jQuery image panning

Image panning with animation easing that works on mouse movement with css and jQuery.

Image panning with animation easing

The markup

Simple markup: an image inside a div

<div class="content">
  <img src="img.jpg" />
</div>

The CSS

.content{
  width: 800px;
  height: 600px;
  overflow: hidden;
}

.content img{
  opacity: 0;
  transition: opacity .6s linear .8s;
}

.content img.loaded{ opacity: 1; }

.img-pan-container, .img-pan-container img{ -webkit-box-sizing: border-box; -moz-box-sizing: border-box; box-sizing: border-box; }

.img-pan-container{
  position: relative;
  overflow: hidden;
  cursor: crosshair;
  height: 100%;
  width: 100%;
}

.img-pan-container img{
  -webkit-transform: translateZ(0); -ms-transform: translateZ(0); transform: translateZ(0);
  position: absolute;
  top: 0;
  left: 0;
}

The javascript

Can be placed inside the head tag or at the bottom of the document right before the closing body tag

More code, better animation/performance (60 fps)

<!-- jQuery -->
<script src="http://ajax.googleapis.com/ajax/libs/jquery/1.11.2/jquery.min.js"></script>

<!-- JS -->
<script>
  (function($){
    
    $(document).ready(function(){
      //call imagePanning fn when DOM is ready
      $(".content img").imagePanning();
    });
    
    //imagePanning fn
    $.fn.imagePanning=function(){
      var init="center",
        speed=800, //animation/tween speed
        //custom js tween
        _tweenTo=function(el,prop,to,duration,easing,overwrite){
          if(!el._mTween){el._mTween={top:{},left:{}};}
          var startTime=_getTime(),_delay,progress=0,from=el.offsetTop,elStyle=el.style,_request,tobj=el._mTween[prop];
          if(prop==="left"){from=el.offsetLeft;}
          var diff=to-from;
          if(overwrite!=="none"){_cancelTween();}
          _startTween();
          function _step(){
            progress=_getTime()-startTime;
            _tween();
            if(progress>=tobj.time){
              tobj.time=(progress>tobj.time) ? progress+_delay-(progress-tobj.time) : progress+_delay-1;
              if(tobj.time<progress+1){tobj.time=progress+1;}
            }
            if(tobj.time<duration){tobj.id=_request(_step);}
          }
          function _tween(){
            if(duration>0){
              tobj.currVal=_ease(tobj.time,from,diff,duration,easing);
              elStyle[prop]=Math.round(tobj.currVal)+"px";
            }else{
              elStyle[prop]=to+"px";
            }
          }
          function _startTween(){
            _delay=1000/60;
            tobj.time=progress+_delay;
            _request=(!window.requestAnimationFrame) ? function(f){_tween(); return setTimeout(f,0.01);} : window.requestAnimationFrame;
            tobj.id=_request(_step);
          }
          function _cancelTween(){
            if(tobj.id==null){return;}
            if(!window.requestAnimationFrame){clearTimeout(tobj.id);
            }else{window.cancelAnimationFrame(tobj.id);}
            tobj.id=null;
          }
          function _ease(t,b,c,d,type){
            var ts=(t/=d)*t,tc=ts*t;
            return b+c*(0.499999999999997*tc*ts + -2.5*ts*ts + 5.5*tc + -6.5*ts + 4*t);
          }
          function _getTime(){
            if(window.performance && window.performance.now){
              return window.performance.now();
            }else{
              if(window.performance && window.performance.webkitNow){
                return window.performance.webkitNow();
              }else{
                if(Date.now){return Date.now();}else{return new Date().getTime();}
              }
            }
          }
        };
      return this.each(function(){
        var $this=$(this),timer,dest;
        if($this.data("imagePanning")) return;
        $this.data("imagePanning",1)
          //create markup
          .wrap("<div class='img-pan-container' />")
          .after("<div class='resize' style='position:absolute; width:auto; height:auto; top:0; right:0; bottom:0; left:0; margin:0; padding:0; overflow:hidden; visibility:hidden; z-index:-1'><iframe style='width:100%; height:0; border:0; visibility:visible; margin:0' /><iframe style='width:0; height:100%; border:0; visibility:visible; margin:0' /></div>")
          //image loaded fn
          .one("load",function(){
            setTimeout(function(){ $this.addClass("loaded").trigger("mousemove",1); },1);
          }).each(function(){ //run load fn even if cached
            if(this.complete) $(this).load();
          })
          //panning fn
          .parent().on("mousemove touchmove MSPointerMove pointermove",function(e,p){
            var cont=$(this);
            e.preventDefault();
            var contH=cont.height(),contW=cont.width(),
              isTouch=e.type.indexOf("touch")!==-1,isPointer=e.type.indexOf("pointer")!==-1,
              evt=isPointer ? e.originalEvent : isTouch ? e.originalEvent.touches[0] || e.originalEvent.changedTouches[0] : e,
              coords=[
                !p ? evt.pageY-cont.offset().top : init==="center" ? contH/2 : 0,
                !p ? evt.pageX-cont.offset().left : init==="center" ? contW/2 : 0
              ];
            dest=[Math.round(($this.outerHeight(true)-contH)*(coords[0]/contH)),Math.round(($this.outerWidth(true)-contW)*(coords[1]/contW))];
          })
          //resize fn
          .find(".resize iframe").each(function(){
            $(this.contentWindow || this).on("resize",function(){
              $this.trigger("mousemove",1);
            });
          });
        //panning animation 60FPS
        if(timer) clearInterval(timer);
        timer=setInterval(function(){
          _tweenTo($this[0],"top",-dest[0],speed);
          _tweenTo($this[0],"left",-dest[1],speed);
        },16.6);
      });
    }
    
  })(jQuery);
</script>

The js code above is more than few lines, simply because it includes a vanilla custom javascript tween for much better performance and smoother animations.

