Mesen/Core/JyCompany.h
2017-04-29 08:29:56 -04:00

404 lines
10 KiB
C++

#pragma once
#include "stdafx.h"
#include "BaseMapper.h"
#include "CPU.h"
#include "MemoryManager.h"
class JyCompany : public BaseMapper
{
private:
enum class JyIrqSource
{
CpuClock = 0,
PpuA12Rise = 1,
PpuRead = 2,
CpuWrite = 3
};
uint8_t _prgRegs[4];
uint8_t _chrLowRegs[8];
uint8_t _chrHighRegs[8];
uint8_t _chrLatch[2];
uint8_t _prgMode;
bool _enablePrgAt6000;
uint8_t _chrMode;
bool _chrBlockMode;
uint8_t _chrBlock;
bool _mirrorChr;
uint8_t _mirroringReg;
bool _advancedNtControl;
bool _disableNtRam;
uint8_t _ntRamSelectBit;
uint8_t _ntLowRegs[4];
uint8_t _ntHighRegs[4];
bool _irqEnabled;
JyIrqSource _irqSource;
uint8_t _irqCountDirection;
bool _irqFunkyMode;
uint8_t _irqFunkyModeReg;
bool _irqSmallPrescaler;
uint8_t _irqPrescaler;
uint8_t _irqCounter;
uint8_t _irqXorReg;
uint8_t _multiplyValue1;
uint8_t _multiplyValue2;
uint8_t _regRamValue;
uint16_t _lastPpuAddr;
protected:
virtual uint16_t GetPRGPageSize() override { return 0x2000; }
virtual uint16_t GetCHRPageSize() override { return 0x0400; }
virtual bool AllowRegisterRead() override { return true; }
void InitMapper() override
{
RemoveRegisterRange(0x8000, 0xFFFF, MemoryOperation::Read);
AddRegisterRange(0x5000, 0x5FFF, MemoryOperation::Any);
_chrLatch[0] = 0;
_chrLatch[1] = 4;
memset(_prgRegs, 0, sizeof(_prgRegs));
memset(_chrLowRegs, 0, sizeof(_chrLowRegs));
memset(_chrHighRegs, 0, sizeof(_chrHighRegs));
_prgMode = 0;
_enablePrgAt6000 = false;
_chrMode = 0;
_chrBlockMode = false;
_chrBlock = 0;
_mirrorChr = false;
_mirroringReg = 0;
_advancedNtControl = false;
_disableNtRam = false;
_ntRamSelectBit = 0;
memset(_ntLowRegs, 0, sizeof(_ntLowRegs));
memset(_ntHighRegs, 0, sizeof(_ntHighRegs));
_irqEnabled = false;
_irqSource = JyIrqSource::CpuClock;
_lastPpuAddr = 0;
_irqCountDirection = 0;
_irqFunkyMode = false;
_irqFunkyModeReg = 0;
_irqSmallPrescaler = false;
_irqPrescaler = 0;
_irqCounter = 0;
_irqXorReg = 0;
_multiplyValue1 = 0;
_multiplyValue2 = 0;
_regRamValue = 0;
UpdateState();
}
void StreamState(bool saving) override
{
BaseMapper::StreamState(saving);
ArrayInfo<uint8_t> prgRegs{ _prgRegs, 4 };
ArrayInfo<uint8_t> chrLowRegs{ _chrLowRegs, 8 };
ArrayInfo<uint8_t> chrHighRegs{ _chrHighRegs, 8 };
ArrayInfo<uint8_t> ntLowRegs{ _ntLowRegs, 4 };
ArrayInfo<uint8_t> ntHighRegs{ _ntHighRegs, 4 };
Stream(_chrLatch[0], _chrLatch[1], _prgMode, _enablePrgAt6000, _chrMode, _chrBlockMode, _chrBlock, _mirrorChr, _mirroringReg, _advancedNtControl,
_disableNtRam, _ntRamSelectBit, _irqEnabled, _irqSource, _lastPpuAddr, _irqCountDirection, _irqFunkyMode, _irqFunkyModeReg, _irqSmallPrescaler,
_irqPrescaler, _irqCounter, _irqXorReg, _multiplyValue1, _multiplyValue2, _regRamValue, prgRegs, chrLowRegs, chrHighRegs, ntLowRegs, ntHighRegs);
if(!saving) {
UpdateState();
}
}
void UpdateState()
{
UpdatePrgState();
UpdateChrState();
UpdateMirroringState();
}
uint8_t InvertPrgBits(uint8_t prgReg, bool needInvert)
{
if(needInvert) {
return (prgReg & 0x01) << 6 | (prgReg & 0x02) << 4 | (prgReg & 0x04) << 2 | (prgReg & 0x10) >> 2 | (prgReg & 0x20) >> 4 | (prgReg & 0x40) >> 6;
} else {
return prgReg;
}
}
