dynamic loading and unloading of sketch.
well, say you change the images for a PImage which has to be preloaded (NB: maybe not?)
or you want to change the canvas size, which has to be the first thing set up in setup.
Also, dynamic unloading of previously loaded code, because otherwise it’ll just start running again
if (oldp) oldp.exit();
Processing.instances[n] does not appear to work, despite assurances in this bug
http://stackoverflow.com/questions/10281747/how-to-know-when-a-processingjs-sketch-has-been-loaded - not evaluated
TODO: some morel links to sources, and notes.
Also, I’ve found that pre-loading a PImage with a data-uri still takes time to load.
// wait until image is REALLY loaded from URI
if (img.pixels.length <= 10) return;