J. Duke | 319a3b9 | 2007-12-01 00:00:00 +0000 | [diff] [blame^] | 1 | /* |
| 2 | * Copyright 1995-2006 Sun Microsystems, Inc. All Rights Reserved. |
| 3 | * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| 4 | * |
| 5 | * This code is free software; you can redistribute it and/or modify it |
| 6 | * under the terms of the GNU General Public License version 2 only, as |
| 7 | * published by the Free Software Foundation. Sun designates this |
| 8 | * particular file as subject to the "Classpath" exception as provided |
| 9 | * by Sun in the LICENSE file that accompanied this code. |
| 10 | * |
| 11 | * This code is distributed in the hope that it will be useful, but WITHOUT |
| 12 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| 13 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| 14 | * version 2 for more details (a copy is included in the LICENSE file that |
| 15 | * accompanied this code). |
| 16 | * |
| 17 | * You should have received a copy of the GNU General Public License version |
| 18 | * 2 along with this work; if not, write to the Free Software Foundation, |
| 19 | * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| 20 | * |
| 21 | * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, |
| 22 | * CA 95054 USA or visit www.sun.com if you need additional information or |
| 23 | * have any questions. |
| 24 | */ |
| 25 | package java.awt; |
| 26 | |
| 27 | import java.awt.geom.AffineTransform; |
| 28 | import java.awt.geom.PathIterator; |
| 29 | import java.awt.geom.Point2D; |
| 30 | import java.awt.geom.Rectangle2D; |
| 31 | import sun.awt.geom.Crossings; |
| 32 | import java.util.Arrays; |
| 33 | |
| 34 | /** |
| 35 | * The <code>Polygon</code> class encapsulates a description of a |
| 36 | * closed, two-dimensional region within a coordinate space. This |
| 37 | * region is bounded by an arbitrary number of line segments, each of |
| 38 | * which is one side of the polygon. Internally, a polygon |
| 39 | * comprises of a list of {@code (x,y)} |
| 40 | * coordinate pairs, where each pair defines a <i>vertex</i> of the |
| 41 | * polygon, and two successive pairs are the endpoints of a |
| 42 | * line that is a side of the polygon. The first and final |
| 43 | * pairs of {@code (x,y)} points are joined by a line segment |
| 44 | * that closes the polygon. This <code>Polygon</code> is defined with |
| 45 | * an even-odd winding rule. See |
| 46 | * {@link java.awt.geom.PathIterator#WIND_EVEN_ODD WIND_EVEN_ODD} |
| 47 | * for a definition of the even-odd winding rule. |
| 48 | * This class's hit-testing methods, which include the |
| 49 | * <code>contains</code>, <code>intersects</code> and <code>inside</code> |
| 50 | * methods, use the <i>insideness</i> definition described in the |
| 51 | * {@link Shape} class comments. |
| 52 | * |
| 53 | * @author Sami Shaio |
| 54 | * @see Shape |
| 55 | * @author Herb Jellinek |
| 56 | * @since 1.0 |
| 57 | */ |
| 58 | public class Polygon implements Shape, java.io.Serializable { |
| 59 | |
| 60 | /** |
| 61 | * The total number of points. The value of <code>npoints</code> |
| 62 | * represents the number of valid points in this <code>Polygon</code> |
| 63 | * and might be less than the number of elements in |
| 64 | * {@link #xpoints xpoints} or {@link #ypoints ypoints}. |
| 65 | * This value can be NULL. |
| 66 | * |
| 67 | * @serial |
| 68 | * @see #addPoint(int, int) |
| 69 | * @since 1.0 |
| 70 | */ |
| 71 | public int npoints; |
| 72 | |
| 73 | /** |
| 74 | * The array of X coordinates. The number of elements in |
| 75 | * this array might be more than the number of X coordinates |
| 76 | * in this <code>Polygon</code>. The extra elements allow new points |
