hammer.js中文文档_hammer.js实现图片手势放大效果

//图片手势放大
     var reqAnimationFrame = (function() {
       return window[Hammer.prefixed(window, "requestAnimationFrame")] || function(callback) {
         window.setTimeout(callback, 1000 / 60);
       };
     })();
     var el = $("img");
     var ticking = false;
     var transform;
     var initScale = 1;
     var _eImg = "";
     for (var m = 0; m < el.length; m++) {
       var mc = new Hammer.Manager(el[m]);
       mc.add(new Hammer.Pan({
         threshold: 0,
         pointers: 0
       }));
       mc.add(new Hammer.Swipe()).recognizeWith(mc.get("pan"));
       mc.add(new Hammer.Pinch({
         threshold: 0
       })).recognizeWith(mc.get("pan"));
       mc.on("panstart panmove", onPan);
       mc.on("pinchstart pinchmove", onPinch);
       mc.on("swipe", onSwipe);
     }
 
     function resetElement() {
       el.addClass("animate");
       transform = {
         translate: {
           x: 0,
           y: 0
         },
         scale: 1,
         angle: 0,
         rx: 0,
         ry: 0,
         rz: 0
       };
       requestElementUpdate();
     }
 
     function updateElementTransform() {
       var value = ["translate3d(" + transform.translate.x + "px, " + transform.translate.y + "px, 0)", "scale(" + transform.scale + ", " + transform.scale + ")", "rotate3d(" + transform.rx + "," + transform.ry + "," + transform.rz + "," + transform.angle + "deg)"];
       value = value.join(" ");
       if (_eImg != "") {
         _eImg.style.webkitTransform = value;
         _eImg.style.mozTransform = value;
         _eImg.style.transform = value;
         //_eImg.css({ "transform": value }, { "-webkit-transform": value });
       }
       ticking = false;
     }
 
     function requestElementUpdate() {
       if (!ticking) {
         reqAnimationFrame(updateElementTransform);
         ticking = true;
       }
     }
 
     function onPan(ev) {
       el.removeClass("animate");
       transform.translate = {
         x: ev.deltaX,
         y: ev.deltaY
       };
     }
 
     function onPinch(ev) {
       if (ev.type == "pinchstart") {
         initScale = transform.scale || 1;
       }
       el.removeClass("animate");
       transform.scale = initScale * ev.scale;
       requestElementUpdate();
       _eImg = ev.target;
       return _eImg;
     }
 
     function onSwipe(ev) {
       var angle = 10;
       transform.ry = (ev.direction & Hammer.DIRECTION_HORIZONTAL) ? 1 : 0;
       transform.rx = (ev.direction & Hammer.DIRECTION_VERTICAL) ? 1 : 0;
       transform.angle = (ev.direction & (Hammer.DIRECTION_RIGHT | Hammer.DIRECTION_UP)) ? angle : -angle;
       requestElementUpdate();
       _eImg = ev.target;
       return _eImg;
     }
     resetElement();