cpu));
+	windows.push_back(new PPUWatcher(&bus->ppu));
+	windows.push_back(new Disassembler(&bus->cpu));
+	windows.push_back(new MemoryViewer(bus));
+	windows.push_back(new NametableViewer(bus));
+}
+
+Debugger::~Debugger()
+{
+	for (DebugWindow* window : windows)
+		delete window;
+}
+
+bool Debugger::Update()
+{
+	if (running)
+		return bus->Frame();
+
+	return true;
+}
+
+void Debugger::Render()
+{
+	ImGui::SetNextWindowSize(ImVec2(400, 600), ImGuiCond_FirstUseEver);
+	if (!ImGui::Begin("Debugger", (bool*)0, ImGuiWindowFlags_MenuBar))
+	{
+		ImGui::End();
+		return;
+	}
+
+	if (ImGui::BeginMenuBar())
+	{
+		if (ImGui::BeginMenu("Tools"))
+		{
+			for (DebugWindow* window : windows)
+			{
+				ImGui::MenuItem(window->title.c_str(), NULL, &window->isOpen);
+			}
+
+			ImGui::EndMenu();
+		}
+
+		ImGui::EndMenuBar();
+	}
+
+	ImGui::Separator();
+
+	if (ImGui::CollapsingHeader("Controls", ImGuiTreeNodeFlags_DefaultOpen))
+	{
+		ImGui::PushItemFlag(ImGuiItemFlags_Disabled, running);
+		if (running)
+			ImGui::PushStyleColor(ImGuiCol_Button, ImVec4{ 0.7f, 0.7f, 0.7f, 0.7f });
+
+		if (ImGui::Button("Single Step"))
+			bus->Instruction();
+
+		ImGui::SameLine();
+
+		if (ImGui::Button("Single Frame"))
+			bus->Frame();
+
+		if (running)
+			ImGui::PopStyleColor();
+		ImGui::PopItemFlag();
+
+		ImGui::SameLine();
+
+		if (ImGui::Button(running ? "Pause" : "Run"))
+			running = !running;
+
+		ImGui::PushItemFlag(ImGuiItemFlags_Disabled, running);
+		if (running)
+			ImGui::PushStyleColor(ImGuiCol_Button, ImVec4{ 0.7f, 0.7f, 0.7f, 0.7f });
+
+		if (ImGui::Button("Reset"))
+		{
+			bus->Reset();
+			if (overrideResetVector)
+				bus->cpu.pc.Raw = resetVector;
+		}
+
+		ImGui::SameLine();
+
+		if (ImGui::Button("Reboot"))
+		{
+			bus->Reboot();
+			if (overrideResetVector)
+				bus->cpu.pc.Raw = resetVector;
+		}
+
+		if (running)
+			ImGui::PopStyleColor();
+		ImGui::PopItemFlag();
+
+
+		ImGui::Separator();
+
+		ImGui::Text("Override Reset Vector: ");
+		ImGui::SameLine();
+		if (ImGui::Button(overrideResetVector ? "Yes" : "No"))
+			overrideResetVector = !overrideResetVector;
+
+		ImGui::InputScalar("Reset Vector", ImGuiDataType_U16, &resetVector, (const void*)0, (const void*)0, "%04X", ImGuiInputTextFlags_CharsHexadecimal);
+	}
+
+	for (DebugWindow* window : windows)
+	{
+		if (window->isOpen) window->OnRender();
+	}
+
+	ImGui::End();
+}

src/debugger/Debugger.hpp

@@ -0,0 +1,27 @@
+#pragma once
+
+#include <vector>
+#include "DebugWindow.hpp"
+
+class Bus;
+
+class Debugger
+{
+public:
+	Debugger(Bus* bus);
+	~Debugger();
+
+	bool Update();
+	void Render();
+
+public:
+	bool isOpen = true;
+
+private:
+	Bus* bus;
+	bool running = false;
+	bool overrideResetVector = false;
+	uint16_t resetVector = 0x0000;
+
+	std::vector<DebugWindow*> windows;
+};

