I really apologize to everyone. Ed and I went back and forth with code changes to this. During that time, I re-installed my OS. I thought I had a clean cut of the code, but I guess it wasn't the working version. What is floating around now is as good as it will get. We never got the alignment correct. There was something with the window size that messes up the placement of the effect. I am not a GLSL programmer so my fiddling with it lead no where. I really hope someone with time and skills can look at what we had, and see if we were on the right track. It also helps if you use a mask/shadow. Create a sprite for the shadow, set it to destination out, then set the glow to the same size. It can mimic the diffusion effect of other engines.