1 files changed, 66 insertions, 0 deletions
diff --git a/src/com/android/camera/ui/motion/InterpolateUtils.java b/src/com/android/camera/ui/motion/InterpolateUtils.java
new file mode 100644
index 000000000..3c3cd532f
--- /dev/null
+++ b/src/com/android/camera/ui/motion/InterpolateUtils.java
@@ -0,0 +1,66 @@
+/*
+ * Copyright (C) 2014 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.camera.ui.motion;
+
+/**
+ * Various static helper functions for interpolating between values.
+ */
+public class InterpolateUtils {
+
+    private InterpolateUtils() {
+    }
+
+    /**
+     * Linear interpolation from v0 to v1 as t goes from 0...1
+     *
+     * @param v0 the value at t=0
+     * @param v1 the value at t=1
+     * @param t value in the range of 0 to 1.
+     * @return the value between v0 and v1 as a ratio between 0 and 1 defined by t.
+     */
+    public static float lerp(float v0, float v1, float t) {
+        return v0 + t * (v1 - v0);
+    }
+
+    /**
+     * Project a value that is within the in(Min/Max) number space into the to(Min/Max) number
+     * space.
+     *
+     * @param v value to scale into the 'to' number space.
+     * @param vMin min value of the values number space.
+     * @param vMax max value of the values number space.
+     * @param pMin min value of the projection number space.
+     * @param pMax max value of the projection number space.
+     * @return the ratio of the value in the source number space as a value in the to(Min/Max)
+     * number space.
+     */
+    public static float scale(float v, float vMin, float vMax, float pMin, float pMax) {
+        return (pMax - pMin) * (v - vMin) / (vMax - vMin) + pMin;
+    }
+
+    /**
+     * Value between 0 and 1 as a ratio between tBegin over tDuration
+     * with no upper bound.
+     */
+    public static float unitRatio(long t, long tBegin, float tDuration) {
+        if (t <= tBegin) {
+            return 0.0f;
+        }
+
+        return (t - tBegin) / tDuration;
+    }
+}