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https://github.com/SourMesen/Mesen2.git
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92 lines
2.5 KiB
C++
92 lines
2.5 KiB
C++
#pragma once
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#include "pch.h"
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#include "NES/BaseMapper.h"
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#include "Utilities/Serializer.h"
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class Action53 : public BaseMapper
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{
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private:
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uint8_t _selectedReg = 0;
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uint8_t _regs[4] = {};
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uint8_t _mirroringBit = 0;
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protected:
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uint16_t GetPrgPageSize() override { return 0x4000; }
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uint16_t GetChrPageSize() override { return 0x2000; }
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void InitMapper() override
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{
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_selectedReg = 0;
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_mirroringBit = 0;
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memset(_regs, 0, sizeof(_regs));
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AddRegisterRange(0x5000, 0x5FFF, MemoryOperation::Write);
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SelectPrgPage(1, -1);
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}
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void Serialize(Serializer& s) override
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{
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BaseMapper::Serialize(s);
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SVArray(_regs, 4);
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SV(_selectedReg);
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SV(_mirroringBit);
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}
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void UpdateState()
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{
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uint8_t mirroring = _regs[2] & 0x03;
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if(!(mirroring & 0x02)) {
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mirroring = _mirroringBit;
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}
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switch(mirroring) {
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case 0: SetMirroringType(MirroringType::ScreenAOnly); break;
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case 1: SetMirroringType(MirroringType::ScreenBOnly); break;
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case 2: SetMirroringType(MirroringType::Vertical); break;
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case 3: SetMirroringType(MirroringType::Horizontal); break;
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}
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uint8_t gameSize = (_regs[2] & 0x30) >> 4;
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uint8_t prgSize = (_regs[2] & 0x08) >> 3;
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uint8_t slotSelect = (_regs[2] & 0x04) >> 2;
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uint8_t chrSelect = _regs[0] & 0x03;
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uint8_t prgSelect = _regs[1] & 0x0F;
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uint16_t outerPrgSelect = _regs[3] << 1;
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SelectChrPage(0, chrSelect);
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if(prgSize) {
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uint8_t bank = (slotSelect ? 0 : 1);
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switch(gameSize) {
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case 0: SelectPrgPage(bank, (outerPrgSelect & 0x1FE) | (prgSelect & 0x01)); break;
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case 1: SelectPrgPage(bank, (outerPrgSelect & 0x1FC) | (prgSelect & 0x03)); break;
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case 2: SelectPrgPage(bank, (outerPrgSelect & 0x1F8) | (prgSelect & 0x07)); break;
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case 3: SelectPrgPage(bank, (outerPrgSelect & 0x1F0) | (prgSelect & 0x0F)); break;
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}
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SelectPrgPage(slotSelect ? 1 : 0, (outerPrgSelect & 0x1FE) | slotSelect);
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} else {
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prgSelect <<= 1;
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uint16_t outerAnd[4]{ 0x1FE, 0x1FC, 0x1F8, 0x1F0 };
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uint8_t innerAnd[4]{ 0x01, 0x03, 0x07, 0x0F };
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SelectPrgPage(0, (outerPrgSelect & outerAnd[gameSize]) | (prgSelect & innerAnd[gameSize]));
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SelectPrgPage(1, (outerPrgSelect & outerAnd[gameSize]) | ((prgSelect | 0x01) & innerAnd[gameSize]));
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}
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}
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void WriteRegister(uint16_t addr, uint8_t value) override
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{
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if(addr <= 0x5FFF) {
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_selectedReg = ((value & 0x80) >> 6) | (value & 0x01);
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} else if(addr >= 0x8000) {
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if(_selectedReg <= 1) {
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_mirroringBit = (value >> 4) & 0x01;
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} else if(_selectedReg == 2) {
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_mirroringBit = (value & 0x01);
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}
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_regs[_selectedReg] = value;
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UpdateState();
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}
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}
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};
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