void UpdatePrgState()
{
bool invertBits = (_prgMode & 0x03) == 0x03;
int prgRegs[4] = { InvertPrgBits(_prgRegs[0], invertBits), InvertPrgBits(_prgRegs[1], invertBits),
InvertPrgBits(_prgRegs[2], invertBits), InvertPrgBits(_prgRegs[3], invertBits) };
int lastPage = (_prgMode & 0x04) ? prgRegs[3] : -1;
switch(_prgMode & 0x03) {
case 0:
SelectPrgPage4x(0, lastPage * 4);
if(_enablePrgAt6000) {
SetCpuMemoryMapping(0x6000, 0x7FFF, prgRegs[3] * 4 + 3, PrgMemoryType::PrgRom);
}
break;
case 1:
SelectPrgPage2x(0, prgRegs[1] << 1);
SelectPrgPage2x(1, lastPage * 2);
if(_enablePrgAt6000) {
SetCpuMemoryMapping(0x6000, 0x7FFF, prgRegs[3] * 2 + 1, PrgMemoryType::PrgRom);
}
break;
case 2:
case 3:
SelectPRGPage(0, prgRegs[0]);
SelectPRGPage(1, prgRegs[1]);
SelectPRGPage(2, prgRegs[2]);
SelectPRGPage(3, lastPage);
if(_enablePrgAt6000) {
SetCpuMemoryMapping(0x6000, 0x7FFF, prgRegs[3], PrgMemoryType::PrgRom);
}
break;
}
if(!_enablePrgAt6000) {
RemoveCpuMemoryMapping(0x6000, 0x7FFF);
}
}
uint16_t GetChrReg(int index)
{
if(_chrMode >= 2 && _mirrorChr && (index == 2 || index == 3)) {
index -= 2;
}
if(_chrBlockMode) {
return _chrLowRegs[index] | (_chrBlock << 8);
} else {
return _chrLowRegs[index] | (_chrHighRegs[index] << 8);
}
}
void UpdateChrState()
{
int chrRegs[8] = { GetChrReg(0), GetChrReg(1), GetChrReg(2), GetChrReg(3), GetChrReg(4), GetChrReg(5), GetChrReg(6), GetChrReg(7) };
switch(_chrMode) {
case 0:
SelectChrPage8x(0, chrRegs[0] << 3);
break;
case 1:
SelectChrPage4x(0, chrRegs[_chrLatch[0]] << 2);
SelectChrPage4x(1, chrRegs[_chrLatch[1]] << 2);
break;
case 2:
SelectChrPage2x(0, chrRegs[0] << 1);
SelectChrPage2x(1, chrRegs[2] << 1);
SelectChrPage2x(2, chrRegs[4] << 1);
SelectChrPage2x(3, chrRegs[6] << 1);
break;
case 3:
for(int i = 0; i < 8; i++) {
SelectCHRPage(i, chrRegs[i]);
}
break;
}
}
void UpdateMirroringState()
{
//"Mapper 211 behaves as though N were always set (1), and mapper 090 behaves as though N were always clear(0)."
if((_advancedNtControl || _mapperID == 211) && _mapperID != 90) {
for(int i = 0; i < 4; i++) {
if(_disableNtRam || (_ntLowRegs[i] & 0x80) != (_ntRamSelectBit & 0x80)) {
SetPpuMemoryMapping(0x2000 + 0x400 * i, 0x23FF + 0x400 * i, _ntLowRegs[i] | (_ntHighRegs[i] << 8), ChrMemoryType::ChrRom);
} else {
SetNametable(i, _ntLowRegs[i] & 0x01);
}
}
} else {
switch(_mirroringReg) {
case 0: SetMirroringType(MirroringType::Vertical); break;
case 1: SetMirroringType(MirroringType::Horizontal); break;
case 2: SetMirroringType(MirroringType::ScreenAOnly); break;
case 3: SetMirroringType(MirroringType::ScreenBOnly); break;
}
}
}
uint8_t ReadRegister(uint16_t addr) override
{
switch(addr & 0xF803) {
case 0x5000: return 0; //Dip switches
case 0x5800: return (_multiplyValue1 * _multiplyValue2) & 0xFF;
case 0x5801: return ((_multiplyValue1 * _multiplyValue2) >> 8) & 0xFF;
case 0x5803: return _regRamValue;
}
return MemoryManager::GetOpenBus();
}
void WriteRegister(uint16_t addr, uint8_t value) override
{
if(addr < 0x8000) {
switch(addr & 0xF803) {
case 0x5800: _multiplyValue1 = value; break;
case 0x5801: _multiplyValue2 = value; break;
case 0x5803: _regRamValue = value; break;
}
} else {
switch(addr & 0xF007) {
