Symbols appear with text, but their background sprites flicker

[peterqliu]

Most conspicuous during zooming and panning.

can be found at https://www.mapbox.com/bites/00151/

cc/ @ansis

[benstadin]

This looks like an OpenGL z-ordering and / or floating point precision issue. This can be hacked around by fiddling with different z values, but the issue will always come up again. To fix these nasty things in the long run, it probably requires to rethink about data hierarchies and parent-child relationships (e.g. what will happen also in cases when you have extruded data, and add a layer with icons and icons should be always on top of them also in perspective view). See also my comment here: #292 (comment)

[ansis]

It looks like this has been fixed. It isn't reproducible with emerald-v8 and master.