Less code, average animation/performance (30 fps)

  $.fn.imagePanning=function(){
    var init="center",
      speed=800; //animation/tween speed
    //add custom easing for jquery animation
    $.extend($.easing,{
      pan:function(x,t,b,c,d){
        return -c * ((t=t/d-1)*t*t*t - 1) + b;
      }
    });
    return this.each(function(){
      var $this=$(this),timer,dest;
      if($this.data("imagePanning")) return;
      $this.data("imagePanning",1)
        //create markup
        .wrap("<div class='img-pan-container' />")
        .after("<div class='resize' style='position:absolute; width:auto; height:auto; top:0; right:0; bottom:0; left:0; margin:0; padding:0; overflow:hidden; visibility:hidden; z-index:-1'><iframe style='width:100%; height:0; border:0; visibility:visible; margin:0' /><iframe style='width:0; height:100%; border:0; visibility:visible; margin:0' /></div>")
        //image loaded fn
        .one("load",function(){
          setTimeout(function(){ $this.addClass("loaded").trigger("mousemove",1); },1);
        }).each(function(){ //run load fn even if cached
          if(this.complete) $(this).load();
        })
        //panning fn
        .parent().on("mousemove touchmove MSPointerMove pointermove",function(e,p){
          var cont=$(this);
          e.preventDefault();
          var contH=cont.height(),contW=cont.width(),
            isTouch=e.type.indexOf("touch")!==-1,isPointer=e.type.indexOf("pointer")!==-1,
            evt=isPointer ? e.originalEvent : isTouch ? e.originalEvent.touches[0] || e.originalEvent.changedTouches[0] : e,
            coords=[
              !p ? evt.pageY-cont.offset().top : init==="center" ? contH/2 : 0,
              !p ? evt.pageX-cont.offset().left : init==="center" ? contW/2 : 0
            ];
          dest=[Math.round(($this.outerHeight(true)-contH)*(coords[0]/contH)),Math.round(($this.outerWidth(true)-contW)*(coords[1]/contW))];
        })
        //resize fn
        .find(".resize iframe").each(function(){
          $(this.contentWindow || this).on("resize",function(){
            $this.trigger("mousemove",1);
          });
        });
      //panning animation 30 FPS
      if(!timer){
        timer=setInterval(function(){
          $this.stop().animate({"top":-dest[0],"left":-dest[1]},speed,"pan");
        },33.3);
      }
    });
  }

Image panning without animation

imagePanning function

  $.fn.imagePanning=function(){
    var init="center";
    return this.each(function(){
      var $this=$(this);
      if($this.data("imagePanning")) return;
      $this.data("imagePanning",1)
        //create markup
        .wrap("<div class='img-pan-container' />")
        .after("<div class='resize' style='position:absolute; width:auto; height:auto; top:0; right:0; bottom:0; left:0; margin:0; padding:0; overflow:hidden; visibility:hidden; z-index:-1'><iframe style='width:100%; height:0; border:0; visibility:visible; margin:0' /><iframe style='width:0; height:100%; border:0; visibility:visible; margin:0' /></div>")
        //image loaded fn
        .one("load",function(){
          setTimeout(function(){ $this.addClass("loaded").trigger("mousemove",1); },1);
        }).each(function(){ //run load fn even if cached
          if(this.complete) $(this).load();
        })
        //panning fn
        .parent().on("mousemove touchmove MSPointerMove pointermove",function(e,p){
          var cont=$(this);
          e.preventDefault();
          var contH=cont.height(),contW=cont.width(),
            isTouch=e.type.indexOf("touch")!==-1,isPointer=e.type.indexOf("pointer")!==-1,
            evt=isPointer ? e.originalEvent : isTouch ? e.originalEvent.touches[0] || e.originalEvent.changedTouches[0] : e,
            coords=[
              !p ? evt.pageY-cont.offset().top : init==="center" ? contH/2 : 0,
              !p ? evt.pageX-cont.offset().left : init==="center" ? contW/2 : 0
            ],
            dest=[Math.round(($this.outerHeight(true)-contH)*(coords[0]/contH)),Math.round(($this.outerWidth(true)-contW)*(coords[1]/contW))];
          $this.css({"top":-dest[0],"left":-dest[1]});
        })
        //resize fn
        .find(".resize iframe").each(function(){
          $(this.contentWindow || this).on("resize",function(){
            $this.trigger("mousemove",1);
          });
        });
    });
  }

As with everything, you can change it, optimize it and pretty much use it anyway and anywhere you like 🙂

 

FAQ

• Can you pan an image map and/or div?
• Can you synchronize the panning of multiple images?