J. Duke | 319a3b9 | 2007-12-01 00:00:00 +0000 | [diff] [blame^] | 1 | /* |
| 2 | * Copyright 2005 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 | * (C) Copyright IBM Corp. 2005, All Rights Reserved. |
| 27 | */ |
| 28 | package sun.font; |
| 29 | |
| 30 | // |
| 31 | // This is the 'simple' mapping implementation. It does things the most |
| 32 | // straightforward way even if that is a bit slow. It won't |
| 33 | // handle complex paths efficiently, and doesn't handle closed paths. |
| 34 | // |
| 35 | |
| 36 | import java.awt.Shape; |
| 37 | import java.awt.font.LayoutPath; |
| 38 | import java.awt.geom.AffineTransform; |
| 39 | import java.awt.geom.GeneralPath; |
| 40 | import java.awt.geom.NoninvertibleTransformException; |
| 41 | import java.awt.geom.PathIterator; |
| 42 | import java.awt.geom.Point2D; |
| 43 | import java.util.Formatter; |
| 44 | import java.util.ArrayList; |
| 45 | |
| 46 | import static java.awt.geom.PathIterator.*; |
| 47 | import static java.lang.Math.abs; |
| 48 | import static java.lang.Math.sqrt; |
| 49 | |
| 50 | public abstract class LayoutPathImpl extends LayoutPath { |
| 51 | |
| 52 | // |
| 53 | // Convenience APIs |
| 54 | // |
| 55 | |
| 56 | public Point2D pointToPath(double x, double y) { |
| 57 | Point2D.Double pt = new Point2D.Double(x, y); |
| 58 | pointToPath(pt, pt); |
| 59 | return pt; |
| 60 | } |
| 61 | |
| 62 | public Point2D pathToPoint(double a, double o, boolean preceding) { |
| 63 | Point2D.Double pt = new Point2D.Double(a, o); |
| 64 | pathToPoint(pt, preceding, pt); |
| 65 | return pt; |
| 66 | } |
| 67 | |
| 68 | public void pointToPath(double x, double y, Point2D pt) { |
| 69 | pt.setLocation(x, y); |
| 70 | pointToPath(pt, pt); |
| 71 | } |
| 72 | |
| 73 | public void pathToPoint(double a, double o, boolean preceding, Point2D pt) { |
| 74 | pt.setLocation(a, o); |
| 75 | pathToPoint(pt, preceding, pt); |
| 76 | } |
| 77 | |
| 78 | // |
| 79 | // extra utility APIs |
| 80 | // |
| 81 | |
| 82 | public abstract double start(); |
| 83 | public abstract double end(); |
| 84 | public abstract double length(); |
| 85 | public abstract Shape mapShape(Shape s); |
| 86 | |
| 87 | // |
| 88 | // debugging flags |
| 89 | // |
| 90 | |
| 91 | private static final boolean LOGMAP = false; |
| 92 | private static final Formatter LOG = new Formatter(System.out); |
| 93 | |
| 94 | /** |
| 95 | * Indicate how positions past the start and limit of the |
| 96 | * path are treated. PINNED adjusts these positions so |
| 97 | * as to be within start and limit. EXTENDED ignores the |
| 98 | * start and limit and effectively extends the first and |
| 99 | * last segments of the path 'infinitely'. CLOSED wraps |
| 100 | * positions around the ends of the path. |
| 101 | */ |
| 102 | public static enum EndType { |
| 103 | PINNED, EXTENDED, CLOSED; |
| 104 | public boolean isPinned() { return this == PINNED; } |
| 105 | public boolean isExtended() { return this == EXTENDED; } |
| 106 | public boolean isClosed() { return this == CLOSED; } |
| 107 | }; |
| 108 | |
| 109 | // |
| 110 | // Top level construction. |
| 111 | // |
| 112 | |
| 113 | /** |
| 114 | * Return a path representing the path from the origin through the points in order. |
| 115 | */ |
| 116 | public static LayoutPathImpl getPath(EndType etype, double ... coords) { |
| 117 | if ((coords.length & 0x1) != 0) { |
| 118 | throw new IllegalArgumentException("odd number of points not allowed"); |
| 119 | } |
| 120 | |
| 121 | return SegmentPath.get(etype, coords); |
| 122 | } |
| 123 | |
| 124 | /** |
| 125 | * Use to build a SegmentPath. This takes the data and preanalyzes it for |
