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