michael@0: /* -*- Mode: Java; c-basic-offset: 4; tab-width: 20; indent-tabs-mode: nil; -*-
michael@0:  * This Source Code Form is subject to the terms of the Mozilla Public
michael@0:  * License, v. 2.0. If a copy of the MPL was not distributed with this
michael@0:  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
michael@0: 
michael@0: package org.mozilla.gecko.gfx;
michael@0: 
michael@0: import org.json.JSONException;
michael@0: import org.json.JSONObject;
michael@0: 
michael@0: import android.util.FloatMath;
michael@0: 
michael@0: public class IntSize {
michael@0:     public final int width, height;
michael@0: 
michael@0:     public IntSize(IntSize size) { width = size.width; height = size.height; }
michael@0:     public IntSize(int inWidth, int inHeight) { width = inWidth; height = inHeight; }
michael@0: 
michael@0:     public IntSize(FloatSize size) {
michael@0:         width = Math.round(size.width);
michael@0:         height = Math.round(size.height);
michael@0:     }
michael@0: 
michael@0:     public IntSize(JSONObject json) {
michael@0:         try {
michael@0:             width = json.getInt("width");
michael@0:             height = json.getInt("height");
michael@0:         } catch (JSONException e) {
michael@0:             throw new RuntimeException(e);
michael@0:         }
michael@0:     }
michael@0: 
michael@0:     public int getArea() {
michael@0:         return width * height;
michael@0:     }
michael@0: 
michael@0:     public boolean equals(IntSize size) {
michael@0:         return ((size.width == width) && (size.height == height));
michael@0:     }
michael@0: 
michael@0:     public boolean isPositive() {
michael@0:         return (width > 0 && height > 0);
michael@0:     }
michael@0: 
michael@0:     @Override
michael@0:     public String toString() { return "(" + width + "," + height + ")"; }
michael@0: 
michael@0:     public IntSize scale(float factor) {
michael@0:         return new IntSize(Math.round(width * factor),
michael@0:                            Math.round(height * factor));
michael@0:     }
michael@0: 
michael@0:     /* Returns the power of two that is greater than or equal to value */
michael@0:     public static int nextPowerOfTwo(int value) {
michael@0:         // code taken from http://acius2.blogspot.com/2007/11/calculating-next-power-of-2.html
michael@0:         if (0 == value--) {
michael@0:             return 1;
michael@0:         }
michael@0:         value = (value >> 1) | value;
michael@0:         value = (value >> 2) | value;
michael@0:         value = (value >> 4) | value;
michael@0:         value = (value >> 8) | value;
michael@0:         value = (value >> 16) | value;
michael@0:         return value + 1;
michael@0:     }
michael@0: 
michael@0:     public IntSize nextPowerOfTwo() {
michael@0:         return new IntSize(nextPowerOfTwo(width), nextPowerOfTwo(height));
michael@0:     }
michael@0: 
michael@0:     public static boolean isPowerOfTwo(int value) {
michael@0:         if (value == 0)
michael@0:             return false;
michael@0:         return (value & (value - 1)) == 0;
michael@0:     }
michael@0: 
michael@0:     public static int largestPowerOfTwoLessThan(float value) {
michael@0:         int val = (int)FloatMath.floor(value);
michael@0:         if (val <= 0) {
michael@0:             throw new IllegalArgumentException("Error: value must be > 0");
michael@0:         }
michael@0:         // keep dropping the least-significant set bits until only one is left
michael@0:         int bestVal = val;
michael@0:         while (val != 0) {
michael@0:             bestVal = val;
michael@0:             val &= (val - 1);
michael@0:         }
michael@0:         return bestVal;
michael@0:     }
michael@0: }
michael@0: