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/*
* Copyright (C) 2015 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 com.android.camera.ui.motion;
/**
* Represents a discrete linear scale function.
*/
public final class LinearScale {
private final float mDomainA;
private final float mDomainB;
private final float mRangeA;
private final float mRangeB;
private final float mScale;
public LinearScale(float domainA, float domainB, float rangeA, float rangeB) {
mDomainA = domainA;
mDomainB = domainB;
mRangeA = rangeA;
mRangeB = rangeB;
// Precomputed ratio between input domain and output range.
float scale = (mRangeB - mRangeA) / (mDomainB - mDomainA);
mScale = Float.isNaN(scale) ? 0.0f : scale;
}
/**
* Clamp a given domain value to the given domain.
*/
public float clamp(float domainValue) {
if (mDomainA > mDomainB) {
return Math.max(mDomainB, Math.min(mDomainA, domainValue));
}
return Math.max(mDomainA, Math.min(mDomainB, domainValue));
}
/**
* Returns true if the value is within the domain.
*/
public boolean isInDomain(float domainValue) {
if (mDomainA > mDomainB) {
return domainValue <= mDomainA && domainValue >= mDomainB;
}
return domainValue >= mDomainA && domainValue <= mDomainB;
}
/**
* Linearly scale a given domain value into the output range.
*/
public float scale(float domainValue) {
return mRangeA + (domainValue - mDomainA) * mScale;
}
/**
* For the current domain and range parameters produce a new scale function
* that is the inverse of the current scale function.
*/
public LinearScale inverse() {
return new LinearScale(mRangeA, mRangeB, mDomainA, mDomainB);
}
@Override
public String toString() {
return "LinearScale{" +
"mDomainA=" + mDomainA +
", mDomainB=" + mDomainB +
", mRangeA=" + mRangeA +
", mRangeB=" + mRangeB + "}";
}
}
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