001 /*
002 * GeoAPI - Java interfaces for OGC/ISO standards
003 * http://www.geoapi.org
004 *
005 * Copyright (C) 2004-2012 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.primitive;
033
034 import org.opengis.geometry.coordinate.GenericCurve;
035 import org.opengis.geometry.coordinate.PointArray;
036 import org.opengis.annotation.Association;
037 import org.opengis.annotation.UML;
038
039 import static org.opengis.annotation.Obligation.*;
040 import static org.opengis.annotation.Specification.*;
041
042
043 /**
044 * Defines a homogeneous segment of a {@linkplain Curve curve}.
045 * Each {@code CurveSegment} shall be in, at most, one {@linkplain Curve curve}.
046 *
047 * @version <A HREF="http://www.opengeospatial.org/standards/as">ISO 19107</A>
048 * @author Martin Desruisseaux (IRD)
049 * @since GeoAPI 1.0
050 */
051 @UML(identifier="GM_CurveSegment", specification=ISO_19107)
052 public interface CurveSegment extends GenericCurve {
053 /**
054 * Returns the curve which own this curve segment. This method is <em>optional</em> since
055 * the association in ISO 19107 is navigable only from {@code Curve} to {@code CurveSegment},
056 * not the other way.
057 *
058 * <blockquote><font size=-1><b>NOTE:</b>
059 * In the specification, curve segments do not appear except in the context of a curve,
060 * and therefore this method should never returns {@code null} which would preclude the
061 * use of curve segments except in this manner. While this would not affect the specification,
062 * allowing {@code null} owner allows other standards based on ISO 19107 one to use curve
063 * segments in a more open-ended manner.
064 * </font></blockquote>
065 *
066 * @return The owner of this curve segment, or {@code null} if the association is
067 * not available or not implemented that way.
068 *
069 * @see Curve#getSegments
070 * @see SurfacePatch#getSurface
071 * @issue http://jira.codehaus.org/browse/GEO-63
072 */
073 @Association("Segmentation")
074 @UML(identifier="curve", obligation=OPTIONAL, specification=ISO_19107)
075 Curve getCurve();
076
077 /**
078 * Specifies the curve interpolation mechanism used for this segment. This mechanism
079 * uses the control points and control parameters to determine the position of this
080 * {@code CurveSegment}.
081 *
082 * @return The interpolation mechanism used for this segment.
083 */
084 @UML(identifier="interpolation", obligation=MANDATORY, specification=ISO_19107)
085 CurveInterpolation getInterpolation();
086
087 /**
088 * Specifies the type of continuity between this curve segment and its immediate neighbors.
089 * If this is the first curve segment in the curve, this value is ignored.
090 *
091 * <blockquote><font size=-1><b>NOTE:</b>
092 * Use of these values is only appropriate when the basic curve definition is an underdetermined
093 * system. For example, line strings and segments cannot support continuity above C<sup>0</sup>,
094 * since there is no spare control parameter to adjust the incoming angle at the end points of
095 * the segment. Spline functions on the other hand often have extra degrees of freedom on end
096 * segments that allow them to adjust the values of the derivatives to support C<sup>1</sup>
097 * or higher continuity.
098 * </font></blockquote>
099 *
100 * @return The type of continuity between this curve segment and its immediate neighbors.
101 *
102 * @see #getNumDerivativesInterior
103 * @see #getNumDerivativesAtEnd
104 */
105 @UML(identifier="numDerivativesAtStart", obligation=MANDATORY, specification=ISO_19107)
106 int getNumDerivativesAtStart();
107
108 /**
109 * Specifies the type of continuity that is guaranteed interior to the curve. The default
110 * value of "0" means simple continuity, which is a mandatory minimum level of continuity.
111 * This level is referred to as "C<sup>0</sup>" in mathematical texts. A value of 1 means
112 * that the function and its first derivative are continuous at the appropriate end point:
113 * "C<sup>1</sup>" continuity. A value of "n" for any integer means the function and its
114 * first <var>n</var> derivatives are continuous: "C<sup>n</sup>" continuity.
