static public Instruction8bit Get8bitInstruction(byte code, byte op1, byte op2)
{
Instruction8bit instruction = GB8bitInstructions[code];
string operation = instruction.GetOperation();
int index;
try
{
if (op1 > 0x00)
{
index = operation.IndexOf("*");
operation = operation.Remove(index, 1);
operation = operation.Insert(index, BitConverter.ToString(new byte[] { op1 }));
instruction = new Instruction8bit(code, operation, GB8bitInstructions[code].size, GB8bitInstructions[code].cycles);
}
// if op2 is not null or empty
if (op2 > 0x00)
{
index = operation.IndexOf("*");
operation = operation.Remove(index, 1);
operation = operation.Insert(index, BitConverter.ToString(new byte[] { op2 }));
instruction = new Instruction8bit(code, operation, GB8bitInstructions[code].size, GB8bitInstructions[code].cycles);
}
}
catch (Exception ex)
{
instruction = new Instruction8bit(code, $"Opcode not found", int.MaxValue, 0);
}
return(instruction);
}
private Instruction8bit Get8bitInstruction(byte code)
{
int size = Instructions.GB8bitInstructions[code].size;
byte op1;
byte op2;
switch (size)
{
case 2:
if (code == 0xE2 || code == 0xF2 || code == 0x10)
{
op1 = 0x00;
op2 = 0x00;
}
else
{
op1 = file[pc + 1];
op2 = 0x00;
}
break;
case 3:
// The Gameboy CPU is little endian, which means the least significant byte comes first
op1 = file[pc + 2];
op2 = file[pc + 1];
break;
default:
op1 = 0x00;
op2 = 0x00;
break;
}
Instruction8bit instruction = Instructions.Get8bitInstruction(code, op1, op2);
return(instruction);
}