Windows Vista (Installing XP shortly)
I’m designing an interface in OpenGL, and it requires drawing to a large texture regularly (the size of the window, to be exact). As a side note, the interface is meant to run on fairly low quality Laptop GPU’s…so no Intel bashing.
Unfortunately, the performance of the two functions in the Subject of the post are terrible. After a bit of googling, I found a few hints that perhaps Intel GFX has bad CopyPixel performance for no apparent reason.
I’ve set the program up to only use those functions when absolutely nessessary, which makes me feel like I’m coding around Intel GFX, which is annoying, and I’m sacrificing CPU time for this workaround.
To clarify, using glCopyTexSubImage2D on an entire window that’s 800x600 drops the framerate to about 5 fps, from 30. Drawing the resultant texture back on to the screen incurs no performance drop whatsoever.
- Is this normal for most graphics cards, or just Intel?
- Is it in any way related to Windows?
Any other info helps as well,