1 files changed, 167 insertions, 0 deletions
diff --git a/js/vendor/oktween.js b/js/vendor/oktween.js
new file mode 100644
index 0000000..41edbb0
--- /dev/null
+++ b/js/vendor/oktween.js
@@ -0,0 +1,167 @@
+/*
+  oktween.add({
+    obj: el.style,
+    units: "px",
+    from: { left: 0 },
+    to: { left: 100 },
+    duration: 1000,
+    easing: oktween.easing.circ_out,
+    update: function(obj){
+      console.log(obj.left)
+    }
+    finished: function(){
+      console.log("done")
+    }
+  })
+*/
+
+var oktween = (function(){
+  var oktween = {}
+  var tweens = oktween.tweens = []
+  var last_t = 0
+  var id = 0
+  oktween.speed = 1
+  oktween.raf = requestAnimationFrame
+  oktween.add = function(tween){
+    tween.id = id++
+    tween.obj = tween.obj || {}
+    if (tween.easing) {
+      if (typeof tween.easing == "string") {
+        tween.easing = oktween.easing[tween.easing]
+      }
+    }
+    else {
+      tween.easing = oktween.easing.linear
+    }
+    if (! ('from' in tween) && ! ('to' in tween)) {
+      tween.keys = []
+    }
+    else if (! ('from' in tween) ) {
+      tween.from = {}
+      tween.keys = Object.keys(tween.to)
+      tween.keys.forEach(function(prop){
+        tween.from[prop] = parseFloat(tween.obj[prop])
+      })
+    }
+    else {
+      tween.keys = Object.keys(tween.from)
+    }
+    tween.delay = tween.delay || 0
+    tween.start = last_t + tween.delay
+    tween.done = false
+    tween.after = tween.after || []
+    tween.then = function(fn){ tween.after.push(fn); return tween }
+    tween.cancel = function(){
+      var index = tweens.indexOf(tween)
+      if (index != -1) tweens.splice(index, 1)
+      tween.obj = null
+      tween.after = null
+      tween.done = null
+    }
+    tween.tick = 0
+    tween.skip = tween.skip || 1
+    tween.dt = 0
+    tweens.push(tween)
+    return tween
+  }
+  oktween.update = function(t) {
+    oktween.raf(oktween.update)
+    last_t = t * oktween.speed
+    if (tweens.length == 0) return
+    var done = false
+    tweens.forEach(function(tween, i){
+      var dt = Math.min(1.0, (t - tween.start) / tween.duration)
+      tween.tick++
+      if (dt < 0 || (dt < 1 && (tween.tick % tween.skip != 0))) return
+      var ddt = tween.dt = tween.easing(dt)
+      tween.keys.forEach(function(prop){
+        val = lerp( ddt, tween.from[prop], tween.to[prop] )
+        if (tween.round) val = Math.round(val)
+        if (tween.units) val = (Math.round(val)) + tween.units
+        tween.obj[prop] = val
+      })
+      tween.update && tween.update(tween.obj, dt)
+      if (dt == 1) {
+        tween.finished && tween.finished(tween)
+        if (tween.after.length) {
+          var twn = tween.after.shift()
+          twn.obj = twn.obj || tween.obj
+          twn.after = tween.after
+          oktween.add(twn)
+        }
+        if (tween.loop) {
+          tween.start = t + tween.delay
+        }
+        else {
+          done = tween.done = true
+        }
+      }
+    })
+    if (done) {
+      tweens = tweens.filter(function(tween){ return ! tween.done })
+    }
+  }
+  function lerp(n,a,b){ return (b-a)*n+a }
+
+  // requestAnimationFrame(oktween.update)
+
+  oktween.easing = {
+    linear: function(t){
+      return t
+    },
+    circ_out: function(t) {
+      return Math.sqrt(1 - (t = t - 1) * t)
+    },
+    circ_in: function(t){
+      return -(Math.sqrt(1 - (t * t)) - 1)
+    },
+    circ_in_out: function(t) {
+      return ((t*=2) < 1) ? -0.5 * (Math.sqrt(1 - t * t) - 1) : 0.5 * (Math.sqrt(1 - (t -= 2) * t) + 1)
+    },
+    quad_in: function(n){
+      return Math.pow(n, 2)
+    },
+    quad_out: function(n){
+      return n * (n - 2) * -1
+    },
+    quad_in_out: function(n){
+      n = n * 2
+      if(n < 1){ return Math.pow(n, 2) / 2 }
+      return -1 * ((--n) * (n - 2) - 1) / 2
+    },
+    cubic_bezier: function (mX1, mY1, mX2, mY2) {
+      function A(aA1, aA2) { return 1.0 - 3.0 * aA2 + 3.0 * aA1; }
+      function B(aA1, aA2) { return 3.0 * aA2 - 6.0 * aA1; }
+      function C(aA1)      { return 3.0 * aA1; }
+
+      // Returns x(t) given t, x1, and x2, or y(t) given t, y1, and y2.
+      function CalcBezier(aT, aA1, aA2) {
+        return ((A(aA1, aA2)*aT + B(aA1, aA2))*aT + C(aA1))*aT;
+      }
+
+      // Returns dx/dt given t, x1, and x2, or dy/dt given t, y1, and y2.
+      function GetSlope(aT, aA1, aA2) {
+        return 3.0 * A(aA1, aA2)*aT*aT + 2.0 * B(aA1, aA2) * aT + C(aA1);
+      }
+
+      function GetTForX(aX) {
+        // Newton raphson iteration
+        var aGuessT = aX;
+        for (var i = 0; i < 10; ++i) {
+          var currentSlope = GetSlope(aGuessT, mX1, mX2);
+          if (currentSlope == 0.0) return aGuessT;
+          var currentX = CalcBezier(aGuessT, mX1, mX2) - aX;
+          aGuessT -= currentX / currentSlope;
+        }
+        return aGuessT;
+      }
+
+      return function(aX) {
+        if (mX1 == mY1 && mX2 == mY2) return aX; // linear
+        return CalcBezier(aX, mY1, mY2);
+      }
+    }
+  }
+  
+  return oktween
+})()