How well does OpenGL (3.2, if it matters) handle modifying or replacing textures that have already been uploaded to the GPU?
I always had the impression that messing with textures was always much more expensive than replacing VBO data, even if the texture is far smaller in byte size, but I'm starting to think this might not be the case.
Is there perhaps a list somewhere that shows what sort of operations are most expensive in OpenGL?
For context, I'm working on a terrain system where the terrain colors can change frequently. I figure I can either do texture mapping, and modify the texture pixels, or put the color in the terrain vertices and rebuild the VBO for each change. I'm accustomed to continually rebuilding dynamic VBOs for other tasks, but in this case I am thinking that a texture would be a lot less data to upload than the block of geometry.