Custom Bitmap Effects - HLSL

In the article Custom Bitmap Effects - Getting started we discovered how to work with HLSL in WPF. Now we are in a position to write more sophisticated shaders and  this means learning some more HLSL. In general shaders can work on vertices - i.e. the basic geometry of a 3D object - or the pixels that are about to be displayed. That is HLSL is a language that has commands that are about