case 0x8000: case 0x8001: case 0x8002: case 0x8003:
case 0x8004: case 0x8005: case 0x8006: case 0x8007:
_prgRegs[addr & 0x03] = value & 0x7F;
break;
case 0x9000: case 0x9001: case 0x9002: case 0x9003:
case 0x9004: case 0x9005: case 0x9006: case 0x9007:
_chrLowRegs[addr & 0x07] = value;
break;
case 0xA000: case 0xA001: case 0xA002: case 0xA003:
case 0xA004: case 0xA005: case 0xA006: case 0xA007:
_chrHighRegs[addr & 0x07] = value;
break;
case 0xB000: case 0xB001: case 0xB002: case 0xB003:
_ntLowRegs[addr & 0x03] = value;
break;
case 0xB004: case 0xB005: case 0xB006: case 0xB007:
_ntHighRegs[addr & 0x03] = value;
break;
case 0xC000:
if(value & 0x01) {
_irqEnabled = true;
} else {
_irqEnabled = false;
CPU::ClearIRQSource(IRQSource::External);
}
break;
case 0xC001:
_irqCountDirection = (value >> 6) & 0x03;
_irqFunkyMode = (value & 0x08) == 0x08;
_irqSmallPrescaler = ((value >> 2) & 0x01) == 0x01;
_irqSource = (JyIrqSource)(value & 0x03);
break;
case 0xC002:
_irqEnabled = false;
CPU::ClearIRQSource(IRQSource::External);
break;
case 0xC003: _irqEnabled = true; break;
case 0xC004: _irqPrescaler = value ^ _irqXorReg; break;
case 0xC005: _irqCounter = value ^ _irqXorReg; break;
case 0xC006: _irqXorReg = value; break;
case 0xC007: _irqFunkyModeReg = value; break;
case 0xD000:
_prgMode = value & 0x07;
_chrMode = (value >> 3) & 0x03;
_advancedNtControl = (value & 0x20) == 0x20;
_disableNtRam = (value & 0x40) == 0x40;
_enablePrgAt6000 = (value & 0x80) == 0x80;
break;
case 0xD001: _mirroringReg = value & 0x03; break;
case 0xD002: _ntRamSelectBit = value & 0x80; break;
case 0xD003:
_mirrorChr = (value & 0x80) == 0x80;
_chrBlockMode = (value & 0x20) == 0x00;
_chrBlock = value & 0x1F;
break;
}
}
UpdateState();
}
void ProcessCpuClock() override
{
if(_irqSource == JyIrqSource::CpuClock || (_irqSource == JyIrqSource::CpuWrite && CPU::IsCpuWrite())) {
TickIrqCounter();
}
}
uint8_t MapperReadVRAM(uint16_t addr, MemoryOperationType type) override
{
if(_irqSource == JyIrqSource::PpuRead && type == MemoryOperationType::PpuRenderingRead) {
TickIrqCounter();
}
return BaseMapper::MapperReadVRAM(addr, type);
}
void NotifyVRAMAddressChange(uint16_t addr) override
{
if(_irqSource == JyIrqSource::PpuA12Rise && (addr & 0x1000) && !(_lastPpuAddr & 0x1000)) {
TickIrqCounter();
}
_lastPpuAddr = addr;
if(_mapperID == 209) {
switch(addr & 0x2FF8) {
case 0x0FD8:
case 0x0FE8:
_chrLatch[addr >> 12] = addr >> 4 & ((addr >> 10 & 0x04) | 0x02);
UpdateChrState();
break;
}
}
}
void TickIrqCounter()
{
bool clockIrqCounter = false;
uint8_t mask = _irqSmallPrescaler ? 0x07 : 0xFF;
uint8_t prescaler = _irqPrescaler & mask;
if(_irqCountDirection == 0x01) {
prescaler++;
if((prescaler & mask) == 0) {
clockIrqCounter = true;
}
} else if(_irqCountDirection == 0x02) {
if(--prescaler == 0) {
clockIrqCounter = true;
}
}
_irqPrescaler = (_irqPrescaler & ~mask) | (prescaler & mask);
if(clockIrqCounter) {
if(_irqCountDirection == 0x01) {
_irqCounter++;
if(_irqCounter == 0 && _irqEnabled) {
CPU::SetIRQSource(IRQSource::External);
}
} else if(_irqCountDirection == 0x02) {
_irqCounter--;
if(_irqCounter == 0xFF && _irqEnabled) {
CPU::SetIRQSource(IRQSource::External);
}
}
}
}
};