I try my hands on scripting with scheme in gimp, and started with something that should be easy: write a script that creates a selection on the upper half of the image.
Something like (set! sel (gimp-create-selection img)) and then work on that selection. But the above function does not exist, nor can I find functions to manipulate selections.
It looks like a selection is not an object type of its own but rather another channel of the image.
So how can I create and manipulate a selection on an image? (Via script, not using the rectangular selection tool.) Is there an overview of gimp data types somewhere?
I know common LISP, so scheme syntax is not the main problem.