Source for java.awt.geom.GeneralPath

   1: /* GeneralPath.java -- represents a shape built from subpaths
   2:    Copyright (C) 2002, 2003, 2004, 2006 Free Software Foundation
   3: 
   4: This file is part of GNU Classpath.
   5: 
   6: GNU Classpath is free software; you can redistribute it and/or modify
   7: it under the terms of the GNU General Public License as published by
   8: the Free Software Foundation; either version 2, or (at your option)
   9: any later version.
  10: 
  11: GNU Classpath is distributed in the hope that it will be useful, but
  12: WITHOUT ANY WARRANTY; without even the implied warranty of
  13: MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14: General Public License for more details.
  15: 
  16: You should have received a copy of the GNU General Public License
  17: along with GNU Classpath; see the file COPYING.  If not, write to the
  18: Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  19: 02110-1301 USA.
  20: 
  21: Linking this library statically or dynamically with other modules is
  22: making a combined work based on this library.  Thus, the terms and
  23: conditions of the GNU General Public License cover the whole
  24: combination.
  25: 
  26: As a special exception, the copyright holders of this library give you
  27: permission to link this library with independent modules to produce an
  28: executable, regardless of the license terms of these independent
  29: modules, and to copy and distribute the resulting executable under
  30: terms of your choice, provided that you also meet, for each linked
  31: independent module, the terms and conditions of the license of that
  32: module.  An independent module is a module which is not derived from
  33: or based on this library.  If you modify this library, you may extend
  34: this exception to your version of the library, but you are not
  35: obligated to do so.  If you do not wish to do so, delete this
  36: exception statement from your version. */
  37: 
  38: 
  39: package java.awt.geom;
  40: 
  41: import java.awt.Rectangle;
  42: import java.awt.Shape;
  43: 
  44: 
  45: /**
  46:  * A general geometric path, consisting of any number of subpaths
  47:  * constructed out of straight lines and cubic or quadratic Bezier
  48:  * curves.
  49:  *
  50:  * <p>The inside of the curve is defined for drawing purposes by a winding
  51:  * rule. Either the WIND_EVEN_ODD or WIND_NON_ZERO winding rule can be chosen.
  52:  *
  53:  * <p><img src="doc-files/GeneralPath-1.png" width="300" height="210"
  54:  * alt="A drawing of a GeneralPath" />
  55:  * <p>The EVEN_ODD winding rule defines a point as inside a path if:
  56:  * A ray from the point towards infinity in an arbitrary direction
  57:  * intersects the path an odd number of times. Points <b>A</b> and
  58:  * <b>C</b> in the image are considered to be outside the path.
  59:  * (both intersect twice)
  60:  * Point <b>B</b> intersects once, and is inside.
  61:  *
  62:  * <p>The NON_ZERO winding rule defines a point as inside a path if:
  63:  * The path intersects the ray in an equal number of opposite directions.
  64:  * Point <b>A</b> in the image is outside (one intersection in the 
  65:  * &#x2019;up&#x2019;
  66:  * direction, one in the &#x2019;down&#x2019; direction) Point <b>B</b> in 
  67:  * the image is inside (one intersection &#x2019;down&#x2019;)
  68:  * Point <b>C</b> in the image is inside (two intersections in the 
  69:  * &#x2019;down&#x2019; direction)
  70:  *
  71:  * @see Line2D
  72:  * @see CubicCurve2D
  73:  * @see QuadCurve2D
  74:  *
  75:  * @author Sascha Brawer (brawer@dandelis.ch)
  76:  * @author Sven de Marothy (sven@physto.se)
  77:  *
  78:  * @since 1.2
  79:  */
  80: public final class GeneralPath implements Shape, Cloneable
  81: {
  82:   /** Same constant as {@link PathIterator#WIND_EVEN_ODD}. */
  83:   public static final int WIND_EVEN_ODD = PathIterator.WIND_EVEN_ODD;
  84: 
  85:   /** Same constant as {@link PathIterator#WIND_NON_ZERO}. */
  86:   public static final int WIND_NON_ZERO = PathIterator.WIND_NON_ZERO;
  87: 
  88:   /** Initial size if not specified. */
  89:   private static final int INIT_SIZE = 10;
  90: 
  91:   /** A big number, but not so big it can't survive a few float operations */
  92:   private static final double BIG_VALUE = Double.MAX_VALUE / 10.0;
  93: 
  94:   /** The winding rule.
  95:    * This is package-private to avoid an accessor method.
  96:    */
  97:   int rule;
  98: 
  99:   /**
 100:    * The path type in points. Note that xpoints[index] and ypoints[index] maps
 101:    * to types[index]; the control points of quad and cubic paths map as
 102:    * well but are ignored.
 103:    * This is package-private to avoid an accessor method.