| 77 | * to be added to this <code>Polygon</code> without re-creating this |
| 78 | * array. The value of {@link #npoints npoints} is equal to the |
| 79 | * number of valid points in this <code>Polygon</code>. |
| 80 | * |
| 81 | * @serial |
| 82 | * @see #addPoint(int, int) |
| 83 | * @since 1.0 |
| 84 | */ |
| 85 | public int xpoints[]; |
| 86 | |
| 87 | /** |
| 88 | * The array of Y coordinates. The number of elements in |
| 89 | * this array might be more than the number of Y coordinates |
| 90 | * in this <code>Polygon</code>. The extra elements allow new points |
| 91 | * to be added to this <code>Polygon</code> without re-creating this |
| 92 | * array. The value of <code>npoints</code> is equal to the |
| 93 | * number of valid points in this <code>Polygon</code>. |
| 94 | * |
| 95 | * @serial |
| 96 | * @see #addPoint(int, int) |
| 97 | * @since 1.0 |
| 98 | */ |
| 99 | public int ypoints[]; |
| 100 | |
| 101 | /** |
| 102 | * The bounds of this {@code Polygon}. |
| 103 | * This value can be null. |
| 104 | * |
| 105 | * @serial |
| 106 | * @see #getBoundingBox() |
| 107 | * @see #getBounds() |
| 108 | * @since 1.0 |
| 109 | */ |
| 110 | protected Rectangle bounds; |
| 111 | |
| 112 | /* |
| 113 | * JDK 1.1 serialVersionUID |
| 114 | */ |
| 115 | private static final long serialVersionUID = -6460061437900069969L; |
| 116 | |
| 117 | /* |
| 118 | * Default length for xpoints and ypoints. |
| 119 | */ |
| 120 | private static final int MIN_LENGTH = 4; |
| 121 | |
| 122 | /** |
| 123 | * Creates an empty polygon. |
| 124 | * @since 1.0 |
| 125 | */ |
| 126 | public Polygon() { |
| 127 | xpoints = new int[MIN_LENGTH]; |
| 128 | ypoints = new int[MIN_LENGTH]; |
| 129 | } |
| 130 | |
| 131 | /** |
| 132 | * Constructs and initializes a <code>Polygon</code> from the specified |
| 133 | * parameters. |
| 134 | * @param xpoints an array of X coordinates |
| 135 | * @param ypoints an array of Y coordinates |
| 136 | * @param npoints the total number of points in the |
| 137 | * <code>Polygon</code> |
| 138 | * @exception NegativeArraySizeException if the value of |
| 139 | * <code>npoints</code> is negative. |
| 140 | * @exception IndexOutOfBoundsException if <code>npoints</code> is |
| 141 | * greater than the length of <code>xpoints</code> |
| 142 | * or the length of <code>ypoints</code>. |
| 143 | * @exception NullPointerException if <code>xpoints</code> or |
| 144 | * <code>ypoints</code> is <code>null</code>. |
| 145 | * @since 1.0 |
| 146 | */ |
| 147 | public Polygon(int xpoints[], int ypoints[], int npoints) { |
| 148 | // Fix 4489009: should throw IndexOutofBoundsException instead |
| 149 | // of OutofMemoryException if npoints is huge and > {x,y}points.length |
| 150 | if (npoints > xpoints.length || npoints > ypoints.length) { |
| 151 | throw new IndexOutOfBoundsException("npoints > xpoints.length || "+ |
| 152 | "npoints > ypoints.length"); |
| 153 | } |
| 154 | // Fix 6191114: should throw NegativeArraySizeException with |
| 155 | // negative npoints |
| 156 | if (npoints < 0) { |
| 157 | throw new NegativeArraySizeException("npoints < 0"); |
| 158 | } |
| 159 | // Fix 6343431: Applet compatibility problems if arrays are not |
| 160 | // exactly npoints in length |
| 161 | this.npoints = npoints; |
| 162 | this.xpoints = Arrays.copyOf(xpoints, npoints); |
| 163 | this.ypoints = Arrays.copyOf(ypoints, npoints); |
| 164 | } |
| 165 | |
| 166 | /** |
| 167 | * Resets this <code>Polygon</code> object to an empty polygon. |
| 168 | * The coordinate arrays and the data in them are left untouched |
| 169 | * but the number of points is reset to zero to mark the old |
| 170 | * vertex data as invalid and to start accumulating new vertex |
