AxibugEmuOnline/AxibugEmuOnline.Client/Assets/MyNes.Core/Mapper245.cs
2024-07-03 18:22:22 +08:00

230 lines
5.7 KiB
C#

using System.IO;
namespace MyNes.Core
{
[BoardInfo("C&E", 245, true, true)]
[HassIssues]
internal class Mapper245 : Board
{
private bool flag_c;
private bool flag_p;
private int address_8001;
private int[] chr_reg;
private int[] prg_reg;
private int prg_or;
private bool irq_enabled;
private byte irq_counter;
private int old_irq_counter;
private byte irq_reload;
private bool irq_clear;
private bool mmc3_alt_behavior;
internal override string Issues => MNInterfaceLanguage.IssueMapper245;
internal override void HardReset()
{
base.HardReset();
flag_c = (flag_p = false);
address_8001 = 0;
prg_reg = new int[4];
prg_or = 0;
prg_reg[0] = 0;
prg_reg[1] = 1;
prg_reg[2] = PRG_ROM_08KB_Mask - 1;
prg_reg[3] = PRG_ROM_08KB_Mask;
chr_reg = new int[6];
for (int i = 0; i < 6; i++)
{
chr_reg[i] = 0;
}
SetupPRG();
SetupCHR();
irq_enabled = false;
irq_counter = 0;
irq_reload = byte.MaxValue;
old_irq_counter = 0;
irq_clear = false;
}
internal override void WritePRG(ref ushort address, ref byte data)
{
switch (address & 0xE001)
{
case 32768:
address_8001 = data & 7;
flag_c = (data & 0x80) != 0;
flag_p = (data & 0x40) != 0;
SetupCHR();
SetupPRG();
break;
case 32769:
switch (address_8001)
{
case 0:
case 1:
case 2:
case 3:
case 4:
case 5:
chr_reg[address_8001] = data;
SetupCHR();
break;
case 6:
prg_reg[0] = data & 0x3F;
SetupPRG();
break;
case 7:
prg_reg[1] = data & 0x3F;
SetupPRG();
break;
}
break;
case 40960:
if (NMT_DEFAULT_MIRROR != Mirroring.Full)
{
Switch01KNMTFromMirroring(((data & 1) == 1) ? Mirroring.Horz : Mirroring.Vert);
}
break;
case 40961:
TogglePRGRAMEnable((data & 0x80) != 0);
TogglePRGRAMWritableEnable((data & 0x40) == 0);
break;
case 49152:
irq_reload = data;
break;
case 49153:
if (mmc3_alt_behavior)
{
irq_clear = true;
}
irq_counter = 0;
break;
case 57344:
irq_enabled = false;
NesEmu.IRQFlags &= -9;
break;
case 57345:
irq_enabled = true;
break;
}
}
private void SetupCHR()
{
if (CHR_ROM_01KB_Count > 0)
{
if (!flag_c)
{
Switch02KCHR(chr_reg[0] >> 1, CHRArea.Area0000);
Switch02KCHR(chr_reg[1] >> 1, CHRArea.Area0800);
Switch01KCHR(chr_reg[2], CHRArea.Area1000);
Switch01KCHR(chr_reg[3], CHRArea.Area1400);
Switch01KCHR(chr_reg[4], CHRArea.Area1800);
Switch01KCHR(chr_reg[5], CHRArea.Area1C00);
}
else
{
Switch02KCHR(chr_reg[0] >> 1, CHRArea.Area1000);
Switch02KCHR(chr_reg[1] >> 1, CHRArea.Area1800);
Switch01KCHR(chr_reg[2], CHRArea.Area0000);
Switch01KCHR(chr_reg[3], CHRArea.Area0400);
Switch01KCHR(chr_reg[4], CHRArea.Area0800);
Switch01KCHR(chr_reg[5], CHRArea.Area0C00);
}
}
else if (!flag_c)
{
Switch04KCHR(0, CHRArea.Area0000);
Switch04KCHR(1, CHRArea.Area1000);
}
else
{
Switch04KCHR(1, CHRArea.Area0000);
Switch04KCHR(0, CHRArea.Area1000);
}
}
private void SetupPRG()
{
prg_or = (chr_reg[0] & 2) << 5;
Switch08KPRG(prg_reg[flag_p ? 2 : 0] | prg_or, PRGArea.Area8000);
Switch08KPRG(prg_reg[1] | prg_or, PRGArea.AreaA000);
Switch08KPRG(prg_reg[(!flag_p) ? 2 : 0] | prg_or, PRGArea.AreaC000);
Switch08KPRG(prg_reg[3] | prg_or, PRGArea.AreaE000);
}
internal override void OnPPUA12RaisingEdge()
{
old_irq_counter = irq_counter;
if (irq_counter == 0 || irq_clear)
{
irq_counter = irq_reload;
}
else
{
irq_counter--;
}
if ((!mmc3_alt_behavior || old_irq_counter != 0 || irq_clear) && irq_counter == 0 && irq_enabled)
{
NesEmu.IRQFlags |= 8;
}
irq_clear = false;
}
internal override void WriteStateData(ref BinaryWriter stream)
{
base.WriteStateData(ref stream);
stream.Write(flag_c);
stream.Write(flag_p);
stream.Write(address_8001);
for (int i = 0; i < chr_reg.Length; i++)
{
stream.Write(chr_reg[i]);
}
for (int j = 0; j < prg_reg.Length; j++)
{
stream.Write(prg_reg[j]);
}
stream.Write(irq_enabled);
stream.Write(irq_counter);
stream.Write(old_irq_counter);
stream.Write(irq_reload);
stream.Write(irq_clear);
stream.Write(prg_or);
}
internal override void ReadStateData(ref BinaryReader stream)
{
base.ReadStateData(ref stream);
flag_c = stream.ReadBoolean();
flag_p = stream.ReadBoolean();
address_8001 = stream.ReadInt32();
for (int i = 0; i < chr_reg.Length; i++)
{
chr_reg[i] = stream.ReadInt32();
}
for (int j = 0; j < prg_reg.Length; j++)
{
prg_reg[j] = stream.ReadInt32();
}
irq_enabled = stream.ReadBoolean();
irq_counter = stream.ReadByte();
old_irq_counter = stream.ReadInt32();
irq_reload = stream.ReadByte();
irq_clear = stream.ReadBoolean();
prg_or = stream.ReadInt32();
}
}
}