| /* |
| * 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 android.support.v17.leanback.animation; |
| |
| import static android.support.annotation.RestrictTo.Scope.LIBRARY_GROUP; |
| |
| import android.animation.TimeInterpolator; |
| import android.support.annotation.RestrictTo; |
| |
| /** |
| * @hide |
| */ |
| @RestrictTo(LIBRARY_GROUP) |
| 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; |
| } |
| } |