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/*
* 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#ceil(double)
*/
public static int floorPosition(int x, int y) {
return floor(x, y) / y;
}
}
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