Mesen/Core/Mapper221.h
2016-12-17 23:14:47 -05:00

63 lines
1.2 KiB
C++

#pragma once
#include "stdafx.h"
#include "BaseMapper.h"
class Mapper221 : public BaseMapper
{
private:
uint16_t _mode;
uint8_t _prgReg;
protected:
virtual uint16_t GetPRGPageSize() override { return 0x4000; }
virtual uint16_t GetCHRPageSize() override { return 0x2000; }
void InitMapper() override
{
_prgReg = 0;
_mode = 0;
SelectCHRPage(0, 0);
UpdateState();
}
void StreamState(bool saving) override
{
BaseMapper::StreamState(saving);
Stream(_mode, _prgReg);
}
void UpdateState()
{
uint16_t outerBank = (_mode & 0xFC) >> 2;
if(_mode & 0x02) {
if(_mode & 0x0100) {
SelectPRGPage(0, outerBank | _prgReg);
SelectPRGPage(1, outerBank | 0x07);
} else {
SelectPrgPage2x(0, outerBank | (_prgReg & 0x06));
}
} else {
SelectPRGPage(0, outerBank | _prgReg);
SelectPRGPage(1, outerBank | _prgReg);
}
SetMirroringType(_mode & 0x01 ? MirroringType::Horizontal : MirroringType::Vertical);
}
void WriteRegister(uint16_t addr, uint8_t value) override
{
switch(addr & 0xC000) {
case 0x8000:
_mode = addr;
UpdateState();
break;
case 0xC000:
_prgReg = addr & 0x07;
UpdateState();
break;
}
}
};