| /* |
| * 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.internal.policy.impl; |
| |
| import android.view.animation.Interpolator; |
| |
| public class LogDecelerateInterpolator implements Interpolator { |
| |
| private int mBase; |
| private int mDrift; |
| private final float mLogScale; |
| |
| public LogDecelerateInterpolator(int base, int drift) { |
| mBase = base; |
| mDrift = drift; |
| |
| mLogScale = 1f / computeLog(1, mBase, mDrift); |
| } |
| |
| private 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; |
| } |
| } |