001/**
002 * Copyright (c) 2011, The University of Southampton and the individual contributors.
003 * All rights reserved.
004 *
005 * Redistribution and use in source and binary forms, with or without modification,
006 * are permitted provided that the following conditions are met:
007 *
008 *   *  Redistributions of source code must retain the above copyright notice,
009 *      this list of conditions and the following disclaimer.
010 *
011 *   *  Redistributions in binary form must reproduce the above copyright notice,
012 *      this list of conditions and the following disclaimer in the documentation
013 *      and/or other materials provided with the distribution.
014 *
015 *   *  Neither the name of the University of Southampton nor the names of its
016 *      contributors may be used to endorse or promote products derived from this
017 *      software without specific prior written permission.
018 *
019 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
020 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
021 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
022 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
023 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
024 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
025 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
026 * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
027 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
028 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
029 */
030package org.openimaj.math.geometry.shape.util.polygon;
031
032import org.openimaj.math.geometry.shape.util.PolygonUtils;
033
034/**
035 * Internal contour / tristrip type
036 */
037public class PolygonNode
038{
039        int active; /* Active flag / vertex count */
040
041        boolean hole; /* Hole / external contour flag */
042
043        VertexNode[] v = new VertexNode[2]; /* Left and right vertex list ptrs */
044
045        PolygonNode next; /* Pointer to next polygon contour */
046
047        PolygonNode proxy; /* Pointer to actual structure used */
048
049        /**
050         * @param next
051         * @param x
052         * @param y
053         */
054        public PolygonNode( PolygonNode next, double x, double y )
055        {
056                /* Make v[LEFT] and v[RIGHT] point to new vertex */
057                VertexNode vn = new VertexNode( x, y );
058                this.v[PolygonUtils.LEFT] = vn;
059                this.v[PolygonUtils.RIGHT] = vn;
060
061                this.next = next;
062                this.proxy = this; /* Initialise proxy to point to p itself */
063                this.active = 1; // TRUE
064        }
065
066        /**
067         * @param x
068         * @param y
069         */
070        public void add_right( double x, double y )
071        {
072                VertexNode nv = new VertexNode( x, y );
073
074                /* Add vertex nv to the right end of the polygon's vertex list */
075                proxy.v[PolygonUtils.RIGHT].next = nv;
076
077                /* Update proxy->v[RIGHT] to point to nv */
078                proxy.v[PolygonUtils.RIGHT] = nv;
079        }
080
081        /**
082         * @param x
083         * @param y
084         */
085        public void add_left( double x, double y )
086        {
087                VertexNode nv = new VertexNode( x, y );
088
089                /* Add vertex nv to the left end of the polygon's vertex list */
090                nv.next = proxy.v[PolygonUtils.LEFT];
091
092                /* Update proxy->[LEFT] to point to nv */
093                proxy.v[PolygonUtils.LEFT] = nv;
094        }
095
096}