001 /* ========================================================================
002 * JCommon : a free general purpose class library for the Java(tm) platform
003 * ========================================================================
004 *
005 * (C) Copyright 2000-2008, by Object Refinery Limited and Contributors.
006 *
007 * Project Info: http://www.jfree.org/jcommon/index.html
008 *
009 * This library is free software; you can redistribute it and/or modify it
010 * under the terms of the GNU Lesser General Public License as published by
011 * the Free Software Foundation; either version 2.1 of the License, or
012 * (at your option) any later version.
013 *
014 * This library is distributed in the hope that it will be useful, but
015 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
016 * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
017 * License for more details.
018 *
019 * You should have received a copy of the GNU Lesser General Public
020 * License along with this library; if not, write to the Free Software
021 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
022 * USA.
023 *
024 * [Java is a trademark or registered trademark of Sun Microsystems, Inc.
025 * in the United States and other countries.]
026 *
027 * -------------------
028 * ShapeUtilities.java
029 * -------------------
030 * (C)opyright 2003-2008, by Object Refinery Limited and Contributors.
031 *
032 * Original Author: David Gilbert (for Object Refinery Limited);
033 * Contributor(s): -;
034 *
035 * $Id: ShapeUtilities.java,v 1.18 2008/06/02 06:58:28 mungady Exp $
036 *
037 * Changes
038 * -------
039 * 13-Aug-2003 : Version 1 (DG);
040 * 16-Mar-2004 : Moved rotateShape() from RefineryUtilities.java to here (DG);
041 * 13-May-2004 : Added new shape creation methods (DG);
042 * 30-Sep-2004 : Added createLineRegion() method (DG);
043 * Moved drawRotatedShape() method from RefineryUtilities class
044 * to this class (DG);
045 * 04-Oct-2004 : Renamed ShapeUtils --> ShapeUtilities (DG);
046 * 26-Oct-2004 : Added a method to test the equality of two Line2D
047 * instances (DG);
048 * 10-Nov-2004 : Added new translateShape() and equal(Ellipse2D, Ellipse2D)
049 * methods (DG);
050 * 11-Nov-2004 : Renamed translateShape() --> createTranslatedShape() (DG);
051 * 07-Jan-2005 : Minor Javadoc fix (DG);
052 * 11-Jan-2005 : Removed deprecated code in preparation for 1.0.0 release (DG);
053 * 21-Jan-2005 : Modified return type of RectangleAnchor.coordinates()
054 * method (DG);
055 * 22-Feb-2005 : Added equality tests for Arc2D and GeneralPath (DG);
056 * 16-Mar-2005 : Fixed bug where equal(Shape, Shape) fails for two Polygon
057 * instances (DG);
058 * 01-Jun-2008 : Fixed bug in equal(GeneralPath, GeneralPath) method (DG);
059 *
060 */
061
062 package org.jfree.util;
063
064 import java.awt.Graphics2D;
065 import java.awt.Polygon;
066 import java.awt.Shape;
067 import java.awt.geom.AffineTransform;
068 import java.awt.geom.Arc2D;
069 import java.awt.geom.Ellipse2D;
070 import java.awt.geom.GeneralPath;
071 import java.awt.geom.Line2D;
072 import java.awt.geom.PathIterator;
073 import java.awt.geom.Point2D;
074 import java.awt.geom.Rectangle2D;
075 import java.util.Arrays;
076
077 import org.jfree.ui.RectangleAnchor;
078
079 /**
080 * Utility methods for {@link Shape} objects.
081 *
082 * @author David Gilbert
083 */
084 public class ShapeUtilities {
085
086 /**
087 * Prevents instantiation.
088 */
089 private ShapeUtilities() {
090 }
091
092 /**
093 * Returns a clone of the specified shape, or <code>null</code>. At the
094 * current time, this method supports cloning for instances of
095 * <code>Line2D</code>, <code>RectangularShape</code>, <code>Area</code>
096 * and <code>GeneralPath</code>.
097 * <p>
098 * <code>RectangularShape</code> includes <code>Arc2D</code>,
099 * <code>Ellipse2D</code>, <code>Rectangle2D</code>,
100 * <code>RoundRectangle2D</code>.
101 *
102 * @param shape the shape to clone (<code>null</code> permitted,
103 * returns <code>null</code>).
