I am wondering whether there is any intention of eventually allowing entry of piecewise-defined functions into graphTool objects. From the PG side, it seems like it would be relatively easy to add domain bounds to graphical elements and to allow GraphTool objects to be arrays of arrays. I am not sure how hard it would be to put that functionality into the Java applet, though.
I ask simply because I have always coded such problems as multiple-choice graph-select problems. This is not a great way to formatively assess students' ability to work with piecewise definitions; it limits students' ability to make mistakes. It is also intensely time consuming to develop and code good distractors.
On a related note, how steep is the learning curve to move from developing problems in WeBWorK to adding to its code base? I wouldn't mind putting some time into developing support for piecewise-defined functions, but I am not sure whether I have the chops for it...