Team:Evry/arbor/src/tween/tween.js

From 2012.igem.org

// // tween.js // // interpolator of .data field members for nodes and edges //

 var Tween = function(){
   var _tweens = {}
   var _done = true
   
   var that = {
     init:function(){
       return that
     },
     
     busy:function(){
       var busy = false
       for (var k in _tweens){ busy=true; break}
       return busy
     },
     
     to:function(node, dur, to){
       var now = new Date().valueOf()
       var seenFields = {}

       var tween = {from:{}, to:{}, colors:{}, node:node, t0:now, t1:now+dur*1000, dur:dur*1000}
       var easing_fn = "linear"
       for (var k in to){
         if (k=='easing'){
           // need to do better here. case insensitive and default to linear
           // also be okay with functions getting passed in
           var ease = to[k].toLowerCase()
           if (ease in Easing) easing_fn = ease
           continue
         }else if (k=='delay'){
           var delay = (to[k]||0) * 1000
           tween.t0 += delay
           tween.t1 += delay
           continue
         }
         
         if (Colors.validate(to[k])){
           // it's a hex color string value
           tween.colors[k] = [Colors.decode(node.data[k]), Colors.decode(to[k]), to[k]]
           seenFields[k] = true
         }else{
           tween.from[k] = (node.data[k]!=undefined) ? node.data[k] : to[k]
           tween.to[k] = to[k]
           seenFields[k] = true
         }
       }
       tween.ease = Easing[easing_fn]

       if (_tweens[node._id]===undefined) _tweens[node._id] = []
       _tweens[node._id].push(tween)
       
       // look through queued prunes for any redundancies
       if (_tweens.length>1){
         for (var i=_tweens.length-2; i>=0; i++){
           var tw = _tweens[i]

           for (var k in tw.to){
             if (k in seenFields) delete tw.to[k]
             else seenFields[k] = true
           }

           for (var k in tw.colors){
             if (k in seenFields) delete tw.colors[k]
             else seenFields[k] = true
           }

           if ($.isEmptyObject(tw.colors) && $.isEmptyObject(tw.to)){
             _tweens.splice(i,1)
           }

         }
       }
       
       _done = false
     },

     interpolate:function(pct, src, dst, ease){
       ease = (ease||"").toLowerCase()
       var easing_fn = Easing.linear
       if (ease in Easing) easing_fn = Easing[ease]

       var proportion = easing_fn( pct, 0,1, 1 )
       if (Colors.validate(src) && Colors.validate(dst)){
         return lerpRGB(proportion, src,dst)
       }else if (!isNaN(src)){
         return lerpNumber(proportion, src,dst)
       }else if (typeof src=='string'){
         return (proportion<.5) ? src : dst
       }
       
     },

     tick:function(){
       var empty = true
       for (var k in _tweens){ empty=false; break}
       if (empty) return
       
       var now = new Date().valueOf()
       
       $.each(_tweens, function(id, tweens){
         var unprunedTweens = false
         
         $.each(tweens, function(i, tween){
           var proportion = tween.ease( (now-tween.t0), 0,1, tween.dur )
           proportion = Math.min(1.0, proportion)
           var from = tween.from
           var to = tween.to
           var colors = tween.colors
           var nodeData = tween.node.data

           var lastTick = (proportion==1.0)

           for (var k in to){
             switch (typeof to[k]){
               case "number":
                 nodeData[k] = lerpNumber(proportion, from[k], to[k])
                 if (k=='alpha') nodeData[k] = Math.max(0,Math.min(1, nodeData[k]))
                 break
               case "string":
                 if (lastTick){
                   nodeData[k] = to[k]
                 }
                 break
             }
           }
           
           for (var k in colors){
             if (lastTick){
               nodeData[k] = colors[k][2]
             }else{
               var rgb = lerpRGB(proportion, colors[k][0], colors[k][1])
               nodeData[k] = Colors.encode(rgb)
             }
           }

           if (lastTick){
              tween.completed = true
              unprunedTweens = true
           }
         })
         
         if (unprunedTweens){
           _tweens[id] = $.map(tweens, function(t){ if (!t.completed) return t})
           if (_tweens[id].length==0) delete _tweens[id]
         }
       })
       
       _done = $.isEmptyObject(_tweens)
       return _done
     }
   }
   return that.init()
 }
 
 var lerpNumber = function(proportion,from,to){
   return from + proportion*(to-from)
 }
 
 var lerpRGB = function(proportion,from,to){
   proportion = Math.max(Math.min(proportion,1),0)
   var mixture = {}
   
   $.each('rgba'.split(""), function(i, c){
     mixture[c] = Math.round( from[c] + proportion*(to[c]-from[c]) )
   })
   return mixture
 }

// })()