public override void Apply(Graphics graphics, Bitmap applyBitmap, Rectangle rect, RenderMode renderMode)
{
Rectangle applyRect = ImageHelper.CreateIntersectRectangle(applyBitmap.Size, rect, Invert);
if (applyRect.Width == 0 || applyRect.Height == 0)
{
// nothing to do
return;
}
GraphicsState state = graphics.Save();
if (Invert)
{
graphics.SetClip(applyRect);
graphics.ExcludeClip(rect);
}
ColorMatrix grayscaleMatrix = new ColorMatrix(new[] {
new[] {.3f, .3f, .3f, 0, 0},
new[] {.59f, .59f, .59f, 0, 0},
new[] {.11f, .11f, .11f, 0, 0},
new float[] {0, 0, 0, 1, 0},
new float[] {0, 0, 0, 0, 1}
});
using (ImageAttributes ia = new ImageAttributes())
{
ia.SetColorMatrix(grayscaleMatrix);
graphics.DrawImage(applyBitmap, applyRect, applyRect.X, applyRect.Y, applyRect.Width, applyRect.Height, GraphicsUnit.Pixel, ia);
}
graphics.Restore(state);
}