001 /* ========================================================================
002 * JCommon : a free general purpose class library for the Java(tm) platform
003 * ========================================================================
004 *
005 * (C) Copyright 2000-2005, 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 2003-2005, 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 1.17 2005/11/02 16:31:50 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 *
059 */
060
061 package org.jfree.util;
062
063 import java.awt.Graphics2D;
064 import java.awt.Polygon;
065 import java.awt.Shape;
066 import java.awt.geom.AffineTransform;
067 import java.awt.geom.Arc2D;
068 import java.awt.geom.Ellipse2D;
069 import java.awt.geom.GeneralPath;
070 import java.awt.geom.Line2D;
071 import java.awt.geom.PathIterator;
072 import java.awt.geom.Point2D;
073 import java.awt.geom.Rectangle2D;
074 import java.util.Arrays;
075
076 import org.jfree.ui.RectangleAnchor;
077
078 /**
079 * Utility methods for {@link Shape} objects.
080 *
081 * @author David Gilbert
082 */
083 public class ShapeUtilities {
084
085 /**
086 * Prevents instantiation.
087 */
088 private ShapeUtilities() {
089 }
090
091 /**
092 * Returns a clone of the specified shape, or <code>null</code>. At the
093 * current time, this method supports cloning for instances of
094 * <code>Line2D</code>, <code>RectangularShape</code>, <code>Area</code>
095 * and <code>GeneralPath</code>.
096 * <p>
097 * <code>RectangularShape</code> includes <code>Arc2D</code>,
098 * <code>Ellipse2D</code>, <code>Rectangle2D</code>,
099 * <code>RoundRectangle2D</code>.
100 *
101 * @param shape the shape to clone (<code>null</code> permitted,
102 * returns <code>null</code>).
103 *
104 * @return A clone or <code>null</code>.
105 */
106 public static Shape clone(final Shape shape) {
107
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 = p1.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 );
321 return transform.createTransformedShape(shape);
322 }
323
324 /**
325 * Translates a shape to a new location such that the anchor point
326 * (relative to the rectangular bounds of the shape) aligns with the
327 * specified (x, y) coordinate in Java2D space.
328 *
329 * @param shape the shape (<code>null</code> not permitted).
330 * @param anchor the anchor (<code>null</code> not permitted).
331 * @param locationX the x-coordinate (in Java2D space).
332 * @param locationY the y-coordinate (in Java2D space).
333 *
334 * @return A new and translated shape.
335 */
336 public static Shape createTranslatedShape(final Shape shape,
337 final RectangleAnchor anchor,
338 final double locationX,
339 final double locationY) {
340 if (shape == null) {
341 throw new IllegalArgumentException("Null 'shape' argument.");
342 }
343 if (anchor == null) {
344 throw new IllegalArgumentException("Null 'anchor' argument.");
345 }
346 Point2D anchorPoint = RectangleAnchor.coordinates(
347 shape.getBounds2D(), anchor
348 );
349 final AffineTransform transform = AffineTransform.getTranslateInstance(
350 locationX - anchorPoint.getX(), locationY - anchorPoint.getY()
351 );
352 return transform.createTransformedShape(shape);
353 }
354
355 /**
356 * Rotates a shape about the specified coordinates.
357 *
358 * @param base the shape (<code>null</code> permitted, returns
359 * <code>null</code>).
360 * @param angle the angle (in radians).
361 * @param x the x coordinate for the rotation point (in Java2D space).
362 * @param y the y coordinate for the rotation point (in Java2D space).
363 *
364 * @return the rotated shape.
365 */
366 public static Shape rotateShape(final Shape base, final double angle,
367 final float x, final float y) {
368 if (base == null) {
369 return null;
370 }
371 final AffineTransform rotate = AffineTransform.getRotateInstance(
372 angle, x, y
373 );
374 final Shape result = rotate.createTransformedShape(base);
375 return result;
376 }
377
378 /**
379 * Draws a shape with the specified rotation about <code>(x, y)</code>.
380 *
381 * @param g2 the graphics device (<code>null</code> not permitted).
