Saving the screen as a bitmap

I heard that it is possible to call a function that writes the current screen to a picture file, is this true? Can anyone offer advice or help on this process.

Also is it possible to write animation files as an output?

Cheers Tom.

glReadPixels doesn’t write directly into a file but into a buffer where you can save it into any format you like. To save an animation you just have to grab each frame and store them using some lib or your own stuff.