| 171 | * data at the beginning. |
| 172 | * All internally-cached data relating to the old vertices |
| 173 | * are discarded. |
| 174 | * Note that since the coordinate arrays from before the reset |
| 175 | * are reused, creating a new empty <code>Polygon</code> might |
| 176 | * be more memory efficient than resetting the current one if |
| 177 | * the number of vertices in the new polygon data is significantly |
| 178 | * smaller than the number of vertices in the data from before the |
| 179 | * reset. |
| 180 | * @see java.awt.Polygon#invalidate |
| 181 | * @since 1.4 |
| 182 | */ |
| 183 | public void reset() { |
| 184 | npoints = 0; |
| 185 | bounds = null; |
| 186 | } |
| 187 | |
| 188 | /** |
| 189 | * Invalidates or flushes any internally-cached data that depends |
| 190 | * on the vertex coordinates of this <code>Polygon</code>. |
| 191 | * This method should be called after any direct manipulation |
| 192 | * of the coordinates in the <code>xpoints</code> or |
| 193 | * <code>ypoints</code> arrays to avoid inconsistent results |
| 194 | * from methods such as <code>getBounds</code> or <code>contains</code> |
| 195 | * that might cache data from earlier computations relating to |
| 196 | * the vertex coordinates. |
| 197 | * @see java.awt.Polygon#getBounds |
| 198 | * @since 1.4 |
| 199 | */ |
| 200 | public void invalidate() { |
| 201 | bounds = null; |
| 202 | } |
| 203 | |
| 204 | /** |
| 205 | * Translates the vertices of the <code>Polygon</code> by |
| 206 | * <code>deltaX</code> along the x axis and by |
| 207 | * <code>deltaY</code> along the y axis. |
| 208 | * @param deltaX the amount to translate along the X axis |
| 209 | * @param deltaY the amount to translate along the Y axis |
| 210 | * @since 1.1 |
| 211 | */ |
| 212 | public void translate(int deltaX, int deltaY) { |
| 213 | for (int i = 0; i < npoints; i++) { |
| 214 | xpoints[i] += deltaX; |
| 215 | ypoints[i] += deltaY; |
| 216 | } |
| 217 | if (bounds != null) { |
| 218 | bounds.translate(deltaX, deltaY); |
| 219 | } |
| 220 | } |
| 221 | |
| 222 | /* |
| 223 | * Calculates the bounding box of the points passed to the constructor. |
| 224 | * Sets <code>bounds</code> to the result. |
| 225 | * @param xpoints[] array of <i>x</i> coordinates |
| 226 | * @param ypoints[] array of <i>y</i> coordinates |
| 227 | * @param npoints the total number of points |
| 228 | */ |
| 229 | void calculateBounds(int xpoints[], int ypoints[], int npoints) { |
| 230 | int boundsMinX = Integer.MAX_VALUE; |
| 231 | int boundsMinY = Integer.MAX_VALUE; |
| 232 | int boundsMaxX = Integer.MIN_VALUE; |
| 233 | int boundsMaxY = Integer.MIN_VALUE; |
| 234 | |
| 235 | for (int i = 0; i < npoints; i++) { |
| 236 | int x = xpoints[i]; |
| 237 | boundsMinX = Math.min(boundsMinX, x); |
| 238 | boundsMaxX = Math.max(boundsMaxX, x); |
| 239 | int y = ypoints[i]; |
| 240 | boundsMinY = Math.min(boundsMinY, y); |
| 241 | boundsMaxY = Math.max(boundsMaxY, y); |
| 242 | } |
| 243 | bounds = new Rectangle(boundsMinX, boundsMinY, |
| 244 | boundsMaxX - boundsMinX, |
| 245 | boundsMaxY - boundsMinY); |
| 246 | } |
| 247 | |
| 248 | /* |
| 249 | * Resizes the bounding box to accomodate the specified coordinates. |
| 250 | * @param x, y the specified coordinates |
| 251 | */ |
| 252 | void updateBounds(int x, int y) { |
| 253 | if (x < bounds.x) { |
| 254 | bounds.width = bounds.width + (bounds.x - x); |
| 255 | bounds.x = x; |
| 256 | } |
| 257 | else { |
| 258 | bounds.width = Math.max(bounds.width, x - bounds.x); |
| 259 | // bounds.x = bounds.x; |
| 260 | } |
| 261 | |
| 262 | if (y < bounds.y) { |
| 263 | bounds.height = bounds.height + (bounds.y - y); |
