Adding ViroKit. Needs AWSCore :(

mobile/ios/ViroKit.framework/Headers/VROTimingFunctionPowerDeceleration.h

@@ -0,0 +1,49 @@
+//
+//  VROTimingFunctionPowerDeceleration.h
+//  ViroRenderer
+//
+//  Created by Raj Advani on 10/22/15.
+//  Copyright © 2016 Viro Media. All rights reserved.
+//
+
+#ifndef __VROPowerDecelerationTimingFunction__
+#define __VROPowerDecelerationTimingFunction__
+
+#include "VROTimingFunction.h"
+#include "VROLog.h"
+
+/*
+ The graph goes from (0,0) smoothly to (1,1).
+ The slope of x=1 is 0, meaning it smoothly comes to a stop.
+ The slope of x=0 is the first derivative of y=x^e for x=1
+ (since this function is y=x^e flipped both horizontally and
+ vertically, such that the (0,0) point is the (1,1) point of
+ y=x^e), which is y'(1)=e, the exponent itself!
+
+ E.g.
+ For y=x^2, the slope at x=1 is 2.
+ For y=x^3, the slope at x=1 is 3.
+ etc.
+
+ 1<x<2: calm slowdown, but abrupt stop.
+ x=2: standard.
+ x>2: quicker slowdown, stop is more graceful.
+ Note that this is also the slope of the "entry" point at (0,0).
+ */
+static const double kPowerFunctionDecelerationExponent = 2.0;
+
+class VROTimingFunctionPowerDeceleration : public VROTimingFunction {
+
+public:
+
+    VROTimingFunctionPowerDeceleration() {}
+    virtual ~VROTimingFunctionPowerDeceleration() {}
+
+    float getT(float t) {
+        passert (t >= 0 && t <= 1);
+        return (float) (1 - pow(1 - t, kPowerFunctionDecelerationExponent));
+    }
+    
+};
+
+#endif /* defined(__VROPowerDecelerationTimingFunction__) */