Rather than discarding uploaded tiles once they fall outside of the valid
region, shuffle them off into a separate tile-store with all the metadata they
need to render them, and render them in the areas that our current valid
region doesn't cover in TiledThebesLayerOGL::RenderLayer.
Rather than discarding uploaded tiles once they fall outside of the valid
region, shuffle them off into a separate tile-store with all the metadata they
need to render them, and render them in the areas that our current valid
region doesn't cover in TiledThebesLayerOGL::RenderLayer.