Chromium Code Reviews| Index: base/android/java/src/org/chromium/base/AndroidMathUtils.java |
| diff --git a/base/android/java/src/org/chromium/base/AndroidMathUtils.java b/base/android/java/src/org/chromium/base/AndroidMathUtils.java |
| new file mode 100644 |
| index 0000000000000000000000000000000000000000..54f2c852eb8a6fd9627fb9588496550e76995add |
| --- /dev/null |
| +++ b/base/android/java/src/org/chromium/base/AndroidMathUtils.java |
| @@ -0,0 +1,80 @@ |
| +// Copyright 2015 The Chromium Authors. All rights reserved. |
| +// Use of this source code is governed by a BSD-style license that can be |
| +// found in the LICENSE file. |
| + |
| +package org.chromium.base; |
| + |
| +/** |
| + * Contains various math utilities used throughout Android. |
| + */ |
| +public class AndroidMathUtils { |
|
Yaron
2015/03/06 22:57:08
There's already a MathUtils class in org.chromium.
David Trainor- moved to gerrit
2015/03/09 20:02:42
Done.
|
| + |
| + private AndroidMathUtils() {} |
| + |
| + /** |
| + * Moves {@code value} forward to {@code target} based on {@code speed}. |
| + * @param value The current value. |
| + * @param target The target value. |
| + * @param speed How far to move {@code value} to {@code target}. 0 doesn't move it at all. 1 |
| + * moves it to {@code target}. |
| + * @return The new interpolated value. |
| + */ |
| + public static float interpolate(float value, float target, float speed) { |
| + return (value + (target - value) * speed); |
| + } |
| + |
| + /** |
| + * Smooth a value between 0 and 1. |
| + * @param t The value to smooth. |
| + * @return The smoothed value between 0 and 1. |
| + */ |
| + public static float smoothstep(float t) { |
| + return t * t * (3.0f - 2.0f * t); |
| + } |
| + |
| + /** |
| + * Scales the provided dimension such that it is just large enough to fit |
| + * the target width and height. |
| + * |
| + * @param dimensions The dimensions to scale |
| + * @param targetWidth The target width |
| + * @param targetHeight The target height |
| + * @return The scale factor applied to dimensions |
| + */ |
| + public static float scaleToFitTargetSize( |
| + int [] dimensions, int targetWidth, int targetHeight) { |
| + if (dimensions.length < 2 || dimensions[0] <= 0 || dimensions[1] <= 0) { |
| + throw new IllegalArgumentException( |
| + "Expected dimensions to have length >= 2 && dimensions[0] > 0 && " |
| + + "dimensions[1] > 0"); |
| + } |
| + float scale = Math.max( |
| + (float) targetWidth / dimensions[0], |
| + (float) targetHeight / dimensions[1]); |
| + dimensions[0] *= scale; |
| + dimensions[1] *= scale; |
| + return scale; |
| + } |
| + |
| + /** |
| + * Flips {@code value} iff {@code flipSign} is {@code true}. |
| + * @param value The value to flip. |
| + * @param flipSign Whether or not to flip the value. |
| + * @return {@code value} iff {@code flipSign} is {@code false}, otherwise negative |
| + * {@code value}. |
| + */ |
| + public static int flipSignIf(int value, boolean flipSign) { |
| + return flipSign ? -value : value; |
| + } |
| + |
| + /** |
| + * Flips {@code value} iff {@code flipSign} is {@code true}. |
| + * @param value The value to flip. |
| + * @param flipSign Whether or not to flip the value. |
| + * @return {@code value} iff {@code flipSign} is {@code false}, otherwise negative |
| + * {@code value}. |
| + */ |
| + public static float flipSignIf(float value, boolean flipSign) { |
| + return flipSign ? -value : value; |
| + } |
| +} |