I’m having serious problems in my program when alt-tabbing from my fullscreen OpenGL program to other software (notepad) in Windows XP, NV8800GT (varying NV hardware, recent drivers, different machines). Appears to depend on the existence of FBOs, and the dimensions of the texture attached to them.
After pressing the keys and the display has switched resolution, there is typically a ~3 sec hang. Other application windows have blacked out elements (some toolbar, text boxes etc) during this hang. After a few more seconds of stutter, everything becomes responsive again. Could be better, but so far so good.
When Alt-Tabbing back into the program, the display switches resolution and the screen becomes black, takes about half a minute before it appears again, several seconds of stutter and unresponsiveness and the program continues to run as expected.
If the FBOs are relatively large/numerous (e.g. 1x 2048x2048 16-bit depth shadow map, 1x 1024x768 RGB8+depth24 RBO, 2x 256x256 RGB8 for post processing) the program becomes as good as unrecoverable. Subsequently significant difficulty to terminate the app via task manager (hard reboot often more convenient). Smaller FBOs make the problem more manageable. There’s even a noticeable difference of several seconds between a 16x16 and 128x128 texture attached to a single FBO.
FBO status are all ‘complete’, cannot detect other GL errors; all appears to be working as expected. No problems at all in windowed mode. Using SDL.
Does anyone have tips to improve ALT-TAB behavior or other hints?