| 264 | bounds.y = y; |
| 265 | } |
| 266 | else { |
| 267 | bounds.height = Math.max(bounds.height, y - bounds.y); |
| 268 | // bounds.y = bounds.y; |
| 269 | } |
| 270 | } |
| 271 | |
| 272 | /** |
| 273 | * Appends the specified coordinates to this <code>Polygon</code>. |
| 274 | * <p> |
| 275 | * If an operation that calculates the bounding box of this |
| 276 | * <code>Polygon</code> has already been performed, such as |
| 277 | * <code>getBounds</code> or <code>contains</code>, then this |
| 278 | * method updates the bounding box. |
| 279 | * @param x the specified X coordinate |
| 280 | * @param y the specified Y coordinate |
| 281 | * @see java.awt.Polygon#getBounds |
| 282 | * @see java.awt.Polygon#contains |
| 283 | * @since 1.0 |
| 284 | */ |
| 285 | public void addPoint(int x, int y) { |
| 286 | if (npoints >= xpoints.length || npoints >= ypoints.length) { |
| 287 | int newLength = npoints * 2; |
| 288 | // Make sure that newLength will be greater than MIN_LENGTH and |
| 289 | // aligned to the power of 2 |
| 290 | if (newLength < MIN_LENGTH) { |
| 291 | newLength = MIN_LENGTH; |
| 292 | } else if ((newLength & (newLength - 1)) != 0) { |
| 293 | newLength = Integer.highestOneBit(newLength); |
| 294 | } |
| 295 | |
| 296 | xpoints = Arrays.copyOf(xpoints, newLength); |
| 297 | ypoints = Arrays.copyOf(ypoints, newLength); |
| 298 | } |
| 299 | xpoints[npoints] = x; |
| 300 | ypoints[npoints] = y; |
| 301 | npoints++; |
| 302 | if (bounds != null) { |
| 303 | updateBounds(x, y); |
| 304 | } |
| 305 | } |
| 306 | |
| 307 | /** |
| 308 | * Gets the bounding box of this <code>Polygon</code>. |
| 309 | * The bounding box is the smallest {@link Rectangle} whose |
| 310 | * sides are parallel to the x and y axes of the |
| 311 | * coordinate space, and can completely contain the <code>Polygon</code>. |
| 312 | * @return a <code>Rectangle</code> that defines the bounds of this |
| 313 | * <code>Polygon</code>. |
| 314 | * @since 1.1 |
| 315 | */ |
| 316 | public Rectangle getBounds() { |
| 317 | return getBoundingBox(); |
| 318 | } |
| 319 | |
| 320 | /** |
| 321 | * Returns the bounds of this <code>Polygon</code>. |
| 322 | * @return the bounds of this <code>Polygon</code>. |
| 323 | * @deprecated As of JDK version 1.1, |
| 324 | * replaced by <code>getBounds()</code>. |
| 325 | * @since 1.0 |
| 326 | */ |
| 327 | @Deprecated |
| 328 | public Rectangle getBoundingBox() { |
| 329 | if (npoints == 0) { |
| 330 | return new Rectangle(); |
| 331 | } |
| 332 | if (bounds == null) { |
| 333 | calculateBounds(xpoints, ypoints, npoints); |
| 334 | } |
| 335 | return bounds.getBounds(); |
| 336 | } |
| 337 | |
| 338 | /** |
| 339 | * Determines whether the specified {@link Point} is inside this |
| 340 | * <code>Polygon</code>. |
| 341 | * @param p the specified <code>Point</code> to be tested |
| 342 | * @return <code>true</code> if the <code>Polygon</code> contains the |
| 343 | * <code>Point</code>; <code>false</code> otherwise. |
| 344 | * @see #contains(double, double) |
| 345 | * @since 1.0 |
| 346 | */ |
| 347 | public boolean contains(Point p) { |
| 348 | return contains(p.x, p.y); |
| 349 | } |
| 350 | |
| 351 | /** |
| 352 | * Determines whether the specified coordinates are inside this |
| 353 | * <code>Polygon</code>. |
| 354 | * <p> |
| 355 | * @param x the specified X coordinate to be tested |
| 356 | * @param y the specified Y coordinate to be tested |
| 357 | * @return {@code true} if this {@code Polygon} contains |
| 358 | * the specified coordinates {@code (x,y)}; |
| 359 | * {@code false} otherwise. |
| 360 | * @see #contains(double, double) |
| 361 | * @since 1.1 |
| 362 | */ |
