[SDL] Input latency in OpenGL?

[Bob Pendleton]

On Sat, 2008-01-19 at 06:06 +0000, Iori Branford wrote:
> I'm on a Windows box with an ATI Radeon X1950 and the latest drivers. In my
> programs, keyboard and joystick events seem to take longer to be processed in
> OpenGL than in software or DirectX. If other OpenGL/SDL programs are lagging,
> I'm not seeing it.
> 
> Even if it is just me, even if this delay won't be noticed in real gameplay, I'm
> interested in whatever I can do to improve input response time. I use Bob
> Pendleton's Fast Events but it doesn't appear to make a difference. 

That's good the hear, it shouldn't make a difference.

Check a couple of things, how are you managing buffer swapping in
OpenGL? Also, check to see if any of your screen settings are
synchronized with V-Blank. Those settings may be different for OpenGL
and the other graphics systems you mentioned. Check to see if you are
using glFlush or glFinish at the end of your gl rendering calls. You
"should" call glFlush and probably not call glFinish. The last thing is
to make sure you are processing all pending events before you swap the
buffers. 

	Bob Pendleton


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