Very nice implementation. Nice texture mapper. I did some raycasters too, but always had problems with rounding errors/ sawthooth artefacts. One problem: mouselook does not respond when WASD is pressed, so I cannot move around corners without to stop etc.

In my own projects I noticed movementX and Y give diffrent values depending on whether a key is pressed or not, so I simply multiplied them x 2.5 when a key is pressed. Could it be you use a threshold for movementX/Y, that may not be reached while a key is pressed? This was on Brave browser BTW, but it seems to be a problem that multiple browsers share.

Hey man, thanks for taking the time and checking out my little engine! I really appreciate it. Yeah, texture-mapping floors and ceilings was indeed a challenge for me too. It may not be perfect, but I’m pretty happy with what I’ve been able to accomplish so far. That aside, would you mind elaborating on the sawtooth artefacts you had with your engine, I may or may not be suffering from the same with mine.

As for the mouse look, yeah, I did notice some of the browsers behaving differently with the movementX and movementY–especially on Safari and Firefox, the values for movementX & Y are literally all over the place and can be a pain to use the mouse to turn around etc. I have never cared for it that much since I thought it was actually a behavior of the pointer lock and mouse listener apis and there was not much I could do about it. Now that you mention it, your approach seems sensible to me, combining it with clamping the values in a window could in fact be a decent workaround for the issue. I will try that and let you know. Thanks!

Not trying to spam your blog, but you asked. See my texels are not aligned to the world, yours are. To be honest, mine was a bloody beginners attempt, with door-spy -like perspective distortion. Nothing to be proud of. Yours seems much more like the original Wolfenstein, or also Doom 1.

BTW, instead of requestPointerLock, the W3 consortium should rather give us PositionPointer. If  You do that every frame (to the screen center), you'll know exactly how fast the mouse was moved away in the mean time. No matter the framerate (cause this already contains the delta factor) or whether any key is pressed (that's silly, mildly spoken). That's how we did it in windows.