| 363 | public boolean contains(int x, int y) { |
| 364 | return contains((double) x, (double) y); |
| 365 | } |
| 366 | |
| 367 | /** |
| 368 | * Determines whether the specified coordinates are contained in this |
| 369 | * <code>Polygon</code>. |
| 370 | * @param x the specified X coordinate to be tested |
| 371 | * @param y the specified Y coordinate to be tested |
| 372 | * @return {@code true} if this {@code Polygon} contains |
| 373 | * the specified coordinates {@code (x,y)}; |
| 374 | * {@code false} otherwise. |
| 375 | * @see #contains(double, double) |
| 376 | * @deprecated As of JDK version 1.1, |
| 377 | * replaced by <code>contains(int, int)</code>. |
| 378 | * @since 1.0 |
| 379 | */ |
| 380 | @Deprecated |
| 381 | public boolean inside(int x, int y) { |
| 382 | return contains((double) x, (double) y); |
| 383 | } |
| 384 | |
| 385 | /** |
| 386 | * {@inheritDoc} |
| 387 | * @since 1.2 |
| 388 | */ |
| 389 | public Rectangle2D getBounds2D() { |
| 390 | return getBounds(); |
| 391 | } |
| 392 | |
| 393 | /** |
| 394 | * {@inheritDoc} |
| 395 | * @since 1.2 |
| 396 | */ |
| 397 | public boolean contains(double x, double y) { |
| 398 | if (npoints <= 2 || !getBoundingBox().contains(x, y)) { |
| 399 | return false; |
| 400 | } |
| 401 | int hits = 0; |
| 402 | |
| 403 | int lastx = xpoints[npoints - 1]; |
| 404 | int lasty = ypoints[npoints - 1]; |
| 405 | int curx, cury; |
| 406 | |
| 407 | // Walk the edges of the polygon |
| 408 | for (int i = 0; i < npoints; lastx = curx, lasty = cury, i++) { |
| 409 | curx = xpoints[i]; |
| 410 | cury = ypoints[i]; |
| 411 | |
| 412 | if (cury == lasty) { |
| 413 | continue; |
| 414 | } |
| 415 | |
| 416 | int leftx; |
| 417 | if (curx < lastx) { |
| 418 | if (x >= lastx) { |
| 419 | continue; |
| 420 | } |
| 421 | leftx = curx; |
| 422 | } else { |
| 423 | if (x >= curx) { |
| 424 | continue; |
| 425 | } |
| 426 | leftx = lastx; |
| 427 | } |
| 428 | |
| 429 | double test1, test2; |
| 430 | if (cury < lasty) { |
| 431 | if (y < cury || y >= lasty) { |
| 432 | continue; |
| 433 | } |
| 434 | if (x < leftx) { |
| 435 | hits++; |
| 436 | continue; |
| 437 | } |
| 438 | test1 = x - curx; |
| 439 | test2 = y - cury; |
| 440 | } else { |
| 441 | if (y < lasty || y >= cury) { |
| 442 | continue; |
| 443 | } |
| 444 | if (x < leftx) { |
| 445 | hits++; |
| 446 | continue; |
| 447 | } |
| 448 | test1 = x - lastx; |
| 449 | test2 = y - lasty; |
| 450 | } |
| 451 | |
| 452 | if (test1 < (test2 / (lasty - cury) * (lastx - curx))) { |
| 453 | hits++; |
| 454 | } |
| 455 | } |
| 456 | |
| 457 | return ((hits & 1) != 0); |
| 458 | } |
| 459 | |
| 460 | private Crossings getCrossings(double xlo, double ylo, |
| 461 | double xhi, double yhi) |
| 462 | { |
| 463 | Crossings cross = new Crossings.EvenOdd(xlo, ylo, xhi, yhi); |
| 464 | int lastx = xpoints[npoints - 1]; |
| 465 | int lasty = ypoints[npoints - 1]; |
| 466 | int curx, cury; |
| 467 | |
| 468 | // Walk the edges of the polygon |
| 469 | for (int i = 0; i < npoints; i++) { |
| 470 | curx = xpoints[i]; |
| 471 | cury = ypoints[i]; |
| 472 | if (cross.accumulateLine(lastx, lasty, curx, cury)) { |
| 473 | return null; |
| 474 | } |
| 475 | lastx = curx; |
| 476 | lasty = cury; |
| 477 | } |
| 478 | |
| 479 | return cross; |
| 480 | } |
| 481 | |
| 482 | /** |
| 483 | * {@inheritDoc} |
| 484 | * @since 1.2 |
| 485 | */ |
| 486 | public boolean contains(Point2D p) { |
| 487 | return contains(p.getX(), p.getY()); |
| 488 | } |
| 489 | |
| 490 | /** |
| 491 | * {@inheritDoc} |
| 492 | * @since 1.2 |
| 493 | */ |
| 494 | public boolean intersects(double x, double y, double w, double h) { |
| 495 | if (npoints <= 0 || !getBoundingBox().intersects(x, y, w, h)) { |
