/// <summary>
/// Checks if all of the pixels in the column (within the bounds of the rectangle) match the specified color.
/// </summary>
private static bool IsConstantColumn(ImageSurface surf, Cairo.Color color, Gdk.Rectangle rect, int x)
{
for (int y = rect.Top; y < rect.Bottom; ++y)
{
if (!color.Equals(surf.GetPixel(x, y)))
{
return(false);
}
}
return(true);
}
/// <summary>
/// Checks if all of the pixels in the row match the specified color.
/// </summary>
private static bool IsConstantRow(ImageSurface surf, Cairo.Color color, int y)
{
for (int x = 0; x < surf.Width; ++x)
{
if (!color.Equals(surf.GetPixel(x, y)))
{
return(false);
}
}
return(true);
}
/// <summary>
/// Gets the final pixel color for the given point, taking layers, opacity, and blend modes into account.
/// </summary>
public ColorBgra GetComputedPixel(int x, int y)
{
using (var dst = new ImageSurface(Format.Argb32, 1, 1)) {
using (var g = new Context(dst)) {
foreach (var layer in GetLayersToPaint())
{
var color = layer.Surface.GetColorBgraUnchecked(x, y).ToCairoColor();
g.SetBlendMode(layer.BlendMode);
g.SetSourceColor(color);
g.Rectangle(dst.GetBounds().ToCairoRectangle());
g.PaintWithAlpha(layer.Opacity);
}
}
return(dst.GetPixel(0, 0).ToColorBgra());
}
}