104 *
105 * @return A clone or <code>null</code>.
106 */
107 public static Shape clone(final Shape shape) {
108 if (shape instanceof Cloneable) {
109 try {
110 return (Shape) ObjectUtilities.clone(shape);
111 }
112 catch (CloneNotSupportedException cnse) {
113 }
114 }
115 final Shape result = null;
116 return result;
117 }
118
119 /**
120 * Tests two shapes for equality. If both shapes are <code>null</code>,
121 * this method will return <code>true</code>.
122 * <p>
123 * In the current implementation, the following shapes are supported:
124 * <code>Ellipse2D</code>, <code>Line2D</code> and <code>Rectangle2D</code>
125 * (implicit).
126 *
127 * @param s1 the first shape (<code>null</code> permitted).
128 * @param s2 the second shape (<code>null</code> permitted).
129 *
130 * @return A boolean.
131 */
132 public static boolean equal(final Shape s1, final Shape s2) {
133 if (s1 instanceof Line2D && s2 instanceof Line2D) {
134 return equal((Line2D) s1, (Line2D) s2);
135 }
136 else if (s1 instanceof Ellipse2D && s2 instanceof Ellipse2D) {
137 return equal((Ellipse2D) s1, (Ellipse2D) s2);
138 }
139 else if (s1 instanceof Arc2D && s2 instanceof Arc2D) {
140 return equal((Arc2D) s1, (Arc2D) s2);
141 }
142 else if (s1 instanceof Polygon && s2 instanceof Polygon) {
143 return equal((Polygon) s1, (Polygon) s2);
144 }
145 else if (s1 instanceof GeneralPath && s2 instanceof GeneralPath) {
146 return equal((GeneralPath) s1, (GeneralPath) s2);
147 }
148 else {
149 // this will handle Rectangle2D...
150 return ObjectUtilities.equal(s1, s2);
151 }
152 }
153
154 /**
155 * Compares two lines are returns <code>true</code> if they are equal or
156 * both <code>null</code>.
157 *
158 * @param l1 the first line (<code>null</code> permitted).
159 * @param l2 the second line (<code>null</code> permitted).
160 *
161 * @return A boolean.
162 */
163 public static boolean equal(final Line2D l1, final Line2D l2) {
164 if (l1 == null) {
165 return (l2 == null);
166 }
167 if (l2 == null) {
168 return false;
169 }
170 if (!l1.getP1().equals(l2.getP1())) {
171 return false;
172 }
173 if (!l1.getP2().equals(l2.getP2())) {
174 return false;
175 }
176 return true;
177 }
178
179 /**
180 * Compares two ellipses and returns <code>true</code> if they are equal or
181 * both <code>null</code>.
182 *
183 * @param e1 the first ellipse (<code>null</code> permitted).
184 * @param e2 the second ellipse (<code>null</code> permitted).
185 *
186 * @return A boolean.
187 */
188 public static boolean equal(final Ellipse2D e1, final Ellipse2D e2) {
189 if (e1 == null) {
190 return (e2 == null);
191 }
192 if (e2 == null) {
193 return false;
194 }
195 if (!e1.getFrame().equals(e2.getFrame())) {
196 return false;
197 }
198 return true;
199 }
200
201 /**
202 * Compares two arcs and returns <code>true</code> if they are equal or
203 * both <code>null</code>.
204 *
205 * @param a1 the first arc (<code>null</code> permitted).
206 * @param a2 the second arc (<code>null</code> permitted).
207 *
208 * @return A boolean.
209 */
210 public static boolean equal(final Arc2D a1, final Arc2D a2) {
211 if (a1 == null) {
212 return (a2 == null);
213 }
214 if (a2 == null) {
215 return false;
216 }
217 if (!a1.getFrame().equals(a2.getFrame())) {
218 return false;
219 }
220 if (a1.getAngleStart() != a2.getAngleStart()) {
221 return false;
222 }
223 if (a1.getAngleExtent() != a2.getAngleExtent()) {
224 return false;
225 }
226 if (a1.getArcType() != a2.getArcType()) {
227 return false;
228 }
229 return true;
230 }
231
232 /**
233 * Tests two polygons for equality. If both are <code>null</code> this
234 * method returns <code>true</code>.
