My understanding is that ARB_texture_rg gives us 1 and 2 component
FBO-renderable formats...if I'm using F32 frame buffers this is a pretty
huge savings in RAM.
But...if I have a pre-made texture and I simply want to use it...can
anyone tell me...
1. If I use GL_ALPHA32F_ARB do I get a one-component 32-bit surface?
(E.g. do I really use my VRAM efficiently without extra "dummy" channels?)
2. If I use GL_LUMINANCE_ALPHA32F_ARB do I get a two-component 64-bit
surface? (E.g. do I really use my VRAM efficiently without extra
I would like the feature I am working on to run on 10.5.8...if these
formats provide everything GL_RED_32F and GL_RG_32F provide except the
sampling semantics and renderability, they'd give me backward compatibility.