[hugoamnov]

The PBR pipeline of toy is not well optimized yet: I'll have more time to tackle this issue now that the heavy lifting work has been done !

Framerates are much better in the non-web version somehow: I suspect some unnecessary texture sampling ops are to blame, but I need to investigate.

Resizing the window to a smaller helps greatly improve the framerate, which tends to show that the bottleneck is in the fragment shaders.