src/debugger/Disassembler.cpp

@@ -0,0 +1,177 @@
+#include "Disassembler.hpp"
+
+#include <iomanip>
+#include <imgui/imgui.h>
+#include "../Mapper.hpp"
+#include "../CPU.hpp"
+
+#define FORMAT std::setfill('0') << std::setw(4) << std::hex << std::uppercase
+
+Disassembler::Disassembler(CPU* cpu) :
+	DebugWindow("Disassembler"), cpu(cpu)
+{
+	
+}
+
+void Disassembler::OnRender()
+{
+	static bool scrollCenter = true;
+
+	ImGui::SetNextWindowSize(ImVec2(400, 400), ImGuiCond_FirstUseEver);
+
+	if (!ImGui::Begin(title.c_str(), &isOpen))
+	{
+		ImGui::End();
+		return;
+	}
+
+	std::string disassembly;
+
+	ImGui::PushStyleColor(ImGuiCol_Text, ImVec4{ 0.8f, 0.8f, 0.8f, 1.0f });
+	if (cpu->pastPCs.size() < 50)
+	{
+		for (int i = 0; i < 50 - cpu->pastPCs.size(); i++)
+		{
+			ImGui::Text("-");
+		}
+	}
+
+	for (Word pc : cpu->pastPCs)
+	{
+		Disassemble(disassembly, pc);
+		ImGui::Text("- %s", disassembly.c_str());
+	}
+	ImGui::PopStyleColor();
+
+	ImGui::Separator();
+
+	uint16_t pc = cpu->pc.Raw;
+	Disassemble(disassembly, pc);
+	ImGui::Text("> %s", disassembly.c_str());
+
+	if (scrollCenter)
+	{
+		ImGui::SetScrollHereY(0.5f);
+		scrollCenter = false;
+	}
+
+	ImGui::Separator();
+
+	ImGui::PushStyleColor(ImGuiCol_Text, ImVec4{ 0.8f, 0.8f, 0.8f, 1.0f });
+	for (int i = 0; i < 50; i++)
+	{
+		Disassemble(disassembly, pc);
+		ImGui::Text("+ %s", disassembly.c_str());
+	}
+	ImGui::PopStyleColor();
+
+	ImGui::End();
+}
+
+void Disassembler::Disassemble(std::string& target, uint16_t& pc)
+{
+	std::stringstream ss;
+	ss <<  FORMAT << pc << ": ";
+	Instruction* currentInstr = &cpu->InstructionTable[cpu->Read(pc)];
+
+	for (int i = 0; i < currentInstr->Size; i++)
+	{
+		ss << FORMAT << std::setw(2) << (Word)cpu->Read(pc + i) << " ";
+	}
+	ss << std::string(15 - ss.str().size(), ' ') << currentInstr->Mnemonic << " ";
+
+	Address absoluteAddress;
+	switch (currentInstr->AddrType)
+	{
+	case Addressing::ACC:
+		ss << "A";
+		break;
+
+	case Addressing::ABS:
+	{
+		absoluteAddress.Bytes.lo = cpu->Read(pc + 1);
+		absoluteAddress.Bytes.hi = cpu->Read(pc + 2);
+
+		ss << "$" << FORMAT << absoluteAddress.Raw;
+	} break;
+
+	case Addressing::ABX:
+	{
+		absoluteAddress.Bytes.lo = cpu->Read(pc + 1);
+		absoluteAddress.Bytes.hi = cpu->Read(pc + 2);
+
+		ss << "$" << FORMAT << absoluteAddress.Raw << ",X";
+	} break;
+
+	case Addressing::ABY:
+	{
+		absoluteAddress.Bytes.lo = cpu->Read(pc + 1);
+		absoluteAddress.Bytes.hi = cpu->Read(pc + 2);
+
+		ss << "$" << FORMAT << absoluteAddress.Raw << ",Y";
+	} break;
+
+	case Addressing::IMM:
+	{
+		Word value = cpu->Read(pc + 1);
+
+		ss << "#$" << FORMAT << std::setw(2) << value;
+	} break;
+
+	case Addressing::IMP: 
+		break;
+
+	case Addressing::IND:
+	{
+		absoluteAddress.Bytes.lo = cpu->Read(pc + 1);
+		absoluteAddress.Bytes.hi = cpu->Read(pc + 2);
+
+		ss << "($" << FORMAT << absoluteAddress.Raw << ")";
+	} break;
+
+	case Addressing::IDX:
+	{
+		absoluteAddress.Bytes.lo = cpu->Read(pc + 1);
+
+		ss << "($" << FORMAT << std::setw(2) << (Word)absoluteAddress.Bytes.lo << ",X)";
+	} break;
+
+	case Addressing::IDY:
+	{
+		absoluteAddress.Bytes.lo = cpu->Read(pc + 1);
+
+		ss << "($" << FORMAT << std::setw(2) << (Word)absoluteAddress.Bytes.lo << "),Y";
+	} break;
+
+	case Addressing::REL:
+	{
+		absoluteAddress.Bytes.lo = cpu->Read(pc + 1);
+
+		ss << "$" << FORMAT << std::setw(2) << (Word)absoluteAddress.Bytes.lo;
+	} break;
+
+	case Addressing::ZPG:
+	{
+		absoluteAddress.Bytes.lo = cpu->Read(pc + 1);
+
+		ss << "$" << FORMAT << std::setw(2) << (Word)absoluteAddress.Bytes.lo;
+	} break;
+
+	case Addressing::ZPX:
+	{
+		absoluteAddress.Bytes.lo = cpu->Read(pc + 1);
+
+		ss << "$" << FORMAT << std::setw(2) << (Word)absoluteAddress.Bytes.lo << ",X";
+	} break;
+
+	case Addressing::ZPY:
+	{
+		absoluteAddress.Bytes.lo = cpu->Read(pc + 1);
+
+		ss << "$" << FORMAT << std::setw(2) << (Word)absoluteAddress.Bytes.lo << ",Y";
+	} break;
+	}
+
+	pc += currentInstr->Size;
+	target = ss.str();
+}