| 126 | * information that the SegmentPath needs, then constructs a SegmentPath |
| 127 | * from that. Mainly, this lets SegmentPath cache the lengths along |
| 128 | * the path to each line segment, and so avoid calculating them over and over. |
| 129 | */ |
| 130 | public static final class SegmentPathBuilder { |
| 131 | private double[] data; |
| 132 | private int w; |
| 133 | private double px; |
| 134 | private double py; |
| 135 | private double a; |
| 136 | private boolean pconnect; |
| 137 | |
| 138 | /** |
| 139 | * Construct a SegmentPathBuilder. |
| 140 | */ |
| 141 | public SegmentPathBuilder() { |
| 142 | } |
| 143 | |
| 144 | /** |
| 145 | * Reset the builder for a new path. Datalen is a hint of how many |
| 146 | * points will be in the path, and the working buffer will be sized |
| 147 | * to accomodate at least this number of points. If datalen is zero, |
| 148 | * the working buffer is freed (it will be allocated on first use). |
| 149 | */ |
| 150 | public void reset(int datalen) { |
| 151 | if (data == null || datalen > data.length) { |
| 152 | data = new double[datalen]; |
| 153 | } else if (datalen == 0) { |
| 154 | data = null; |
| 155 | } |
| 156 | w = 0; |
| 157 | px = py = 0; |
| 158 | pconnect = false; |
| 159 | } |
| 160 | |
| 161 | /** |
| 162 | * Automatically build from a list of points represented by pairs of |
| 163 | * doubles. Initial advance is zero. |
| 164 | */ |
| 165 | public SegmentPath build(EndType etype, double... pts) { |
| 166 | assert(pts.length % 2 == 0); |
| 167 | |
| 168 | reset(pts.length / 2 * 3); |
| 169 | |
| 170 | for (int i = 0; i < pts.length; i += 2) { |
| 171 | nextPoint(pts[i], pts[i+1], i != 0); |
| 172 | } |
| 173 | |
| 174 | return complete(etype); |
| 175 | } |
| 176 | |
| 177 | /** |
| 178 | * Move to a new point. If there is no data, this will become the |
| 179 | * first point. If there is data, and the previous call was a lineTo, this |
| 180 | * point is checked against the previous point, and if different, this |
| 181 | * starts a new segment at the same advance as the end of the last |
| 182 | * segment. If there is data, and the previous call was a moveTo, this |
| 183 | * replaces the point used for that previous call. |
| 184 | * |
| 185 | * Calling this is optional, lineTo will suffice and the initial point |
| 186 | * will be set to 0, 0. |
| 187 | */ |
| 188 | public void moveTo(double x, double y) { |
| 189 | nextPoint(x, y, false); |
| 190 | } |
| 191 | |
| 192 | /** |
| 193 | * Connect to a new point. If there is no data, the previous point |
| 194 | * is presumed to be 0, 0. This point is checked against |
| 195 | * the previous point, and if different, this point is added to |
| 196 | * the path and the advance extended. If this point is the same as the |
| 197 | * previous point, the path remains unchanged. |
| 198 | */ |
| 199 | public void lineTo(double x, double y) { |
| 200 | nextPoint(x, y, true); |
| 201 | } |
| 202 | |
| 203 | /** |
| 204 | * Add a new point, and increment advance if connect is true. |
| 205 | * |
| 206 | * This automatically rejects duplicate points and multiple disconnected points. |
| 207 | */ |
| 208 | private void nextPoint(double x, double y, boolean connect) { |
| 209 | |
| 210 | // if zero length move or line, ignore |
| 211 | if (x == px && y == py) { |
| 212 | return; |
| 213 | } |
| 214 | |
| 215 | if (w == 0) { // this is the first point, make sure we have space |
| 216 | if (data == null) { |
| 217 | data = new double[6]; |
| 218 | } |
| 219 | if (connect) { |
| 220 | w = 3; // default first point to 0, 0 |
