001 /*
002 * Copyright 1997 Sun Microsystems, Inc. All Rights Reserved.
003 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
004 *
005 * This code is free software; you can redistribute it and/or modify it
006 * under the terms of the GNU General Public License version 2 only, as
007 * published by the Free Software Foundation. Sun designates this
008 * particular file as subject to the "Classpath" exception as provided
009 * by Sun in the LICENSE file that accompanied this code.
010 *
011 * This code is distributed in the hope that it will be useful, but WITHOUT
012 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
013 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
014 * version 2 for more details (a copy is included in the LICENSE file that
015 * accompanied this code).
016 *
017 * You should have received a copy of the GNU General Public License version
018 * 2 along with this work; if not, write to the Free Software Foundation,
019 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
020 *
021 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
022 * CA 95054 USA or visit www.sun.com if you need additional information or
023 * have any questions.
024 */
025
026 package java.awt.geom;
027
028 import java.util.*;
029
030 /**
031 * A utility class to iterate over the path segments of a quadratic curve
032 * segment through the PathIterator interface.
033 *
034 * @version 10 Feb 1997
035 * @author Jim Graham
036 */
037 class QuadIterator implements PathIterator {
038 QuadCurve2D quad;
039 AffineTransform affine;
040 int index;
041
042 QuadIterator(QuadCurve2D q, AffineTransform at) {
043 this .quad = q;
044 this .affine = at;
045 }
046
047 /**
048 * Return the winding rule for determining the insideness of the
049 * path.
050 * @see #WIND_EVEN_ODD
051 * @see #WIND_NON_ZERO
052 */
053 public int getWindingRule() {
054 return WIND_NON_ZERO;
055 }
056
057 /**
058 * Tests if there are more points to read.
059 * @return true if there are more points to read
060 */
061 public boolean isDone() {
062 return (index > 1);
063 }
064
065 /**
066 * Moves the iterator to the next segment of the path forwards
067 * along the primary direction of traversal as long as there are
068 * more points in that direction.
069 */
070 public void next() {
071 index++;
072 }
073
074 /**
075 * Returns the coordinates and type of the current path segment in
076 * the iteration.
077 * The return value is the path segment type:
078 * SEG_MOVETO, SEG_LINETO, SEG_QUADTO, SEG_CUBICTO, or SEG_CLOSE.
079 * A float array of length 6 must be passed in and may be used to
080 * store the coordinates of the point(s).
081 * Each point is stored as a pair of float x,y coordinates.
082 * SEG_MOVETO and SEG_LINETO types will return one point,
083 * SEG_QUADTO will return two points,
084 * SEG_CUBICTO will return 3 points
085 * and SEG_CLOSE will not return any points.
086 * @see #SEG_MOVETO
087 * @see #SEG_LINETO
088 * @see #SEG_QUADTO
089 * @see #SEG_CUBICTO
090 * @see #SEG_CLOSE
091 */
092 public int currentSegment(float[] coords) {
093 if (isDone()) {
094 throw new NoSuchElementException(
095 "quad iterator iterator out of bounds");
096 }
097 int type;
098 if (index == 0) {
099 coords[0] = (float) quad.getX1();
100 coords[1] = (float) quad.getY1();
101 type = SEG_MOVETO;
102 } else {
103 coords[0] = (float) quad.getCtrlX();
104 coords[1] = (float) quad.getCtrlY();
105 coords[2] = (float) quad.getX2();
106 coords[3] = (float) quad.getY2();
107 type = SEG_QUADTO;
108 }
109 if (affine != null) {
110 affine.transform(coords, 0, coords, 0, index == 0 ? 1 : 2);
111 }
112 return type;
113 }
114
115 /**
116 * Returns the coordinates and type of the current path segment in
117 * the iteration.
118 * The return value is the path segment type:
119 * SEG_MOVETO, SEG_LINETO, SEG_QUADTO, SEG_CUBICTO, or SEG_CLOSE.
120 * A double array of length 6 must be passed in and may be used to
121 * store the coordinates of the point(s).
122 * Each point is stored as a pair of double x,y coordinates.
123 * SEG_MOVETO and SEG_LINETO types will return one point,
124 * SEG_QUADTO will return two points,
125 * SEG_CUBICTO will return 3 points
126 * and SEG_CLOSE will not return any points.
127 * @see #SEG_MOVETO
128 * @see #SEG_LINETO
129 * @see #SEG_QUADTO
130 * @see #SEG_CUBICTO
131 * @see #SEG_CLOSE
132 */
133 public int currentSegment(double[] coords) {
134 if (isDone()) {
135 throw new NoSuchElementException(
136 "quad iterator iterator out of bounds");
137 }
138 int type;
139 if (index == 0) {
140 coords[0] = quad.getX1();
141 coords[1] = quad.getY1();
142 type = SEG_MOVETO;
143 } else {
144 coords[0] = quad.getCtrlX();
145 coords[1] = quad.getCtrlY();
146 coords[2] = quad.getX2();
147 coords[3] = quad.getY2();
148 type = SEG_QUADTO;
149 }
150 if (affine != null) {
151 affine.transform(coords, 0, coords, 0, index == 0 ? 1 : 2);
152 }
153 return type;
154 }
155 }
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