When the fractional part of a float fixes your shader

The other night I wanted to implement a small Voronoi-diagram shader to use as a background to a music video, to show up the music project I recently finished. Voronoi Noise is type of algorithm I never implemented before, and I was always mesmerized by the geometric and often organic-ish way it looks. Without much direction in mind, I started implementing it and experimenting. I got it looking pretty cool and I was about to call it a day, but then next morning I found out that, in one of my computers only, there was a weird stutter to the animation. So I decided to dig into it to find out what the problem was. This is the write-up of my whole adventure of a week debugging and disassemblying shaders. There are a few plot twists to the story, and hopefully a lot of interesting information too. This is the final shader. You can also check it on Shadertoy. I still haven’t worked on the video, but you can check the music on all digital platforms: stuffy knows. The Shader This shader is…