 104:    */
 105:   byte[] types;
 106: 
 107:   /**
 108:    * The list of all points seen. Since you can only append floats, it makes
 109:    * sense for these to be float[]. I have no idea why Sun didn't choose to
 110:    * allow a general path of double precision points.
 111:    * Note: Storing x and y coords seperately makes for a slower transforms,
 112:    * But it speeds up and simplifies box-intersection checking a lot.
 113:    * These are package-private to avoid accessor methods.
 114:    */
 115:   float[] xpoints;
 116:   float[] ypoints;
 117: 
 118:   /** The index of the most recent moveto point, or null. */
 119:   private int subpath = -1;
 120: 
 121:   /** The next available index into points.
 122:    * This is package-private to avoid an accessor method.
 123:    */
 124:   int index;
 125: 
 126:   /**
 127:    * Constructs a GeneralPath with the default (NON_ZERO)
 128:    * winding rule and initial capacity (20).
 129:    */
 130:   public GeneralPath()
 131:   {
 132:     this(WIND_NON_ZERO, INIT_SIZE);
 133:   }
 134: 
 135:   /**
 136:    * Constructs a GeneralPath with a specific winding rule
 137:    * and the default initial capacity (20).
 138:    * @param rule the winding rule ({@link #WIND_NON_ZERO} or 
 139:    *     {@link #WIND_EVEN_ODD})
 140:    *     
 141:    * @throws IllegalArgumentException if <code>rule</code> is not one of the
 142:    *     listed values.
 143:    */
 144:   public GeneralPath(int rule)
 145:   {
 146:     this(rule, INIT_SIZE);
 147:   }
 148: 
 149:   /**
 150:    * Constructs a GeneralPath with a specific winding rule
 151:    * and the initial capacity. The initial capacity should be
 152:    * the approximate number of path segments to be used.
 153:    * @param rule the winding rule ({@link #WIND_NON_ZERO} or 
 154:    *     {@link #WIND_EVEN_ODD})
 155:    * @param capacity the inital capacity, in path segments
 156:    * 
 157:    * @throws IllegalArgumentException if <code>rule</code> is not one of the
 158:    *     listed values.
 159:    */
 160:   public GeneralPath(int rule, int capacity)
 161:   {
 162:     if (rule != WIND_EVEN_ODD && rule != WIND_NON_ZERO)
 163:       throw new IllegalArgumentException();
 164:     this.rule = rule;
 165:     if (capacity < INIT_SIZE)
 166:       capacity = INIT_SIZE;
 167:     types = new byte[capacity];
 168:     xpoints = new float[capacity];
 169:     ypoints = new float[capacity];
 170:   }
 171: 
 172:   /**
 173:    * Constructs a GeneralPath from an arbitrary shape object.
 174:    * The Shapes PathIterator path and winding rule will be used.
 175:    * 
 176:    * @param s the shape (<code>null</code> not permitted).
 177:    * 
 178:    * @throws NullPointerException if <code>shape</code> is <code>null</code>.
 179:    */
 180:   public GeneralPath(Shape s)
 181:   {
 182:     types = new byte[INIT_SIZE];
 183:     xpoints = new float[INIT_SIZE];
 184:     ypoints = new float[INIT_SIZE];
 185:     PathIterator pi = s.getPathIterator(null);
 186:     setWindingRule(pi.getWindingRule());
 187:     append(pi, false);
 188:   }
 189: 
 190:   /**
 191:    * Adds a new point to a path.
 192:    * 
 193:    * @param x  the x-coordinate.
 194:    * @param y  the y-coordinate.
 195:    */
 196:   public void moveTo(float x, float y)
 197:   {
 198:     subpath = index;
 199:     ensureSize(index + 1);
 200:     types[index] = PathIterator.SEG_MOVETO;
 201:     xpoints[index] = x;
 202:     ypoints[index++] = y;
 203:   }
 204: 
 205:   /**
 206:    * Appends a straight line to the current path.
 207:    * @param x x coordinate of the line endpoint.
 208:    * @param y y coordinate of the line endpoint.
 209:    */
 210:   public void lineTo(float x, float y)
 211:   {
 212:     ensureSize(index + 1);
 213:     types[index] = PathIterator.SEG_LINETO;
 214:     xpoints[index] = x;
 215:     ypoints[index++] = y;
 216:   }
 217: 
 218:   /**
 219:    * Appends a quadratic Bezier curve to the current path.
 220:    * @param x1 x coordinate of the control point
 221:    * @param y1 y coordinate of the control point
 222:    * @param x2 x coordinate of the curve endpoint.
 223:    * @param y2 y coordinate of the curve endpoint.
