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-   -   Anyone else find glPixelZoom(1,-1) reeeeealy slow? (http://www.nvnews.net/vbulletin/showthread.php?t=6085)

grmoc 01-08-03 10:36 AM

Anyone else find glPixelZoom(1,-1) reeeeealy slow?
 
I'm finding glPixelZoom(1,-1) to be incredible slow under 4192.

Anyone else experiencing this?

example:
(setup 1:1 pixel->vertex correspondence for the proj matrix, etc)
glPixelZoom(1,-1);
glRasterPos2i(0,486);
glCopyPixels(0,0,720,486);


That takes nealy half a second to complete!

ACK!?

grmoc 01-08-03 11:09 AM

From bad to worse
 
Hmm, it wasn't any better under 3123.

:mad:

grmoc 01-09-03 03:15 AM

On even further inspection,
glCopyPixels is DOG slow with glPixelZoom(1,-1),
but glDrawPixels is fast as ever.

Hey Nvidia- FIX IT! Arg! This one should really be easy!

The following should -not- run with software fallback:

// assume glOrtho set up for 720,486.
glXMakeContextCurrent(display,writeDrawable,readDr awable, glxcontext );
// where writeDrawable!=readDrawable, but you should be able to fast-blit vertical-flipped in the same drawable
glPixelZoom(1,-1);
glRasterPos(0,486);
glCopyPixels(0,0,720,486,GL_COLOR);


As it stands, there is currently no easy way to blit in video (right-side-up), render on top of it, and blit it out (upside-down).

Fixing glCopyPixels would make it possible to do this at framerate (29.97 fps) instead of at 2 fps.


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