How I failed to make a game: Raycasting on the GBA

Tangentially related, I've been extremely impressed following 3DSage's work. I've only dipped my toe into GBA programming ("hello world"-level stuff), and the fact that they built a real-time 3D level editor is mind-blowing to me.

https://www.youtube.com/watch?v=msM_oYqUMT0

I'm personally a bit more impressed by the Tomb Raider port mentioned in another thread, the linked game is doom/duke3d-esque and the GBA cpu should be roughly on par with a 486sx both in terms of clock speed and instructions per second (assuming you spend most of your time in code using the fast-ram).

The editor and looking at another video from sage3d also the rendering method, seems extremely reminiscent of duke3d. You can see a review of the duke3d rendering and sector setup on Fabians page.

Why the Tomb Raider port impresses more is because Duke3d-like renderers can work on straight spans and only interpolate textures in on direction and also get "free" hidden-surface culling (ie they never draw more than is seen), Tomb Raider on the other hand seems to have arbitrary texturing probably more overlap as well.

https://fabiensanglard.net/duke3d/