src/debugger/Disassembler.hpp

@@ -0,0 +1,20 @@
+#pragma once
+
+#include "DebugWindow.hpp"
+
+class CPU;
+
+class Disassembler :
+	public DebugWindow
+{
+public:
+	Disassembler(CPU* cpu);
+	
+	virtual void OnRender() override;
+
+private:
+	void Disassemble(std::string& target, uint16_t& pc);
+
+private:
+	CPU* cpu;
+};

src/debugger/MemoryViewer.cpp

@@ -0,0 +1,78 @@
+#include "MemoryViewer.hpp"
+
+#include <imgui/imgui.h>
+#include "../Bus.hpp"
+
+MemoryViewer::MemoryViewer(Bus* bus) :
+	DebugWindow("Memory Viewer"), bus(bus)
+{
+}
+
+void MemoryViewer::OnRender()
+{
+	ImGui::SetNextWindowSize(ImVec2(400, 400), ImGuiCond_FirstUseEver);
+
+	if (!ImGui::Begin(title.c_str(), &isOpen))
+	{
+		ImGui::End();
+		return;
+	}
+
+	ImGui::BeginTabBar("Pages");
+
+	for (Byte page = 0; page < 8; page++)
+	{
+		char title[7];
+		std::sprintf(title, "Page %d", page);
+		if (ImGui::BeginTabItem(title))
+		{
+			DrawPage(page);
+			ImGui::EndTabItem();
+		}
+	}
+
+	ImGui::EndTabBar();
+	ImGui::End();
+}
+
+void MemoryViewer::DrawPage(Byte page)
+{
+	Word baseAddr = ((Word)page << 8);
+	if (ImGui::BeginTable("memorymap", 17))
+	{
+		ImGui::TableNextColumn();
+		ImGui::PushStyleColor(ImGuiCol_Text, ImVec4(0.7f, 0.7f, 0.7f, 1.0f));
+		for (Byte header = 0x0; header < 0x10; header++)
+		{
+			ImGui::TableNextColumn();
+			ImGui::Text("%X", header);
+		}
+		ImGui::PopStyleColor();
+
+		for (Byte hi = 0x0; hi <= 0xF; hi++)
+		{
+			Byte hiOffset = hi << 4;
+			ImGui::TableNextColumn();
+
+			ImGui::PushStyleColor(ImGuiCol_Text, ImVec4(0.7f, 0.7f, 0.7f, 1.0f));
+			ImGui::Text("%04X", baseAddr | hiOffset);
+			ImGui::PopStyleColor();
+
+			for (Byte lo = 0x0; lo <= 0xF; lo++)
+			{
+				ImGui::TableNextColumn();
+
+				Byte entry = bus->RAM[baseAddr | hiOffset | lo];
+
+				if (entry == 0x00)
+					ImGui::PushStyleColor(ImGuiCol_Text, ImVec4(0.7f, 0.7f, 0.7f, 1.0f));
+
+				ImGui::Text("%02X", entry);
+
+				if (entry == 0x00)
+					ImGui::PopStyleColor();
+			}
+		}
+		ImGui::EndTable();
+	}
+}

src/debugger/MemoryViewer.hpp

@@ -0,0 +1,21 @@
+#pragma once
+
+#include "DebugWindow.hpp"
+#include "../Types.hpp"
+
+class Bus;
+
+class MemoryViewer :
+	public DebugWindow
+{
+public:
+	MemoryViewer(Bus* bus);
+
+	virtual void OnRender() override;
+
+private:
+	void DrawPage(Byte page);
+
+private:
+	Bus* bus;
+};

