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harnas

OpenGL GLX/Linux and delayed reaction

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harnas    122
Hi, I wrote visualization program based on NeHe tutorials. I am using GLX on Linux with nvidia drivers. The program is working nicely when displaying small number of objects (let say up to 200 gluSpheres). I have problems when it draws more objects (ex. 200 gluSpheres, 200gluCylinders and 5000 glVertex3f at the same time). The animation runs smoothly but the window seems to have a delayed reaction to the events like: 1) keypressed, when I press ESC to kill the application, the openGL window closes after 20-30 seconds 2) when I run the program as 2 threads (one operating Opengl, the other controling rotation variables) it seems that the OpenGL window is changed with a big delay comparing to changes of variables that describe the opengl scene. It only happens when I am ploting large number of objects. It looks like OpenGL renders the frames for few seconds ahead. Do you know this problem ? How can I fix it ? It is early stage of the project so I can still switch to SDL, if it helps in this case. Thanks, harnas

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benjamin bunny    838
Quote:
Original post by harnas
Hi,

I wrote visualization program based on NeHe tutorials. I am using GLX on Linux with nvidia drivers. The program is working nicely when displaying small number of objects (let say up to 200 gluSpheres).
I have problems when it draws more objects (ex. 200 gluSpheres, 200gluCylinders and 5000 glVertex3f at the same time). The animation runs smoothly but the window seems to have a delayed reaction to the events like:
1) keypressed, when I press ESC to kill the application, the openGL window closes after 20-30 seconds
2) when I run the program as 2 threads (one operating Opengl, the other controling rotation variables) it seems that the OpenGL window is changed with a big delay comparing to changes of variables that describe the opengl scene.
It only happens when I am ploting large number of objects. It looks like OpenGL renders the frames for few seconds ahead.

Do you know this problem ? How can I fix it ?
It is early stage of the project so I can still switch to SDL, if it helps in this case.

Thanks, harnas


If the frame rate is smooth then it sounds like a problem with your window code; I don't know what the linux equivilant of the Windows message pump looks like, but if this was a Windows application, that's where I'd look. If that's the case then using SDL should fix it anyway.

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owl    376
post your window creation/message handling routines. I'll try to remember how is the correct way of doing it (if it happens to be your problem). Handling messages incorrectly in X was a problem for me once.

Quote:
Original post by benjamin bunny
If that's the case then using SDL should fix it anyway.


Doesn't SDL use GLX for window context attachment and xlib for message handling?
If I could find a static lib to handle sound on linux, I wouldn't need SDL anymore.

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harnas    122
I have used event handling loops from NeHe tutorial.
I tried to add XSync() function. The code seems to work correctly now.
The glx window reacts fast to both key-press event and
changes of scene parameters by the other thread.

Thank a lot!

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