J. Duke | 319a3b9 | 2007-12-01 00:00:00 +0000 | [diff] [blame^] | 1 | /* |
| 2 | * Copyright 1997-2006 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 | |
| 26 | package java.awt.geom; |
| 27 | |
| 28 | import java.awt.Shape; |
| 29 | import java.awt.Rectangle; |
| 30 | import java.io.Serializable; |
| 31 | |
| 32 | /** |
| 33 | * This <code>Line2D</code> represents a line segment in {@code (x,y)} |
| 34 | * coordinate space. This class, like all of the Java 2D API, uses a |
| 35 | * default coordinate system called <i>user space</i> in which the y-axis |
| 36 | * values increase downward and x-axis values increase to the right. For |
| 37 | * more information on the user space coordinate system, see the |
| 38 | * <a href="http://java.sun.com/j2se/1.3/docs/guide/2d/spec/j2d-intro.fm2.html#61857"> |
| 39 | * Coordinate Systems</a> section of the Java 2D Programmer's Guide. |
| 40 | * <p> |
| 41 | * This class is only the abstract superclass for all objects that |
| 42 | * store a 2D line segment. |
| 43 | * The actual storage representation of the coordinates is left to |
| 44 | * the subclass. |
| 45 | * |
| 46 | * @author Jim Graham |
| 47 | * @since 1.2 |
| 48 | */ |
| 49 | public abstract class Line2D implements Shape, Cloneable { |
| 50 | |
| 51 | /** |
| 52 | * A line segment specified with float coordinates. |
| 53 | * @since 1.2 |
| 54 | */ |
| 55 | public static class Float extends Line2D implements Serializable { |
| 56 | /** |
| 57 | * The X coordinate of the start point of the line segment. |
| 58 | * @since 1.2 |
| 59 | * @serial |
| 60 | */ |
| 61 | public float x1; |
| 62 | |
| 63 | /** |
| 64 | * The Y coordinate of the start point of the line segment. |
| 65 | * @since 1.2 |
| 66 | * @serial |
| 67 | */ |
| 68 | public float y1; |
| 69 | |
| 70 | /** |
| 71 | * The X coordinate of the end point of the line segment. |
| 72 | * @since 1.2 |
| 73 | * @serial |
| 74 | */ |
| 75 | public float x2; |
| 76 | |
| 77 | /** |
| 78 | * The Y coordinate of the end point of the line segment. |
| 79 | * @since 1.2 |
| 80 | * @serial |
| 81 | */ |
| 82 | public float y2; |
| 83 | |
| 84 | /** |
| 85 | * Constructs and initializes a Line with coordinates (0, 0) -> (0, 0). |
| 86 | * @since 1.2 |
| 87 | */ |
| 88 | public Float() { |
| 89 | } |
| 90 | |
| 91 | /** |
| 92 | * Constructs and initializes a Line from the specified coordinates. |
| 93 | * @param x1 the X coordinate of the start point |
| 94 | * @param y1 the Y coordinate of the start point |
| 95 | * @param x2 the X coordinate of the end point |
| 96 | * @param y2 the Y coordinate of the end point |
| 97 | * @since 1.2 |
| 98 | */ |
| 99 | public Float(float x1, float y1, float x2, float y2) { |
| 100 | setLine(x1, y1, x2, y2); |
| 101 | } |
| 102 | |
| 103 | /** |
| 104 | * Constructs and initializes a <code>Line2D</code> from the |
| 105 | * specified <code>Point2D</code> objects. |
| 106 | * @param p1 the start <code>Point2D</code> of this line segment |
| 107 | * @param p2 the end <code>Point2D</code> of this line segment |
| 108 | * @since 1.2 |
| 109 | */ |
| 110 | public Float(Point2D p1, Point2D p2) { |
| 111 | setLine(p1, p2); |
| 112 | } |
| 113 | |
| 114 | /** |
| 115 | * {@inheritDoc} |
| 116 | * @since 1.2 |
| 117 | */ |
| 118 | public double getX1() { |
| 119 | return (double) x1; |
| 120 | } |
| 121 | |
| 122 | /** |
| 123 | * {@inheritDoc} |
| 124 | * @since 1.2 |
| 125 | */ |
| 126 | public double getY1() { |
| 127 | return (double) y1; |
| 128 | } |
| 129 | |
| 130 | /** |
| 131 | * {@inheritDoc} |
| 132 | * @since 1.2 |
| 133 | */ |
| 134 | public Point2D getP1() { |
| 135 | return new Point2D.Float(x1, y1); |
| 136 | } |
| 137 | |
| 138 | /** |
| 139 | * {@inheritDoc} |
| 140 | * @since 1.2 |
| 141 | */ |
| 142 | public double getX2() { |
| 143 | return (double) x2; |
| 144 | } |
| 145 | |
| 146 | /** |
| 147 | * {@inheritDoc} |
| 148 | * @since 1.2 |
| 149 | */ |
| 150 | public double getY2() { |
| 151 | return (double) y2; |
| 152 | } |
| 153 | |
| 154 | /** |
| 155 | * {@inheritDoc} |
| 156 | * @since 1.2 |
| 157 | */ |
| 158 | public Point2D getP2() { |
| 159 | return new Point2D.Float(x2, y2); |
| 160 | } |
| 161 | |
| 162 | /** |
| 163 | * {@inheritDoc} |
| 164 | * @since 1.2 |
| 165 | */ |
| 166 | public void setLine(double x1, double y1, double x2, double y2) { |
| 167 | this.x1 = (float) x1; |
| 168 | this.y1 = (float) y1; |
| 169 | this.x2 = (float) x2; |
| 170 | this.y2 = (float) y2; |
| 171 | } |
| 172 | |
| 173 | /** |
| 174 | * Sets the location of the end points of this <code>Line2D</code> |
| 175 | * to the specified float coordinates. |
| 176 | * @param x1 the X coordinate of the start point |
| 177 | * @param y1 the Y coordinate of the start point |
| 178 | * @param x2 the X coordinate of the end point |
| 179 | * @param y2 the Y coordinate of the end point |
| 180 | * @since 1.2 |
| 181 | */ |
| 182 | public void setLine(float x1, float y1, float x2, float y2) { |
| 183 | this.x1 = x1; |
| 184 | this.y1 = y1; |
| 185 | this.x2 = x2; |
| 186 | this.y2 = y2; |
| 187 | } |
| 188 | |
| 189 | /** |
| 190 | * {@inheritDoc} |
| 191 | * @since 1.2 |
| 192 | */ |
| 193 | public Rectangle2D getBounds2D() { |
| 194 | float x, y, w, h; |
| 195 | if (x1 < x2) { |
| 196 | x = x1; |
| 197 | w = x2 - x1; |
| 198 | } else { |
| 199 | x = x2; |
| 200 | w = x1 - x2; |
| 201 | } |
| 202 | if (y1 < y2) { |
| 203 | y = y1; |
| 204 | h = y2 - y1; |
| 205 | } else { |
| 206 | y = y2; |
| 207 | h = y1 - y2; |
