webGL Voronoi Filter

https://www.shadertoy.com/view/lsf3DS I got a voronoi filter going a few months ago, but it wouldn't compile in webGL though it worked fine on desktop. After a bunch of headscratching, and one failed attempt to do what I did to solve this today, I solved the compilation problem by changing almost every uniform or non-constant value into a value defined at runtime. Even declaring "const" in front of some of these in earlier attempts instead of the runtime defines failed. That said, I'm not sure if all of the defines were necessary. Perhaps the branching goes haywire in webGL without. To check it out, try to use Google Chrome, Firefox, or Safari with WebGL enabled in the developer preferences.