| /* |
| * Licensed to the Apache Software Foundation (ASF) under one or more |
| * contributor license agreements. See the NOTICE file distributed with |
| * this work for additional information regarding copyright ownership. |
| * The ASF licenses this file to You 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. |
| */ |
| |
| /* $Id$ */ |
| |
| package org.apache.fop.render.txt; |
| |
| /** |
| * This class has a few convenient static methods for number quantization. |
| */ |
| public final class Helper { |
| |
| /** |
| * Don't let anyone instantiate this class. |
| */ |
| private Helper() { } |
| |
| /** |
| * Returns nearest integer to <code>x</code>, divisible by |
| * <code>quantum</code>. |
| * |
| * @param x integer for quantization |
| * @param quantum integer, representing quantization |
| * @return computed nearest integer |
| */ |
| public static int round(int x, int quantum) { |
| int ceil = ceil(x, quantum); |
| int floor = floor(x, quantum); |
| return (ceil - x < x - floor) ? ceil : floor; |
| } |
| |
| /** |
| * Returns minimal possible integer, greater or equal than |
| * <code>x</code>, divisible by <code>quantum</code>. |
| * |
| * @param x integer for quantization |
| * @param quantum integer, representing quantization |
| * @return computed nearest integer |
| */ |
| public static int ceil(int x, int quantum) { |
| int dx = (x < 0) || (x % quantum == 0) ? 0 : 1; |
| return (x / quantum + dx) * quantum; |
| } |
| |
| /** |
| * Returns maximum possible integer, less or equal than |
| * <code>oldValue</code>, divisible by <code>quantum</code>. |
| * |
| * @param x integer for quantization |
| * @param quantum integer, representing quantization |
| * @return computed nearest integer |
| */ |
| public static int floor(int x, int quantum) { |
| int dx = (x > 0) || (x % quantum == 0) ? 0 : -1; |
| return (x / quantum + dx) * quantum; |
| } |
| |
| /** |
| * Returns the closest integer to <code>x/y</code> fraction. |
| * It's possible to consider this methos as a analog of Math.round(x/y), |
| * without having deal with non-integer. |
| * |
| * @param x integer, fraction numerator |
| * @param y integer, fraction denominator |
| * @return the value of the fraction rounded to the nearest |
| * @see java.lang.Math#round(double) |
| */ |
| public static int roundPosition(int x, int y) { |
| return round(x, y) / y; |
| } |
| |
| /** |
| * Returns the smallest integer that is greater than or equal to the |
| * <code>x/y</code> fraction. |
| * It's possible to consider this function as a analog of Math.ceil(x/y), |
| * without having deal with non-integer. |
| * |
| * @param x integer, fraction numerator |
| * @param y integer, fraction denominator |
| * @return the smallest integer that is greater than or equal to |
| * <code>x/y</code> fraction |
| * @see java.lang.Math#ceil(double) |
| */ |
| public static int ceilPosition(int x, int y) { |
| return ceil(x, y) / y; |
| } |
| |
| |
| /** |
| * Returns the largest integer that is less than or equal to the |
| * argument and is equal to <code>x/y</code> fraction. |
| * It's possible to consider this function as a analog of Math.floor(x/y), |
| * without having deal with non-integer. |
| * |
| * @param x integer, fraction numerator |
| * @param y integer, fraction denominator |
| * @return the largest integer that is less than or equal to |
| * the argument and is equal to <code>x/y</code> fraction |
| * @see java.lang.Math#floor(double) |
| */ |
| public static int floorPosition(int x, int y) { |
| return floor(x, y) / y; |
| } |
| } |