Hi, I'm working on a terrain engine where I want to encode various terrain types in a texture. This texture will primarily be used in the shader for specular calculations, placement of vegetation and possibly also texture splatting.
I need no more than 16 land classes, so a 4-bit texture would do nicely.
What texture format would be best for this purpose? I know there are the new RGTC compressed formats, but I'm not sure lossy compression would work very well here, since I don't want vegetation in odd places for example.
I couldn't find any uncompressed 4-bit single-channel texture formats in the GL spec, but maybe I haven't looked good enough?
I also need to consider which formats are well supported in older hardware (at least 4-5 years back).