I'm trying to draw an image, with a source Bitmap and an alpha mask Bitmap, using the System.Drawing.Graphics object.
At the moment I loop X and Y and use GetPixel and SetPixel to write the source color and mask alpha to a third Bitmap, and then render that.
However this is very inefficient and I am wondering if there is an faster way to achieve this?
The effect I'm after looks like this:
The grid pattern represents transparency; you probably knew that.