 224:    */
 225:   public void quadTo(float x1, float y1, float x2, float y2)
 226:   {
 227:     ensureSize(index + 2);
 228:     types[index] = PathIterator.SEG_QUADTO;
 229:     xpoints[index] = x1;
 230:     ypoints[index++] = y1;
 231:     xpoints[index] = x2;
 232:     ypoints[index++] = y2;
 233:   }
 234: 
 235:   /**
 236:    * Appends a cubic Bezier curve to the current path.
 237:    * @param x1 x coordinate of the first control point
 238:    * @param y1 y coordinate of the first control point
 239:    * @param x2 x coordinate of the second control point
 240:    * @param y2 y coordinate of the second control point
 241:    * @param x3 x coordinate of the curve endpoint.
 242:    * @param y3 y coordinate of the curve endpoint.
 243:    */
 244:   public void curveTo(float x1, float y1, float x2, float y2, float x3,
 245:                       float y3)
 246:   {
 247:     ensureSize(index + 3);
 248:     types[index] = PathIterator.SEG_CUBICTO;
 249:     xpoints[index] = x1;
 250:     ypoints[index++] = y1;
 251:     xpoints[index] = x2;
 252:     ypoints[index++] = y2;
 253:     xpoints[index] = x3;
 254:     ypoints[index++] = y3;
 255:   }
 256: 
 257:   /**
 258:    * Closes the current subpath by drawing a line
 259:    * back to the point of the last moveTo, unless the path is already closed.
 260:    */
 261:   public void closePath()
 262:   {
 263:     if (index >= 1 && types[index - 1] == PathIterator.SEG_CLOSE)
 264:       return;
 265:     ensureSize(index + 1);
 266:     types[index] = PathIterator.SEG_CLOSE;
 267:     xpoints[index] = xpoints[subpath];
 268:     ypoints[index++] = ypoints[subpath];
 269:   }
 270: 
 271:   /**
 272:    * Appends the segments of a Shape to the path. If <code>connect</code> is 
 273:    * true, the new path segments are connected to the existing one with a line.
 274:    * The winding rule of the Shape is ignored.
 275:    * 
 276:    * @param s  the shape (<code>null</code> not permitted).
 277:    * @param connect  whether to connect the new shape to the existing path.
 278:    * 
 279:    * @throws NullPointerException if <code>s</code> is <code>null</code>.
 280:    */
 281:   public void append(Shape s, boolean connect)
 282:   {
 283:     append(s.getPathIterator(null), connect);
 284:   }
 285: 
 286:   /**
 287:    * Appends the segments of a PathIterator to this GeneralPath.
 288:    * Optionally, the initial {@link PathIterator#SEG_MOVETO} segment
 289:    * of the appended path is changed into a {@link
 290:    * PathIterator#SEG_LINETO} segment.
 291:    *
 292:    * @param iter the PathIterator specifying which segments shall be
 293:    *     appended (<code>null</code> not permitted).
 294:    *
 295:    * @param connect <code>true</code> for substituting the initial
 296:    * {@link PathIterator#SEG_MOVETO} segment by a {@link
 297:    * PathIterator#SEG_LINETO}, or <code>false</code> for not
 298:    * performing any substitution. If this GeneralPath is currently
 299:    * empty, <code>connect</code> is assumed to be <code>false</code>,
 300:    * thus leaving the initial {@link PathIterator#SEG_MOVETO}
 301:    * unchanged.
 302:    */
 303:   public void append(PathIterator iter, boolean connect)
 304:   {
 305:     // A bad implementation of this method had caused Classpath bug #6076.
 306:     float[] f = new float[6];
 307:     while (! iter.isDone())
 308:       {
 309:     switch (iter.currentSegment(f))
 310:       {
 311:       case PathIterator.SEG_MOVETO:
 312:         if (! connect || (index == 0))
 313:           {
 314:         moveTo(f[0], f[1]);
 315:         break;
 316:           }
 317:         if ((index >= 1) && (types[index - 1] == PathIterator.SEG_CLOSE)
 318:             && (f[0] == xpoints[index - 1])
 319:             && (f[1] == ypoints[index - 1]))
 320:           break;
 321: 
 322:       // Fall through.
 323:       case PathIterator.SEG_LINETO:
 324:         lineTo(f[0], f[1]);
 325:         break;
 326:       case PathIterator.SEG_QUADTO:
 327:         quadTo(f[0], f[1], f[2], f[3]);
 328:         break;
 329:       case PathIterator.SEG_CUBICTO:
 330:         curveTo(f[0], f[1], f[2], f[3], f[4], f[5]);
 331:         break;
 332:       case PathIterator.SEG_CLOSE:
 333:         closePath();
 334:         break;
 335:       }
 336: 
 337:     connect = false;
 338:     iter.next();
 339:       }
 340:   }
 341: 
 342:   /**
 343:    * Returns the path&#x2019;s current winding rule.
 344:    * 
 345:    * @return {@link #WIND_EVEN_ODD} or {@link #WIND_NON_ZERO}.
