Manipulate Pixels

Hello, I’m new in OGL and i wonder how I can manipulate individual pixels on the screen or perform a bit block transer (like the Blit function in DirectDraw). How can I get a pointer to the Screen surface data ?
Hope you can help me with that.

no,no and no
render to textures and preform texel operations instead… dont touch the pixeldata. ( you can read about why in nearly every openglforum atleast 10 times)

There must be a way to manipulate them. Without glDrawPixel and such functions. With a pointer to the video memory.

Originally posted by Guest:
There must be a way to manipulate them. Without glDrawPixel and such functions. With a pointer to the video memory.

No.

Not sure what you are trying to do, but when working with 3D vs. 2D.
When working with 3D, you must think diffrently from when you where programming in 2D.

Originally posted by Guest:
There must be a way to manipulate them. Without glDrawPixel and such functions. With a pointer to the video memory.