Remove NaN uniform

[Pessimistress]

Background

Avoid sending NaN as uniform as it is believed to cause issues in some browsers.

Int value -1 (all ones) is NaN when interpreted as float32: https://en.wikipedia.org/wiki/Single-precision_floating-point_format#Exponent_encoding

According intBitsToFloat this solution may subject to GPU-specific behavior:

If the encoding of a NaN is passed in x, it will not signal and the resulting value will be undefined.

Change List

• Avoid sending NaN as uniform.

[felixpalmer]

Tested on M3 and working well (with this fix)

[coveralls]

coverage: 91.758% (-0.001%) from 91.759%
when pulling 93dc2c5 on x/nan
into 03145fb on master.

[ibgreen]

Strongly approve. The less we rely on NaN's the better. They are notorious for having surprising behavior and causing problems. (I'd personally try to find ways to avoid them inside the shaders too).