Older Qualcomm drivers rotated the framebuffer 90 degrees and this fix didn't work.
Now for some obscene reason it rotates a full 180 degrees.
This can at least be worked around by flipping around the image on our end.
OSX has their own driver, so performance issues aren't shared with the nvidia driver (unlike the closed source linux and windows nvidia driver). So now they'll also use the MapAndSync backend like all other osx drivers.
fixes issue 6596
I've also cleaned up the if/else block selecting the best backend a bit.
Some information on this bug since this isn't quite true.
Seemingly with the v53 driver, Qualcomm has actually fixed this bug. So we can dynamically access UBO array members.
The issue that is cropping up is actually converting our attribute 'fposmtx' to an integer.
int posmtx = int(fpostmtx);
This line causes some seemingly garbage values to enter in to the posmtx variable.
Not sure exactly why it is failing, probably them just not actually converting the float to an integer and just handling the float directly as a integer.
So the bug is going to stay active with Qualcomm devices until we convert this vertex attribute from a float to a integer.
