arbitrary screen-drawing program?
I'm looking for a program that can arbitrarily display an image at a certain location on the screen which draws on top of any program, terminal, etc. that could potentially lie in the same location (similar to how a cursor is drawn on the screen, only static and having nothing to do with input.) It needs to be command-line or have a complete command-line front-end because I need to be able to execute it via .bashrc with image/location specifics supplied as arguments.
Does anyone know of a program capable of this? Or, if anyone experienced with OpenGL is reading this, how hard do you think it would be to write one? It doesn't sound like too involved of a task to me, but I wouldn't know.