private void HandleOpcode(OpCode code)
{
switch (code.code & 0xF000)
{
case 0x0000:
switch (code.code & 0x000F)
{
case 0x0000:
ClearDisplay();
PC_I();
draw = true;
break;
case 0x000E:
PC = stack[stackPointer--];
PC_I();
break;
default:
PC_I();
break;
}
break;
case 0x1000:
PC = (ushort)code.Addr();
break;
case 0x2000:
stack[++stackPointer] = PC;
PC = code.Addr();
break;
case 0x3000:
if (VRegs[code.X()] == code.KK())
{
PC_I();
}
PC_I();
break;
case 0x4000:
if (VRegs[code.X()] != code.KK())
{
PC_I();
}
PC_I();
break;
case 0x5000:
if (VRegs[code.Y()] == VRegs[code.X()])
{
PC_I();
}
PC_I();
break;
case 0x6000:
VRegs[code.X()] = (byte)code.KK();
PC_I();
break;
case 0x7000:
VRegs[code.X()] += (byte)code.KK();
PC_I();
break;
case 0x8000:
switch (code.code & 0x000F)
{
case 0x0000:
VRegs[code.X()] = VRegs[code.Y()];
PC_I();
break;
case 0x0001:
VRegs[code.X()] |= VRegs[code.Y()];
PC_I();
break;
case 0x0002:
VRegs[code.X()] &= VRegs[code.Y()];
PC_I();
break;
case 0x0003:
VRegs[code.X()] ^= VRegs[code.Y()];
PC_I();
break;
case 0x0004:
VRegs[0xF] = (byte)((VRegs[code.X()] + VRegs[code.Y()]) > 0xFF ? 1 : 0);
VRegs[code.X()] += VRegs[code.Y()];
PC_I();
break;
case 0x0005:
VRegs[0xF] = (byte)(VRegs[code.X()] > VRegs[code.Y()] ? 1 : 0);
VRegs[code.X()] -= VRegs[code.Y()];
PC_I();
break;
case 0x0006:
VRegs[0xf] = (byte)(VRegs[code.X()] & 0x1);
VRegs[code.X()] /= 2;
PC_I();
break;
case 0x0007:
VRegs[0xF] = (byte)(VRegs[code.Y()] > VRegs[code.X()] ? 1 : 0);
VRegs[code.X()] = (byte)(VRegs[code.Y()] - VRegs[code.X()]);
PC_I();
break;
case 0x000E:
VRegs[0xf] = (byte)((VRegs[code.X()] & 0x80) != 0 ? 1 : 0);
VRegs[code.X()] *= 2;
PC_I();
break;
}
break;
case 0x9000:
if (VRegs[code.X()] != VRegs[code.Y()])
{
PC_I();
}
PC_I();
break;
case 0xA000:
I = code.Addr();
PC_I();
break;
case 0xB000:
PC = (ushort)(code.Addr() + VRegs[0]);
//PC_I();
break;
case 0xC000:
VRegs[code.X()] = (byte)(random.Next(255) & code.KK());
PC_I();
break;
case 0xD000:
VRegs[0xf] = 0;
ushort x = VRegs[code.X()];
ushort y = VRegs[code.Y()];
ushort nibl = code.N();
ushort xj, yi;
xj = yi = 0;
byte pixel;
for (int i = 0; i < nibl; ++i)
{
pixel = Memory[I + i];
for (int j = 0; j < 8; ++j)
{
if ((pixel & (0x80 >> j)) != 0)
{
//if(x+j >= 0 && x+j< 64 && y+i >= 0 && y+i < 32)
//{
ushort pos = (ushort)(((x + j) + ((y + i) * 64)) % 2048);
if (display[pos] == true)
{
VRegs[0xf] = 1;
}
display[pos] ^= true;
//}
//VRegs[0xf] = display[pos] == true ? (byte)1 : (byte)0;
}
}
}
draw = true;
PC_I();
break;
case 0xE000:
switch (code.code & 0x00FF)
{
case 0x009E:
if (key[VRegs[code.X()]])
{
PC_I();
}
PC_I();
break;
case 0x00A1:
if (!key[VRegs[code.X()]])
{
PC_I();
}
PC_I();
break;
}
//PC_I();
break;
case 0xF000:
switch (code.code & 0x00FF)
{
case 0x0007:
VRegs[code.X()] = (byte)delayTimer;
PC_I();
break;
case 0x000A:
for (int i = 0x0; i < 0xf; ++i)
{
if (key[i])
{
VRegs[code.X()] = (byte)i;
PC_I();
break;
}
}
break;
case 0x0015:
delayTimer = VRegs[code.X()];
PC_I();
break;
case 0x0018:
soundTimer = VRegs[code.X()];
PC_I();
break;
case 0x001E:
I += VRegs[code.X()];
PC_I();
break;
case 0x0029:
I = (ushort)(VRegs[code.X()] * 5);
PC_I();
break;
case 0x0033:
var value = VRegs[code.X()];
Memory[I + 2] = (byte)((value % 100) % 10);
Memory[I + 1] = (byte)((value / 10) % 10);
Memory[I] = (byte)(value / 100);
PC_I();
break;
case 0x0055:
for (int i = 0; i < code.X(); ++i)
{
Memory[I + i] = VRegs[i];
}
I += (ushort)(code.X() + 1);
PC_I();
break;
case 0x0065:
for (int i = 0; i < code.X(); ++i)
{
VRegs[i] = Memory[I + i];
}
I += (ushort)(code.X() + 1);
PC_I();
break;
}
break;
default:
Console.WriteLine($"{code.code} not implemented yet.");
break;
}
}
