The source is a highly interesting read: hal.science/hal-02143706...

"calculatorElement" and Annex F in this doc: color.org/specificatio...

www.shadertoy.com/view/433czr

Demo: editor.p5js.org/AlexandruIca...
Original: ttnghia.github.io/posts/quadra...

Not sure how relevant this is, but a few chapters from the CG Cinematography book by Chris Brejon about colors seem like a great reference:
- chrisbrejon.com/cg-cinematog...
- chrisbrejon.com/cg-cinematog...
- chrisbrejon.com/cg-cinematog...

> I’m glad I worked on this headless rendering test, but I had enough trouble making my code working headless that I want to look for an easier approach next time.

Sums up my experience with headless testing graphics. :)

Demo: editor.p5js.org/AlexandruIca...

www.inf.usi.ch/hormann/pape...

This is how it works in Skia in case anyone's curious: www.youtube.com/watch?v=Omfl...

Basically instead of doing union(union(p0, p1), ...) I did union(union(p0, p1, p2, ...), ...). I think this is a textbook example of an optimization that's completely unintuitive when you look at it. Unless you're familiar with how `union` works it makes no sense.