I've got a couple of questions about texture compression:
1. Can I dynamically create a texture (e.g. in a pbuffer or in the back buffer in a preprocessing step) then compress it on the fly and use it to replace a part of a compressed texture (w/ glCompressedTexSubImage)? And how fast would that be?
I need it to be fast and I need compression because I want to update a huge texture (1024x1024 or 2048x2048 depending on the HW) small bits at a time. And in this case, I need this texture to be double-buffered, so this would take twice the amount of memory and can't be done without compression.
2. Can normal maps be compressed or would this have too much of an impact on the normals?