| 208 | } |
| 209 | return new Rectangle2D.Float(x, y, w, h); |
| 210 | } |
| 211 | |
| 212 | /* |
| 213 | * JDK 1.6 serialVersionUID |
| 214 | */ |
| 215 | private static final long serialVersionUID = 6161772511649436349L; |
| 216 | } |
| 217 | |
| 218 | /** |
| 219 | * A line segment specified with double coordinates. |
| 220 | * @since 1.2 |
| 221 | */ |
| 222 | public static class Double extends Line2D implements Serializable { |
| 223 | /** |
| 224 | * The X coordinate of the start point of the line segment. |
| 225 | * @since 1.2 |
| 226 | * @serial |
| 227 | */ |
| 228 | public double x1; |
| 229 | |
| 230 | /** |
| 231 | * The Y coordinate of the start point of the line segment. |
| 232 | * @since 1.2 |
| 233 | * @serial |
| 234 | */ |
| 235 | public double y1; |
| 236 | |
| 237 | /** |
| 238 | * The X coordinate of the end point of the line segment. |
| 239 | * @since 1.2 |
| 240 | * @serial |
| 241 | */ |
| 242 | public double x2; |
| 243 | |
| 244 | /** |
| 245 | * The Y coordinate of the end point of the line segment. |
| 246 | * @since 1.2 |
| 247 | * @serial |
| 248 | */ |
| 249 | public double y2; |
| 250 | |
| 251 | /** |
| 252 | * Constructs and initializes a Line with coordinates (0, 0) -> (0, 0). |
| 253 | * @since 1.2 |
| 254 | */ |
| 255 | public Double() { |
| 256 | } |
| 257 | |
| 258 | /** |
| 259 | * Constructs and initializes a <code>Line2D</code> from the |
| 260 | * specified coordinates. |
| 261 | * @param x1 the X coordinate of the start point |
| 262 | * @param y1 the Y coordinate of the start point |
| 263 | * @param x2 the X coordinate of the end point |
| 264 | * @param y2 the Y coordinate of the end point |
| 265 | * @since 1.2 |
| 266 | */ |
| 267 | public Double(double x1, double y1, double x2, double y2) { |
| 268 | setLine(x1, y1, x2, y2); |
| 269 | } |
| 270 | |
| 271 | /** |
| 272 | * Constructs and initializes a <code>Line2D</code> from the |
| 273 | * specified <code>Point2D</code> objects. |
| 274 | * @param p1 the start <code>Point2D</code> of this line segment |
| 275 | * @param p2 the end <code>Point2D</code> of this line segment |
| 276 | * @since 1.2 |
| 277 | */ |
| 278 | public Double(Point2D p1, Point2D p2) { |
| 279 | setLine(p1, p2); |
| 280 | } |
| 281 | |
| 282 | /** |
| 283 | * {@inheritDoc} |
| 284 | * @since 1.2 |
| 285 | */ |
| 286 | public double getX1() { |
| 287 | return x1; |
| 288 | } |
| 289 | |
| 290 | /** |
| 291 | * {@inheritDoc} |
| 292 | * @since 1.2 |
| 293 | */ |
| 294 | public double getY1() { |
| 295 | return y1; |
| 296 | } |
| 297 | |
| 298 | /** |
| 299 | * {@inheritDoc} |
| 300 | * @since 1.2 |
| 301 | */ |
| 302 | public Point2D getP1() { |
| 303 | return new Point2D.Double(x1, y1); |
| 304 | } |
| 305 | |
| 306 | /** |
| 307 | * {@inheritDoc} |
| 308 | * @since 1.2 |
| 309 | */ |
| 310 | public double getX2() { |
| 311 | return x2; |
| 312 | } |
| 313 | |
| 314 | /** |
| 315 | * {@inheritDoc} |
| 316 | * @since 1.2 |
| 317 | */ |
| 318 | public double getY2() { |
| 319 | return y2; |
| 320 | } |
| 321 | |
| 322 | /** |
| 323 | * {@inheritDoc} |
| 324 | * @since 1.2 |
| 325 | */ |
| 326 | public Point2D getP2() { |
| 327 | return new Point2D.Double(x2, y2); |
| 328 | } |
| 329 | |
| 330 | /** |
| 331 | * {@inheritDoc} |
| 332 | * @since 1.2 |
| 333 | */ |
| 334 | public void setLine(double x1, double y1, double x2, double y2) { |
| 335 | this.x1 = x1; |
| 336 | this.y1 = y1; |
| 337 | this.x2 = x2; |
| 338 | this.y2 = y2; |
| 339 | } |
| 340 | |
| 341 | /** |
| 342 | * {@inheritDoc} |
| 343 | * @since 1.2 |
| 344 | */ |
| 345 | public Rectangle2D getBounds2D() { |
| 346 | double x, y, w, h; |
| 347 | if (x1 < x2) { |
| 348 | x = x1; |
| 349 | w = x2 - x1; |
| 350 | } else { |
| 351 | x = x2; |
| 352 | w = x1 - x2; |
| 353 | } |
| 354 | if (y1 < y2) { |
| 355 | y = y1; |
| 356 | h = y2 - y1; |
| 357 | } else { |
| 358 | y = y2; |
| 359 | h = y1 - y2; |
| 360 | } |
| 361 | return new Rectangle2D.Double(x, y, w, h); |
| 362 | } |
| 363 | |
| 364 | /* |
| 365 | * JDK 1.6 serialVersionUID |
| 366 | */ |
| 367 | private static final long serialVersionUID = 7979627399746467499L; |
| 368 | } |
| 369 | |
| 370 | /** |
| 371 | * This is an abstract class that cannot be instantiated directly. |
| 372 | * Type-specific implementation subclasses are available for |
| 373 | * instantiation and provide a number of formats for storing |
| 374 | * the information necessary to satisfy the various accessory |
| 375 | * methods below. |
| 376 | * |
| 377 | * @see java.awt.geom.Line2D.Float |
| 378 | * @see java.awt.geom.Line2D.Double |
| 379 | * @since 1.2 |
| 380 | */ |
| 381 | protected Line2D() { |
| 382 | } |
| 383 | |
| 384 | /** |
| 385 | * Returns the X coordinate of the start point in double precision. |
| 386 | * @return the X coordinate of the start point of this |
| 387 | * {@code Line2D} object. |
| 388 | * @since 1.2 |
| 389 | */ |
| 390 | public abstract double getX1(); |
| 391 | |
| 392 | /** |
| 393 | * Returns the Y coordinate of the start point in double precision. |
| 394 | * @return the Y coordinate of the start point of this |
| 395 | * {@code Line2D} object. |
| 396 | * @since 1.2 |
| 397 | */ |
| 398 | public abstract double getY1(); |
| 399 | |
| 400 | /** |
| 401 | * Returns the start <code>Point2D</code> of this <code>Line2D</code>. |
| 402 | * @return the start <code>Point2D</code> of this <code>Line2D</code>. |
| 403 | * @since 1.2 |
| 404 | */ |
| 405 | public abstract Point2D getP1(); |