 346:    */
 347:   public int getWindingRule()
 348:   {
 349:     return rule;
 350:   }
 351: 
 352:   /**
 353:    * Sets the path&#x2019;s winding rule, which controls which areas are 
 354:    * considered &#x2019;inside&#x2019; or &#x2019;outside&#x2019; the path 
 355:    * on drawing. Valid rules are WIND_EVEN_ODD for an even-odd winding rule, 
 356:    * or WIND_NON_ZERO for a non-zero winding rule.
 357:    * 
 358:    * @param rule  the rule ({@link #WIND_EVEN_ODD} or {@link #WIND_NON_ZERO}).
 359:    */
 360:   public void setWindingRule(int rule)
 361:   {
 362:     if (rule != WIND_EVEN_ODD && rule != WIND_NON_ZERO)
 363:       throw new IllegalArgumentException();
 364:     this.rule = rule;
 365:   }
 366: 
 367:   /**
 368:    * Returns the current appending point of the path.
 369:    * 
 370:    * @return The point.
 371:    */
 372:   public Point2D getCurrentPoint()
 373:   {
 374:     if (subpath < 0)
 375:       return null;
 376:     return new Point2D.Float(xpoints[index - 1], ypoints[index - 1]);
 377:   }
 378: 
 379:   /**
 380:    * Resets the path. All points and segments are destroyed.
 381:    */
 382:   public void reset()
 383:   {
 384:     subpath = -1;
 385:     index = 0;
 386:   }
 387: 
 388:   /**
 389:    * Applies a transform to the path.
 390:    * 
 391:    * @param xform  the transform (<code>null</code> not permitted).
 392:    */
 393:   public void transform(AffineTransform xform)
 394:   {
 395:     double nx;
 396:     double ny;
 397:     double[] m = new double[6];
 398:     xform.getMatrix(m);
 399:     for (int i = 0; i < index; i++)
 400:       {
 401:     nx = m[0] * xpoints[i] + m[2] * ypoints[i] + m[4];
 402:     ny = m[1] * xpoints[i] + m[3] * ypoints[i] + m[5];
 403:     xpoints[i] = (float) nx;
 404:     ypoints[i] = (float) ny;
 405:       }
 406:   }
 407: 
 408:   /**
 409:    * Creates a transformed version of the path.
 410:    * @param xform the transform to apply
 411:    * @return a new transformed GeneralPath
 412:    */
 413:   public Shape createTransformedShape(AffineTransform xform)
 414:   {
 415:     GeneralPath p = new GeneralPath(this);
 416:     p.transform(xform);
 417:     return p;
 418:   }
 419: 
 420:   /**
 421:    * Returns the path&#x2019;s bounding box.
 422:    */
 423:   public Rectangle getBounds()
 424:   {
 425:     return getBounds2D().getBounds();
 426:   }
 427: 
 428:   /**
 429:    * Returns the path&#x2019;s bounding box, in <code>float</code> precision
 430:    */
 431:   public Rectangle2D getBounds2D()
 432:   {
 433:     float x1;
 434:     float y1;
 435:     float x2;
 436:     float y2;
 437: 
 438:     if (index > 0)
 439:       {
 440:     x1 = x2 = xpoints[0];
 441:     y1 = y2 = ypoints[0];
 442:       }
 443:     else
 444:       x1 = x2 = y1 = y2 = 0.0f;
 445: 
 446:     for (int i = 0; i < index; i++)
 447:       {
 448:     x1 = Math.min(xpoints[i], x1);
 449:     y1 = Math.min(ypoints[i], y1);
 450:     x2 = Math.max(xpoints[i], x2);
 451:     y2 = Math.max(ypoints[i], y2);
 452:       }
 453:     return (new Rectangle2D.Float(x1, y1, x2 - x1, y2 - y1));
 454:   }
 455: 
 456:   /**
 457:    * Evaluates if a point is within the GeneralPath,
 458:    * The NON_ZERO winding rule is used, regardless of the
 459:    * set winding rule.
 460:    * @param x x coordinate of the point to evaluate
 461:    * @param y y coordinate of the point to evaluate
 462:    * @return true if the point is within the path, false otherwise
 463:    */
 464:   public boolean contains(double x, double y)
 465:   {
 466:     return (getWindingNumber(x, y) != 0);
 467:   }
 468: 
 469:   /**
 470:    * Evaluates if a Point2D is within the GeneralPath,
 471:    * The NON_ZERO winding rule is used, regardless of the
 472:    * set winding rule.
 473:    * @param p The Point2D to evaluate
 474:    * @return true if the point is within the path, false otherwise
 475:    */
 476:   public boolean contains(Point2D p)
 477:   {
 478:     return contains(p.getX(), p.getY());
 479:   }
 480: 
 481:   /**
 482:    * Evaluates if a rectangle is completely contained within the path.
