Mesen/Core/Mapper15.h
2018-04-01 14:47:22 -04:00

55 lines
1.2 KiB
C++

#pragma once
#include "stdafx.h"
#include "BaseMapper.h"
class Mapper15 : public BaseMapper
{
protected:
virtual uint16_t GetPRGPageSize() override { return 0x2000; }
virtual uint16_t GetCHRPageSize() override { return 0x2000; }
void InitMapper() override
{
SelectCHRPage(0, 0);
}
void Reset(bool softReset) override
{
WriteRegister(0x8000, 0);
}
void WriteRegister(uint16_t addr, uint8_t value) override
{
SetMirroringType(value & 0x40 ? MirroringType::Horizontal : MirroringType::Vertical);
uint8_t subBank = value >> 7;
uint8_t bank = (value & 0x7F) << 1;
switch(addr & 0x03) {
case 0:
SelectPRGPage(0, bank ^ subBank);
SelectPRGPage(1, (bank + 1) ^ subBank);
SelectPRGPage(2, (bank + 2) ^ subBank);
SelectPRGPage(3, (bank + 3) ^ subBank);
break;
case 1:
case 3:
bank |= subBank;
SelectPRGPage(0, bank);
SelectPRGPage(1, bank + 1);
bank = ((addr & 0x02) ? bank : 0xFE) | subBank;
SelectPRGPage(2, bank + 0);
SelectPRGPage(3, bank + 1);
break;
case 2:
bank |= subBank;
SelectPRGPage(0, bank);
SelectPRGPage(1, bank);
SelectPRGPage(2, bank);
SelectPRGPage(3, bank);
break;
}
}
};