| 406 | |
| 407 | /** |
| 408 | * Returns the X coordinate of the end point in double precision. |
| 409 | * @return the X coordinate of the end point of this |
| 410 | * {@code Line2D} object. |
| 411 | * @since 1.2 |
| 412 | */ |
| 413 | public abstract double getX2(); |
| 414 | |
| 415 | /** |
| 416 | * Returns the Y coordinate of the end point in double precision. |
| 417 | * @return the Y coordinate of the end point of this |
| 418 | * {@code Line2D} object. |
| 419 | * @since 1.2 |
| 420 | */ |
| 421 | public abstract double getY2(); |
| 422 | |
| 423 | /** |
| 424 | * Returns the end <code>Point2D</code> of this <code>Line2D</code>. |
| 425 | * @return the end <code>Point2D</code> of this <code>Line2D</code>. |
| 426 | * @since 1.2 |
| 427 | */ |
| 428 | public abstract Point2D getP2(); |
| 429 | |
| 430 | /** |
| 431 | * Sets the location of the end points of this <code>Line2D</code> to |
| 432 | * the specified double coordinates. |
| 433 | * @param x1 the X coordinate of the start point |
| 434 | * @param y1 the Y coordinate of the start point |
| 435 | * @param x2 the X coordinate of the end point |
| 436 | * @param y2 the Y coordinate of the end point |
| 437 | * @since 1.2 |
| 438 | */ |
| 439 | public abstract void setLine(double x1, double y1, double x2, double y2); |
| 440 | |
| 441 | /** |
| 442 | * Sets the location of the end points of this <code>Line2D</code> to |
| 443 | * the specified <code>Point2D</code> coordinates. |
| 444 | * @param p1 the start <code>Point2D</code> of the line segment |
| 445 | * @param p2 the end <code>Point2D</code> of the line segment |
| 446 | * @since 1.2 |
| 447 | */ |
| 448 | public void setLine(Point2D p1, Point2D p2) { |
| 449 | setLine(p1.getX(), p1.getY(), p2.getX(), p2.getY()); |
| 450 | } |
| 451 | |
| 452 | /** |
| 453 | * Sets the location of the end points of this <code>Line2D</code> to |
| 454 | * the same as those end points of the specified <code>Line2D</code>. |
| 455 | * @param l the specified <code>Line2D</code> |
| 456 | * @since 1.2 |
| 457 | */ |
| 458 | public void setLine(Line2D l) { |
| 459 | setLine(l.getX1(), l.getY1(), l.getX2(), l.getY2()); |
| 460 | } |
| 461 | |
| 462 | /** |
| 463 | * Returns an indicator of where the specified point |
| 464 | * {@code (px,py)} lies with respect to the line segment from |
| 465 | * {@code (x1,y1)} to {@code (x2,y2)}. |
| 466 | * The return value can be either 1, -1, or 0 and indicates |
| 467 | * in which direction the specified line must pivot around its |
| 468 | * first end point, {@code (x1,y1)}, in order to point at the |
| 469 | * specified point {@code (px,py)}. |
| 470 | * <p>A return value of 1 indicates that the line segment must |
| 471 | * turn in the direction that takes the positive X axis towards |
| 472 | * the negative Y axis. In the default coordinate system used by |
| 473 | * Java 2D, this direction is counterclockwise. |
| 474 | * <p>A return value of -1 indicates that the line segment must |
| 475 | * turn in the direction that takes the positive X axis towards |
| 476 | * the positive Y axis. In the default coordinate system, this |
| 477 | * direction is clockwise. |
| 478 | * <p>A return value of 0 indicates that the point lies |
| 479 | * exactly on the line segment. Note that an indicator value |
| 480 | * of 0 is rare and not useful for determining colinearity |
| 481 | * because of floating point rounding issues. |
| 482 | * <p>If the point is colinear with the line segment, but |
| 483 | * not between the end points, then the value will be -1 if the point |
| 484 | * lies "beyond {@code (x1,y1)}" or 1 if the point lies |
| 485 | * "beyond {@code (x2,y2)}". |
| 486 | * |
| 487 | * @param x1 the X coordinate of the start point of the |
| 488 | * specified line segment |
| 489 | * @param y1 the Y coordinate of the start point of the |
| 490 | * specified line segment |
| 491 | * @param x2 the X coordinate of the end point of the |
| 492 | * specified line segment |
| 493 | * @param y2 the Y coordinate of the end point of the |
| 494 | * specified line segment |
| 495 | * @param px the X coordinate of the specified point to be |
| 496 | * compared with the specified line segment |
| 497 | * @param py the Y coordinate of the specified point to be |
| 498 | * compared with the specified line segment |
| 499 | * @return an integer that indicates the position of the third specified |
| 500 | * coordinates with respect to the line segment formed |
| 501 | * by the first two specified coordinates. |
| 502 | * @since 1.2 |
| 503 | */ |
| 504 | public static int relativeCCW(double x1, double y1, |
| 505 | double x2, double y2, |
| 506 | double px, double py) |
| 507 | { |
| 508 | x2 -= x1; |
| 509 | y2 -= y1; |
| 510 | px -= x1; |
| 511 | py -= y1; |
| 512 | double ccw = px * y2 - py * x2; |
| 513 | if (ccw == 0.0) { |
| 514 | // The point is colinear, classify based on which side of |
| 515 | // the segment the point falls on. We can calculate a |
| 516 | // relative value using the projection of px,py onto the |
| 517 | // segment - a negative value indicates the point projects |
| 518 | // outside of the segment in the direction of the particular |
| 519 | // endpoint used as the origin for the projection. |
| 520 | ccw = px * x2 + py * y2; |
| 521 | if (ccw > 0.0) { |
| 522 | // Reverse the projection to be relative to the original x2,y2 |
| 523 | // x2 and y2 are simply negated. |
| 524 | // px and py need to have (x2 - x1) or (y2 - y1) subtracted |
