Just got a reply from a colleague (John Christie) citing Sol's work as well:
"What your finding is what would be predicted. Sol discovered this same problem some time ago in OpenGL based software in general. What happens is that the double buffer is asynchronous when it can be. So, if the buffers are clear and there's no pending request then the call returns immediately. But, if the buffers are full, i.e. already processing a flip, then control doesn't return to the program until the flip is done. So, at values of <=1 you'll get proper behaviour. There's a simple and obvious solution of course... always start one frame back and redraw your current image and then immediately draw the subsequent one. The call will return at the border of a refresh." On Mar 24, 8:01 pm, Andrew Straw <[email protected]> wrote: > Hi Mike, > > I'm not sure if this explains what you're concerned about, but Sol > Simpson did some pretty exhaustive testing of the timing of video > display, and I wrote this up in my article on the Vision Egg. This has > nothing to do with the Vision Egg per se, however, and Sol found results > with pure C OpenGL implementations in Linux and Windows using AMD and > nVidia drivers. Anyhow, the writeup is > athttp://frontiersin.org/neuroinformatics/paper/10.3389/neuro.11/004.20... > in the "Drawing in OpenGL" section. > > -Andrew > > Mike Lawrence wrote: > > Wrapping messed up when I pasted that code in the window. Here's a > > link to the text file of the script: > >http://drop.io/wqc1bhy > > -- > Andrew D. Straw, Ph.D. > California Institute of Technologyhttp://www.its.caltech.edu/~astraw/ --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "pyglet-users" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/pyglet-users?hl=en -~----------~----~----~----~------~----~------~--~---
