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Diffstat (limited to 'src/com/android/camera/ui/motion/LinearScale.java')
-rw-r--r-- | src/com/android/camera/ui/motion/LinearScale.java | 85 |
1 files changed, 85 insertions, 0 deletions
diff --git a/src/com/android/camera/ui/motion/LinearScale.java b/src/com/android/camera/ui/motion/LinearScale.java new file mode 100644 index 000000000..5886f6882 --- /dev/null +++ b/src/com/android/camera/ui/motion/LinearScale.java @@ -0,0 +1,85 @@ +/* + * 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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