title: How to composite multiple PNG into a single PNG using GTK/Cairo
body: <p>I'm somewhat new to GTK and very new to Cairo. I've been tasked to create an application that needs to take a PNG as a background and composite multiple PNG files that contains letters and numbers onto the background PNG so that I end up with a single PNG that can then be transformed, rotated, scaled etc. Any hints, tutorials, code samples that I might find useful? As is the case with GTK, the Cairo documentation appears somewhat lacking for a beginner trying to do something more complex than drawing shapes.</p>