| 221 | } |
| 222 | } |
| 223 | |
| 224 | // if multiple disconnected move, just update position, leave advance alone |
| 225 | if (w != 0 && !connect && !pconnect) { |
| 226 | data[w-3] = px = x; |
| 227 | data[w-2] = py = y; |
| 228 | return; |
| 229 | } |
| 230 | |
| 231 | // grow data to deal with new point |
| 232 | if (w == data.length) { |
| 233 | double[] t = new double[w * 2]; |
| 234 | System.arraycopy(data, 0, t, 0, w); |
| 235 | data = t; |
| 236 | } |
| 237 | |
| 238 | if (connect) { |
| 239 | double dx = x - px; |
| 240 | double dy = y - py; |
| 241 | a += sqrt(dx * dx + dy * dy); |
| 242 | } |
| 243 | |
| 244 | // update data |
| 245 | data[w++] = x; |
| 246 | data[w++] = y; |
| 247 | data[w++] = a; |
| 248 | |
| 249 | // update state |
| 250 | px = x; |
| 251 | py = y; |
| 252 | pconnect = connect; |
| 253 | } |
| 254 | |
| 255 | public SegmentPath complete() { |
| 256 | return complete(EndType.EXTENDED); |
| 257 | } |
| 258 | |
| 259 | /** |
| 260 | * Complete building a SegmentPath. Once this is called, the builder is restored |
| 261 | * to its initial state and information about the previous path is released. The |
| 262 | * end type indicates whether to treat the path as closed, extended, or pinned. |
| 263 | */ |
| 264 | public SegmentPath complete(EndType etype) { |
| 265 | SegmentPath result; |
| 266 | |
| 267 | if (data == null || w < 6) { |
| 268 | return null; |
| 269 | } |
| 270 | |
| 271 | if (w == data.length) { |
| 272 | result = new SegmentPath(data, etype); |
| 273 | reset(0); // releases pointer to data |
| 274 | } else { |
| 275 | double[] dataToAdopt = new double[w]; |
| 276 | System.arraycopy(data, 0, dataToAdopt, 0, w); |
| 277 | result = new SegmentPath(dataToAdopt, etype); |
| 278 | reset(2); // reuses data, since we held on to it |
| 279 | } |
| 280 | |
| 281 | return result; |
| 282 | } |
| 283 | } |
| 284 | |
| 285 | /** |
| 286 | * Represents a path built from segments. Each segment is |
| 287 | * represented by a triple: x, y, and cumulative advance. |
| 288 | * These represent the end point of the segment. The start |
| 289 | * point of the first segment is represented by the triple |
| 290 | * at position 0. |
| 291 | * |
| 292 | * The path might have breaks in it, e.g. it is not connected. |
| 293 | * These will be represented by pairs of triplets that share the |
| 294 | * same advance. |
| 295 | * |
| 296 | * The path might be extended, pinned, or closed. If extended, |
| 297 | * the initial and final segments are considered to extend |
| 298 | * 'indefinitely' past the bounds of the advance. If pinned, |
| 299 | * they end at the bounds of the advance. If closed, |
| 300 | * advances before the start or after the end 'wrap around' the |
| 301 | * path. |
| 302 | * |
| 303 | * The start of the path is the initial triple. This provides |
| 304 | * the nominal advance at the given x, y position (typically |
| 305 | * zero). The end of the path is the final triple. This provides |
| 306 | * the advance at the end, the total length of the path is |
| 307 | * thus the ending advance minus the starting advance. |
| 308 | * |
| 309 | * Note: We might want to cache more auxiliary data than the |
| 310 | * advance, but this seems adequate for now. |
| 311 | */ |
| 312 | public static final class SegmentPath extends LayoutPathImpl { |
| 313 | private double[] data; // triplets x, y, a |
| 314 | EndType etype; |
| 315 | |
| 316 | public static SegmentPath get(EndType etype, double... pts) { |
| 317 | return new SegmentPathBuilder().build(etype, pts); |
| 318 | } |
| 319 | |
| 320 | /** |
