I know this has been discussed in the past, but I am trying to figure out the best way to save/restore the background in a modeling app (not a game). I have been using glReadPixels/glDrawPixels to system memory, which seems to work consistently, but slowly.
I just recently implemented the KTX_buffer_region extension, and performance has improved immensely. The problem with this is that it appears to be flakey on a number of devices (drivers), and is not uniformly supported.
We use multiple overlapping windows under Windoze, and when we switch context or try to re-allocate the “region buffers” for a window resize, it often crashes the driver.
I have tried to find information on using this extension, but it is not well documented.
Is there an alternative that is better supported and provides the speed of KTX_region_buffer?
TIA,
John Lynch