Merge "Preliminary work on Material Transitions" into ub-now-master

1 files changed, 26 insertions, 0 deletions

diff --git a/src/com/android/launcher3/LogDecelerateInterpolator.java b/src/com/android/launcher3/LogDecelerateInterpolator.java
new file mode 100644
index 000000000..4c5f6f08c
--- /dev/null
+++ b/src/com/android/launcher3/LogDecelerateInterpolator.java
@@ -0,0 +1,26 @@
+package com.android.launcher3;
+
+import android.animation.TimeInterpolator;
+
+public class LogDecelerateInterpolator implements TimeInterpolator {
+
+    int mBase;
+    int mDrift;
+    final float mLogScale;
+
+    public LogDecelerateInterpolator(int base, int drift) {
+        mBase = base;
+        mDrift = drift;
+
+        mLogScale = 1f / computeLog(1, mBase, mDrift);
+    }
+
+    static float computeLog(float t, int base, int drift) {
+        return (float) -Math.pow(base, -t) + 1 + (drift * t);
+    }
+
+    @Override
+    public float getInterpolation(float t) {
+        return computeLog(t, mBase, mDrift) * mLogScale;
+    }
+}