Mesen/Core/MMC3_14.h

#pragma once
#include "stdafx.h"
#include "MMC3.h"

class MMC3_14 : public MMC3
{
private:
	uint8_t _vrcChrRegs[8];
	uint8_t _vrcPrgRegs[2];
	uint8_t _vrcMirroring;
	uint8_t _mode;

protected:
	virtual void InitMapper()
	{
		_mode = 0;
		_vrcMirroring = 0;
		memset(_vrcPrgRegs, 0, sizeof(_vrcPrgRegs));
		memset(_vrcChrRegs, 0, sizeof(_vrcChrRegs));

		MMC3::InitMapper();
	}

	virtual void StreamState(bool saving)
	{
		MMC3::StreamState(saving);
		ArrayInfo<uint8_t> prgRegs{ _vrcPrgRegs, 2 };
		ArrayInfo<uint8_t> chrRegs{ _vrcChrRegs, 8 };
		Stream(_mode, _vrcMirroring, prgRegs, chrRegs);
	}

	virtual void SelectCHRPage(uint16_t slot, uint16_t page, ChrMemoryType memoryType = ChrMemoryType::Default)
	{
		if(_mode & 0x02) {
			if(slot <= 3) {
				if(!_chrMode && (_mode & 0x80) || _chrMode && slot <= 1 && (_mode & 0x20) || _chrMode && slot >= 2 && (_mode & 0x08)) {
					page |= 0x100;
				}
			} else {
				if(_chrMode && (_mode & 0x80) || !_chrMode && slot <= 5 && (_mode & 0x20) || !_chrMode && slot >= 6 && (_mode & 0x08)) {
					page |= 0x100;
				}
			}
		}
		MMC3::SelectCHRPage(slot, page, memoryType);
	}

	void UpdateVrcState()
	{
		SelectPRGPage(0, _vrcPrgRegs[0]);
		SelectPRGPage(1, _vrcPrgRegs[1]);
		SelectPRGPage(2, -2);
		SelectPRGPage(3, -1);

		for(int i = 0; i < 8; i++) {
			SelectCHRPage(i, _vrcChrRegs[i]);
		}
		
		SetMirroringType(_vrcMirroring & 0x01 ? MirroringType::Horizontal : MirroringType::Vertical);
	}

	void WriteRegister(uint16_t addr, uint8_t value)
	{
		if(addr == 0xA131) {
			_mode = value;
		}

		if(_mode & 0x02) {
			MMC3::UpdateState();
			MMC3::WriteRegister(addr, value);
		} else {
			if(addr >= 0xB000 && addr <= 0xEFFF) {
				uint8_t regNumber = ((((addr >> 12) & 0x07) - 3) << 1) + ((addr >> 1) & 0x01);
				bool lowBits = (addr & 0x01) == 0x00;
				if(lowBits) {
					_vrcChrRegs[regNumber] = (_vrcChrRegs[regNumber] & 0xF0) | value & 0x0F;
				} else {
					_vrcChrRegs[regNumber] = (_vrcChrRegs[regNumber] & 0x0F) | ((value & 0x0F) << 4);
				}
			} else {
				switch(addr & 0xF003) {
					case 0x8000: _vrcPrgRegs[0] = value; break;
					case 0x9000: _vrcMirroring = value; break;
					case 0xA000: _vrcPrgRegs[1] = value; break;
				}
			}
			UpdateVrcState();
		}
	}
};