| 496 | return false; |
| 497 | } |
| 498 | |
| 499 | Crossings cross = getCrossings(x, y, x+w, y+h); |
| 500 | return (cross == null || !cross.isEmpty()); |
| 501 | } |
| 502 | |
| 503 | /** |
| 504 | * {@inheritDoc} |
| 505 | * @since 1.2 |
| 506 | */ |
| 507 | public boolean intersects(Rectangle2D r) { |
| 508 | return intersects(r.getX(), r.getY(), r.getWidth(), r.getHeight()); |
| 509 | } |
| 510 | |
| 511 | /** |
| 512 | * {@inheritDoc} |
| 513 | * @since 1.2 |
| 514 | */ |
| 515 | public boolean contains(double x, double y, double w, double h) { |
| 516 | if (npoints <= 0 || !getBoundingBox().intersects(x, y, w, h)) { |
| 517 | return false; |
| 518 | } |
| 519 | |
| 520 | Crossings cross = getCrossings(x, y, x+w, y+h); |
| 521 | return (cross != null && cross.covers(y, y+h)); |
| 522 | } |
| 523 | |
| 524 | /** |
| 525 | * {@inheritDoc} |
| 526 | * @since 1.2 |
| 527 | */ |
| 528 | public boolean contains(Rectangle2D r) { |
| 529 | return contains(r.getX(), r.getY(), r.getWidth(), r.getHeight()); |
| 530 | } |
| 531 | |
| 532 | /** |
| 533 | * Returns an iterator object that iterates along the boundary of this |
| 534 | * <code>Polygon</code> and provides access to the geometry |
| 535 | * of the outline of this <code>Polygon</code>. An optional |
| 536 | * {@link AffineTransform} can be specified so that the coordinates |
| 537 | * returned in the iteration are transformed accordingly. |
| 538 | * @param at an optional <code>AffineTransform</code> to be applied to the |
| 539 | * coordinates as they are returned in the iteration, or |
| 540 | * <code>null</code> if untransformed coordinates are desired |
| 541 | * @return a {@link PathIterator} object that provides access to the |
| 542 | * geometry of this <code>Polygon</code>. |
| 543 | * @since 1.2 |
| 544 | */ |
| 545 | public PathIterator getPathIterator(AffineTransform at) { |
| 546 | return new PolygonPathIterator(this, at); |
| 547 | } |
| 548 | |
| 549 | /** |
| 550 | * Returns an iterator object that iterates along the boundary of |
| 551 | * the <code>Shape</code> and provides access to the geometry of the |
| 552 | * outline of the <code>Shape</code>. Only SEG_MOVETO, SEG_LINETO, and |
| 553 | * SEG_CLOSE point types are returned by the iterator. |
| 554 | * Since polygons are already flat, the <code>flatness</code> parameter |
| 555 | * is ignored. An optional <code>AffineTransform</code> can be specified |
| 556 | * in which case the coordinates returned in the iteration are transformed |
| 557 | * accordingly. |
| 558 | * @param at an optional <code>AffineTransform</code> to be applied to the |
| 559 | * coordinates as they are returned in the iteration, or |
| 560 | * <code>null</code> if untransformed coordinates are desired |
| 561 | * @param flatness the maximum amount that the control points |
| 562 | * for a given curve can vary from colinear before a subdivided |
| 563 | * curve is replaced by a straight line connecting the |
| 564 | * endpoints. Since polygons are already flat the |
| 565 | * <code>flatness</code> parameter is ignored. |
| 566 | * @return a <code>PathIterator</code> object that provides access to the |
| 567 | * <code>Shape</code> object's geometry. |
| 568 | * @since 1.2 |
| 569 | */ |
| 570 | public PathIterator getPathIterator(AffineTransform at, double flatness) { |
| 571 | return getPathIterator(at); |
| 572 | } |
| 573 | |
| 574 | class PolygonPathIterator implements PathIterator { |
| 575 | Polygon poly; |
| 576 | AffineTransform transform; |
| 577 | int index; |
| 578 | |
| 579 | public PolygonPathIterator(Polygon pg, AffineTransform at) { |
| 580 | poly = pg; |
| 581 | transform = at; |