235 *
236 * @param p1 polygon 1 (<code>null</code> permitted).
237 * @param p2 polygon 2 (<code>null</code> permitted).
238 *
239 * @return A boolean.
240 */
241 public static boolean equal(final Polygon p1, final Polygon p2) {
242 if (p1 == null) {
243 return (p2 == null);
244 }
245 if (p2 == null) {
246 return false;
247 }
248 if (p1.npoints != p2.npoints) {
249 return false;
250 }
251 if (!Arrays.equals(p1.xpoints, p2.xpoints)) {
252 return false;
253 }
254 if (!Arrays.equals(p1.ypoints, p2.ypoints)) {
255 return false;
256 }
257 return true;
258 }
259
260 /**
261 * Tests two polygons for equality. If both are <code>null</code> this
262 * method returns <code>true</code>.
263 *
264 * @param p1 path 1 (<code>null</code> permitted).
265 * @param p2 path 2 (<code>null</code> permitted).
266 *
267 * @return A boolean.
268 */
269 public static boolean equal(final GeneralPath p1, final GeneralPath p2) {
270 if (p1 == null) {
271 return (p2 == null);
272 }
273 if (p2 == null) {
274 return false;
275 }
276 if (p1.getWindingRule() != p2.getWindingRule()) {
277 return false;
278 }
279 PathIterator iterator1 = p1.getPathIterator(null);
280 PathIterator iterator2 = p2.getPathIterator(null);
281 double[] d1 = new double[6];
282 double[] d2 = new double[6];
283 boolean done = iterator1.isDone() && iterator2.isDone();
284 while (!done) {
285 if (iterator1.isDone() != iterator2.isDone()) {
286 return false;
287 }
288 int seg1 = iterator1.currentSegment(d1);
289 int seg2 = iterator2.currentSegment(d2);
290 if (seg1 != seg2) {
291 return false;
292 }
293 if (!Arrays.equals(d1, d2)) {
294 return false;
295 }
296 iterator1.next();
297 iterator2.next();
298 done = iterator1.isDone() && iterator2.isDone();
299 }
300 return true;
301 }
302
303 /**
304 * Creates and returns a translated shape.
305 *
306 * @param shape the shape (<code>null</code> not permitted).
307 * @param transX the x translation (in Java2D space).
308 * @param transY the y translation (in Java2D space).
309 *
310 * @return The translated shape.
311 */
312 public static Shape createTranslatedShape(final Shape shape,
313 final double transX,
314 final double transY) {
315 if (shape == null) {
316 throw new IllegalArgumentException("Null 'shape' argument.");
317 }
318 final AffineTransform transform = AffineTransform.getTranslateInstance(
319 transX, transY);
320 return transform.createTransformedShape(shape);
321 }
322
323 /**
324 * Translates a shape to a new location such that the anchor point
325 * (relative to the rectangular bounds of the shape) aligns with the
326 * specified (x, y) coordinate in Java2D space.
327 *
328 * @param shape the shape (<code>null</code> not permitted).
329 * @param anchor the anchor (<code>null</code> not permitted).
330 * @param locationX the x-coordinate (in Java2D space).
331 * @param locationY the y-coordinate (in Java2D space).
332 *
333 * @return A new and translated shape.
334 */
335 public static Shape createTranslatedShape(final Shape shape,
336 final RectangleAnchor anchor,
337 final double locationX,
338 final double locationY) {
339 if (shape == null) {
340 throw new IllegalArgumentException("Null 'shape' argument.");
341 }
342 if (anchor == null) {
343 throw new IllegalArgumentException("Null 'anchor' argument.");
344 }
345 Point2D anchorPoint = RectangleAnchor.coordinates(
346 shape.getBounds2D(), anchor);
347 final AffineTransform transform = AffineTransform.getTranslateInstance(
348 locationX - anchorPoint.getX(), locationY - anchorPoint.getY());
349 return transform.createTransformedShape(shape);
350 }
351
352 /**
353 * Rotates a shape about the specified coordinates.
354 *
355 * @param base the shape (<code>null</code> permitted, returns
356 * <code>null</code>).
357 * @param angle the angle (in radians).
358 * @param x the x coordinate for the rotation point (in Java2D space).
359 * @param y the y coordinate for the rotation point (in Java2D space).
