Merge pull request #129 from wheremyfoodat/cheats

Add preliminary cheat support

include/action_replay.hpp

@@ -0,0 +1,43 @@
+#pragma once
+#include <array>
+#include <vector>
+
+#include "helpers.hpp"
+#include "memory.hpp"
+
+class ActionReplay {
+	using Cheat = std::vector<u32>;  // A cheat is really just a bunch of 64-bit opcodes neatly encoded into 32-bit chunks
+
+	u32 offset1, offset2;    // Memory offset registers. Non-persistent.
+	u32 data1, data2;        // Data offset registers. Non-persistent.
+	u32 storage1, storage2;  // Storage registers. Persistent.
+
+	// When an instruction does not specify which offset or data register to use, we use the "active" one
+	// Which is by default #1 and may be changed by certain AR operations
+	u32 *activeOffset, *activeData, *activeStorage;
+	
+	// Program counter
+	u32 pc = 0;
+	Memory& mem;
+
+	// Has the cheat ended?
+	bool running = false;
+	// Run 1 AR instruction
+	void runInstruction(const Cheat& cheat, u32 instruction);
+
+	// Action Replay has a billion D-type opcodes so this handles all of them
+	void executeDType(const Cheat& cheat, u32 instruction);
+
+	u8 read8(u32 addr);
+	u16 read16(u32 addr);
+	u32 read32(u32 addr);
+
+	void write8(u32 addr, u8 value);
+	void write16(u32 addr, u16 value);
+	void write32(u32 addr, u32 value);
+
+  public:
+	ActionReplay(Memory& mem);
+	void runCheat(const Cheat& cheat);
+	void reset();
+};

include/cheats.hpp

@@ -0,0 +1,31 @@
+#pragma once
+#include <array>
+#include <vector>
+
+#include "action_replay.hpp"
+#include "helpers.hpp"
+
+// Forward-declare this since it's just passed and we don't want to include memory.hpp and increase compile time
+class Memory;
+
+class Cheats {
+  public:
+	enum class CheatType {
+		ActionReplay,  // CTRPF cheats
+		Gateway,
+	};
+
+	struct Cheat {
+		CheatType type;
+		std::vector<u32> instructions;
+	};
+
+	Cheats(Memory& mem);
+	void addCheat(const Cheat& cheat);
+	void reset();
+	void run();
+
+  private:
+	ActionReplay ar; // An ActionReplay cheat machine for executing CTRPF codes
+	std::vector<Cheat> cheats;
+};

include/emulator.hpp

@@ -7,6 +7,7 @@
 #include <optional>
 
 #include "PICA/gpu.hpp"
+#include "cheats.hpp"
 #include "config.hpp"
 #include "cpu.hpp"
 #include "crypto/aes_engine.hpp"
@@ -31,6 +32,7 @@ class Emulator {
 	Memory memory;
 	Kernel kernel;
 	Crypto::AESEngine aesEngine;
+	Cheats cheats;
 
 	SDL_Window* window;
 
@@ -41,6 +43,9 @@ class Emulator {
 	SDL_GameController* gameController = nullptr;
 	int gameControllerID;
 
+	// Shows whether we've loaded any action replay codes
+	bool haveCheats = false;
+
 	// Variables to keep track of whether the user is controlling the 3DS analog stick with their keyboard
 	// This is done so when a gamepad is connected, we won't automatically override the 3DS analog stick settings with the gamepad's state
 	// And so the user can still use the keyboard to control the analog