| 582 | if (pg.npoints == 0) { |
| 583 | // Prevent a spurious SEG_CLOSE segment |
| 584 | index = 1; |
| 585 | } |
| 586 | } |
| 587 | |
| 588 | /** |
| 589 | * Returns the winding rule for determining the interior of the |
| 590 | * path. |
| 591 | * @return an integer representing the current winding rule. |
| 592 | * @see PathIterator#WIND_NON_ZERO |
| 593 | */ |
| 594 | public int getWindingRule() { |
| 595 | return WIND_EVEN_ODD; |
| 596 | } |
| 597 | |
| 598 | /** |
| 599 | * Tests if there are more points to read. |
| 600 | * @return <code>true</code> if there are more points to read; |
| 601 | * <code>false</code> otherwise. |
| 602 | */ |
| 603 | public boolean isDone() { |
| 604 | return index > poly.npoints; |
| 605 | } |
| 606 | |
| 607 | /** |
| 608 | * Moves the iterator forwards, along the primary direction of |
| 609 | * traversal, to the next segment of the path when there are |
| 610 | * more points in that direction. |
| 611 | */ |
| 612 | public void next() { |
| 613 | index++; |
| 614 | } |
| 615 | |
| 616 | /** |
| 617 | * Returns the coordinates and type of the current path segment in |
| 618 | * the iteration. |
| 619 | * The return value is the path segment type: |
| 620 | * SEG_MOVETO, SEG_LINETO, or SEG_CLOSE. |
| 621 | * A <code>float</code> array of length 2 must be passed in and |
| 622 | * can be used to store the coordinates of the point(s). |
| 623 | * Each point is stored as a pair of <code>float</code> x, y |
| 624 | * coordinates. SEG_MOVETO and SEG_LINETO types return one |
| 625 | * point, and SEG_CLOSE does not return any points. |
| 626 | * @param coords a <code>float</code> array that specifies the |
| 627 | * coordinates of the point(s) |
| 628 | * @return an integer representing the type and coordinates of the |
| 629 | * current path segment. |
| 630 | * @see PathIterator#SEG_MOVETO |
| 631 | * @see PathIterator#SEG_LINETO |
| 632 | * @see PathIterator#SEG_CLOSE |
| 633 | */ |
| 634 | public int currentSegment(float[] coords) { |
| 635 | if (index >= poly.npoints) { |
| 636 | return SEG_CLOSE; |
| 637 | } |
| 638 | coords[0] = poly.xpoints[index]; |
| 639 | coords[1] = poly.ypoints[index]; |
| 640 | if (transform != null) { |
| 641 | transform.transform(coords, 0, coords, 0, 1); |
| 642 | } |
| 643 | return (index == 0 ? SEG_MOVETO : SEG_LINETO); |
| 644 | } |
| 645 | |
| 646 | /** |
| 647 | * Returns the coordinates and type of the current path segment in |
| 648 | * the iteration. |
| 649 | * The return value is the path segment type: |
| 650 | * SEG_MOVETO, SEG_LINETO, or SEG_CLOSE. |
| 651 | * A <code>double</code> array of length 2 must be passed in and |
| 652 | * can be used to store the coordinates of the point(s). |
| 653 | * Each point is stored as a pair of <code>double</code> x, y |
| 654 | * coordinates. |
| 655 | * SEG_MOVETO and SEG_LINETO types return one point, |
| 656 | * and SEG_CLOSE does not return any points. |
| 657 | * @param coords a <code>double</code> array that specifies the |
| 658 | * coordinates of the point(s) |
| 659 | * @return an integer representing the type and coordinates of the |
| 660 | * current path segment. |
| 661 | * @see PathIterator#SEG_MOVETO |
| 662 | * @see PathIterator#SEG_LINETO |
| 663 | * @see PathIterator#SEG_CLOSE |
| 664 | */ |
| 665 | public int currentSegment(double[] coords) { |
| 666 | if (index >= poly.npoints) { |
| 667 | return SEG_CLOSE; |
| 668 | } |
| 669 | coords[0] = poly.xpoints[index]; |
| 670 | coords[1] = poly.ypoints[index]; |
| 671 | if (transform != null) { |
| 672 | transform.transform(coords, 0, coords, 0, 1); |
| 673 | } |
| 674 | return (index == 0 ? SEG_MOVETO : SEG_LINETO); |
| 675 | } |
| 676 | } |
| 677 | } |