a complete rewrite of particleground.js

only a third file size (to be fair: without jQuery-stuff and, raf polyfill), better performance, and some additional options.

even if it has almost no impact on the performance, code like this...

var ratioX = (winW - 0) / (30 - -30);
pointerX = (tiltX - -30) * ratioX + 0;

...is bloat! What is wrong with:

pointerX = (tiltX +30) * (winW/60);

The thing that really hits performance is the drawing routine. It is possible to only call ctx.stroke() once in a frame and leave the ctx style properties totally untouched, combine positioning and drawing into a single loop, avoid clunky Particle-Objects, and the ugly switch statements,

even if there is no equal codebase anymore, you maybe want to merge some of these _ideas_ into your library:

• use plain Arrays or POJOs instead of an extra Class to store the particle values.
• use a supervised drawing routine instead of an instance method to draw to canvas
• call ctx.stroke() only once per frame!
• remove orientationSupport && !desktop - when you get a proper event in the callback, you know that you have support
• calculate values only once (or once per frame) if they don´t change and not on every frame and for every particle (e.g.: pointerX - (winW / 2) could be calculated in the mousemove and orientation handler)
• remove the stackPos thing and just use the index of the array you keep the particles in.
• don´t combine in options the wall bouncing behaviour with the direction the particles move. They are not necessary related.
• combine resizeEvent handling and init (the adjustement of the number of particles is the same)