I made a custom mark for showing complex functions. It can be changed simply to render GLSL shaders. I tried my best to avoid any memory leak and optimized it as much as I knew and was able, but if you find something I missed, let me know.
Wow, this is awesome. Great use of a custom mark in Observable Plot, and integrating d3-zoom! We think this might be the first example weâve seen of using GLSL in a custom Plot mark.
There are some similarities with Ricky Reusserâs complex function plotter (see implementation). Ricky also has a fantastic notebook on adaptive contouring. Check those out if you havenât seen them already.
Fil and I are hoping to bring native support for zooming to Plot soon (or, eventually), which might make this slightly easier. In any case, well done, and thank you for sharing! 
Thanks! There is one issue I havenât figured out how to fix. When the resolution is smaller than the plot, it gets stretched to fit the screen, and d3-zoom breaks.