 483:    * This method will return false in the cases when the box
 484:    * intersects an inner segment of the path.
 485:    * (i.e.: The method is accurate for the EVEN_ODD winding rule)
 486:    */
 487:   public boolean contains(double x, double y, double w, double h)
 488:   {
 489:     if (! getBounds2D().intersects(x, y, w, h))
 490:       return false;
 491: 
 492:     /* Does any edge intersect? */
 493:     if (getAxisIntersections(x, y, false, w) != 0 /* top */
 494:         || getAxisIntersections(x, y + h, false, w) != 0 /* bottom */
 495:         || getAxisIntersections(x + w, y, true, h) != 0 /* right */
 496:         || getAxisIntersections(x, y, true, h) != 0) /* left */
 497:       return false;
 498: 
 499:     /* No intersections, is any point inside? */
 500:     if (getWindingNumber(x, y) != 0)
 501:       return true;
 502: 
 503:     return false;
 504:   }
 505: 
 506:   /**
 507:    * Evaluates if a rectangle is completely contained within the path.
 508:    * This method will return false in the cases when the box
 509:    * intersects an inner segment of the path.
 510:    * (i.e.: The method is accurate for the EVEN_ODD winding rule)
 511:    * @param r the rectangle
 512:    * @return <code>true</code> if the rectangle is completely contained
 513:    * within the path, <code>false</code> otherwise
 514:    */
 515:   public boolean contains(Rectangle2D r)
 516:   {
 517:     return contains(r.getX(), r.getY(), r.getWidth(), r.getHeight());
 518:   }
 519: 
 520:   /**
 521:    * Evaluates if a rectangle intersects the path.
 522:    * @param x x coordinate of the rectangle
 523:    * @param y y coordinate of the rectangle
 524:    * @param w width of the rectangle
 525:    * @param h height of the rectangle
 526:    * @return <code>true</code> if the rectangle intersects the path,
 527:    * <code>false</code> otherwise
 528:    */
 529:   public boolean intersects(double x, double y, double w, double h)
 530:   {
 531:     /* Does any edge intersect? */
 532:     if (getAxisIntersections(x, y, false, w) != 0 /* top */
 533:         || getAxisIntersections(x, y + h, false, w) != 0 /* bottom */
 534:         || getAxisIntersections(x + w, y, true, h) != 0 /* right */
 535:         || getAxisIntersections(x, y, true, h) != 0) /* left */
 536:       return true;
 537: 
 538:     /* No intersections, is any point inside? */
 539:     if (getWindingNumber(x, y) != 0)
 540:       return true;
 541: 
 542:     return false;
 543:   }
 544: 
 545:   /**
 546:    * Evaluates if a Rectangle2D intersects the path.
 547:    * @param r The rectangle
 548:    * @return <code>true</code> if the rectangle intersects the path,
 549:    * <code>false</code> otherwise
 550:    */
 551:   public boolean intersects(Rectangle2D r)
 552:   {
 553:     return intersects(r.getX(), r.getY(), r.getWidth(), r.getHeight());
 554:   }
 555: 
 556:   /**
 557:    * A PathIterator that iterates over the segments of a GeneralPath.
 558:    *
 559:    * @author Sascha Brawer (brawer@dandelis.ch)
 560:    */
 561:   private static class GeneralPathIterator implements PathIterator
 562:   {
 563:     /**
 564:      * The number of coordinate values for each segment type.
 565:      */
 566:     private static final int[] NUM_COORDS = { 
 567:                                             /* 0: SEG_MOVETO */ 1, 
 568:                                             /* 1: SEG_LINETO */ 1, 
 569:                                             /* 2: SEG_QUADTO */ 2, 
 570:                                             /* 3: SEG_CUBICTO */ 3, 
 571:                                             /* 4: SEG_CLOSE */ 0};
 572: 
 573:     /**
 574:      * The GeneralPath whose segments are being iterated.
 575:      * This is package-private to avoid an accessor method.
 576:      */
 577:     final GeneralPath path;
 578: 
 579:     /**
 580:      * The affine transformation used to transform coordinates.
 581:      */
 582:     private final AffineTransform transform;
 583: 
 584:     /**
 585:      * The current position of the iterator.
 586:      */
 587:     private int pos;
 588: 
 589:     /**
 590:      * Constructs a new iterator for enumerating the segments of a
 591:      * GeneralPath.
 592:      *
 593:      * @param path the path to enumerate
 594:      * @param transform an affine transformation for projecting the returned
 595:      * points, or <code>null</code> to return the original points
 596:      * without any mapping.
 597:      */
 598:     GeneralPathIterator(GeneralPath path, AffineTransform transform)
 599:     {
 600:       this.path = path;
 601:       this.transform = transform;
 602:     }
 603: 
 604:     /**
 605:      * Returns the current winding rule of the GeneralPath.
