@toxiccomputer Thanks for the feedback. It was hard to get it working in a playable framerate when using any of the canvas drawing API's as drawing a pixel at a time was incredibly slow, hence I switched to using a memory buffer and then pushing that to the canvas in a single draw operation, got things performant (with some bugs which i've since fixed).
Did you notice that the code is Open Source? That might be a good place to start if you want to see exactly how I did it. The specific code that you're after is [here](https://github.com/NuclearRedeye/ludumdare48/blob/master/src/ts/raycaster.ts#L128-L218). I've since the submission tweaked it further fixing some bugs I had but I still have some further improvements planned to try and squeeze a little more out of it.
I'm not really active on any platforms, but happy if you want to start a [new discussion on GitHub](https://github.com/NuclearRedeye/ludumdare48/discussions) and I'll do my best to help you out.