This is something that earlier versions of flash did very well. You could start by creating graphics, then turn them into frames in an animation. In order to make those frames dynamic you had to learn some programming, and you'd get instant feedback.
It wasn't just some toy, you could create production applications this way. Unfortunately the low bar resulted in a lot of low quality applications (in terms of ux and engineering) which led to it's downfall.
Processing is more like a framework and comes in python and java flavour (although I think the language doesn't really matter as long as you grasp how loops work and what can be done with it).
Something like this:
The concepts learned by just playing around with this are valuable in any language.