Revert ease interface.

Related #13.

src/back.js

@@ -1,28 +1,37 @@
 var overshoot = 1.70158;
 
-export var backIn = (function backIn(s) {
-  return s = +s, {
-    overshoot: backIn,
-    ease: function(t) {
-      return t * t * ((s + 1) * t - s);
-    }
-  };
+export var backIn = (function custom(s) {
+  s = +s;
+
+  function backIn(t) {
+    return t * t * ((s + 1) * t - s);
+  }
+
+  backIn.overshoot = custom;
+
+  return backIn;
 })(overshoot);
 
-export var backOut = (function backOut(s) {
-  return s = +s, {
-    overshoot: backOut,
-    ease: function(t) {
-      return --t * t * ((s + 1) * t + s) + 1;
-    }
-  };
+export var backOut = (function custom(s) {
+  s = +s;
+
+  function backOut(t) {
+    return --t * t * ((s + 1) * t + s) + 1;
+  }
+
+  backOut.overshoot = custom;
+
+  return backOut;
 })(overshoot);
 
-export var backInOut = (function backInOut(s) {
-  return s = +s, {
-    overshoot: backInOut,
-    ease: function(t) {
-      return ((t *= 2) < 1 ? t * t * ((s + 1) * t - s) : (t -= 2) * t * ((s + 1) * t + s) + 2) / 2;
-    }
-  };
+export var backInOut = (function custom(s) {
+  s = +s;
+
+  function backInOut(t) {
+    return ((t *= 2) < 1 ? t * t * ((s + 1) * t - s) : (t -= 2) * t * ((s + 1) * t + s) + 2) / 2;
+  }
+
+  backInOut.overshoot = custom;
+
+  return backInOut;
 })(overshoot);

src/bounce.js

@@ -9,22 +9,14 @@ var b1 = 4 / 11,
     b9 = 63 / 64,
     b0 = 1 / b1 / b1;
 
-function bounce(t) {
-  return (t = +t) < b1 ? b0 * t * t : t < b3 ? b0 * (t -= b2) * t + b4 : t < b6 ? b0 * (t -= b5) * t + b7 : b0 * (t -= b8) * t + b9;
+export function bounceIn(t) {
+  return 1 - bounceOut(1 - t);
 }
 
-export var bounceIn = {
-  ease: function(t) {
-    return 1 - bounce(1 - t);
-  }
-};
-
-export var bounceOut = {
-  ease: bounce
-};
+export function bounceOut(t) {
+  return (t = +t) < b1 ? b0 * t * t : t < b3 ? b0 * (t -= b2) * t + b4 : t < b6 ? b0 * (t -= b5) * t + b7 : b0 * (t -= b8) * t + b9;
+}
 
-export var bounceInOut = {
-  ease: function(t) {
-    return ((t *= 2) <= 1 ? 1 - bounce(1 - t) : bounce(t - 1) + 1) / 2;
-  }
-};
+export function bounceInOut(t) {
+  return ((t *= 2) <= 1 ? 1 - bounceOut(1 - t) : bounceOut(t - 1) + 1) / 2;
+}

src/circle.js

@@ -1,17 +1,11 @@
-export var circleIn = {
-  ease: function(t) {
-    return 1 - Math.sqrt(1 - t * t);
-  }
-};
+export function circleIn(t) {
+  return 1 - Math.sqrt(1 - t * t);
+}
 
-export var circleOut = {
-  ease: function(t) {
-    return Math.sqrt(1 - --t * t);
-  }
-};
+export function circleOut(t) {
+  return Math.sqrt(1 - --t * t);
+}
 
-export var circleInOut = {
-  ease: function(t) {
-    return ((t *= 2) <= 1 ? 1 - Math.sqrt(1 - t * t) : Math.sqrt(1 - (t -= 2) * t) + 1) / 2;
-  }
-};
+export function circleInOut(t) {
+  return ((t *= 2) <= 1 ? 1 - Math.sqrt(1 - t * t) : Math.sqrt(1 - (t -= 2) * t) + 1) / 2;
+}

src/cubic.js

@@ -1,17 +1,11 @@
-export var cubicIn = {
-  ease: function(t) {
-    return t * t * t;
-  }
-};
+export function cubicIn(t) {
+  return t * t * t;
+}
 