| 525 | // from them (based on the original values) |
| 526 | // Since we really want to get a positive answer when the |
| 527 | // point is "beyond (x2,y2)", then we want to calculate |
| 528 | // the inverse anyway - thus we leave x2 & y2 negated. |
| 529 | px -= x2; |
| 530 | py -= y2; |
| 531 | ccw = px * x2 + py * y2; |
| 532 | if (ccw < 0.0) { |
| 533 | ccw = 0.0; |
| 534 | } |
| 535 | } |
| 536 | } |
| 537 | return (ccw < 0.0) ? -1 : ((ccw > 0.0) ? 1 : 0); |
| 538 | } |
| 539 | |
| 540 | /** |
| 541 | * Returns an indicator of where the specified point |
| 542 | * {@code (px,py)} lies with respect to this line segment. |
| 543 | * See the method comments of |
| 544 | * {@link #relativeCCW(double, double, double, double, double, double)} |
| 545 | * to interpret the return value. |
| 546 | * @param px the X coordinate of the specified point |
| 547 | * to be compared with this <code>Line2D</code> |
| 548 | * @param py the Y coordinate of the specified point |
| 549 | * to be compared with this <code>Line2D</code> |
| 550 | * @return an integer that indicates the position of the specified |
| 551 | * coordinates with respect to this <code>Line2D</code> |
| 552 | * @see #relativeCCW(double, double, double, double, double, double) |
| 553 | * @since 1.2 |
| 554 | */ |
| 555 | public int relativeCCW(double px, double py) { |
| 556 | return relativeCCW(getX1(), getY1(), getX2(), getY2(), px, py); |
| 557 | } |
| 558 | |
| 559 | /** |
| 560 | * Returns an indicator of where the specified <code>Point2D</code> |
| 561 | * lies with respect to this line segment. |
| 562 | * See the method comments of |
| 563 | * {@link #relativeCCW(double, double, double, double, double, double)} |
| 564 | * to interpret the return value. |
| 565 | * @param p the specified <code>Point2D</code> to be compared |
| 566 | * with this <code>Line2D</code> |
| 567 | * @return an integer that indicates the position of the specified |
| 568 | * <code>Point2D</code> with respect to this <code>Line2D</code> |
| 569 | * @see #relativeCCW(double, double, double, double, double, double) |
| 570 | * @since 1.2 |
| 571 | */ |
| 572 | public int relativeCCW(Point2D p) { |
| 573 | return relativeCCW(getX1(), getY1(), getX2(), getY2(), |
| 574 | p.getX(), p.getY()); |
| 575 | } |
| 576 | |
| 577 | /** |
| 578 | * Tests if the line segment from {@code (x1,y1)} to |
| 579 | * {@code (x2,y2)} intersects the line segment from {@code (x3,y3)} |
| 580 | * to {@code (x4,y4)}. |
| 581 | * |
| 582 | * @param x1 the X coordinate of the start point of the first |
| 583 | * specified line segment |
| 584 | * @param y1 the Y coordinate of the start point of the first |
| 585 | * specified line segment |
| 586 | * @param x2 the X coordinate of the end point of the first |
| 587 | * specified line segment |
| 588 | * @param y2 the Y coordinate of the end point of the first |
| 589 | * specified line segment |
| 590 | * @param x3 the X coordinate of the start point of the second |
| 591 | * specified line segment |
| 592 | * @param y3 the Y coordinate of the start point of the second |
| 593 | * specified line segment |
| 594 | * @param x4 the X coordinate of the end point of the second |
| 595 | * specified line segment |
| 596 | * @param y4 the Y coordinate of the end point of the second |
| 597 | * specified line segment |
| 598 | * @return <code>true</code> if the first specified line segment |
| 599 | * and the second specified line segment intersect |
| 600 | * each other; <code>false</code> otherwise. |
| 601 | * @since 1.2 |
| 602 | */ |
| 603 | public static boolean linesIntersect(double x1, double y1, |
| 604 | double x2, double y2, |
| 605 | double x3, double y3, |
| 606 | double x4, double y4) |
| 607 | { |
| 608 | return ((relativeCCW(x1, y1, x2, y2, x3, y3) * |
| 609 | relativeCCW(x1, y1, x2, y2, x4, y4) <= 0) |
| 610 | && (relativeCCW(x3, y3, x4, y4, x1, y1) * |
| 611 | relativeCCW(x3, y3, x4, y4, x2, y2) <= 0)); |
| 612 | } |
| 613 | |
| 614 | /** |
| 615 | * Tests if the line segment from {@code (x1,y1)} to |
| 616 | * {@code (x2,y2)} intersects this line segment. |
| 617 | * |
| 618 | * @param x1 the X coordinate of the start point of the |
| 619 | * specified line segment |
| 620 | * @param y1 the Y coordinate of the start point of the |
| 621 | * specified line segment |
| 622 | * @param x2 the X coordinate of the end point of the |
| 623 | * specified line segment |
| 624 | * @param y2 the Y coordinate of the end point of the |
| 625 | * specified line segment |
| 626 | * @return <true> if this line segment and the specified line segment |
| 627 | * intersect each other; <code>false</code> otherwise. |
| 628 | * @since 1.2 |
| 629 | */ |
| 630 | public boolean intersectsLine(double x1, double y1, double x2, double y2) { |
| 631 | return linesIntersect(x1, y1, x2, y2, |
| 632 | getX1(), getY1(), getX2(), getY2()); |
| 633 | } |
| 634 | |
| 635 | /** |
| 636 | * Tests if the specified line segment intersects this line segment. |
| 637 | * @param l the specified <code>Line2D</code> |
| 638 | * @return <code>true</code> if this line segment and the specified line |
| 639 | * segment intersect each other; |
| 640 | * <code>false</code> otherwise. |
| 641 | * @since 1.2 |
| 642 | */ |
| 643 | public boolean intersectsLine(Line2D l) { |
| 644 | return linesIntersect(l.getX1(), l.getY1(), l.getX2(), l.getY2(), |
| 645 | getX1(), getY1(), getX2(), getY2()); |
| 646 | } |
| 647 | |
| 648 | /** |
