mapTo.js

/*
 * Re-maps a number from one range to another, akin to map() in Processing and Arduino
 *
 * @param  {Number} value  The number to map
 * @param  {Number} inMin  The lower bound of the value's current range
 * @param  {Number} inMax  The upper bound of the value's current range
 * @param  {Number} outMin The lower bound of the value's target range
 * @param  {Number} outMax The upper bound of the value's target range
 * @param  {boolean} capped Set to true to cap to the min/max target range, even if the input was outwith the current range
 *
 * @return {Number}        The mapped value
 */

mapTo = function(value, inMin, inMax, outMin, outMax, capped) {
  var newVal = (value - inMin) * (outMax - outMin) / (inMax - inMin) + outMin;

  if (capped !== null && capped) {
    return Math.max(outMin, Math.min(newVal, outMax));
  }

  return newVal;
};