* Helpers for create methods.

* Helper fxn to measure ascent and descent. * Adapted from http://stackoverflow.com/a/25355178

* turn a two dimensional array into one dimensional array * @param {Array} arr 2-dimensional array * @return {Array} 1-dimensional array * [[1

* Returns a file extension, or another string * if the provided parameter has no extension. * * @param {String} filename * @return {Array}

* Validates clipping params. Per drawImage spec sWidth and sHight cannot be * negative or greater than image intrinsic width and height * @private

VIDEO STUFF

* Helper function for select and selectAll

* turn a p5.Vector Array into a one dimensional number array * @param {Array} arr an array of p5.Vector * @return {Array]} a one dimensional a

* Helper function for getElement and getElements.