Parsing header of SPC file format and stop update (for now)

sources/Cartridge/Cartridge.cpp

@@ -98,13 +98,15 @@ namespace ComSquare::Cartridge
 
 	uint32_t Cartridge::_getHeaderAddress()
 	{
-		const std::vector<uint32_t> address = {0x7FC0, 0xFFC0, 0x81C0, 0x101C0};
+		const std::vector<uint32_t> address = {0x7FC0, 0xFFC0};
+		unsigned int smc = this->_size % 1024;
 		int bestScore = -1;
 		uint32_t bestAddress = 0;
 
 		for (uint32_t addr : address) {
 			int score = 0;
 
+			addr += smc;
 			if (addr + 0x32u >= this->_size)
 				continue;
 
@@ -156,10 +158,30 @@ namespace ComSquare::Cartridge
 		return bestAddress;
 	}
 
+	bool Cartridge::_isSPCFile()
+	{
+		std::string str = std::string(reinterpret_cast<char *>(this->_data), 0x21);
+
+		if (str != "SNES-SPC700 Sound File Data v0.30")
+			return false;
+		if (this->_data[0x21] != 0x1A || this->_data[0x22] != 0x1A)
+			return false;
+		if (this->_data[0x23] != 0x1A && this->_data[0x23] != 0x1B)
+			return false;
+		if (this->_data[0x24] != 0x1E)
+			return false;
+		return true;
+	}
+
 	bool Cartridge::_loadHeader()
 	{
+		if (this->_isSPCFile()) {
+			this->_type = Audio;
+			return false;
+		}
 		uint32_t headerAddress = this->_getHeaderAddress();
 
+		this->_type = Game;
 		this->header = this->_mapHeader(headerAddress);
 		this->header.gameName = std::string(reinterpret_cast<char *>(&this->_data[headerAddress]), 21);
 		if ((headerAddress + 0x40u) & 0x200u) {
@@ -169,4 +191,9 @@ namespace ComSquare::Cartridge
 		}
 		return false;
 	}
+
+	CartridgeType Cartridge::getType()
+	{
+		return this->_type;
+	}
 }

sources/Cartridge/Cartridge.hpp

@@ -13,6 +13,11 @@
 
 namespace ComSquare::Cartridge
 {
+	enum CartridgeType {
+		Game,
+		Audio
+	};
+
 	#define ADDMAPPINGMODE(x, flag) (x = static_cast<MappingMode>(x | (flag)))
 	enum MappingMode {
 		LoRom = 1u << 0u,
@@ -75,6 +80,8 @@ namespace ComSquare::Cartridge
 		//! @brief Set the public variable header by parsing the header in the ROM.
 		//! @return True if this cartridge has a SCM header, false otherwise.
 		bool _loadHeader();
+		//! @brief Check if the cartridge is not a game but a SPC audio dump
+		bool _isSPCFile();
 		//! @brief Get the address of the header.
 		//! @return The address of this cartridge header.
 		uint32_t _getHeaderAddress();
@@ -82,6 +89,8 @@ namespace ComSquare::Cartridge
 		//! @param headerAddress The address you want to parse.
 		//! @return A header struct representing the data at the memory address you passed.
 		Header _mapHeader(uint32_t headerAddress);
+		//! @brief Current type of the cartridge
+		CartridgeType _type;
 	public:
 		//! @brief Load a rom from it's path.
 		explicit Cartridge(const std::string &romPath);
@@ -94,6 +103,8 @@ namespace ComSquare::Cartridge
 
 		//! @brief The header of the cartridge.
 		Header header;
+		//! @brief Return current type of the cartridge
+		CartridgeType getType();
 		//! @brief Read from the rom.
 		//! @param addr The address to read from. The address 0x0 should refer to the first byte of the rom's memory.
 		//! @throw InvalidAddress will be thrown if the address is more than the size of the rom's memory.

sources/SNES.cpp

@@ -28,6 +28,9 @@ namespace ComSquare
 
 	void SNES::update()
 	{
+		if (this->cartridge->getType() == Cartridge::Audio)
+			return;
+
 		unsigned cycleCount = this->cpu->update();
 		this->ppu->update(cycleCount);
 		this->apu->update(cycleCount);