Posh: Type-Safe Graphics Programming in Rust

Using Rust for writing shaders may sound appealing, but that puts a language that is slow to compile into a domain where fast iteration times are crucial. Most shaders can be compiled in milliseconds and e.g. graphical authoring tools rely on this.

Why build upon OpenGL ES rather than wgpu?

SL looks like an absolute dog's breakfast. I'll be sticking with Go and Ebitengine's Kage shader language.