[DanielRibeiro]

Yes, however the raycasting is drawing pixel by pixel. That part is not hardware accelerated, and that is the expensive part. That is that part that shaders speedup a lot, by delegating a lot of the work to the GPU.

Just compare with this pure fragment shader demo: https://www.shadertoy.com/view/MsS3W3

[ANTSANTS]

That page froze my browser (Firefox 29) and started leaking oodles of memory until I killed it (along with a bunch of other shit I was working on), so I guess I'll count that as a point in favor of software raycasting.