382 * @param shape the shape (<code>null</code> not permitted).
383 * @param angle the angle (in radians).
384 * @param x the x coordinate for the rotation point.
385 * @param y the y coordinate for the rotation point.
386 */
387 public static void drawRotatedShape(final Graphics2D g2, final Shape shape,
388 final double angle,
389 final float x, final float y) {
390
391 final AffineTransform saved = g2.getTransform();
392 final AffineTransform rotate = AffineTransform.getRotateInstance(
393 angle, x, y
394 );
395 g2.transform(rotate);
396 g2.draw(shape);
397 g2.setTransform(saved);
398
399 }
400
401 /** A useful constant used internally. */
402 private static final float SQRT2 = (float) Math.pow(2.0, 0.5);
403
404 /**
405 * Creates a diagonal cross shape.
406 *
407 * @param l the length of each 'arm'.
408 * @param t the thickness.
409 *
410 * @return A diagonal cross shape.
411 */
412 public static Shape createDiagonalCross(final float l, final float t) {
413 final GeneralPath p0 = new GeneralPath();
414 p0.moveTo(-l - t, -l + t);
415 p0.lineTo(-l + t, -l - t);
416 p0.lineTo(0.0f, -t * SQRT2);
417 p0.lineTo(l - t, -l - t);
418 p0.lineTo(l + t, -l + t);
419 p0.lineTo(t * SQRT2, 0.0f);
420 p0.lineTo(l + t, l - t);
421 p0.lineTo(l - t, l + t);
422 p0.lineTo(0.0f, t * SQRT2);
423 p0.lineTo(-l + t, l + t);
424 p0.lineTo(-l - t, l - t);
425 p0.lineTo(-t * SQRT2, 0.0f);
426 p0.closePath();
427 return p0;
428 }
429
430 /**
431 * Creates a diagonal cross shape.
432 *
433 * @param l the length of each 'arm'.
434 * @param t the thickness.
435 *
436 * @return A diagonal cross shape.
437 */
438 public static Shape createRegularCross(final float l, final float t) {
439 final GeneralPath p0 = new GeneralPath();
440 p0.moveTo(-l, t);
441 p0.lineTo(-t, t);
442 p0.lineTo(-t, l);
443 p0.lineTo(t, l);
444 p0.lineTo(t, t);
445 p0.lineTo(l, t);
446 p0.lineTo(l, -t);
447 p0.lineTo(t, -t);
448 p0.lineTo(t, -l);
449 p0.lineTo(-t, -l);
450 p0.lineTo(-t, -t);
451 p0.lineTo(-l, -t);
452 p0.closePath();
453 return p0;
454 }
455
456 /**
457 * Creates a diamond shape.
458 *
459 * @param s the size factor (equal to half the height of the diamond).
460 *
461 * @return A diamond shape.
462 */
463 public static Shape createDiamond(final float s) {
464 final GeneralPath p0 = new GeneralPath();
465 p0.moveTo(0.0f, -s);
466 p0.lineTo(s, 0.0f);
467 p0.lineTo(0.0f, s);
468 p0.lineTo(-s, 0.0f);
469 p0.closePath();
470 return p0;
471 }
472
473 /**
474 * Creates a triangle shape that points upwards.
475 *
476 * @param s the size factor (equal to half the height of the triangle).
477 *
478 * @return A triangle shape.
479 */
480 public static Shape createUpTriangle(final float s) {
481 final GeneralPath p0 = new GeneralPath();
482 p0.moveTo(0.0f, -s);
483 p0.lineTo(s, s);
484 p0.lineTo(-s, s);
485 p0.closePath();
486 return p0;
487 }
488
489 /**
490 * Creates a triangle shape that points downwards.
491 *
492 * @param s the size factor (equal to half the height of the triangle).
493 *
494 * @return A triangle shape.