 606:      */
 607:     public int getWindingRule()
 608:     {
 609:       return path.rule;
 610:     }
 611: 
 612:     /**
 613:      * Determines whether the iterator has reached the last segment in
 614:      * the path.
 615:      */
 616:     public boolean isDone()
 617:     {
 618:       return pos >= path.index;
 619:     }
 620: 
 621:     /**
 622:      * Advances the iterator position by one segment.
 623:      */
 624:     public void next()
 625:     {
 626:       int seg;
 627: 
 628:       /*
 629:        * Increment pos by the number of coordinate pairs.
 630:        */
 631:       seg = path.types[pos];
 632:       if (seg == SEG_CLOSE)
 633:     pos++;
 634:       else
 635:     pos += NUM_COORDS[seg];
 636:     }
 637: 
 638:     /**
 639:      * Returns the current segment in float coordinates.
 640:      */
 641:     public int currentSegment(float[] coords)
 642:     {
 643:       int seg;
 644:       int numCoords;
 645: 
 646:       seg = path.types[pos];
 647:       numCoords = NUM_COORDS[seg];
 648:       if (numCoords > 0)
 649:         {
 650:       for (int i = 0; i < numCoords; i++)
 651:         {
 652:           coords[i << 1] = path.xpoints[pos + i];
 653:           coords[(i << 1) + 1] = path.ypoints[pos + i];
 654:         }
 655: 
 656:       if (transform != null)
 657:         transform.transform( /* src */
 658:         coords, /* srcOffset */
 659:         0, /* dest */ coords, /* destOffset */
 660:         0, /* numPoints */ numCoords);
 661:         }
 662:       return seg;
 663:     }
 664: 
 665:     /**
 666:      * Returns the current segment in double coordinates.
 667:      */
 668:     public int currentSegment(double[] coords)
 669:     {
 670:       int seg;
 671:       int numCoords;
 672: 
 673:       seg = path.types[pos];
 674:       numCoords = NUM_COORDS[seg];
 675:       if (numCoords > 0)
 676:         {
 677:       for (int i = 0; i < numCoords; i++)
 678:         {
 679:           coords[i << 1] = (double) path.xpoints[pos + i];
 680:           coords[(i << 1) + 1] = (double) path.ypoints[pos + i];
 681:         }
 682:       if (transform != null)
 683:         transform.transform( /* src */
 684:         coords, /* srcOffset */
 685:         0, /* dest */ coords, /* destOffset */
 686:         0, /* numPoints */ numCoords);
 687:         }
 688:       return seg;
 689:     }
 690:   }
 691: 
 692:   /**
 693:    * Creates a PathIterator for iterating along the segments of the path.
 694:    *
 695:    * @param at an affine transformation for projecting the returned
 696:    * points, or <code>null</code> to let the created iterator return
 697:    * the original points without any mapping.
 698:    */
 699:   public PathIterator getPathIterator(AffineTransform at)
 700:   {
 701:     return new GeneralPathIterator(this, at);
 702:   }
 703: 
 704:   /**
 705:    * Creates a new FlatteningPathIterator for the path
 706:    */
 707:   public PathIterator getPathIterator(AffineTransform at, double flatness)
 708:   {
 709:     return new FlatteningPathIterator(getPathIterator(at), flatness);
 710:   }
 711: 
 712:   /**
 713:    * Creates a new shape of the same run-time type with the same contents 
 714:    * as this one.
 715:    *
 716:    * @return the clone
 717:    *
 718:    * @exception OutOfMemoryError If there is not enough memory available.
 719:    *
 720:    * @since 1.2
 721:    */
 722:   public Object clone()
 723:   {
 724:     // This class is final; no need to use super.clone().
 725:     return new GeneralPath(this);
 726:   }
 727: 
 728:   /**
 729:    * Helper method - ensure the size of the data arrays,
 730:    * otherwise, reallocate new ones twice the size
 731:    * 
 732:    * @param size  the minimum array size.
 733:    */
 734:   private void ensureSize(int size)
 735:   {
 736:     if (subpath < 0)
 737:       throw new IllegalPathStateException("need initial moveto");
 738:     if (size <= xpoints.length)
 739:       return;
 740:     byte[] b = new byte[types.length << 1];
 741:     System.arraycopy(types, 0, b, 0, index);
 742:     types = b;
 743:     float[] f = new float[xpoints.length << 1];
 744:     System.arraycopy(xpoints, 0, f, 0, index);
 745:     xpoints = f;
 746:     f = new float[ypoints.length << 1];
 747:     System.arraycopy(ypoints, 0, f, 0, index);
 748:     ypoints = f;
 749:   }
 750: 
 751:   /**
 752:    * Helper method - Get the total number of intersections from (x,y) along 
 753:    * a given axis, within a given distance.
