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Electron

new OGL SDK drivers? Is it possible?

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Electron    122
I a wondering if there is possible to update the OGL SDK library? And, if so, where can i find it? I''m having trouble with my current library. When i use glBegin() and glVertex() on an algorithm drawing about 20,000 triangles, i get about 60-70 fps. When i rewrote it to use glDrawElements() instead, (Which would go faster, in my oppinion), my FPS drops down to <1. I scanned the algorithm and there is nothing in my code that could do such difference. My only explanation would be that the internal code for glDrawPolygon() is bad. Are there different versions of the SDK, and if so, where can i find it? Don''t just say www.opengl.org, since i scanned the entire page, and found nothing.

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Guest Anonymous Poster   
Guest Anonymous Poster
I don''t believe that there would be such a loss of performance due to the use of glDrawElements because of a driver problem. I don''t know what 3D card you have, but eg. Nvidia claims that glDrawElements is ultra-fast. It''s a so widely used function that no OGL driver will have *such* a bad optimization.

I has to be a problem with your code. If you switched from glBegin()... to glDrawElements, then that means you switched to VAs. I suspect you are repopulating your VAs every frame. Thats the only explanantion I have for such a huge performance drop.

- AH

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zedzeek    529
20000 is way to much for drawelements for most cards
use 5x4000 instead (but experiment yourself)
also check the drawrangeelements extension for info on querying to see the max indices/vertices for a reasonable framerate

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