Mesen/Core/Bmc70in1.h
2016-12-17 23:14:47 -05:00

100 lines
1.9 KiB
C++

#pragma once
#include "stdafx.h"
#include "BaseMapper.h"
class Bmc70in1 : public BaseMapper
{
private:
uint8_t _bankMode;
uint8_t _outerBank;
uint8_t _prgReg;
uint8_t _chrReg;
uint8_t _dipSwitch;
bool _useOuterBank;
protected:
uint16_t GetPRGPageSize() override { return 0x4000; }
uint16_t GetCHRPageSize() override { return 0x2000; }
bool AllowRegisterRead() override { return true; }
void InitMapper() override
{
_prgReg = 0;
_chrReg = 0;
if(HasChrRom()) {
_useOuterBank = false;
_dipSwitch = 0x0C;
} else {
_useOuterBank = true;
_dipSwitch = 0x05;
}
SelectCHRPage(0, 0);
UpdateState();
}
void StreamState(bool saving) override
{
BaseMapper::StreamState(saving);
Stream(_bankMode, _outerBank, _prgReg, _chrReg, _dipSwitch);
}
void Reset(bool softReset) override
{
BaseMapper::Reset(softReset);
_bankMode = 0;
_outerBank = 0;
_dipSwitch = (_dipSwitch + 1) & 0x0F;
}
void UpdateState()
{
switch(_bankMode) {
case 0x00: case 0x10:
SelectPRGPage(0, _outerBank | _prgReg);
SelectPRGPage(1, _outerBank | 7);
break;
case 0x20:
SelectPrgPage2x(0, (_outerBank | _prgReg) & 0xFE);
break;
case 0x30:
SelectPRGPage(0, _outerBank | _prgReg);
SelectPRGPage(1, _outerBank | _prgReg);
break;
}
if(!_useOuterBank) {
SelectCHRPage(0, _chrReg);
}
}
uint8_t ReadRegister(uint16_t addr) override
{
if(_bankMode == 0x10) {
return InternalReadRam((addr & 0xFFF0) | _dipSwitch);
} else {
return InternalReadRam(addr);
}
}
void WriteRegister(uint16_t addr, uint8_t value) override
{
if(addr & 0x4000) {
_bankMode = addr & 0x30;
_prgReg = addr & 0x07;
} else {
SetMirroringType(addr & 0x20 ? MirroringType::Horizontal : MirroringType::Vertical);
if(_useOuterBank) {
_outerBank = (addr & 0x03) << 3;
} else {
_chrReg = addr & 0x07;
}
}
UpdateState();
}
};