001 /*
002 * GeoAPI - Java interfaces for OGC/ISO standards
003 * http://www.geoapi.org
004 *
005 * Copyright (C) 2007-2012 Open Geospatial Consortium, Inc.
006 * All Rights Reserved. http://www.opengeospatial.org/ogc/legal
007 *
008 * Permission to use, copy, and modify this software and its documentation, with
009 * or without modification, for any purpose and without fee or royalty is hereby
010 * granted, provided that you include the following on ALL copies of the software
011 * and documentation or portions thereof, including modifications, that you make:
012 *
013 * 1. The full text of this NOTICE in a location viewable to users of the
014 * redistributed or derivative work.
015 * 2. Notice of any changes or modifications to the OGC files, including the
016 * date changes were made.
017 *
018 * THIS SOFTWARE AND DOCUMENTATION IS PROVIDED "AS IS," AND COPYRIGHT HOLDERS MAKE
019 * NO REPRESENTATIONS OR WARRANTIES, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED
020 * TO, WARRANTIES OF MERCHANTABILITY OR FITNESS FOR ANY PARTICULAR PURPOSE OR THAT
021 * THE USE OF THE SOFTWARE OR DOCUMENTATION WILL NOT INFRINGE ANY THIRD PARTY
022 * PATENTS, COPYRIGHTS, TRADEMARKS OR OTHER RIGHTS.
023 *
024 * COPYRIGHT HOLDERS WILL NOT BE LIABLE FOR ANY DIRECT, INDIRECT, SPECIAL OR
025 * CONSEQUENTIAL DAMAGES ARISING OUT OF ANY USE OF THE SOFTWARE OR DOCUMENTATION.
026 *
027 * The name and trademarks of copyright holders may NOT be used in advertising or
028 * publicity pertaining to the software without specific, written prior permission.
029 * Title to copyright in this software and any associated documentation will at all
030 * times remain with copyright holders.
031 */
032 package org.opengis.geometry;
033
034
035 /**
036 * Specifies the precision model of the {@linkplain DirectPosition direct positions}
037 * in a {@linkplain Geometry geometry}.
038 * <p>
039 * A precision model defines a grid of allowable points. The {@link #round} method
040 * allows to round a direct position to the nearest allowed point. The {@link #getType}
041 * method describes the collapsing behavior of a direct position.
042 * <p>
043 * {@code Precision} instances can be sorted by their {@linkplain #getScale scale}.
044 * </p>
045 *
046 * @author Jody Garnett
047 * @since GeoAPI 2.1
048 */
049 public interface Precision extends Comparable<Precision> {
050 /**
051 * Compares this precision model with the specified one. Returns -1 is this model is
052 * less accurate than the other one, +1 if it is more accurate, or 0 if they have the
053 * same accuracy.
054 *
055 * @param other Other precision model to compare against.
056 * @return a negative integer, zero, or a positive integer as this object
057 * is less than, equal to, or greater than the other.
058 */
059 int compareTo(Precision other);
060
061 /**
062 * Returns the maximum number of significant digits provided by this precision model..
063 * <p>
064 * Apparently this is usually used for output, note GML generation usually has its own concept
065 * of significant digits. You may be able to capture this in terms of the getScale().
066 * </p>
067 *
068 * @return number of significant digits
069 * @see #getScale()
070 *
071 * @deprecated This is redundant with {@link #getScale}.
072 */
073 @Deprecated
074 int getMaximumSignificantDigits();
075
076 /**
077 * Multiplying factor used to obtain a precise ordinate.
078 * <p>
079 * Multiply by this value and then divide by this value to round correctly:
080 *
081 * <blockquote><pre>
082 * double scale = pm.getScale();
083 * return Math.round(value * scale) / scale;
084 * </pre></blockquote>
085 *
086 * So to round to {@code 3} significant digits we would have a scale of {@code 1000}.
087 * Tip: the number of significant digits can be computed as below:
088 *
089 * <blockquote><pre>
090 * int significantDigits = (int) Math.ceil(Math.log10(pm.getScale()));
091 * </pre></blockquote>
092 *
093 * @return Multiplying factor used before rounding.
094 */
095 double getScale();
096
097 /**
098 * Returns the type of this precision model.
099 */
100 PrecisionType getType();
101
102 /**
103 * Rounds a direct position to this precision model in place.
104 * <p>
105 * It is likely that a {@code Precision} instance will keep different rounding rules for different
106 * axis (example <var>x</var> & <var>y</var> ordinates may be handled differently then height),
107 * by always rounding a direct position as a whole we will enable this functionality.
108 */
109 void round(DirectPosition position);
110 }