 754:    */
 755:   private int getAxisIntersections(double x, double y, boolean useYaxis,
 756:                                    double distance)
 757:   {
 758:     return (evaluateCrossings(x, y, false, useYaxis, distance));
 759:   }
 760: 
 761:   /**
 762:    * Helper method - returns the winding number of a point.
 763:    */
 764:   private int getWindingNumber(double x, double y)
 765:   {
 766:     /* Evaluate the crossings from x,y to infinity on the y axis (arbitrary 
 767:        choice). Note that we don't actually use Double.INFINITY, since that's 
 768:        slower, and may cause problems. */
 769:     return (evaluateCrossings(x, y, true, true, BIG_VALUE));
 770:   }
 771: 
 772:   /**
 773:    * Helper method - evaluates the number of intersections on an axis from 
 774:    * the point (x,y) to the point (x,y+distance) or (x+distance,y).
 775:    * @param x x coordinate.
 776:    * @param y y coordinate.
 777:    * @param neg True if opposite-directed intersections should cancel, 
 778:    * false to sum all intersections.
 779:    * @param useYaxis Use the Y axis, false uses the X axis.
 780:    * @param distance Interval from (x,y) on the selected axis to find 
 781:    * intersections.
 782:    */
 783:   private int evaluateCrossings(double x, double y, boolean neg,
 784:                                 boolean useYaxis, double distance)
 785:   {
 786:     float cx = 0.0f;
 787:     float cy = 0.0f;
 788:     float firstx = 0.0f;
 789:     float firsty = 0.0f;
 790: 
 791:     int negative = (neg) ? -1 : 1;
 792:     double x0;
 793:     double x1;
 794:     double x2;
 795:     double x3;
 796:     double y0;
 797:     double y1;
 798:     double y2;
 799:     double y3;
 800:     double[] r = new double[4];
 801:     int nRoots;
 802:     double epsilon = 0.0;
 803:     int pos = 0;
 804:     int windingNumber = 0;
 805:     boolean pathStarted = false;
 806: 
 807:     if (index == 0)
 808:       return (0);
 809:     if (useYaxis)
 810:       {
 811:     float[] swap1;
 812:     swap1 = ypoints;
 813:     ypoints = xpoints;
 814:     xpoints = swap1;
 815:     double swap2;
 816:     swap2 = y;
 817:     y = x;
 818:     x = swap2;
 819:       }
 820: 
 821:     /* Get a value which is hopefully small but not insignificant relative
 822:      the path. */
 823:     epsilon = ypoints[0] * 1E-7;
 824: 
 825:     if(epsilon == 0) 
 826:       epsilon = 1E-7;
 827: 
 828:     pos = 0;
 829:     while (pos < index)
 830:       {
 831:     switch (types[pos])
 832:       {
 833:       case PathIterator.SEG_MOVETO:
 834:         if (pathStarted) // close old path
 835:           {
 836:         x0 = cx;
 837:         y0 = cy;
 838:         x1 = firstx;
 839:         y1 = firsty;
 840: 
 841:         if (y0 == 0.0)
 842:           y0 -= epsilon;
 843:         if (y1 == 0.0)
 844:           y1 -= epsilon;
 845:         if (Line2D.linesIntersect(x0, y0, x1, y1, 
 846:                       epsilon, 0.0, distance, 0.0))
 847:           windingNumber += (y1 < y0) ? 1 : negative;
 848: 
 849:         cx = firstx;
 850:         cy = firsty;
 851:           }
 852:         cx = firstx = xpoints[pos] - (float) x;
 853:         cy = firsty = ypoints[pos++] - (float) y;
 854:         pathStarted = true;
 855:         break;
 856:       case PathIterator.SEG_CLOSE:
 857:         x0 = cx;
 858:         y0 = cy;
 859:         x1 = firstx;
 860:         y1 = firsty;
 861: 
 862:         if (y0 == 0.0)
 863:           y0 -= epsilon;
 864:         if (y1 == 0.0)
 865:           y1 -= epsilon;
 866:         if (Line2D.linesIntersect(x0, y0, x1, y1, 
 867:                       epsilon, 0.0, distance, 0.0))
 868:           windingNumber += (y1 < y0) ? 1 : negative;
 869: 
 870:         cx = firstx;
 871:         cy = firsty;
 872:         pos++;
 873:         pathStarted = false;
 874:         break;
 875:       case PathIterator.SEG_LINETO:
 876:         x0 = cx;
 877:         y0 = cy;
 878:         x1 = xpoints[pos] - (float) x;
 879:         y1 = ypoints[pos++] - (float) y;
 880: 
 881:         if (y0 == 0.0)