| 649 | * Returns the square of the distance from a point to a line segment. |
| 650 | * The distance measured is the distance between the specified |
| 651 | * point and the closest point between the specified end points. |
| 652 | * If the specified point intersects the line segment in between the |
| 653 | * end points, this method returns 0.0. |
| 654 | * |
| 655 | * @param x1 the X coordinate of the start point of the |
| 656 | * specified line segment |
| 657 | * @param y1 the Y coordinate of the start point of the |
| 658 | * specified line segment |
| 659 | * @param x2 the X coordinate of the end point of the |
| 660 | * specified line segment |
| 661 | * @param y2 the Y coordinate of the end point of the |
| 662 | * specified line segment |
| 663 | * @param px the X coordinate of the specified point being |
| 664 | * measured against the specified line segment |
| 665 | * @param py the Y coordinate of the specified point being |
| 666 | * measured against the specified line segment |
| 667 | * @return a double value that is the square of the distance from the |
| 668 | * specified point to the specified line segment. |
| 669 | * @see #ptLineDistSq(double, double, double, double, double, double) |
| 670 | * @since 1.2 |
| 671 | */ |
| 672 | public static double ptSegDistSq(double x1, double y1, |
| 673 | double x2, double y2, |
| 674 | double px, double py) |
| 675 | { |
| 676 | // Adjust vectors relative to x1,y1 |
| 677 | // x2,y2 becomes relative vector from x1,y1 to end of segment |
| 678 | x2 -= x1; |
| 679 | y2 -= y1; |
| 680 | // px,py becomes relative vector from x1,y1 to test point |
| 681 | px -= x1; |
| 682 | py -= y1; |
| 683 | double dotprod = px * x2 + py * y2; |
| 684 | double projlenSq; |
| 685 | if (dotprod <= 0.0) { |
| 686 | // px,py is on the side of x1,y1 away from x2,y2 |
| 687 | // distance to segment is length of px,py vector |
| 688 | // "length of its (clipped) projection" is now 0.0 |
| 689 | projlenSq = 0.0; |
| 690 | } else { |
| 691 | // switch to backwards vectors relative to x2,y2 |
| 692 | // x2,y2 are already the negative of x1,y1=>x2,y2 |
| 693 | // to get px,py to be the negative of px,py=>x2,y2 |
| 694 | // the dot product of two negated vectors is the same |
| 695 | // as the dot product of the two normal vectors |
| 696 | px = x2 - px; |
| 697 | py = y2 - py; |
| 698 | dotprod = px * x2 + py * y2; |
| 699 | if (dotprod <= 0.0) { |
| 700 | // px,py is on the side of x2,y2 away from x1,y1 |
| 701 | // distance to segment is length of (backwards) px,py vector |
| 702 | // "length of its (clipped) projection" is now 0.0 |
| 703 | projlenSq = 0.0; |
| 704 | } else { |
| 705 | // px,py is between x1,y1 and x2,y2 |
| 706 | // dotprod is the length of the px,py vector |
| 707 | // projected on the x2,y2=>x1,y1 vector times the |
| 708 | // length of the x2,y2=>x1,y1 vector |
| 709 | projlenSq = dotprod * dotprod / (x2 * x2 + y2 * y2); |
| 710 | } |
| 711 | } |
| 712 | // Distance to line is now the length of the relative point |
| 713 | // vector minus the length of its projection onto the line |
| 714 | // (which is zero if the projection falls outside the range |
| 715 | // of the line segment). |
| 716 | double lenSq = px * px + py * py - projlenSq; |
| 717 | if (lenSq < 0) { |
| 718 | lenSq = 0; |
| 719 | } |
| 720 | return lenSq; |
| 721 | } |
| 722 | |
| 723 | /** |
| 724 | * Returns the distance from a point to a line segment. |
| 725 | * The distance measured is the distance between the specified |
| 726 | * point and the closest point between the specified end points. |
| 727 | * If the specified point intersects the line segment in between the |
| 728 | * end points, this method returns 0.0. |
| 729 | * |
| 730 | * @param x1 the X coordinate of the start point of the |
| 731 | * specified line segment |
| 732 | * @param y1 the Y coordinate of the start point of the |
| 733 | * specified line segment |
| 734 | * @param x2 the X coordinate of the end point of the |
| 735 | * specified line segment |
| 736 | * @param y2 the Y coordinate of the end point of the |
| 737 | * specified line segment |
| 738 | * @param px the X coordinate of the specified point being |
| 739 | * measured against the specified line segment |
| 740 | * @param py the Y coordinate of the specified point being |
| 741 | * measured against the specified line segment |
| 742 | * @return a double value that is the distance from the specified point |
| 743 | * to the specified line segment. |
| 744 | * @see #ptLineDist(double, double, double, double, double, double) |
| 745 | * @since 1.2 |
| 746 | */ |
| 747 | public static double ptSegDist(double x1, double y1, |
| 748 | double x2, double y2, |
| 749 | double px, double py) |
| 750 | { |
| 751 | return Math.sqrt(ptSegDistSq(x1, y1, x2, y2, px, py)); |
| 752 | } |
| 753 | |
| 754 | /** |
| 755 | * Returns the square of the distance from a point to this line segment. |
| 756 | * The distance measured is the distance between the specified |
| 757 | * point and the closest point between the current line's end points. |
| 758 | * If the specified point intersects the line segment in between the |
| 759 | * end points, this method returns 0.0. |
| 760 | * |
| 761 | * @param px the X coordinate of the specified point being |
| 762 | * measured against this line segment |
| 763 | * @param py the Y coordinate of the specified point being |
| 764 | * measured against this line segment |
| 765 | * @return a double value that is the square of the distance from the |
