How is the default return value of the texture function family defined?
the texture functions are specified to return always gvec4. But what happens if you sample e.g. a RG texture?
Are the b and a components than undefined or have they a default value?
On my machine the b component is always 0 and the a component is always 1 for a RG32F texture. But that doesn’t proof anything.
I searched the whole specifcation of GLSL 4.6 but didn’t find anything. But maybe i missed something: