From 9e89faf08cee399207a5224a1ef8f4618b4207ad Mon Sep 17 00:00:00 2001
From: Frankie Robertson <frankie@robertson.name>
Date: Sun, 31 Jan 2016 17:30:25 +0200
Subject: [PATCH] Change interpolation to cubic ease in/ease out

---
 src/scrollsnap-polyfill.js | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/src/scrollsnap-polyfill.js b/src/scrollsnap-polyfill.js
index 9c3714e..1863c3d 100644
--- a/src/scrollsnap-polyfill.js
+++ b/src/scrollsnap-polyfill.js
@@ -583,8 +583,11 @@
    * @param  {Number} t timing
    * @return {Number}   easing factor
    */
-  var easeInCubic = function(t) {
-    return t*t*t;
+  var easeInOutCubic = function(t) {
+      t *= 2;
+      if (t < 1) return t*t*t * 0.5;
+      t -= 2;
+      return (t*t*t + 2) * 0.5;
   };
 
 
@@ -600,7 +603,7 @@
       if (elapsed > duration) {
         return end;
       }
-      return start + (end - start) * easeInCubic(elapsed / duration);
+      return start + (end - start) * easeInOutCubic(elapsed / duration);
   };
 
   // a current animation frame