Cartridge.cpp

/*
	olc::NES - Cartridge
	"Thanks Dad for believing computers were gonna be a big deal..." - javidx9

	License (OLC-3)
	~~~~~~~~~~~~~~~

	Copyright 2018-2019 OneLoneCoder.com

	Redistribution and use in source and binary forms, with or without
	modification, are permitted provided that the following conditions
	are met:

	1. Redistributions or derivations of source code must retain the above
	copyright notice, this list of conditions and the following disclaimer.

	2. Redistributions or derivative works in binary form must reproduce
	the above copyright notice. This list of conditions and the following
	disclaimer must be reproduced in the documentation and/or other
	materials provided with the distribution.

	3. Neither the name of the copyright holder nor the names of its
	contributors may be used to endorse or promote products derived
	from this software without specific prior written permission.

	THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
	"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
	LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
	A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
	HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
	SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
	LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
	DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
	THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
	(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
	OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.


	Relevant Video: https://youtu.be/-THeUXqR3zY

	Links
	~~~~~
	YouTube:	https://www.youtube.com/javidx9
				https://www.youtube.com/javidx9extra
	Discord:	https://discord.gg/WhwHUMV
	Twitter:	https://www.twitter.com/javidx9
	Twitch:		https://www.twitch.tv/javidx9
	GitHub:		https://www.github.com/onelonecoder
	Patreon:	https://www.patreon.com/javidx9
	Homepage:	https://www.onelonecoder.com

	Author
	~~~~~~
	David Barr, aka javidx9, �OneLoneCoder 2019
*/

#include "Cartridge.h"

Cartridge::Cartridge(const std::string& sFileName)
{
    // iNES Format Header
    struct sHeader
    {
        char name[4];
        uint8_t prg_rom_chunks;
        uint8_t chr_rom_chunks;
        uint8_t mapper1;
        uint8_t mapper2;
        uint8_t prg_ram_size;
        uint8_t tv_system1;
        uint8_t tv_system2;
        char unused[5];
    } header;

    bImageValid = false;

    std::ifstream ifs;
    ifs.open(sFileName, std::ifstream::binary);
    if (ifs.is_open())
    {
        // Read file header
        ifs.read((char*)&header, sizeof(sHeader));

        // If a "trainer" exists we just need to read past
        // it before we get to the good stuff
        if (header.mapper1 & 0x04)
            ifs.seekg(512, std::ios_base::cur);

        // Determine Mapper ID
        nMapperID = ((header.mapper2 >> 4) << 4) | (header.mapper1 >> 4);
        mirror = (header.mapper1 & 0x01) ? VERTICAL : HORIZONTAL;

        // "Discover" File Format
        uint8_t nFileType = 1;

        if (nFileType == 0)
        {

        }

        if (nFileType == 1)
        {
            nPRGBanks = header.prg_rom_chunks;
            vPRGMemory.resize(nPRGBanks * 16384);
            ifs.read((char*)vPRGMemory.data(), vPRGMemory.size());

			nCHRBanks = header.chr_rom_chunks;
			if (nCHRBanks == 0)
			{
				// Create CHR RAM
				vCHRMemory.resize(8192);
			}
			else
			{
				// Allocate for ROM
				vCHRMemory.resize(nCHRBanks * 8192);
			}
			ifs.read((char*)vCHRMemory.data(), vCHRMemory.size());
		}

        if (nFileType == 2)
        {

        }

		// Load appropriate mapper
		switch (nMapperID)
		{
		case   0: pMapper = std::make_shared<Mapper_000>(nPRGBanks, nCHRBanks); break;
		//case   2: pMapper = std::make_shared<Mapper_002>(nPRGBanks, nCHRBanks); break;
		//case   3: pMapper = std::make_shared<Mapper_003>(nPRGBanks, nCHRBanks); break;
		//case  66: pMapper = std::make_shared<Mapper_066>(nPRGBanks, nCHRBanks); break;
		}

        bImageValid = true;
        ifs.close();
    }

}


Cartridge::~Cartridge()
{
}

bool Cartridge::ImageValid()
{
    return bImageValid;
}

bool Cartridge::cpuRead(uint16_t addr, uint8_t &data)
{
    uint32_t mapped_addr = 0;
    if (pMapper->cpuMapRead(addr, mapped_addr))
    {
        data = vPRGMemory[mapped_addr];
        return true;
    }
    else
        return false;
}

bool Cartridge::cpuWrite(uint16_t addr, uint8_t data)
{
    uint32_t mapped_addr = 0;
    if (pMapper->cpuMapWrite(addr, mapped_addr))
    {
        vPRGMemory[mapped_addr] = data;
        return true;
    }
    else
        return false;
}

bool Cartridge::ppuRead(uint16_t addr, uint8_t & data)
{
    uint32_t mapped_addr = 0;
    if (pMapper->ppuMapRead(addr, mapped_addr))
    {
        data = vCHRMemory[mapped_addr];
        return true;
    }
    else
        return false;
}

bool Cartridge::ppuWrite(uint16_t addr, uint8_t data)
{
    uint32_t mapped_addr = 0;
    if (pMapper->ppuMapRead(addr, mapped_addr))
    {
        vCHRMemory[mapped_addr] = data;
        return true;
    }
    else
        return false;
}


void Cartridge::reset()
{
	// Note: This does not reset the ROM contents,
	// but does reset the mapper.
	if (pMapper != nullptr)
		pMapper->reset();
}