360 *
361 * @return the rotated shape.
362 */
363 public static Shape rotateShape(final Shape base, final double angle,
364 final float x, final float y) {
365 if (base == null) {
366 return null;
367 }
368 final AffineTransform rotate = AffineTransform.getRotateInstance(
369 angle, x, y);
370 final Shape result = rotate.createTransformedShape(base);
371 return result;
372 }
373
374 /**
375 * Draws a shape with the specified rotation about <code>(x, y)</code>.
376 *
377 * @param g2 the graphics device (<code>null</code> not permitted).
378 * @param shape the shape (<code>null</code> not permitted).
379 * @param angle the angle (in radians).
380 * @param x the x coordinate for the rotation point.
381 * @param y the y coordinate for the rotation point.
382 */
383 public static void drawRotatedShape(final Graphics2D g2, final Shape shape,
384 final double angle,
385 final float x, final float y) {
386
387 final AffineTransform saved = g2.getTransform();
388 final AffineTransform rotate = AffineTransform.getRotateInstance(
389 angle, x, y);
390 g2.transform(rotate);
391 g2.draw(shape);
392 g2.setTransform(saved);
393
394 }
395
396 /** A useful constant used internally. */
397 private static final float SQRT2 = (float) Math.pow(2.0, 0.5);
398
399 /**
400 * Creates a diagonal cross shape.
401 *
402 * @param l the length of each 'arm'.
403 * @param t the thickness.
404 *
405 * @return A diagonal cross shape.
406 */
407 public static Shape createDiagonalCross(final float l, final float t) {
408 final GeneralPath p0 = new GeneralPath();
409 p0.moveTo(-l - t, -l + t);
410 p0.lineTo(-l + t, -l - t);
411 p0.lineTo(0.0f, -t * SQRT2);
412 p0.lineTo(l - t, -l - t);
413 p0.lineTo(l + t, -l + t);
414 p0.lineTo(t * SQRT2, 0.0f);
415 p0.lineTo(l + t, l - t);
416 p0.lineTo(l - t, l + t);
417 p0.lineTo(0.0f, t * SQRT2);
418 p0.lineTo(-l + t, l + t);
419 p0.lineTo(-l - t, l - t);
420 p0.lineTo(-t * SQRT2, 0.0f);
421 p0.closePath();
422 return p0;
423 }
424
425 /**
426 * Creates a diagonal cross shape.
427 *
428 * @param l the length of each 'arm'.
429 * @param t the thickness.
430 *
431 * @return A diagonal cross shape.
432 */
433 public static Shape createRegularCross(final float l, final float t) {
434 final GeneralPath p0 = new GeneralPath();
435 p0.moveTo(-l, t);
436 p0.lineTo(-t, t);
437 p0.lineTo(-t, l);
438 p0.lineTo(t, l);
439 p0.lineTo(t, t);
440 p0.lineTo(l, t);
441 p0.lineTo(l, -t);
442 p0.lineTo(t, -t);
443 p0.lineTo(t, -l);
444 p0.lineTo(-t, -l);
445 p0.lineTo(-t, -t);
446 p0.lineTo(-l, -t);
447 p0.closePath();
448 return p0;
449 }
450
451 /**
452 * Creates a diamond shape.
453 *
454 * @param s the size factor (equal to half the height of the diamond).
455 *
456 * @return A diamond shape.
457 */
458 public static Shape createDiamond(final float s) {
459 final GeneralPath p0 = new GeneralPath();
460 p0.moveTo(0.0f, -s);
461 p0.lineTo(s, 0.0f);
462 p0.lineTo(0.0f, s);
463 p0.lineTo(-s, 0.0f);
464 p0.closePath();
465 return p0;
466 }
467
468 /**
469 * Creates a triangle shape that points upwards.
470 *
471 * @param s the size factor (equal to half the height of the triangle).
472 *
473 * @return A triangle shape.
474 */
475 public static Shape createUpTriangle(final float s) {
476 final GeneralPath p0 = new GeneralPath();
477 p0.moveTo(0.0f, -s);
478 p0.lineTo(s, s);
479 p0.lineTo(-s, s);
480 p0.closePath();
481 return p0;
482 }
483
484 /**
485 * Creates a triangle shape that points downwards.
486 *
487 * @param s the size factor (equal to half the height of the triangle).
