mobile/android/base/gfx/IntSize.java@b8a032363ba2 (annotated)
mobile/android/base/gfx/IntSize.java
Thu, 22 Jan 2015 13:21:57 +0100
- author
- Michael Schloh von Bennewitz <michael@schloh.com>
- date
- Thu, 22 Jan 2015 13:21:57 +0100
- branch
- TOR_BUG_9701
- changeset 15
- b8a032363ba2
- permissions
- -rw-r--r--
Incorporate requested changes from Mozilla in review:
https://bugzilla.mozilla.org/show_bug.cgi?id=1123480#c6
| michael@0 | 1 | /* -*- Mode: Java; c-basic-offset: 4; tab-width: 20; indent-tabs-mode: nil; -*- |
| michael@0 | 2 | * This Source Code Form is subject to the terms of the Mozilla Public |
| michael@0 | 3 | * License, v. 2.0. If a copy of the MPL was not distributed with this |
| michael@0 | 4 | * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ |
| michael@0 | 5 | |
| michael@0 | 6 | package org.mozilla.gecko.gfx; |
| michael@0 | 7 | |
| michael@0 | 8 | import org.json.JSONException; |
| michael@0 | 9 | import org.json.JSONObject; |
| michael@0 | 10 | |
| michael@0 | 11 | import android.util.FloatMath; |
| michael@0 | 12 | |
| michael@0 | 13 | public class IntSize { |
| michael@0 | 14 | public final int width, height; |
| michael@0 | 15 | |
| michael@0 | 16 | public IntSize(IntSize size) { width = size.width; height = size.height; } |
| michael@0 | 17 | public IntSize(int inWidth, int inHeight) { width = inWidth; height = inHeight; } |
| michael@0 | 18 | |
| michael@0 | 19 | public IntSize(FloatSize size) { |
| michael@0 | 20 | width = Math.round(size.width); |
| michael@0 | 21 | height = Math.round(size.height); |
| michael@0 | 22 | } |
| michael@0 | 23 | |
| michael@0 | 24 | public IntSize(JSONObject json) { |
| michael@0 | 25 | try { |
| michael@0 | 26 | width = json.getInt("width"); |
| michael@0 | 27 | height = json.getInt("height"); |
| michael@0 | 28 | } catch (JSONException e) { |
| michael@0 | 29 | throw new RuntimeException(e); |
| michael@0 | 30 | } |
| michael@0 | 31 | } |
| michael@0 | 32 | |
| michael@0 | 33 | public int getArea() { |
| michael@0 | 34 | return width * height; |
| michael@0 | 35 | } |
| michael@0 | 36 | |
| michael@0 | 37 | public boolean equals(IntSize size) { |
| michael@0 | 38 | return ((size.width == width) && (size.height == height)); |
| michael@0 | 39 | } |
| michael@0 | 40 | |
| michael@0 | 41 | public boolean isPositive() { |
| michael@0 | 42 | return (width > 0 && height > 0); |
| michael@0 | 43 | } |
| michael@0 | 44 | |
| michael@0 | 45 | @Override |
| michael@0 | 46 | public String toString() { return "(" + width + "," + height + ")"; } |
| michael@0 | 47 | |
| michael@0 | 48 | public IntSize scale(float factor) { |
| michael@0 | 49 | return new IntSize(Math.round(width * factor), |
| michael@0 | 50 | Math.round(height * factor)); |
| michael@0 | 51 | } |
| michael@0 | 52 | |
| michael@0 | 53 | /* Returns the power of two that is greater than or equal to value */ |
| michael@0 | 54 | public static int nextPowerOfTwo(int value) { |
| michael@0 | 55 | // code taken from http://acius2.blogspot.com/2007/11/calculating-next-power-of-2.html |
| michael@0 | 56 | if (0 == value--) { |
| michael@0 | 57 | return 1; |
| michael@0 | 58 | } |
| michael@0 | 59 | value = (value >> 1) | value; |
| michael@0 | 60 | value = (value >> 2) | value; |
| michael@0 | 61 | value = (value >> 4) | value; |
| michael@0 | 62 | value = (value >> 8) | value; |
| michael@0 | 63 | value = (value >> 16) | value; |
| michael@0 | 64 | return value + 1; |
| michael@0 | 65 | } |
| michael@0 | 66 | |
| michael@0 | 67 | public IntSize nextPowerOfTwo() { |
| michael@0 | 68 | return new IntSize(nextPowerOfTwo(width), nextPowerOfTwo(height)); |
| michael@0 | 69 | } |
| michael@0 | 70 | |
| michael@0 | 71 | public static boolean isPowerOfTwo(int value) { |
| michael@0 | 72 | if (value == 0) |
| michael@0 | 73 | return false; |
| michael@0 | 74 | return (value & (value - 1)) == 0; |
| michael@0 | 75 | } |
| michael@0 | 76 | |
| michael@0 | 77 | public static int largestPowerOfTwoLessThan(float value) { |
| michael@0 | 78 | int val = (int)FloatMath.floor(value); |
| michael@0 | 79 | if (val <= 0) { |
| michael@0 | 80 | throw new IllegalArgumentException("Error: value must be > 0"); |
| michael@0 | 81 | } |
| michael@0 | 82 | // keep dropping the least-significant set bits until only one is left |
| michael@0 | 83 | int bestVal = val; |
| michael@0 | 84 | while (val != 0) { |
| michael@0 | 85 | bestVal = val; |
| michael@0 | 86 | val &= (val - 1); |
| michael@0 | 87 | } |
| michael@0 | 88 | return bestVal; |
| michael@0 | 89 | } |
| michael@0 | 90 | } |
| michael@0 | 91 |
