Mesen/Core/MMC3_Coolboy.h
2016-12-17 23:14:47 -05:00

106 lines
2.7 KiB
C++

#pragma once
#include "stdafx.h"
#include "MMC3.h"
//Mostly taken from FCEUX's code
class MMC3_Coolboy : public MMC3
{
private:
uint8_t _exRegs[4];
protected:
uint16_t RegisterStartAddress() override { return 0x6000; }
uint32_t GetChrRamSize() override { return 0x40000; }
void Reset(bool softReset) override
{
memset(_exRegs, 0, sizeof(_exRegs));
BaseMapper::Reset(softReset);
MMC3::ResetMmc3();
UpdateState();
}
void StreamState(bool saving) override
{
MMC3::StreamState(saving);
Stream(_exRegs[0], _exRegs[1], _exRegs[2], _exRegs[3]);
}
void SelectCHRPage(uint16_t slot, uint16_t page, ChrMemoryType memoryType = ChrMemoryType::Default) override
{
uint16_t addr = slot * 0x400;
uint32_t mask = 0xFF ^ (_exRegs[0] & 0x80);
int cbase = _chrMode ? 0x1000 : 0;
if(_exRegs[3] & 0x10) {
if(_exRegs[3] & 0x40) {
switch(cbase ^ addr) {
case 0x0400:
case 0x0C00: page &= 0x7F; break;
}
}
MMC3::SelectCHRPage(slot,
(page & 0x80 & mask) | ((((_exRegs[0] & 0x08) << 4) & ~mask))
| ((_exRegs[2] & 0x0F) << 3)
| slot
);
} else {
if(_exRegs[3] & 0x40) {
switch(cbase ^ addr) {
case 0x0000: page = _registers[0]; break;
case 0x0800: page = _registers[1]; break;
case 0x0400:
case 0x0C00: page = 0; break;
}
}
MMC3::SelectCHRPage(slot, (page & mask) | (((_exRegs[0] & 0x08) << 4) & ~mask));
}
}
void SelectPRGPage(uint16_t slot, uint16_t page, PrgMemoryType memoryType = PrgMemoryType::PrgRom) override
{
uint16_t addr = 0x8000 + slot * 0x2000;
uint32_t mask = ((0x3F | (_exRegs[1] & 0x40) | ((_exRegs[1] & 0x20) << 2)) ^ ((_exRegs[0] & 0x40) >> 2)) ^ ((_exRegs[1] & 0x80) >> 2);
uint32_t base = ((_exRegs[0] & 0x07) >> 0) | ((_exRegs[1] & 0x10) >> 1) | ((_exRegs[1] & 0x0C) << 2) | ((_exRegs[0] & 0x30) << 2);
if((_exRegs[3] & 0x40) && (page >= 0xFE) && _prgMode) {
switch(slot) {
case 1: if(_prgMode) page = 0; break;
case 2: if(!_prgMode) page = 0; break;
case 3: page = 0; break;
}
}
if(!(_exRegs[3] & 0x10)) {
MMC3::SelectPRGPage(slot, (((base << 4) & ~mask)) | (page & mask));
} else {
mask &= 0xF0;
uint8_t emask;
if((((_exRegs[1] & 0x02) != 0))) {
emask = (_exRegs[3] & 0x0C) | ((addr & 0x4000) >> 13);
} else {
emask = _exRegs[3] & 0x0E;
}
MMC3::SelectPRGPage(slot, ((base << 4) & ~mask) | (page & mask) | emask | (slot & 0x01));
}
}
void WriteRegister(uint16_t addr, uint8_t value) override
{
if(addr < 0x8000) {
if(GetState().RegA001 & 0x80) {
WritePrgRam(addr, value);
}
if((_exRegs[3] & 0x90) != 0x80) {
_exRegs[addr & 0x03] = value;
UpdateState();
}
} else {
MMC3::WriteRegister(addr, value);
}
}
};