core/src/ons/gesture-detector.js
function getScale(start, end) {
    // need two fingers...
    if (start.length >= 2 && end.length >= 2) {
      return this.getDistance(end[0], end[1]) / this.getDistance(start[0], start[1]);
    }
    return 1;
  }
function getScale(start, end) {
    // need two fingers...
    if (start.length >= 2 && end.length >= 2) {
      return this.getDistance(end[0], end[1]) / this.getDistance(start[0], start[1]);
    }
    return 1;
  }
function getScale ( start , end ) { // need two fingers... if ( start . length >= 2 && end . length >= 2 ) { return this . getDistance ( end [ 0 ] , end [ 1 ] ) / this . getDistance ( start [ 0 ] , start [ 1 ] ) ; } return 1 ; }
calculate the scale factor between two touchLists
no scale is 1, and goes down to 0 when pinched together, and bigger when pinched out
@param {Array} start array of touches
@param {Array} end array of touches
@return {Number} scale
calculate the scale factor between two touchLists no scale is 1 and goes down to 0 when pinched together and bigger when pinched out