public static void Resize(I <Vector3> source, IntRect sourceRect, I <Vector3> destination, ResizeFilterType filterType, CancellationToken cancel = default(CancellationToken))
{
if (source == null)
{
throw new ArgumentNullException("buffer");
}
if (destination == null)
{
throw new ArgumentNullException("destination");
}
sourceRect = sourceRect.Clip(new IntRect(0, 0, source.Width, source.Height));
if (sourceRect.Width <= 0 || sourceRect.Height <= 0 || source.Channels <= 0)
{
throw new ArgumentNullException("Source image must not be empty");
}
if (destination.Width <= 0 || destination.Height <= 0 || destination.Channels <= 0)
{
return;
}
var s = source.Data.Buffer;
var d = destination.Data.Buffer;
var contribX = ImageBufferResize.CreateContributors(filterType, source.Width, sourceRect.Left, sourceRect.Right, destination.Width);
var contribY = ImageBufferResize.CreateContributors(filterType, source.Height, sourceRect.Top, sourceRect.Bottom, destination.Height);
float filterRadius = ImageBufferResize.GetFilterRadius(filterType);
int ringBufferLines = contribY.Max(x => x.N);
var ringBuffer = new Vector3[destination.Width * ringBufferLines];
var ranges = destination.Format.ChannelRanges;
var low = new Vector3((float)ranges[0].Low, (float)ranges[1].Low, (float)ranges[2].Low);
var high = new Vector3((float)ranges[0].High, (float)ranges[1].High, (float)ranges[2].High);
int sY = sourceRect.Top;
int dX, j;
int offset = 0;
int positionInRing = sY % ringBufferLines;
for (int dY = 0; dY < destination.Height; ++dY)
{
if ((dY % 128) == 0 && cancel.IsCancellationRequested)
{
break;
}
int rowIn, rowOut;
while (sY < sourceRect.Bottom && sY <= contribY[dY].MaxPixel)
{
rowIn = sY * source.Width;
rowOut = positionInRing * destination.Width;
for (dX = 0; dX < destination.Width; ++dX)
{
var contrib = contribX[dX];
var value = Vector3.Zero;
for (j = 0; j < contribX[dX].N; ++j)
{
float weight = contrib.P[j].Weight;
if (weight != 0)
{
offset = contrib.P[j].Pixel;
value = value + s[rowIn + offset] * weight;
}
}
ringBuffer[rowOut] = value * contrib.Normalize;
++rowOut;
}
++sY;
positionInRing = (positionInRing + 1) % ringBufferLines;
}
// resize lines vertically
for (int k = 0; k < destination.Width; ++k)
{
var contrib = contribY[dY];
var value = Vector3.Zero;
for (j = 0; j < contrib.N; ++j)
{
float weight = contrib.P[j].Weight;
if (weight != 0)
{
offset = contrib.P[j].Pixel % ringBufferLines;
offset = offset * destination.Width + k;
value = value + ringBuffer[offset] * weight;
}
}
value = Vector3.Max(Vector3.Min(value * contrib.Normalize, high), low);
d[dY * destination.Width + k] = value;
}
}
}