495 */
496 public static Shape createDownTriangle(final float s) {
497 final GeneralPath p0 = new GeneralPath();
498 p0.moveTo(0.0f, s);
499 p0.lineTo(s, -s);
500 p0.lineTo(-s, -s);
501 p0.closePath();
502 return p0;
503 }
504
505 /**
506 * Creates a region surrounding a line segment by 'widening' the line
507 * segment. A typical use for this method is the creation of a
508 * 'clickable' region for a line that is displayed on-screen.
509 *
510 * @param line the line (<code>null</code> not permitted).
511 * @param width the width of the region.
512 *
513 * @return A region that surrounds the line.
514 */
515 public static Shape createLineRegion(final Line2D line, final float width) {
516 final GeneralPath result = new GeneralPath();
517 final float x1 = (float) line.getX1();
518 final float x2 = (float) line.getX2();
519 final float y1 = (float) line.getY1();
520 final float y2 = (float) line.getY2();
521 if ((x2 - x1) != 0.0) {
522 final double theta = Math.atan((y2 - y1) / (x2 - x1));
523 final float dx = (float) Math.sin(theta) * width;
524 final float dy = (float) Math.cos(theta) * width;
525 result.moveTo(x1 - dx, y1 + dy);
526 result.lineTo(x1 + dx, y1 - dy);
527 result.lineTo(x2 + dx, y2 - dy);
528 result.lineTo(x2 - dx, y2 + dy);
529 result.closePath();
530 }
531 else {
532 // special case, vertical line
533 result.moveTo(x1 - width / 2.0f, y1);
534 result.lineTo(x1 + width / 2.0f, y1);
535 result.lineTo(x2 + width / 2.0f, y2);
536 result.lineTo(x2 - width / 2.0f, y2);
537 result.closePath();
538 }
539 return result;
540 }
541
542 /**
543 * Returns a point based on (x, y) but constrained to be within the bounds
544 * of a given rectangle.
545 *
546 * @param x the x-coordinate.
547 * @param y the y-coordinate.
548 * @param area the constraining rectangle (<code>null</code> not
549 * permitted).
550 *
551 * @return A point within the rectangle.
552 *
553 * @throws NullPointerException if <code>area</code> is <code>null</code>.
554 */
555 public static Point2D getPointInRectangle(double x, double y,
556 final Rectangle2D area) {
557
558 x = Math.max(area.getMinX(), Math.min(x, area.getMaxX()));
559 y = Math.max(area.getMinY(), Math.min(y, area.getMaxY()));
560 return new Point2D.Double(x, y);
561
562 }
563
564 /**
565 * Checks, whether the given rectangle1 fully contains rectangle 2
566 * (even if rectangle 2 has a height or width of zero!).
567 *
568 * @param rect1 the first rectangle.
569 * @param rect2 the second rectangle.
570 *
571 * @return A boolean.
572 */
573 public static boolean contains(final Rectangle2D rect1,
574 final Rectangle2D rect2) {
575
576 final double x0 = rect1.getX();
577 final double y0 = rect1.getY();
578 final double x = rect2.getX();
579 final double y = rect2.getY();
580 final double w = rect2.getWidth();
581 final double h = rect2.getHeight();
582
583 return ((x >= x0) && (y >= y0)
584 && ((x + w) <= (x0 + rect1.getWidth()))
585 && ((y + h) <= (y0 + rect1.getHeight())));
586
587 }
588
589
590 /**
591 * Checks, whether the given rectangle1 fully contains rectangle 2
592 * (even if rectangle 2 has a height or width of zero!).
593 *
594 * @param rect1 the first rectangle.
595 * @param rect2 the second rectangle.
596 *
597 * @return A boolean.
598 */
599 public static boolean intersects (final Rectangle2D rect1,
600 final Rectangle2D rect2) {
601
602 final double x0 = rect1.getX();
603 final double y0 = rect1.getY();
604
605 final double x = rect2.getX();
606 final double width = rect2.getWidth();
607 final double y = rect2.getY();
608 final double height = rect2.getHeight();
609 return (x + width >= x0 && y + height >= y0 && x <= x0 + rect1.getWidth()
610 && y <= y0 + rect1.getHeight());
611 }
612 }