mapbox/mapbox-gl-native — pull request #439 by kkaefer (2014-08-21 13:09:05+00:00)
Title: Compute unique clip IDSs per tile

This takes covering children into account, so we will never draw the parent tile over child tiles of the same(!) source. In the case of multiple sources, the subsequent sources try to reuse ClipIDs from the previous sources if the ID and associated children match.