115 *
116 * @return The type of continuity that is guaranteed interior to the curve.
117 *
118 * @see #getNumDerivativesAtStart
119 * @see #getNumDerivativesAtEnd
120 */
121 @UML(identifier="numDerivativesInterior", obligation=MANDATORY, specification=ISO_19107)
122 int getNumDerivativesInterior();
123
124 /**
125 * Specifies the type of continuity between this curve segment and its immediate neighbors.
126 * If this is the last curve segment in the curve, this value is ignored.
127 *
128 * <blockquote><font size=-1><b>NOTE:</b>
129 * Use of these values is only appropriate when the basic curve definition is an underdetermined
130 * system. For example, line strings and segments cannot support continuity above C<sup>0</sup>,
131 * since there is no spare control parameter to adjust the incoming angle at the end points of
132 * the segment. Spline functions on the other hand often have extra degrees of freedom on end
133 * segments that allow them to adjust the values of the derivatives to support C<sup>1</sup>
134 * or higher continuity.
135 * </font></blockquote>
136 *
137 * @return The type of continuity between this curve segment and its immediate neighbors.
138 *
139 * @see #getNumDerivativesAtStart
140 * @see #getNumDerivativesInterior
141 */
142 @UML(identifier="numDerivativesAtEnd", obligation=MANDATORY, specification=ISO_19107)
143 int getNumDerivativesAtEnd();
144
145 /**
146 * Returns an ordered array of point values that lie on the {@linkplain CurveSegment curve segment}.
147 * In most cases, these will be related to control points used in the construction of the segment.
148 * The control points of a curve segment are use to control its shape, and are not always on the
149 * curve segment itself. For example in a spline curve, the curve segment is given as a weighted
150 * vector sum of the control points. Each weight function will have a maximum within the
151 * constructive parameter interval, which will roughly correspond to the point on the curve
152 * where it passes closest that the corresponding control point. These points, the values of
153 * the curve at the maxima of the weight functions, will be the sample points for the curve
154 * segment.
155 *
156 * @return The control points.
157 *
158 * @todo This interface has been removed from ISO 19107:2008 draft, since it is now
159 * inherited from {@link GenericCurve}.
160 */
161 @UML(identifier="samplePoint", obligation=MANDATORY, specification=ISO_19107)
162 PointArray getSamplePoints();
163
164 /**
165 * Returns an ordered pair of points, which are the start point and end point of the curve.
166 * This method operates with the same semantics as that on {@linkplain Curve#getBoundary curve}
167 * except that the end points of a {@code CurveSegment} are not necessarily existing
168 * {@linkplain Point points} and thus the boundary may contain transient {@linkplain Point points}.
169 *
170 * <blockquote><font size=-1><b>NOTE:</b>
171 * The above {@linkplain CurveBoundary curve boundary} will almost always be two distinct
172 * positions, but, like {@linkplain Curve curves}, {@code CurveSegment}s can be cycles in
173 * themselves. The most likely scenario is that all of the points used will be transients
174 * (constructed to support the return value), except for the start point and end point of
175 * the aggregated {@linkplain Curve curve}. These two positions, in the case where the
176 * {@linkplain Curve curve} is involved in a {@linkplain org.opengis.geometry.complex.Complex complex},
177 * will be represented as {@linkplain Point points} in the same complex.
178 * </font></blockquote>
179 *
180 * @return The sets of positions on the boundary.
181 *
182 * @todo This interface has been removed from ISO 19107:2008 draft, since it is now
183 * inherited from {@link GenericCurve}.
184 */
185 @UML(identifier="boundary", obligation=MANDATORY, specification=ISO_19107)
186 CurveBoundary getBoundary();
187
188 /**
189 * Reverses the orientation of the parameterizations of the segment.
190 *
191 * @return The reverse of this curve segment.
192 */
193 @UML(identifier="reverse", obligation=MANDATORY, specification=ISO_19107)
194 CurveSegment reverse();
195 }