/// <summary>
/// Get the a pixel row at a given position with a length of the tile width. Mirrors pixels which exceeds the edges.
/// </summary>
/// <param name="source">The source image.</param>
/// <param name="rowPixels">Pre-allocated pixel row span of the size of a the tile width.</param>
/// <param name="x">The x position.</param>
/// <param name="y">The y position.</param>
/// <param name="tileWidth">The width in pixels of a tile.</param>
/// <param name="configuration">The configuration.</param>
private void CopyPixelRow(
ImageFrame <TPixel> source,
Span <Vector4> rowPixels,
int x,
int y,
int tileWidth,
Configuration configuration)
{
if (y < 0)
{
y = Numerics.Abs(y);
}
else if (y >= source.Height)
{
int diff = y - source.Height;
y = source.Height - diff - 1;
}
// Special cases for the left and the right border where DangerousGetRowSpan can not be used.
if (x < 0)
{
rowPixels.Clear();
int idx = 0;
for (int dx = x; dx < x + tileWidth; dx++)
{
rowPixels[idx] = source[Numerics.Abs(dx), y].ToVector4();
idx++;
}
return;
}
else if (x + tileWidth > source.Width)
{
rowPixels.Clear();
int idx = 0;
for (int dx = x; dx < x + tileWidth; dx++)
{
if (dx >= source.Width)
{
int diff = dx - source.Width;
rowPixels[idx] = source[dx - diff - 1, y].ToVector4();
}
else
{
rowPixels[idx] = source[dx, y].ToVector4();
}
idx++;
}
return;
}
this.CopyPixelRowFast(source.PixelBuffer, rowPixels, x, y, tileWidth, configuration);
}
public void Abs(int x)
{
int expected = Math.Abs(x);
Assert.Equal(expected, Numerics.Abs(x));
}