CurveFit.java
/*
* Copyright (C) 2020 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 androidx.constraintlayout.core.motion.utils;
/**
* Base class for curve fitting / interpolation
* Curve fits must be capable of being differentiable and extend beyond the points (extrapolate)
*
* @suppress
*/
public abstract class CurveFit {
public static final int SPLINE = 0;
public static final int LINEAR = 1;
public static final int CONSTANT = 2;
public static CurveFit get(int type, double[] time, double[][] y) {
if (time.length == 1) {
type = CONSTANT;
}
switch (type) {
case SPLINE:
return new MonotonicCurveFit(time, y);
case CONSTANT:
return new Constant(time[0], y[0]);
default:
return new LinearCurveFit(time, y);
}
}
public static CurveFit getArc(int[] arcModes, double[] time, double[][] y) {
return new ArcCurveFit(arcModes, time, y);
}
public abstract void getPos(double t, double[] v);
public abstract void getPos(double t, float[] v);
public abstract double getPos(double t, int j);
public abstract void getSlope(double t, double[] v);
public abstract double getSlope(double t, int j);
public abstract double[] getTimePoints();
static class Constant extends CurveFit {
double mTime;
double[] mValue;
Constant(double time, double[] value) {
mTime = time;
mValue = value;
}
@Override
public void getPos(double t, double[] v) {
System.arraycopy(mValue, 0, v, 0, mValue.length);
}
@Override
public void getPos(double t, float[] v) {
for (int i = 0; i < mValue.length; i++) {
v[i] = (float) mValue[i];
}
}
@Override
public double getPos(double t, int j) {
return mValue[j];
}
@Override
public void getSlope(double t, double[] v) {
for (int i = 0; i < mValue.length; i++) {
v[i] = 0;
}
}
@Override
public double getSlope(double t, int j) {
return 0;
}
@Override
public double[] getTimePoints() {
return new double[]{mTime};
}
}
}