| 321 | * Internal, use SegmentPathBuilder or one of the static |
| 322 | * helper functions to construct a SegmentPath. |
| 323 | */ |
| 324 | SegmentPath(double[] data, EndType etype) { |
| 325 | this.data = data; |
| 326 | this.etype = etype; |
| 327 | } |
| 328 | |
| 329 | // |
| 330 | // LayoutPath API |
| 331 | // |
| 332 | |
| 333 | public void pathToPoint(Point2D location, boolean preceding, Point2D point) { |
| 334 | locateAndGetIndex(location, preceding, point); |
| 335 | } |
| 336 | |
| 337 | // the path consists of line segments, which i'll call |
| 338 | // 'path vectors'. call each run of path vectors a 'path segment'. |
| 339 | // no path vector in a path segment is zero length (in the |
| 340 | // data, such vectors start a new path segment). |
| 341 | // |
| 342 | // for each path segment... |
| 343 | // |
| 344 | // for each path vector... |
| 345 | // |
| 346 | // we look at the dot product of the path vector and the vector from the |
| 347 | // origin of the path vector to the test point. if <0 (case |
| 348 | // A), the projection of the test point is before the start of |
| 349 | // the path vector. if > the square of the length of the path vector |
| 350 | // (case B), the projection is past the end point of the |
| 351 | // path vector. otherwise (case C), it lies on the path vector. |
| 352 | // determine the closeset point on the path vector. if case A, it |
| 353 | // is the start of the path vector. if case B and this is the last |
| 354 | // path vector in the path segment, it is the end of the path vector. If |
| 355 | // case C, it is the projection onto the path vector. Otherwise |
| 356 | // there is no closest point. |
| 357 | // |
| 358 | // if we have a closest point, compare the distance from it to |
| 359 | // the test point against our current closest distance. |
| 360 | // (culling should be fast, currently i am using distance |
| 361 | // squared, but there's probably better ways). if we're |
| 362 | // closer, save the new point as the current closest point, |
| 363 | // and record the path vector index so we can determine the final |
| 364 | // info if this turns out to be the closest point in the end. |
| 365 | // |
| 366 | // after we have processed all the segments we will have |
| 367 | // tested each path vector and each endpoint. if our point is not on |
| 368 | // an endpoint, we're done; we can compute the position and |
| 369 | // offset again, or if we saved it off we can just use it. if |
| 370 | // we're on an endpoint we need to see which path vector we should |
| 371 | // associate with. if we're at the start or end of a path segment, |
| 372 | // we're done-- the first or last vector of the segment is the |
| 373 | // one we associate with. we project against that vector to |
| 374 | // get the offset, and pin to that vector to get the length. |
| 375 | // |
| 376 | // otherwise, we compute the information as follows. if the |
| 377 | // dot product (see above) with the following vector is zero, |
| 378 | // we associate with that vector. otherwise, if the dot |
| 379 | // product with the previous vector is zero, we associate with |
| 380 | // that vector. otherwise we're beyond the end of the |
| 381 | // previous vector and before the start of the current vector. |
| 382 | // we project against both vectors and get the distance from |
| 383 | // the test point to the projection (this will be the offset). |
| 384 | // if they are the same, we take the following vector. |
| 385 | // otherwise use the vector from which the test point is the |
| 386 | // _farthest_ (this is because the point lies most clearly in |
