propane is a ruby wrapper for processing-3.3.6. Create processing sketches in ruby using regular ruby-2.3 syntax, and use the magic JRuby to run them. You can use both rubygems and and regular processing libraries in your sketches. Run them with jruby.

In general where there is a choice of using a java (processing) method or a regular ruby method you should choose the ruby method (eg use rand in place of random). Further you should prefer to use JRuby classes Vec2D and Vec3D instead of processings PVector class. Processing has a number of convenience methods which are not needed in ruby (eg ‘pow’ use ** in propane) and some static methods have not been implemented in propane. For the processing map method prefer map1d (see example) or use p5map if you must. Another thing to watch is color which is implemented differently in propane (see example).

See also my blog for more code ideas.