Comment 3 for bug 1661375

Thank you Eric to go into these depths. I had tried to build apitrace for sending the trace for the whiteout issue but was stuck with a build error.

I think your VC4 drivers are a big leap forward to great graphics on the small devices! May the final issues be found soon!

What version of Qt do you have to run Stellarium 0.15 on a Pi? Current development has changed the use of a few important OpenGL-related widget classes which only came to completion in Qt5.4. Debian likely is more up-to-date than Raspbian with its Qt5.3.2. When you say, clearing color and depth hurts non-tiles renderers, maybe this is what happens now. We saw a performance loss on Windows, but gain on Linux, both on NVidia hardware (of different generations, though). Rather strange.

I hope my colleagues with more in-depth knowledge of OpenGL can have a look into this. Is it possible to identify tiled from non-tiled renderers and decide at runtime whether to glClear() or not?