src/debugger/NametableViewer.cpp

@@ -0,0 +1,78 @@
+#include "NametableViewer.hpp"
+
+#include <imgui/imgui.h>
+#include "../Bus.hpp"
+
+NametableViewer::NametableViewer(Bus* bus) :
+	DebugWindow("Nametable Viewer"), bus(bus)
+{
+}
+
+void NametableViewer::OnRender()
+{
+	ImGui::SetNextWindowSize(ImVec2(400, 400), ImGuiCond_FirstUseEver);
+	if (!ImGui::Begin(title.c_str(), &isOpen))
+	{
+		ImGui::End();
+		return;
+	}
+
+	ImGui::BeginTabBar("Nametables");
+	for (uint8_t index = 0; index < 4; index++)
+	{
+		char baseAddress[6];
+		std::sprintf(baseAddress, "$2%X00", index * 4);
+		if (ImGui::BeginTabItem(baseAddress))
+		{
+			DisplayNametable(index);
+			ImGui::EndTabItem();
+		}
+
+	}
+	ImGui::EndTabBar();
+
+	ImGui::End();
+}
+
+void NametableViewer::DisplayNametable(uint8_t index)
+{
+	Word baseAddr = 0x400 * index;
+	Word displayBaseAddr = 0x2000 + baseAddr;
+	if (ImGui::BeginTable("memorymap", 17))
+	{
+		ImGui::TableNextColumn();
+		ImGui::PushStyleColor(ImGuiCol_Text, ImVec4(0.7f, 0.7f, 0.7f, 1.0f));
+		for (Byte header = 0x0; header < 0x10; header++)
+		{
+			ImGui::TableNextColumn();
+			ImGui::Text("%X", header);
+		}
+		ImGui::PopStyleColor();
+
+		for (Word hi = 0x0; hi <= 0x3F; hi++)
+		{
+			Byte hiOffset = hi << 4;
+			ImGui::TableNextColumn();
+
+			ImGui::PushStyleColor(ImGuiCol_Text, ImVec4(0.7f, 0.7f, 0.7f, 1.0f));
+			ImGui::Text("%04X", displayBaseAddr | hiOffset);
+			ImGui::PopStyleColor();
+
+			for (Byte lo = 0x0; lo <= 0xF; lo++)
+			{
+				ImGui::TableNextColumn();
+
+				Byte entry = bus->VRAM[baseAddr | hiOffset | lo];
+
+				if (entry == 0x00)
+					ImGui::PushStyleColor(ImGuiCol_Text, ImVec4(0.7f, 0.7f, 0.7f, 1.0f));
+
+				ImGui::Text("%02X", entry);
+
+				if (entry == 0x00)
+					ImGui::PopStyleColor();
+			}
+		}
+		ImGui::EndTable();
+	}
+}

src/debugger/NametableViewer.hpp

@@ -0,0 +1,20 @@
+#pragma once
+
+#include "DebugWindow.hpp"
+
+class Bus;
+
+class NametableViewer :
+	public DebugWindow
+{
+public:
+	NametableViewer(Bus* bus);
+
+	virtual void OnRender() override;
+	
+private:
+	void DisplayNametable(uint8_t index);
+
+private:
+	Bus* bus;
+};

src/debugger/PPUWatcher.cpp

@@ -0,0 +1,152 @@
+#include "PPUWatcher.hpp"
+
+#include <imgui/imgui.h>
+#include "../PPU.hpp"
+
+PPUWatcher::PPUWatcher(PPU* ppu) :
+	DebugWindow("PPU Watch"), ppu(ppu)
+{
+}
+
+void PPUWatcher::OnRender()
+{
+	ImGui::SetNextWindowSize(ImVec2(400, 400), ImGuiCond_FirstUseEver);
+	if (!ImGui::Begin(title.c_str(), &isOpen))
+	{
+		ImGui::End();
+		return;
+	}
+
+	ImGui::Text("On Pixel (%d, %d)", ppu->x, ppu->y);
+
+	ImGui::Separator();
+
+	if (ImGui::CollapsingHeader("PPUCTRL"))
+	{
+		if (ImGui::BeginTable("ppuctrl", 2))
+		{
+			ImGui::TableNextColumn();
+			ImGui::Text("Base Nametable Addr");
+			ImGui::TableNextColumn();
+			ImGui::Text("$%04X", 0x2000 + 0x400 * ppu->ppuctrl.Flag.BaseNametableAddr);
+
+			ImGui::TableNextColumn();
+			ImGui::Text("VRAM Addr Increment");
+			ImGui::TableNextColumn();
+			ImGui::Text("%d", ppu->ppuctrl.Flag.VRAMAddrIncrement ? 32 : 1);
+
+			ImGui::TableNextColumn();
+			ImGui::Text("Sprite Pattern Table Addr");
+			ImGui::TableNextColumn();
+			ImGui::Text("$%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();
+		}
+	}
+
+	if (ImGui::CollapsingHeader("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();
+		}
+	}
+
+	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();
+}

src/debugger/PPUWatcher.hpp

@@ -0,0 +1,17 @@
+#pragma once
+
+#include "DebugWindow.hpp"
+
+class PPU;
+
+class PPUWatcher :
+	public DebugWindow
+{
+public:
+	PPUWatcher(PPU* ppu);
+
+	virtual void OnRender() override;
+
+private:
+	PPU* ppu;
+};