BizHawk/BizHawk.Emulation.Cores/Consoles/PC Engine/VCE.cs

90 lines
2.1 KiB
C#

using BizHawk.Common;
namespace BizHawk.Emulation.Cores.PCEngine
{
// HuC6260 Video Color Encoder
public sealed class VCE
{
public ushort VceAddress;
public ushort[] VceData = new ushort[512];
public int[] Palette = new int[512];
public byte CR;
public int NumberOfScanlines => (CR & 4) != 0 ? 263 : 262;
public void WriteVCE(int port, byte value)
{
port &= 0x07;
switch (port)
{
case 0: // Control Port
CR = value;
break;
case 2: // Address LSB
VceAddress &= 0xFF00;
VceAddress |= value;
break;
case 3: // Address MSB
VceAddress &= 0x00FF;
VceAddress |= (ushort)(value << 8);
VceAddress &= 0x01FF;
break;
case 4: // Data LSB
VceData[VceAddress] &= 0xFF00;
VceData[VceAddress] |= value;
PrecomputePalette(VceAddress);
break;
case 5: // Data MSB
VceData[VceAddress] &= 0x00FF;
VceData[VceAddress] |= (ushort)(value << 8);
PrecomputePalette(VceAddress);
VceAddress++;
VceAddress &= 0x1FF;
break;
}
}
public byte ReadVCE(int port)
{
port &= 0x07;
switch (port)
{
case 4: // Data LSB
return (byte)(VceData[VceAddress] & 0xFF);
case 5: // Data MSB
byte value = (byte)((VceData[VceAddress] >> 8) | 0xFE);
VceAddress++;
VceAddress &= 0x1FF;
return value;
default: return 0xFF;
}
}
private static readonly byte[] PalConvert = { 0, 36, 72, 109, 145, 182, 218, 255 };
public void PrecomputePalette(int slot)
{
byte r = PalConvert[(VceData[slot] >> 3) & 7];
byte g = PalConvert[(VceData[slot] >> 6) & 7];
byte b = PalConvert[VceData[slot] & 7];
Palette[slot] = Colors.ARGB(r, g, b);
}
public void SyncState(Serializer ser)
{
ser.BeginSection("VCE");
ser.Sync("VceAddress", ref VceAddress);
ser.Sync("CR", ref CR);
ser.Sync("VceData", ref VceData, false);
ser.EndSection();
if (ser.IsReader)
{
for (int i = 0; i < VceData.Length; i++)
{
PrecomputePalette(i);
}
}
}
}
}