* Fix FXAA computations in mediump
UV coordinates computed in highp should be passed to the FXAA function
in highp as well. This change also fixes a potential division by 0 which
was causing dir1 to have components set to inifinity, thus breaking the
texture sampling calls below. We fix this with an early exit when a
potential division by 0 is detected. The original code contained a bias
to try to avoid this problem but that bias was not always enough. It
was frequent in mediump to cancel out the bias.
* Update shaders/src/fxaa.fs
Co-Authored-By: romainguy <romainguy@curious-creature.com>
4901f6f72a