So are these border pixels part of the pixel data or are they separate properties that can be set in opengl? For example this texture chunk is 1024x1024. If adding border would increase dimension, suppose it's 4 pixel border. Wouldn't it make it 1028x1028 thus violating non power of two requirements? but it's interesting though. I'll look it up more later
It would, so you have to let the usable part of the texture be 1016x1016 to add 4 pixel borders at each edge. This usually isn't a problem as with bilinear filtering and scaling anyway it won't look any different, just set the texture coords to be [4/1024, 1020/1024] instead of [0, 1].