mirror of
https://github.com/SourMesen/Mesen.git
synced 2024-06-02 11:28:17 -04:00
114 lines
2.9 KiB
C++
114 lines
2.9 KiB
C++
#pragma once
|
|
#include "stdafx.h"
|
|
#include "BaseMapper.h"
|
|
|
|
class Tf1201 : public BaseMapper
|
|
{
|
|
private:
|
|
uint8_t _chrRegs[8];
|
|
uint8_t _prgRegs[2];
|
|
bool _swapPrg;
|
|
uint8_t _irqCounter;
|
|
uint8_t _irqReloadValue;
|
|
int16_t _irqScaler;
|
|
bool _irqEnabled;
|
|
|
|
protected:
|
|
virtual uint16_t GetPRGPageSize() override { return 0x2000; }
|
|
virtual uint16_t GetCHRPageSize() override { return 0x400; }
|
|
|
|
void InitMapper() override
|
|
{
|
|
memset(_prgRegs, 0, sizeof(_prgRegs));
|
|
memset(_chrRegs, 0, sizeof(_chrRegs));
|
|
_swapPrg = false;
|
|
|
|
_irqCounter = 0;
|
|
_irqReloadValue = 0;
|
|
_irqScaler = 0;
|
|
_irqEnabled = false;
|
|
|
|
UpdateChr();
|
|
UpdatePrg();
|
|
}
|
|
|
|
void StreamState(bool saving) override
|
|
{
|
|
BaseMapper::StreamState(saving);
|
|
ArrayInfo<uint8_t> prgRegs{ _prgRegs, 2 };
|
|
ArrayInfo<uint8_t> chrRegs{ _chrRegs, 2 };
|
|
Stream(prgRegs, chrRegs, _swapPrg, _irqCounter, _irqReloadValue, _irqScaler, _irqEnabled);
|
|
}
|
|
|
|
void UpdateChr()
|
|
{
|
|
for(int i = 0; i < 8; i++) {
|
|
SelectCHRPage(i, _chrRegs[i]);
|
|
}
|
|
}
|
|
|
|
void UpdatePrg()
|
|
{
|
|
if(_swapPrg) {
|
|
SelectPRGPage(0, -2);
|
|
SelectPRGPage(2, _prgRegs[0]);
|
|
} else {
|
|
SelectPRGPage(0, _prgRegs[0]);
|
|
SelectPRGPage(2, -2);
|
|
}
|
|
SelectPRGPage(1, _prgRegs[1]);
|
|
SelectPRGPage(3, -1);
|
|
}
|
|
|
|
void ProcessCpuClock() override
|
|
{
|
|
if(_irqEnabled) {
|
|
_irqScaler -= 3;
|
|
if(_irqScaler <= 0) {
|
|
_irqScaler += 341;
|
|
_irqCounter++;
|
|
if(_irqCounter == 0) {
|
|
_console->GetCpu()->SetIrqSource(IRQSource::External);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
void WriteRegister(uint16_t addr, uint8_t value) override
|
|
{
|
|
addr = (addr & 0xF003) | ((addr & 0x0C) >> 2);
|
|
if(addr >= 0xB000 && addr <= 0xE003) {
|
|
int slot = (((addr >> 11) - 6) | (addr & 0x01)) & 0x07;
|
|
int shift = ((addr & 0x02) << 1);
|
|
_chrRegs[slot] = (_chrRegs[slot] & (0xF0 >> shift)) | ((value & 0x0F) << shift);
|
|
UpdateChr();
|
|
} else {
|
|
switch(addr & 0xF003) {
|
|
case 0x8000: _prgRegs[0] = value; UpdatePrg(); break;
|
|
case 0xA000: _prgRegs[1] = value; UpdatePrg(); break;
|
|
case 0x9000: SetMirroringType(value & 0x01 ? MirroringType::Horizontal : MirroringType::Vertical); break;
|
|
case 0x9001: _swapPrg = (value & 0x03) != 0; UpdatePrg(); break;
|
|
|
|
case 0xF000: _irqReloadValue = (_irqReloadValue & 0xF0) | (value & 0x0F); break;
|
|
case 0xF002: _irqReloadValue = (_irqReloadValue & 0x0F) | (value << 4); break;
|
|
|
|
case 0xF001:
|
|
//VRC-like IRQs? This seems to make more sense than A12-based IRQs
|
|
//considering FCEUX/puNES both adjust the counter value based on when
|
|
//on the screen the IRQ is enabled.
|
|
//This still some glitches on the screen, but relatively minor ones.
|
|
_irqEnabled = (value & 0x02) == 0x02;
|
|
if(_irqEnabled) {
|
|
_irqScaler = 341;
|
|
_irqCounter = _irqReloadValue;
|
|
}
|
|
_console->GetCpu()->ClearIrqSource(IRQSource::External);
|
|
break;
|
|
|
|
case 0xF003:
|
|
_console->GetCpu()->ClearIrqSource(IRQSource::External);
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
}; |