Does GL_PACK_SKIP_ROWS and GL_PACK_SKIP_PIXELS do anything?

I’m trying to use them with glCopyTexImage2D to copy for my 800x600 frame buffer to a 256x256 texture. I was under the impression that pack and unpack worked for reading and writing to the frame buffer or is this just a bad way to copy the frame buffer. I’m trying to avoid rendering the scene twice, because my biggest bottleneck is the volume of vertex data being sent to the video card.

Thanks…

John.

r u trying to copy the whole framebuffer in one hit from 800x600 ->256x256?

if so then its not possible

if youre wanting just 256x256 of the framebuffer to go into the texture then glCopyTexSubImage2D is what u want ie skiprows etc aint necessary

Zed,

yes I was hoping to copy 800x600 to 256x256. I was hoping that it would work like glDrawPixels and unpack.

John.