when defining a source rect for bitmapData when apply a shaderFilter to it, the rect is ignored when processing pixels. It seems that every pixel is examined regardless of what the source rect is. Why?
I'm defining the rectangle of which I want the shader to examine, so why does it keep examining pixels outside of this?
I'm forced to create a new bitmapData every time I want to run my shader, then define coordinates in the shader as parameters. This doesn't seem like a very practical approach.