accessing the framebuffer

Accelerated Computing CUDA CUDA Programming and Performance
1

Hello,

is it possible to read the current image data from the framebuffer using CUDA?

The project I have in mind is quite similar to VNC, I want to

  • read the current image data
  • and compress it directly on the graphic card
  • then pass it down to the cpu and let it handle the rest

thanks in advance
~fog

2

No. CUDA has no direct access to anything inside an OpenGL context. Only PBOs can be mapped to linear memory CUDA buffers. So you need to copy the framebuffer to a PBO and map that one to a CUDA buffer. As CUDA and OpenGL live in different contexts, the mapping involves another copy.

Peter

3

Also VBOs.

4

what about FBO’s ?

5

No, not directly.

We’re investigating ways to improve graphics interop in future releases.