1 /* 2 * Copyright (C) 2010 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 package com.replica.replicaisland; 18 19 public final class Lerp { 20 21 public static float lerp(float start, float target, float duration, float timeSinceStart) 22 { 23 float value = start; 24 if (timeSinceStart > 0.0f && timeSinceStart < duration) 25 { 26 final float range = target - start; 27 final float percent = timeSinceStart / duration; 28 value = start + (range * percent); 29 } 30 else if (timeSinceStart >= duration) 31 { 32 value = target; 33 } 34 return value; 35 } 36 37 public static float ease(float start, float target, float duration, float timeSinceStart) 38 { 39 float value = start; 40 if (timeSinceStart > 0.0f && timeSinceStart < duration) 41 { 42 final float range = target - start; 43 final float percent = timeSinceStart / (duration / 2.0f); 44 if (percent < 1.0f) 45 { 46 value = start + ((range / 2.0f) * percent * percent * percent); 47 } 48 else 49 { 50 final float shiftedPercent = percent - 2.0f; 51 value = start + ((range / 2.0f) * 52 ((shiftedPercent * shiftedPercent * shiftedPercent) + 2.0f)); 53 } 54 } 55 else if (timeSinceStart >= duration) 56 { 57 value = target; 58 } 59 return value; 60 } 61 } 62
