blob: d740c038f36dfa431d61725dedcae879ea9e3744 [file] [log] [blame]
/*
* 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.
*/
#include "Interpolator.h"
#include <algorithm>
#include <log/log.h>
#include "utils/MathUtils.h"
namespace android {
namespace uirenderer {
Interpolator* Interpolator::createDefaultInterpolator() {
return new AccelerateDecelerateInterpolator();
}
float AccelerateDecelerateInterpolator::interpolate(float input) {
return (float)(cosf((input + 1) * M_PI) / 2.0f) + 0.5f;
}
float AccelerateInterpolator::interpolate(float input) {
if (mFactor == 1.0f) {
return input * input;
} else {
return pow(input, mDoubleFactor);
}
}
float AnticipateInterpolator::interpolate(float t) {
return t * t * ((mTension + 1) * t - mTension);
}
static float a(float t, float s) {
return t * t * ((s + 1) * t - s);
}
static float o(float t, float s) {
return t * t * ((s + 1) * t + s);
}
float AnticipateOvershootInterpolator::interpolate(float t) {
if (t < 0.5f) return 0.5f * a(t * 2.0f, mTension);
else return 0.5f * (o(t * 2.0f - 2.0f, mTension) + 2.0f);
}
static float bounce(float t) {
return t * t * 8.0f;
}
float BounceInterpolator::interpolate(float t) {
t *= 1.1226f;
if (t < 0.3535f) return bounce(t);
else if (t < 0.7408f) return bounce(t - 0.54719f) + 0.7f;
else if (t < 0.9644f) return bounce(t - 0.8526f) + 0.9f;
else return bounce(t - 1.0435f) + 0.95f;
}
float CycleInterpolator::interpolate(float input) {
return sinf(2 * mCycles * M_PI * input);
}
float DecelerateInterpolator::interpolate(float input) {
float result;
if (mFactor == 1.0f) {
result = 1.0f - (1.0f - input) * (1.0f - input);
} else {
result = 1.0f - pow((1.0f - input), 2 * mFactor);
}
return result;
}
float OvershootInterpolator::interpolate(float t) {
t -= 1.0f;
return t * t * ((mTension + 1) * t + mTension) + 1.0f;
}
float PathInterpolator::interpolate(float t) {
if (t <= 0) {
return 0;
} else if (t >= 1) {
return 1;
}
// Do a binary search for the correct x to interpolate between.
size_t startIndex = 0;
size_t endIndex = mX.size() - 1;
while (endIndex > startIndex + 1) {
int midIndex = (startIndex + endIndex) / 2;
if (t < mX[midIndex]) {
endIndex = midIndex;
} else {
startIndex = midIndex;
}
}
float xRange = mX[endIndex] - mX[startIndex];
if (xRange == 0) {
return mY[startIndex];
}
float tInRange = t - mX[startIndex];
float fraction = tInRange / xRange;
float startY = mY[startIndex];
float endY = mY[endIndex];
return startY + (fraction * (endY - startY));
}
LUTInterpolator::LUTInterpolator(float* values, size_t size)
: mValues(values)
, mSize(size) {
}
LUTInterpolator::~LUTInterpolator() {
}
float LUTInterpolator::interpolate(float input) {
// lut position should only be at the end of the table when input is 1f.
float lutpos = input * (mSize - 1);
if (lutpos >= (mSize - 1)) {
return mValues[mSize - 1];
}
float ipart, weight;
weight = modff(lutpos, &ipart);
int i1 = (int) ipart;
int i2 = std::min(i1 + 1, (int) mSize - 1);
LOG_ALWAYS_FATAL_IF(i1 < 0 || i2 < 0, "negatives in interpolation!"
" i1=%d, i2=%d, input=%f, lutpos=%f, size=%zu, values=%p, ipart=%f, weight=%f",
i1, i2, input, lutpos, mSize, mValues.get(), ipart, weight);
float v1 = mValues[i1];
float v2 = mValues[i2];
return MathUtils::lerp(v1, v2, weight);
}
} /* namespace uirenderer */
} /* namespace android */