unfortunately "little slower" in this case may be as much as 10x slower or even a bit more, shader compilation also becomes many times slower and long shaders may run into instruction count limits. Every mediump floating point intermediate value needs to be run through a 6-step function for the emulation. It costs way too much to have it on all the time.
On Nov 6, 2014, at 9:58 PM, Olli Etuaho <email@example.com> wrote:
The extension does not require any support from the GL drivers, so that's why I've submitted the proposal only to the WebGL registry at this point. It can be implemented purely as a transformation of the GLSL code. If there's a strong reason for adding it also as a native extension, I have nothing against that, of course.