AxibugEmuOnline/AxibugEmuOnline.Client/Assets/VirtualNes.Core/Mapper/Mapper112.cs

166 lines
4.9 KiB
C#

//////////////////////////////////////////////////////////////////////////
// Mapper112 Nintendo MMC3 //
//////////////////////////////////////////////////////////////////////////
using static VirtualNes.MMU;
using BYTE = System.Byte;
using INT = System.Int32;
namespace VirtualNes.Core
{
public class Mapper112 : Mapper
{
BYTE[] reg = new byte[4];
BYTE prg0, prg1;
BYTE chr01, chr23, chr4, chr5, chr6, chr7;
public Mapper112(NES parent) : base(parent)
{
}
public override void Reset()
{
for (INT i = 0; i < 4; i++)
{
reg[i] = 0x00;
}
prg0 = 0;
prg1 = 1;
SetBank_CPU();
chr01 = 0;
chr23 = 2;
chr4 = 4;
chr5 = 5;
chr6 = 6;
chr7 = 7;
SetBank_PPU();
}
//void Mapper112::Write(WORD addr, BYTE data)
public override void Write(ushort addr, byte data)
{
switch (addr)
{
case 0x8000:
reg[0] = data;
SetBank_CPU();
SetBank_PPU();
break;
case 0xA000:
reg[1] = data;
switch (reg[0] & 0x07)
{
case 0x00:
prg0 = (byte)((data & (PROM_8K_SIZE - 1)));
SetBank_CPU();
break;
case 0x01:
prg1 = (byte)((data & (PROM_8K_SIZE - 1)));
SetBank_CPU();
break;
case 0x02:
chr01 = (byte)(data & 0xFE);
SetBank_PPU();
break;
case 0x03:
chr23 = (byte)(data & 0xFE);
SetBank_PPU();
break;
case 0x04:
chr4 = data;
SetBank_PPU();
break;
case 0x05:
chr5 = data;
SetBank_PPU();
break;
case 0x06:
chr6 = data;
SetBank_PPU();
break;
case 0x07:
chr7 = data;
SetBank_PPU();
break;
}
break;
case 0xC000:
reg[3] = data;
SetBank_PPU();
break;//hum 源码居然没有break 语法差异呗
case 0xE000:
reg[2] = data;
if (!nes.rom.Is4SCREEN())
{
if ((data & 0x01) != 0) SetVRAM_Mirror(VRAM_HMIRROR);
else SetVRAM_Mirror(VRAM_VMIRROR);
}
SetBank_PPU();
break;
}
}
void SetBank_CPU()
{
SetPROM_32K_Bank(prg0, prg1, PROM_8K_SIZE - 2, PROM_8K_SIZE - 1);
}
void SetBank_PPU()
{
if ((reg[2] & 0x02) != 0)
{
SetVROM_8K_Bank(chr01, chr01 + 1, chr23, chr23 + 1, chr4, chr5, chr6, chr7);
}
else
{
SetVROM_8K_Bank(((reg[3] << 6) & 0x100) + chr01,
((reg[3] << 6) & 0x100) + chr01 + 1,
((reg[3] << 5) & 0x100) + chr23,
((reg[3] << 5) & 0x100) + chr23 + 1,
((reg[3] << 4) & 0x100) + chr4,
((reg[3] << 3) & 0x100) + chr5,
((reg[3] << 2) & 0x100) + chr6,
((reg[3] << 1) & 0x100) + chr7);
}
}
//void Mapper112::SaveState(LPBYTE p)
public override void SaveState(byte[] p)
{
for (INT i = 0; i < 4; i++)
{
p[i] = reg[i];
}
p[4] = chr01;
p[5] = chr23;
p[6] = chr4;
p[7] = chr5;
p[8] = chr6;
p[9] = chr7;
}
//void Mapper112::LoadState(LPBYTE p)
public override void LoadState(byte[] p)
{
for (byte i = 0; i < 4; i++)
{
reg[i] = p[i];
}
chr01 = p[4];
chr23 = p[5];
chr4 = p[6];
chr5 = p[7];
chr6 = p[8];
chr7 = p[9];
}
public override bool IsStateSave()
{
return true;
}
}
}