| 387 | // the half of the plane defined by extending that vector). |
| 388 | // |
| 389 | // the returned position is the path length to the (possibly |
| 390 | // pinned) point, the offset is the projection onto the line |
| 391 | // along the vector, and we have a boolean flag which if false |
| 392 | // indicates that we associate with the previous vector at a |
| 393 | // junction (which is necessary when projecting such a |
| 394 | // location back to a point). |
| 395 | |
| 396 | public boolean pointToPath(Point2D pt, Point2D result) { |
| 397 | double x = pt.getX(); // test point |
| 398 | double y = pt.getY(); |
| 399 | |
| 400 | double bx = data[0]; // previous point |
| 401 | double by = data[1]; |
| 402 | double bl = data[2]; |
| 403 | |
| 404 | // start with defaults |
| 405 | double cd2 = Double.MAX_VALUE; // current best distance from path, squared |
| 406 | double cx = 0; // current best x |
| 407 | double cy = 0; // current best y |
| 408 | double cl = 0; // current best position along path |
| 409 | int ci = 0; // current best index into data |
| 410 | |
| 411 | for (int i = 3; i < data.length; i += 3) { |
| 412 | double nx = data[i]; // current end point |
| 413 | double ny = data[i+1]; |
| 414 | double nl = data[i+2]; |
| 415 | |
| 416 | double dx = nx - bx; // vector from previous to current |
| 417 | double dy = ny - by; |
| 418 | double dl = nl - bl; |
| 419 | |
| 420 | double px = x - bx; // vector from previous to test point |
| 421 | double py = y - by; |
| 422 | |
| 423 | // determine sign of dot product of vectors from bx, by |
| 424 | // if < 0, we're before the start of this vector |
| 425 | |
| 426 | double dot = dx * px + dy * py; // dot product |
| 427 | double vcx, vcy, vcl; // hold closest point on vector as x, y, l |
| 428 | int vi; // hold index of line, is data.length if last point on path |
| 429 | do { // use break below, lets us avoid initializing vcx, vcy... |
| 430 | if (dl == 0 || // moveto, or |
| 431 | (dot < 0 && // before path vector and |
| 432 | (!etype.isExtended() || |
| 433 | i != 3))) { // closest point is start of vector |
| 434 | vcx = bx; |
| 435 | vcy = by; |
| 436 | vcl = bl; |
| 437 | vi = i; |
| 438 | } else { |
| 439 | double l2 = dl * dl; // aka dx * dx + dy * dy, square of length |
| 440 | if (dot <= l2 || // closest point is not past end of vector, or |
| 441 | (etype.isExtended() && // we're extended and at the last segment |
| 442 | i == data.length - 3)) { |
| 443 | double p = dot / l2; // get parametric along segment |
| 444 | vcx = bx + p * dx; // compute closest point |
| 445 | vcy = by + p * dy; |
| 446 | vcl = bl + p * dl; |
| 447 | vi = i; |
| 448 | } else { |
| 449 | if (i == data.length - 3) { |
| 450 | vcx = nx; // special case, always test last point |
| 451 | vcy = ny; |
| 452 | vcl = nl; |
| 453 | vi = data.length; |
| 454 | } else { |
| 455 | break; // typical case, skip point, we'll pick it up next iteration |
| 456 | } |
| 457 | } |
| 458 | } |
| 459 | |
| 460 | double tdx = x - vcx; // compute distance from (usually pinned) projection to test point |
| 461 | double tdy = y - vcy; |
| 462 | double td2 = tdx * tdx + tdy * tdy; |
| 463 | if (td2 <= cd2) { // new closest point, record info on it |
| 464 | cd2 = td2; |
| 465 | cx = vcx; |
| 466 | cy = vcy; |
| 467 | cl = vcl; |
| 468 | ci = vi; |
| 469 | } |
| 470 | } while (false); |
| 471 | |
| 472 | bx = nx; |
| 473 | by = ny; |
| 474 | bl = nl; |
| 475 | } |
| 476 | |
| 477 | // we have our closest point, get the info |
| 478 | bx = data[ci-3]; |
| 479 | by = data[ci-2]; |