-export var cubicOut = {
-  ease: function(t) {
-    return --t * t * t + 1;
-  }
-};
+export function cubicOut(t) {
+  return --t * t * t + 1;
+}
 
-export var cubicInOut = {
-  ease: function(t) {
-    return ((t *= 2) <= 1 ? t * t * t : (t -= 2) * t * t + 2) / 2;
-  }
-};
+export function cubicInOut(t) {
+  return ((t *= 2) <= 1 ? t * t * t : (t -= 2) * t * t + 2) / 2;
+}

src/elastic.js

@@ -2,37 +2,43 @@ var tau = 2 * Math.PI,
     amplitude = 1,
     period = 0.3;
 
-export var elasticIn = (function elasticIn(a, p) {
+export var elasticIn = (function custom(a, p) {
   var s = Math.asin(1 / (a = Math.max(1, a))) * (p /= tau);
-  return {
-    amplitude: function(a) { return elasticIn(a, p * tau); },
-    period: function(p) { return elasticIn(a, p); },
-    ease: function(t) {
-      return a * Math.pow(2, 10 * --t) * Math.sin((s - t) / p);
-    }
-  };
+
+  function elasticIn(t) {
+    return a * Math.pow(2, 10 * --t) * Math.sin((s - t) / p);
+  }
+
+  elasticIn.amplitude = function(a) { return custom(a, p * tau); };
+  elasticIn.period = function(p) { return custom(a, p); };
+
+  return elasticIn;
 })(amplitude, period);
 
-export var elasticOut = (function elasticOut(a, p) {
+export var elasticOut = (function custom(a, p) {
   var s = Math.asin(1 / (a = Math.max(1, a))) * (p /= tau);
-  return {
-    amplitude: function(a) { return elasticOut(a, p * tau); },
-    period: function(p) { return elasticOut(a, p); },
-    ease: function(t) {
-      return 1 - a * Math.pow(2, -10 * (t = +t)) * Math.sin((t + s) / p);
-    }
-  };
+
+  function elasticOut(t) {
+    return 1 - a * Math.pow(2, -10 * (t = +t)) * Math.sin((t + s) / p);
+  }
+
+  elasticOut.amplitude = function(a) { return custom(a, p * tau); };
+  elasticOut.period = function(p) { return custom(a, p); };
+
+  return elasticOut;
 })(amplitude, period);
 
-export var elasticInOut = (function elasticInOut(a, p) {
+export var elasticInOut = (function custom(a, p) {
   var s = Math.asin(1 / (a = Math.max(1, a))) * (p /= tau);
-  return {
-    amplitude: function(a) { return elasticInOut(a, p * tau); },
-    period: function(p) { return elasticInOut(a, p); },
-    ease: function(t) {
-      return ((t = t * 2 - 1) < 0
-          ? a * Math.pow(2, 10 * t) * Math.sin((s - t) / p)
-          : 2 - a * Math.pow(2, -10 * t) * Math.sin((s + t) / p)) / 2;
-    }
-  };
+
+  function elasticInOut(t) {
+    return ((t = t * 2 - 1) < 0
+        ? a * Math.pow(2, 10 * t) * Math.sin((s - t) / p)
+        : 2 - a * Math.pow(2, -10 * t) * Math.sin((s + t) / p)) / 2;
+  }
+
+  elasticInOut.amplitude = function(a) { return custom(a, p * tau); };
+  elasticInOut.period = function(p) { return custom(a, p); };
+
+  return elasticInOut;
 })(amplitude, period);

src/exp.js

@@ -1,17 +1,11 @@
-export var expIn = {
-  ease: function(t) {
-    return Math.pow(2, 10 * t - 10);
-  }
-};
+export function expIn(t) {
+  return Math.pow(2, 10 * t - 10);
+}
 
