Is it possible output HALFs to a buffer using OpenGL's transform feedback? I've been trying it for a while without success. I can't find an example on how to do it. My code works with floats, but I can't make it work with halfs, using packHalf2x16 on the vertex shader.
const vec3 pos = vec3(0.0, 0.0, 1.0);
O0 = uvec4(packHalf2x16(pos.xy), packHalf2x16(vec2(pos.z, 0.0)), 0u, 0u);
works, but if I remove "const" it doesn't work. Why? Is it supposed to be like that or is it a driver bug (old ATI Mobility Radeon HD 4650 with the latest windows 8.1 64bits drivers or similar)?
I've ended up coding my very own sluggish packHalf2x16 and everything's working. So it's either a bug or I don't know how to properly use GLSL extensions. Shouldn't just adding "#extension GL_ARB_shading_language_packing : require" make it all work?