60 lines
1.7 KiB
C#
60 lines
1.7 KiB
C#
using System.Globalization;
|
|
using Chip8.Core;
|
|
|
|
namespace Chip8.Replay;
|
|
|
|
public static class FramebufferHash
|
|
{
|
|
const ulong fnvOffsetBasis = 14695981039346656037UL;
|
|
const ulong fnvPrime = 1099511628211UL;
|
|
|
|
public static ulong compute(Machine machine) => compute(FramebufferSnapshot.capture(machine));
|
|
|
|
public static ulong compute(FramebufferSnapshot snapshot)
|
|
{
|
|
ulong hash = fnvOffsetBasis;
|
|
hash = mix(hash, (byte)(snapshot.width & 0xFF));
|
|
hash = mix(hash, (byte)((snapshot.width >> 8) & 0xFF));
|
|
hash = mix(hash, (byte)(snapshot.height & 0xFF));
|
|
hash = mix(hash, (byte)((snapshot.height >> 8) & 0xFF));
|
|
foreach (byte color in snapshot.colors)
|
|
{
|
|
hash = mix(hash, color);
|
|
}
|
|
return hash;
|
|
}
|
|
|
|
public static ulong computeWithRegisters(Machine machine)
|
|
{
|
|
ulong hash = compute(machine);
|
|
foreach (byte register in machine.v)
|
|
{
|
|
hash = mix(hash, register);
|
|
}
|
|
hash = mix16(hash, machine.i);
|
|
hash = mix16(hash, machine.pc);
|
|
hash = mix(hash, machine.sp);
|
|
hash = mix(hash, machine.delayTimer);
|
|
hash = mix(hash, machine.soundTimer);
|
|
return hash;
|
|
}
|
|
|
|
public static string toHex(Machine machine) => format(compute(machine));
|
|
|
|
public static string format(ulong hash) => hash.ToString("X16", CultureInfo.InvariantCulture);
|
|
|
|
static ulong mix(ulong hash, byte value)
|
|
{
|
|
hash ^= value;
|
|
hash *= fnvPrime;
|
|
return hash;
|
|
}
|
|
|
|
static ulong mix16(ulong hash, ushort value)
|
|
{
|
|
hash = mix(hash, (byte)(value & 0xFF));
|
|
hash = mix(hash, (byte)((value >> 8) & 0xFF));
|
|
return hash;
|
|
}
|
|
}
|