1 /* 2 * Copyright (C) 2014 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 #define LOG_TAG "Interpolator" 18 19 #include "Interpolator.h" 20 21 #include <cmath> 22 #include <cutils/log.h> 23 24 #include "utils/MathUtils.h" 25 26 namespace android { 27 namespace uirenderer { 28 29 Interpolator* Interpolator::createDefaultInterpolator() { 30 return new AccelerateDecelerateInterpolator(); 31 } 32 33 float AccelerateDecelerateInterpolator::interpolate(float input) { 34 return (float)(cosf((input + 1) * M_PI) / 2.0f) + 0.5f; 35 } 36 37 float AccelerateInterpolator::interpolate(float input) { 38 if (mFactor == 1.0f) { 39 return input * input; 40 } else { 41 return pow(input, mDoubleFactor); 42 } 43 } 44 45 float AnticipateInterpolator::interpolate(float t) { 46 return t * t * ((mTension + 1) * t - mTension); 47 } 48 49 static float a(float t, float s) { 50 return t * t * ((s + 1) * t - s); 51 } 52 53 static float o(float t, float s) { 54 return t * t * ((s + 1) * t + s); 55 } 56 57 float AnticipateOvershootInterpolator::interpolate(float t) { 58 if (t < 0.5f) return 0.5f * a(t * 2.0f, mTension); 59 else return 0.5f * (o(t * 2.0f - 2.0f, mTension) + 2.0f); 60 } 61 62 static float bounce(float t) { 63 return t * t * 8.0f; 64 } 65 66 float BounceInterpolator::interpolate(float t) { 67 t *= 1.1226f; 68 if (t < 0.3535f) return bounce(t); 69 else if (t < 0.7408f) return bounce(t - 0.54719f) + 0.7f; 70 else if (t < 0.9644f) return bounce(t - 0.8526f) + 0.9f; 71 else return bounce(t - 1.0435f) + 0.95f; 72 } 73 74 float CycleInterpolator::interpolate(float input) { 75 return sinf(2 * mCycles * M_PI * input); 76 } 77 78 float DecelerateInterpolator::interpolate(float input) { 79 float result; 80 if (mFactor == 1.0f) { 81 result = 1.0f - (1.0f - input) * (1.0f - input); 82 } else { 83 result = 1.0f - pow((1.0f - input), 2 * mFactor); 84 } 85 return result; 86 } 87 88 float OvershootInterpolator::interpolate(float t) { 89 t -= 1.0f; 90 return t * t * ((mTension + 1) * t + mTension) + 1.0f; 91 } 92 93 LUTInterpolator::LUTInterpolator(float* values, size_t size) { 94 mValues = values; 95 mSize = size; 96 } 97 98 LUTInterpolator::~LUTInterpolator() { 99 delete mValues; 100 mValues = 0; 101 } 102 103 float LUTInterpolator::interpolate(float input) { 104 float lutpos = input * mSize; 105 if (lutpos >= (mSize - 1)) { 106 return mValues[mSize - 1]; 107 } 108 109 float ipart, weight; 110 weight = modff(lutpos, &ipart); 111 112 int i1 = (int) ipart; 113 int i2 = MathUtils::min(i1 + 1, (int) mSize - 1); 114 115 LOG_ALWAYS_FATAL_IF(i1 < 0 || i2 < 0, "negatives in interpolation!" 116 " i1=%d, i2=%d, input=%f, lutpos=%f, size=%zu, values=%p, ipart=%f, weight=%f", 117 i1, i2, input, lutpos, mSize, mValues, ipart, weight); 118 119 float v1 = mValues[i1]; 120 float v2 = mValues[i2]; 121 122 return MathUtils::lerp(v1, v2, weight); 123 } 124 125 126 } /* namespace uirenderer */ 127 } /* namespace android */ 128