| 480 | if (cx != bx || cy != by) { // not on endpoint, no need to resolve |
| 481 | double nx = data[ci]; |
| 482 | double ny = data[ci+1]; |
| 483 | double co = sqrt(cd2); // have a true perpendicular, so can use distance |
| 484 | if ((x-cx)*(ny-by) > (y-cy)*(nx-bx)) { |
| 485 | co = -co; // determine sign of offset |
| 486 | } |
| 487 | result.setLocation(cl, co); |
| 488 | return false; |
| 489 | } else { // on endpoint, we need to resolve which segment |
| 490 | boolean havePrev = ci != 3 && data[ci-1] != data[ci-4]; |
| 491 | boolean haveFoll = ci != data.length && data[ci-1] != data[ci+2]; |
| 492 | boolean doExtend = etype.isExtended() && (ci == 3 || ci == data.length); |
| 493 | if (havePrev && haveFoll) { |
| 494 | Point2D.Double pp = new Point2D.Double(x, y); |
| 495 | calcoffset(ci - 3, doExtend, pp); |
| 496 | Point2D.Double fp = new Point2D.Double(x, y); |
| 497 | calcoffset(ci, doExtend, fp); |
| 498 | if (abs(pp.y) > abs(fp.y)) { |
| 499 | result.setLocation(pp); |
| 500 | return true; // associate with previous |
| 501 | } else { |
| 502 | result.setLocation(fp); |
| 503 | return false; // associate with following |
| 504 | } |
| 505 | } else if (havePrev) { |
| 506 | result.setLocation(x, y); |
| 507 | calcoffset(ci - 3, doExtend, result); |
| 508 | return true; |
| 509 | } else { |
| 510 | result.setLocation(x, y); |
| 511 | calcoffset(ci, doExtend, result); |
| 512 | return false; |
| 513 | } |
| 514 | } |
| 515 | } |
| 516 | |
| 517 | /** |
| 518 | * Return the location of the point passed in result as mapped to the |
| 519 | * line indicated by index. If doExtend is true, extend the |
| 520 | * x value without pinning to the ends of the line. |
| 521 | * this assumes that index is valid and references a line that has |
| 522 | * non-zero length. |
| 523 | */ |
| 524 | private void calcoffset(int index, boolean doExtend, Point2D result) { |
| 525 | double bx = data[index-3]; |
| 526 | double by = data[index-2]; |
| 527 | double px = result.getX() - bx; |
| 528 | double py = result.getY() - by; |
| 529 | double dx = data[index] - bx; |
| 530 | double dy = data[index+1] - by; |
| 531 | double l = data[index+2] - data[index - 1]; |
| 532 | |
| 533 | // rx = A dot B / |B| |
| 534 | // ry = A dot invB / |B| |
| 535 | double rx = (px * dx + py * dy) / l; |
| 536 | double ry = (px * -dy + py * dx) / l; |
| 537 | if (!doExtend) { |
| 538 | if (rx < 0) rx = 0; |
| 539 | else if (rx > l) rx = l; |
| 540 | } |
| 541 | rx += data[index-1]; |
| 542 | result.setLocation(rx, ry); |
| 543 | } |
| 544 | |
| 545 | // |
| 546 | // LayoutPathImpl API |
| 547 | // |
| 548 | |
| 549 | public Shape mapShape(Shape s) { |
| 550 | return new Mapper().mapShape(s); |
| 551 | } |
| 552 | |
| 553 | public double start() { |
| 554 | return data[2]; |
| 555 | } |
| 556 | |
| 557 | public double end() { |
| 558 | return data[data.length - 1]; |
| 559 | } |
| 560 | |
| 561 | public double length() { |
| 562 | return data[data.length-1] - data[2]; |
| 563 | } |
| 564 | |
| 565 | // |
| 566 | // Utilities |
| 567 | // |
| 568 | |
| 569 | /** |
| 570 | * Get the 'modulus' of an advance on a closed path. |
| 571 | */ |
| 572 | private double getClosedAdvance(double a, boolean preceding) { |
| 573 | if (etype.isClosed()) { |
| 574 | a -= data[2]; |
| 575 | int count = (int)(a/length()); |
| 576 | a -= count * length(); |
| 577 | if (a < 0 || (a == 0 && preceding)) { |
| 578 | a += length(); |
| 579 | |
| 580 | } |
| 581 | a += data[2]; |
| 582 | } |
| 583 | return a; |
| 584 | } |
| 585 | |
| 586 | /** |
| 587 | * Return the index of the segment associated with advance. This |
