In OpengGL ES 2.0 Programming Guide:
"One thing you need to be
careful of, though, is that if you access a vector with a non-constant integral
expression (e.g., using an integer variable index), then this might not be
supported in OpenGL ES 2.0."
"OpenGL ES 2.0 spec does not mandate support for this behavior except for
on a specific variable type (namely, uniform variables)."
Does the 2nd sentence say "uniforms can be used as array subscripts" or "can indexing uniform vectors"?
Based on my understanding, uniforms are actually constant for shaders, so it is safe to use it?
Thanks!