Mesen2/Core/NES/Mappers/JyCompany/Mapper35.h
2024-09-26 22:41:57 +09:00

75 lines
1.7 KiB
C++

#pragma once
#include "pch.h"
#include "NES/BaseMapper.h"
#include "NES/Mappers/A12Watcher.h"
#include "NES/NesCpu.h"
#include "NES/BaseNesPpu.h"
class Mapper35 : public BaseMapper
{
private:
uint8_t _irqCounter = 0;
bool _irqEnabled = false;
A12Watcher _a12Watcher;
protected:
uint16_t GetPrgPageSize() override { return 0x2000; }
uint16_t GetChrPageSize() override { return 0x0400; }
bool EnableVramAddressHook() override { return true; }
void InitMapper() override
{
_irqEnabled = false;
_irqCounter = 0;
SelectPrgPage(3, -1);
}
void Serialize(Serializer& s) override
{
BaseMapper::Serialize(s);
SV(_a12Watcher);
SV(_irqCounter);
SV(_irqEnabled);
}
void WriteRegister(uint16_t addr, uint8_t value) override
{
switch(addr & 0xF007) {
case 0x8000: case 0x8001: case 0x8002: case 0x8003:
SelectPrgPage(addr & 0x03, value);
break;
case 0x9000: case 0x9001: case 0x9002: case 0x9003:
case 0x9004: case 0x9005: case 0x9006: case 0x9007:
SelectChrPage(addr & 0x07, value);
break;
case 0xC002:
_irqEnabled = false;
_console->GetCpu()->ClearIrqSource(IRQSource::External);
break;
case 0xC003: _irqEnabled = true; break;
case 0xC005: _irqCounter = value; break;
case 0xD001:
SetMirroringType(value & 0x01 ? MirroringType::Horizontal : MirroringType::Vertical);
break;
}
}
void NotifyVramAddressChange(uint16_t addr) override
{
//MMC3-style A12 IRQ counter
if(_a12Watcher.UpdateVramAddress(addr, _console->GetPpu()->GetFrameCycle()) == A12StateChange::Rise) {
if(_irqEnabled) {
_irqCounter--;
if(_irqCounter == 0) {
_irqEnabled = false;
_console->GetCpu()->SetIrqSource(IRQSource::External);
}
}
}
}
};