| 766 | * specified point to the current line segment. |
| 767 | * @see #ptLineDistSq(double, double) |
| 768 | * @since 1.2 |
| 769 | */ |
| 770 | public double ptSegDistSq(double px, double py) { |
| 771 | return ptSegDistSq(getX1(), getY1(), getX2(), getY2(), px, py); |
| 772 | } |
| 773 | |
| 774 | /** |
| 775 | * Returns the square of the distance from a <code>Point2D</code> to |
| 776 | * this line segment. |
| 777 | * The distance measured is the distance between the specified |
| 778 | * point and the closest point between the current line's end points. |
| 779 | * If the specified point intersects the line segment in between the |
| 780 | * end points, this method returns 0.0. |
| 781 | * @param pt the specified <code>Point2D</code> being measured against |
| 782 | * this line segment. |
| 783 | * @return a double value that is the square of the distance from the |
| 784 | * specified <code>Point2D</code> to the current |
| 785 | * line segment. |
| 786 | * @see #ptLineDistSq(Point2D) |
| 787 | * @since 1.2 |
| 788 | */ |
| 789 | public double ptSegDistSq(Point2D pt) { |
| 790 | return ptSegDistSq(getX1(), getY1(), getX2(), getY2(), |
| 791 | pt.getX(), pt.getY()); |
| 792 | } |
| 793 | |
| 794 | /** |
| 795 | * Returns the distance from a point to this line segment. |
| 796 | * The distance measured is the distance between the specified |
| 797 | * point and the closest point between the current line's end points. |
| 798 | * If the specified point intersects the line segment in between the |
| 799 | * end points, this method returns 0.0. |
| 800 | * |
| 801 | * @param px the X coordinate of the specified point being |
| 802 | * measured against this line segment |
| 803 | * @param py the Y coordinate of the specified point being |
| 804 | * measured against this line segment |
| 805 | * @return a double value that is the distance from the specified |
| 806 | * point to the current line segment. |
| 807 | * @see #ptLineDist(double, double) |
| 808 | * @since 1.2 |
| 809 | */ |
| 810 | public double ptSegDist(double px, double py) { |
| 811 | return ptSegDist(getX1(), getY1(), getX2(), getY2(), px, py); |
| 812 | } |
| 813 | |
| 814 | /** |
| 815 | * Returns the distance from a <code>Point2D</code> to this line |
| 816 | * segment. |
| 817 | * The distance measured is the distance between the specified |
| 818 | * point and the closest point between the current line's end points. |
| 819 | * If the specified point intersects the line segment in between the |
| 820 | * end points, this method returns 0.0. |
| 821 | * @param pt the specified <code>Point2D</code> being measured |
| 822 | * against this line segment |
| 823 | * @return a double value that is the distance from the specified |
| 824 | * <code>Point2D</code> to the current line |
| 825 | * segment. |
| 826 | * @see #ptLineDist(Point2D) |
| 827 | * @since 1.2 |
| 828 | */ |
| 829 | public double ptSegDist(Point2D pt) { |
| 830 | return ptSegDist(getX1(), getY1(), getX2(), getY2(), |
| 831 | pt.getX(), pt.getY()); |
| 832 | } |
| 833 | |
| 834 | /** |
| 835 | * Returns the square of the distance from a point to a line. |
| 836 | * The distance measured is the distance between the specified |
| 837 | * point and the closest point on the infinitely-extended line |
| 838 | * defined by the specified coordinates. If the specified point |
| 839 | * intersects the line, this method returns 0.0. |
| 840 | * |
| 841 | * @param x1 the X coordinate of the start point of the specified line |
| 842 | * @param y1 the Y coordinate of the start point of the specified line |
| 843 | * @param x2 the X coordinate of the end point of the specified line |
| 844 | * @param y2 the Y coordinate of the end point of the specified line |
| 845 | * @param px the X coordinate of the specified point being |
| 846 | * measured against the specified line |
| 847 | * @param py the Y coordinate of the specified point being |
| 848 | * measured against the specified line |
| 849 | * @return a double value that is the square of the distance from the |
| 850 | * specified point to the specified line. |
| 851 | * @see #ptSegDistSq(double, double, double, double, double, double) |
| 852 | * @since 1.2 |
| 853 | */ |
| 854 | public static double ptLineDistSq(double x1, double y1, |
| 855 | double x2, double y2, |
| 856 | double px, double py) |
| 857 | { |
| 858 | // Adjust vectors relative to x1,y1 |
| 859 | // x2,y2 becomes relative vector from x1,y1 to end of segment |
| 860 | x2 -= x1; |
| 861 | y2 -= y1; |
| 862 | // px,py becomes relative vector from x1,y1 to test point |
| 863 | px -= x1; |
| 864 | py -= y1; |
| 865 | double dotprod = px * x2 + py * y2; |
| 866 | // dotprod is the length of the px,py vector |
| 867 | // projected on the x1,y1=>x2,y2 vector times the |
| 868 | // length of the x1,y1=>x2,y2 vector |
| 869 | double projlenSq = dotprod * dotprod / (x2 * x2 + y2 * y2); |
| 870 | // Distance to line is now the length of the relative point |
| 871 | // vector minus the length of its projection onto the line |
| 872 | double lenSq = px * px + py * py - projlenSq; |
| 873 | if (lenSq < 0) { |
| 874 | lenSq = 0; |
| 875 | } |
| 876 | return lenSq; |
| 877 | } |
| 878 | |
| 879 | /** |
| 880 | * Returns the distance from a point to a line. |
| 881 | * The distance measured is the distance between the specified |
| 882 | * point and the closest point on the infinitely-extended line |