488 *
489 * @return A triangle shape.
490 */
491 public static Shape createDownTriangle(final float s) {
492 final GeneralPath p0 = new GeneralPath();
493 p0.moveTo(0.0f, s);
494 p0.lineTo(s, -s);
495 p0.lineTo(-s, -s);
496 p0.closePath();
497 return p0;
498 }
499
500 /**
501 * Creates a region surrounding a line segment by 'widening' the line
502 * segment. A typical use for this method is the creation of a
503 * 'clickable' region for a line that is displayed on-screen.
504 *
505 * @param line the line (<code>null</code> not permitted).
506 * @param width the width of the region.
507 *
508 * @return A region that surrounds the line.
509 */
510 public static Shape createLineRegion(final Line2D line, final float width) {
511 final GeneralPath result = new GeneralPath();
512 final float x1 = (float) line.getX1();
513 final float x2 = (float) line.getX2();
514 final float y1 = (float) line.getY1();
515 final float y2 = (float) line.getY2();
516 if ((x2 - x1) != 0.0) {
517 final double theta = Math.atan((y2 - y1) / (x2 - x1));
518 final float dx = (float) Math.sin(theta) * width;
519 final float dy = (float) Math.cos(theta) * width;
520 result.moveTo(x1 - dx, y1 + dy);
521 result.lineTo(x1 + dx, y1 - dy);
522 result.lineTo(x2 + dx, y2 - dy);
523 result.lineTo(x2 - dx, y2 + dy);
524 result.closePath();
525 }
526 else {
527 // special case, vertical line
528 result.moveTo(x1 - width / 2.0f, y1);
529 result.lineTo(x1 + width / 2.0f, y1);
530 result.lineTo(x2 + width / 2.0f, y2);
531 result.lineTo(x2 - width / 2.0f, y2);
532 result.closePath();
533 }
534 return result;
535 }
536
537 /**
538 * Returns a point based on (x, y) but constrained to be within the bounds
539 * of a given rectangle.
540 *
541 * @param x the x-coordinate.
542 * @param y the y-coordinate.
543 * @param area the constraining rectangle (<code>null</code> not
544 * permitted).
545 *
546 * @return A point within the rectangle.
547 *
548 * @throws NullPointerException if <code>area</code> is <code>null</code>.
549 */
550 public static Point2D getPointInRectangle(double x, double y,
551 final Rectangle2D area) {
552
553 x = Math.max(area.getMinX(), Math.min(x, area.getMaxX()));
554 y = Math.max(area.getMinY(), Math.min(y, area.getMaxY()));
555 return new Point2D.Double(x, y);
556
557 }
558
559 /**
560 * Checks, whether the given rectangle1 fully contains rectangle 2
561 * (even if rectangle 2 has a height or width of zero!).
562 *
563 * @param rect1 the first rectangle.
564 * @param rect2 the second rectangle.
565 *
566 * @return A boolean.
567 */
568 public static boolean contains(final Rectangle2D rect1,
569 final Rectangle2D rect2) {
570
571 final double x0 = rect1.getX();
572 final double y0 = rect1.getY();
573 final double x = rect2.getX();
574 final double y = rect2.getY();
575 final double w = rect2.getWidth();
576 final double h = rect2.getHeight();
577
578 return ((x >= x0) && (y >= y0)
579 && ((x + w) <= (x0 + rect1.getWidth()))
580 && ((y + h) <= (y0 + rect1.getHeight())));
581
582 }
583
584
585 /**
586 * Checks, whether the given rectangle1 fully contains rectangle 2
587 * (even if rectangle 2 has a height or width of zero!).
588 *
589 * @param rect1 the first rectangle.
590 * @param rect2 the second rectangle.
591 *
592 * @return A boolean.
593 */
594 public static boolean intersects (final Rectangle2D rect1,
595 final Rectangle2D rect2) {
596
597 final double x0 = rect1.getX();
598 final double y0 = rect1.getY();
599
600 final double x = rect2.getX();
601 final double width = rect2.getWidth();
602 final double y = rect2.getY();
603 final double height = rect2.getHeight();
604 return (x + width >= x0 && y + height >= y0 && x <= x0 + rect1.getWidth()
605 && y <= y0 + rect1.getHeight());
606 }
607
608 }