Yeah, there have been many moments when I needed localized UV space. I would just send the center of the sprite as a uniform and compare the vertex positions with that to determine which corner is which.
@jhonny.goransson You don’t need all that information. Just a vertex attribute that is (0,0) in the bottom-left corner of the sprite and (1,1) in the top-right corner of the sprite, regardless of the actual UV coordinates in the atlas. The rest can be inferred from these values, if needed.
Usage example: Masking or gradient-ing a texture for a HP bar