| 883 | * defined by the specified coordinates. If the specified point |
| 884 | * intersects the line, this method returns 0.0. |
| 885 | * |
| 886 | * @param x1 the X coordinate of the start point of the specified line |
| 887 | * @param y1 the Y coordinate of the start point of the specified line |
| 888 | * @param x2 the X coordinate of the end point of the specified line |
| 889 | * @param y2 the Y coordinate of the end point of the specified line |
| 890 | * @param px the X coordinate of the specified point being |
| 891 | * measured against the specified line |
| 892 | * @param py the Y coordinate of the specified point being |
| 893 | * measured against the specified line |
| 894 | * @return a double value that is the distance from the specified |
| 895 | * point to the specified line. |
| 896 | * @see #ptSegDist(double, double, double, double, double, double) |
| 897 | * @since 1.2 |
| 898 | */ |
| 899 | public static double ptLineDist(double x1, double y1, |
| 900 | double x2, double y2, |
| 901 | double px, double py) |
| 902 | { |
| 903 | return Math.sqrt(ptLineDistSq(x1, y1, x2, y2, px, py)); |
| 904 | } |
| 905 | |
| 906 | /** |
| 907 | * Returns the square of the distance from a point to this line. |
| 908 | * The distance measured is the distance between the specified |
| 909 | * point and the closest point on the infinitely-extended line |
| 910 | * defined by this <code>Line2D</code>. If the specified point |
| 911 | * intersects the line, this method returns 0.0. |
| 912 | * |
| 913 | * @param px the X coordinate of the specified point being |
| 914 | * measured against this line |
| 915 | * @param py the Y coordinate of the specified point being |
| 916 | * measured against this line |
| 917 | * @return a double value that is the square of the distance from a |
| 918 | * specified point to the current line. |
| 919 | * @see #ptSegDistSq(double, double) |
| 920 | * @since 1.2 |
| 921 | */ |
| 922 | public double ptLineDistSq(double px, double py) { |
| 923 | return ptLineDistSq(getX1(), getY1(), getX2(), getY2(), px, py); |
| 924 | } |
| 925 | |
| 926 | /** |
| 927 | * Returns the square of the distance from a specified |
| 928 | * <code>Point2D</code> to this line. |
| 929 | * The distance measured is the distance between the specified |
| 930 | * point and the closest point on the infinitely-extended line |
| 931 | * defined by this <code>Line2D</code>. If the specified point |
| 932 | * intersects the line, this method returns 0.0. |
| 933 | * @param pt the specified <code>Point2D</code> being measured |
| 934 | * against this line |
| 935 | * @return a double value that is the square of the distance from a |
| 936 | * specified <code>Point2D</code> to the current |
| 937 | * line. |
| 938 | * @see #ptSegDistSq(Point2D) |
| 939 | * @since 1.2 |
| 940 | */ |
| 941 | public double ptLineDistSq(Point2D pt) { |
| 942 | return ptLineDistSq(getX1(), getY1(), getX2(), getY2(), |
| 943 | pt.getX(), pt.getY()); |
| 944 | } |
| 945 | |
| 946 | /** |
| 947 | * Returns the distance from a point to this line. |
| 948 | * The distance measured is the distance between the specified |
| 949 | * point and the closest point on the infinitely-extended line |
| 950 | * defined by this <code>Line2D</code>. If the specified point |
| 951 | * intersects the line, this method returns 0.0. |
| 952 | * |
| 953 | * @param px the X coordinate of the specified point being |
| 954 | * measured against this line |
| 955 | * @param py the Y coordinate of the specified point being |
| 956 | * measured against this line |
| 957 | * @return a double value that is the distance from a specified point |
| 958 | * to the current line. |
| 959 | * @see #ptSegDist(double, double) |
| 960 | * @since 1.2 |
| 961 | */ |
| 962 | public double ptLineDist(double px, double py) { |
| 963 | return ptLineDist(getX1(), getY1(), getX2(), getY2(), px, py); |
| 964 | } |
| 965 | |
| 966 | /** |
| 967 | * Returns the distance from a <code>Point2D</code> to this line. |
| 968 | * The distance measured is the distance between the specified |
| 969 | * point and the closest point on the infinitely-extended line |
| 970 | * defined by this <code>Line2D</code>. If the specified point |
| 971 | * intersects the line, this method returns 0.0. |
| 972 | * @param pt the specified <code>Point2D</code> being measured |
| 973 | * @return a double value that is the distance from a specified |
| 974 | * <code>Point2D</code> to the current line. |
| 975 | * @see #ptSegDist(Point2D) |
| 976 | * @since 1.2 |
| 977 | */ |
| 978 | public double ptLineDist(Point2D pt) { |
| 979 | return ptLineDist(getX1(), getY1(), getX2(), getY2(), |
| 980 | pt.getX(), pt.getY()); |
| 981 | } |
| 982 | |
| 983 | /** |
| 984 | * Tests if a specified coordinate is inside the boundary of this |
| 985 | * <code>Line2D</code>. This method is required to implement the |
| 986 | * {@link Shape} interface, but in the case of <code>Line2D</code> |
| 987 | * objects it always returns <code>false</code> since a line contains |
| 988 | * no area. |
| 989 | * @param x the X coordinate of the specified point to be tested |
| 990 | * @param y the Y coordinate of the specified point to be tested |
| 991 | * @return <code>false</code> because a <code>Line2D</code> contains |
| 992 | * no area. |
| 993 | * @since 1.2 |
| 994 | */ |
| 995 | public boolean contains(double x, double y) { |
| 996 | return false; |
| 997 | } |
| 998 | |
| 999 | /** |
| 1000 | * Tests if a given <code>Point2D</code> is inside the boundary of |
