public unsafe void Capture(int frame)
{
Sync();
if (!_active)
{
return;
}
if (_masterFrame == -1)
{
var sss = new SaveStateStream(this);
_stateSource.SaveStateBinary(new BinaryWriter(sss));
(_master, _scratch) = (_scratch, _master);
_masterLength = (int)sss.Position;
_masterFrame = frame;
_count++;
return;
}
if (!_buffer.WillCapture(_masterFrame))
{
return;
}
{
var sss = new SaveStateStream(this);
_stateSource.SaveStateBinary(new BinaryWriter(sss));
Work(() =>
{
_buffer.Capture(_masterFrame, underlyingStream_ =>
{
var zeldas = SpanStream.GetOrBuild(underlyingStream_);
if (_master.Length < _scratch.Length)
{
var replacement = new byte[_scratch.Length];
Array.Copy(_master, replacement, _master.Length);
_master = replacement;
}
var lengthHolder = _masterLength;
var lengthHolderSpan = new ReadOnlySpan <byte>(&lengthHolder, 4);
zeldas.Write(lengthHolderSpan);
fixed(byte *older_ = _master)
fixed(byte *newer_ = _scratch)
{
int *older = (int *)older_;
int *newer = (int *)newer_;
int lastIndex = (Math.Min(_masterLength, (int)sss.Position) + 3) / 4;
int lastOldIndex = (_masterLength + 3) / 4;
int *olderEnd = older + lastIndex;
int *from = older;
int *to = older;
while (older < olderEnd)
{
if (*older++ == *newer++)
{
if (to < from)
{
// Save on [to, from]
lengthHolder = (int)(from - to);
zeldas.Write(lengthHolderSpan);
zeldas.Write(new ReadOnlySpan <byte>(to, lengthHolder * 4));
}
to = older;
}
else
{
if (from < to)
{
// encode gap [from, to]
lengthHolder = (int)(to - from) | IS_GAP;
zeldas.Write(lengthHolderSpan);
}
from = older;
}
}
if (from < to)
{
// encode gap [from, to]
lengthHolder = (int)(to - from) | IS_GAP;
zeldas.Write(lengthHolderSpan);
}
if (lastOldIndex > lastIndex)
{
from += lastOldIndex - lastIndex;
}
if (to < from)
{
// Save on [to, from]
lengthHolder = (int)(from - to);
zeldas.Write(lengthHolderSpan);
zeldas.Write(new ReadOnlySpan <byte>(to, lengthHolder * 4));
}
}
(_master, _scratch) = (_scratch, _master);
_masterLength = (int)sss.Position;
_masterFrame = frame;
_count++;
});
});
}
}
