Running Propane Without a Display

Apparently this is possible according to @jtoy see https://github.com/processing/processing/wiki/Running-without-a-Display.

Important if you need to save images, make sure you provide full path eg

save(data_path('a.jpg'))

data_path is a convenience wrapper from propane that provides a path to the data folder (in the same directory as your sketch), and if the folder doesn't exist it gets created. This is done from the ruby-side, which is important to avoid guessing from the java side of processing, that will most likely cause a security issue.

The data_path wrapper is equally good when reading data from the sketches data folder (and is why it got created) Mac users complained that they could not pick up files from data folder, also security issue meant shader sketches etc would not run with jruby (in ruby-processing the --jruby flag was created to deal with this problem, because when started with java the problem went away).