 882:           y0 -= epsilon;
 883:         if (y1 == 0.0)
 884:           y1 -= epsilon;
 885:         if (Line2D.linesIntersect(x0, y0, x1, y1, 
 886:                       epsilon, 0.0, distance, 0.0))
 887:           windingNumber += (y1 < y0) ? 1 : negative;
 888: 
 889:         cx = xpoints[pos - 1] - (float) x;
 890:         cy = ypoints[pos - 1] - (float) y;
 891:         break;
 892:       case PathIterator.SEG_QUADTO:
 893:         x0 = cx;
 894:         y0 = cy;
 895:         x1 = xpoints[pos] - x;
 896:         y1 = ypoints[pos++] - y;
 897:         x2 = xpoints[pos] - x;
 898:         y2 = ypoints[pos++] - y;
 899: 
 900:         /* check if curve may intersect X+ axis. */
 901:         if ((x0 > 0.0 || x1 > 0.0 || x2 > 0.0)
 902:             && (y0 * y1 <= 0 || y1 * y2 <= 0))
 903:           {
 904:         if (y0 == 0.0)
 905:           y0 -= epsilon;
 906:         if (y2 == 0.0)
 907:           y2 -= epsilon;
 908: 
 909:         r[0] = y0;
 910:         r[1] = 2 * (y1 - y0);
 911:         r[2] = (y2 - 2 * y1 + y0);
 912: 
 913:         /* degenerate roots (=tangent points) do not
 914:            contribute to the winding number. */
 915:         if ((nRoots = QuadCurve2D.solveQuadratic(r)) == 2)
 916:           for (int i = 0; i < nRoots; i++)
 917:             {
 918:               float t = (float) r[i];
 919:               if (t > 0.0f && t < 1.0f)
 920:                 {
 921:               double crossing = t * t * (x2 - 2 * x1 + x0)
 922:                                 + 2 * t * (x1 - x0) + x0;
 923:               if (crossing >= 0.0 && crossing <= distance)
 924:                 windingNumber += (2 * t * (y2 - 2 * y1 + y0)
 925:                                + 2 * (y1 - y0) < 0) ? 1 : negative;
 926:                 }
 927:             }
 928:           }
 929: 
 930:         cx = xpoints[pos - 1] - (float) x;
 931:         cy = ypoints[pos - 1] - (float) y;
 932:         break;
 933:       case PathIterator.SEG_CUBICTO:
 934:         x0 = cx;
 935:         y0 = cy;
 936:         x1 = xpoints[pos] - x;
 937:         y1 = ypoints[pos++] - y;
 938:         x2 = xpoints[pos] - x;
 939:         y2 = ypoints[pos++] - y;
 940:         x3 = xpoints[pos] - x;
 941:         y3 = ypoints[pos++] - y;
 942: 
 943:         /* check if curve may intersect X+ axis. */
 944:         if ((x0 > 0.0 || x1 > 0.0 || x2 > 0.0 || x3 > 0.0)
 945:             && (y0 * y1 <= 0 || y1 * y2 <= 0 || y2 * y3 <= 0))
 946:           {
 947:         if (y0 == 0.0)
 948:           y0 -= epsilon;
 949:         if (y3 == 0.0)
 950:           y3 -= epsilon;
 951: 
 952:         r[0] = y0;
 953:         r[1] = 3 * (y1 - y0);
 954:         r[2] = 3 * (y2 + y0 - 2 * y1);
 955:         r[3] = y3 - 3 * y2 + 3 * y1 - y0;
 956: 
 957:         if ((nRoots = CubicCurve2D.solveCubic(r)) != 0)
 958:           for (int i = 0; i < nRoots; i++)
 959:             {
 960:               float t = (float) r[i];
 961:               if (t > 0.0 && t < 1.0)
 962:                 {
 963:               double crossing = -(t * t * t) * (x0 - 3 * x1
 964:                                 + 3 * x2 - x3)
 965:                                 + 3 * t * t * (x0 - 2 * x1 + x2)
 966:                                 + 3 * t * (x1 - x0) + x0;
 967:               if (crossing >= 0 && crossing <= distance)
 968:                 windingNumber += (3 * t * t * (y3 + 3 * y1
 969:                                  - 3 * y2 - y0)
 970:                                  + 6 * t * (y0 - 2 * y1 + y2)
 971:                                + 3 * (y1 - y0) < 0) ? 1 : negative;
 972:                 }
 973:             }
 974:           }
 975: 
 976:         cx = xpoints[pos - 1] - (float) x;
 977:         cy = ypoints[pos - 1] - (float) y;
 978:         break;
 979:       }
 980:       }
 981: 
 982:     // swap coordinates back
 983:     if (useYaxis)
 984:       {
 985:     float[] swap;
 986:     swap = ypoints;
 987:     ypoints = xpoints;
 988:     xpoints = swap;
 989:       }
 990:     return (windingNumber);
 991:   }
 992: } // class GeneralPath