Imagination PowerVR SDK Blog

Problems with OpenGL ES 2.0 and OpenVG


I am trying to get OpenVG to draw on top of OpenGL ES 2.0 and am having very little luck.  It seems like GL is drawing on the onscreen buffer, and VG is drawing on the back buffer, I’ve tried changing my order of operations around till I’m blue in the face, but nothing seems to fix it.  I can get it to work if I basically exchange ES 2.0 for 1.1, but I don’t want to do that now that I have several nice shaders written.

Is this a common problem, or anybody encounter it before?  I could post source, but there’s a lot of it and it’s spread out over several files.  I’m basically drawing in GL, swapping context to VG, drawing VG, and swapping buffers (with EGL).  The documentation is all pretty vague when it comes to drawing GL and VG on the same screen. 

Should I just scrap trying to use 2 apis, and draw everything in GL?  (I like being able to draw 2d polygons without a lot of fuss…)

Oh, and hardware – Omap 3530 running on a Cogent sodimm carrier board.  Everything else is going fine, we’re even running a demo at a tradeshow with just the 3d part of our app.


Did you try this use-case with the PVR2D front library (non flip) ? You can change the library in the init script. Also please share more information on the SDK used and code snippet if possible.