| 1001 | * this <code>Line2D</code>. |
| 1002 | * This method is required to implement the {@link Shape} interface, |
| 1003 | * but in the case of <code>Line2D</code> objects it always returns |
| 1004 | * <code>false</code> since a line contains no area. |
| 1005 | * @param p the specified <code>Point2D</code> to be tested |
| 1006 | * @return <code>false</code> because a <code>Line2D</code> contains |
| 1007 | * no area. |
| 1008 | * @since 1.2 |
| 1009 | */ |
| 1010 | public boolean contains(Point2D p) { |
| 1011 | return false; |
| 1012 | } |
| 1013 | |
| 1014 | /** |
| 1015 | * {@inheritDoc} |
| 1016 | * @since 1.2 |
| 1017 | */ |
| 1018 | public boolean intersects(double x, double y, double w, double h) { |
| 1019 | return intersects(new Rectangle2D.Double(x, y, w, h)); |
| 1020 | } |
| 1021 | |
| 1022 | /** |
| 1023 | * {@inheritDoc} |
| 1024 | * @since 1.2 |
| 1025 | */ |
| 1026 | public boolean intersects(Rectangle2D r) { |
| 1027 | return r.intersectsLine(getX1(), getY1(), getX2(), getY2()); |
| 1028 | } |
| 1029 | |
| 1030 | /** |
| 1031 | * Tests if the interior of this <code>Line2D</code> entirely contains |
| 1032 | * the specified set of rectangular coordinates. |
| 1033 | * This method is required to implement the <code>Shape</code> interface, |
| 1034 | * but in the case of <code>Line2D</code> objects it always returns |
| 1035 | * false since a line contains no area. |
| 1036 | * @param x the X coordinate of the upper-left corner of the |
| 1037 | * specified rectangular area |
| 1038 | * @param y the Y coordinate of the upper-left corner of the |
| 1039 | * specified rectangular area |
| 1040 | * @param w the width of the specified rectangular area |
| 1041 | * @param h the height of the specified rectangular area |
| 1042 | * @return <code>false</code> because a <code>Line2D</code> contains |
| 1043 | * no area. |
| 1044 | * @since 1.2 |
| 1045 | */ |
| 1046 | public boolean contains(double x, double y, double w, double h) { |
| 1047 | return false; |
| 1048 | } |
| 1049 | |
| 1050 | /** |
| 1051 | * Tests if the interior of this <code>Line2D</code> entirely contains |
| 1052 | * the specified <code>Rectangle2D</code>. |
| 1053 | * This method is required to implement the <code>Shape</code> interface, |
| 1054 | * but in the case of <code>Line2D</code> objects it always returns |
| 1055 | * <code>false</code> since a line contains no area. |
| 1056 | * @param r the specified <code>Rectangle2D</code> to be tested |
| 1057 | * @return <code>false</code> because a <code>Line2D</code> contains |
| 1058 | * no area. |
| 1059 | * @since 1.2 |
| 1060 | */ |
| 1061 | public boolean contains(Rectangle2D r) { |
| 1062 | return false; |
| 1063 | } |
| 1064 | |
| 1065 | /** |
| 1066 | * {@inheritDoc} |
| 1067 | * @since 1.2 |
| 1068 | */ |
| 1069 | public Rectangle getBounds() { |
| 1070 | return getBounds2D().getBounds(); |
| 1071 | } |
| 1072 | |
| 1073 | /** |
| 1074 | * Returns an iteration object that defines the boundary of this |
| 1075 | * <code>Line2D</code>. |
| 1076 | * The iterator for this class is not multi-threaded safe, |
| 1077 | * which means that this <code>Line2D</code> class does not |
| 1078 | * guarantee that modifications to the geometry of this |
| 1079 | * <code>Line2D</code> object do not affect any iterations of that |
| 1080 | * geometry that are already in process. |
| 1081 | * @param at the specified {@link AffineTransform} |
| 1082 | * @return a {@link PathIterator} that defines the boundary of this |
| 1083 | * <code>Line2D</code>. |
| 1084 | * @since 1.2 |
| 1085 | */ |
| 1086 | public PathIterator getPathIterator(AffineTransform at) { |
| 1087 | return new LineIterator(this, at); |
| 1088 | } |
| 1089 | |
| 1090 | /** |
| 1091 | * Returns an iteration object that defines the boundary of this |
| 1092 | * flattened <code>Line2D</code>. |
| 1093 | * The iterator for this class is not multi-threaded safe, |
| 1094 | * which means that this <code>Line2D</code> class does not |
| 1095 | * guarantee that modifications to the geometry of this |
| 1096 | * <code>Line2D</code> object do not affect any iterations of that |
| 1097 | * geometry that are already in process. |
| 1098 | * @param at the specified <code>AffineTransform</code> |
| 1099 | * @param flatness the maximum amount that the control points for a |
| 1100 | * given curve can vary from colinear before a subdivided |
| 1101 | * curve is replaced by a straight line connecting the |
| 1102 | * end points. Since a <code>Line2D</code> object is |
| 1103 | * always flat, this parameter is ignored. |
| 1104 | * @return a <code>PathIterator</code> that defines the boundary of the |
| 1105 | * flattened <code>Line2D</code> |
| 1106 | * @since 1.2 |
| 1107 | */ |
| 1108 | public PathIterator getPathIterator(AffineTransform at, double flatness) { |
| 1109 | return new LineIterator(this, at); |
| 1110 | } |
| 1111 | |
| 1112 | /** |
| 1113 | * Creates a new object of the same class as this object. |
| 1114 | * |
| 1115 | * @return a clone of this instance. |
| 1116 | * @exception OutOfMemoryError if there is not enough memory. |
| 1117 | * @see java.lang.Cloneable |
| 1118 | * @since 1.2 |
| 1119 | */ |
| 1120 | public Object clone() { |
| 1121 | try { |
| 1122 | return super.clone(); |
| 1123 | } catch (CloneNotSupportedException e) { |
| 1124 | // this shouldn't happen, since we are Cloneable |
| 1125 | throw new InternalError(); |
| 1126 | } |
| 1127 | } |
| 1128 | } |