-export var expOut = {
-  ease: function(t) {
-    return 1 - Math.pow(2, -10 * t);
-  }
-};
+export function expOut(t) {
+  return 1 - Math.pow(2, -10 * t);
+}
 
-export var expInOut = {
-  ease: function(t) {
-    return ((t *= 2) <= 1 ? Math.pow(2, 10 * t - 10) : 2 - Math.pow(2, 10 - 10 * t)) / 2;
-  }
-};
+export function expInOut(t) {
+  return ((t *= 2) <= 1 ? Math.pow(2, 10 * t - 10) : 2 - Math.pow(2, 10 - 10 * t)) / 2;
+}

src/linear.js

@@ -1,5 +1,3 @@
-export var linear = {
-  ease: function(t) {
-    return +t;
-  }
-};
+export function linear(t) {
+  return +t;
+}

src/poly.js

@@ -1,28 +1,37 @@
 var exponent = 3;
 
-export var polyIn = (function polyIn(e) {
-  return e = +e, {
-    exponent: polyIn,
-    ease: function(t) {
-      return Math.pow(t, e);
-    }
-  };
+export var polyIn = (function custom(e) {
+  e = +e;
+
+  function polyIn(t) {
+    return Math.pow(t, e);
+  }
+
+  polyIn.exponent = custom;
+
+  return polyIn;
 })(exponent);
 
-export var polyOut = (function polyOut(e) {
-  return e = +e, {
-    exponent: polyOut,
-    ease: function(t) {
-      return 1 - Math.pow(1 - t, e);
-    }
-  };
+export var polyOut = (function custom(e) {
+  e = +e;
+
+  function polyOut(t) {
+    return 1 - Math.pow(1 - t, e);
+  }
+
+  polyOut.exponent = custom;
+
+  return polyOut;
 })(exponent);
 
-export var polyInOut = (function polyInOut(e) {
-  return e = +e, {
-    exponent: polyInOut,
-    ease: function(t) {
-      return ((t *= 2) <= 1 ? Math.pow(t, e) : 2 - Math.pow(2 - t, e)) / 2;
-    }
-  };
+export var polyInOut = (function custom(e) {
+  e = +e;
+
+  function polyInOut(t) {
+    return ((t *= 2) <= 1 ? Math.pow(t, e) : 2 - Math.pow(2 - t, e)) / 2;
+  }
+
+  polyInOut.exponent = custom;
+
+  return polyInOut;
 })(exponent);

src/quad.js

@@ -1,17 +1,11 @@
-export var quadIn = {
-  ease: function(t) {
-    return t * t;
-  }
-};
+export function quadIn(t) {
+  return t * t;
+}
 
-export var quadOut = {
-  ease: function(t) {
-    return t * (2 - t);
-  }
-};
+export function quadOut(t) {
+  return t * (2 - t);
+}
 
-export var quadInOut = {
-  ease: function(t) {
-    return ((t *= 2) <= 1 ? t * t : --t * (2 - t) + 1) / 2;
-  }
-};
+export function quadInOut(t) {
+  return ((t *= 2) <= 1 ? t * t : --t * (2 - t) + 1) / 2;
+}

src/sin.js

@@ -1,20 +1,14 @@
 var pi = Math.PI,
     halfPi = pi / 2;
 
-export var sinIn = {
-  ease: function(t) {
-    return 1 - Math.cos(t * halfPi);
-  }
-};
+export function sinIn(t) {
+  return 1 - Math.cos(t * halfPi);
+}
 
-export var sinOut = {
-  ease: function(t) {
-    return Math.sin(t * halfPi);
-  }
-};
+export function sinOut(t) {
+  return Math.sin(t * halfPi);
+}
 
-export var sinInOut = {
-  ease: function(t) {
-    return (1 - Math.cos(pi * t)) / 2;
-  }
-};
+export function sinInOut(t) {
+  return (1 - Math.cos(pi * t)) / 2;
+}