| 588 | * points to the start of the triple and is a multiple of 3 between |
| 589 | * 3 and data.length-3 inclusive. It never points to a 'moveto' triple. |
| 590 | * |
| 591 | * If the path is closed, 'a' is mapped to |
| 592 | * a value between the start and end of the path, inclusive. |
| 593 | * If preceding is true, and 'a' lies on a segment boundary, |
| 594 | * return the index of the preceding segment, else return the index |
| 595 | * of the current segment (if it is not a moveto segment) otherwise |
| 596 | * the following segment (which is never a moveto segment). |
| 597 | * |
| 598 | * Note: if the path is not closed, the advance might not actually |
| 599 | * lie on the returned segment-- it might be before the first, or |
| 600 | * after the last. The first or last segment (as appropriate) |
| 601 | * will be returned in this case. |
| 602 | */ |
| 603 | private int getSegmentIndexForAdvance(double a, boolean preceding) { |
| 604 | // must have local advance |
| 605 | a = getClosedAdvance(a, preceding); |
| 606 | |
| 607 | // note we must avoid 'moveto' segments. the first segment is |
| 608 | // always a moveto segment, so we always skip it. |
| 609 | int i, lim; |
| 610 | for (i = 5, lim = data.length-1; i < lim; i += 3) { |
| 611 | double v = data[i]; |
| 612 | if (a < v || (a == v && preceding)) { |
| 613 | break; |
| 614 | } |
| 615 | } |
| 616 | return i-2; // adjust to start of segment |
| 617 | } |
| 618 | |
| 619 | /** |
| 620 | * Map a location based on the provided segment, returning in pt. |
| 621 | * Seg must be a valid 'lineto' segment. Note: if the path is |
| 622 | * closed, x must be within the start and end of the path. |
| 623 | */ |
| 624 | private void map(int seg, double a, double o, Point2D pt) { |
| 625 | double dx = data[seg] - data[seg-3]; |
| 626 | double dy = data[seg+1] - data[seg-2]; |
| 627 | double dl = data[seg+2] - data[seg-1]; |
| 628 | |
| 629 | double ux = dx/dl; // could cache these, but is it worth it? |
| 630 | double uy = dy/dl; |
| 631 | |
| 632 | a -= data[seg-1]; |
| 633 | |
| 634 | pt.setLocation(data[seg-3] + a * ux - o * uy, |
| 635 | data[seg-2] + a * uy + o * ux); |
| 636 | } |
| 637 | |
| 638 | /** |
| 639 | * Map the point, and return the segment index. |
| 640 | */ |
| 641 | private int locateAndGetIndex(Point2D loc, boolean preceding, Point2D result) { |
| 642 | double a = loc.getX(); |
| 643 | double o = loc.getY(); |
| 644 | int seg = getSegmentIndexForAdvance(a, preceding); |
| 645 | map(seg, a, o, result); |
| 646 | |
| 647 | return seg; |
| 648 | } |
| 649 | |
| 650 | // |
| 651 | // Mapping classes. |
| 652 | // Map the path onto each path segment. |
| 653 | // Record points where the advance 'enters' and 'exits' the path segment, and connect successive |
| 654 | // points when appropriate. |
| 655 | // |
| 656 | |
| 657 | /** |
| 658 | * This represents a line segment from the iterator. Each target segment will |
| 659 | * interpret it, and since this process needs slope along the line |
| 660 | * segment, this lets us compute it once and pass it around easily. |
| 661 | */ |
| 662 | class LineInfo { |
| 663 | double sx, sy; // start |
| 664 | double lx, ly; // limit |
| 665 | double m; // slope dy/dx |
| 666 | |
| 667 | /** |
| 668 | * Set the lineinfo to this line |
| 669 | */ |
| 670 | void set(double sx, double sy, double lx, double ly) { |
| 671 | this.sx = sx; |
| 672 | this.sy = sy; |
| 673 | this.lx = lx; |
| 674 | this.ly = ly; |
| 675 | double dx = lx - sx; |
| 676 | if (dx == 0) { |
| 677 | m = 0; // we'll check for this elsewhere |
| 678 | } else { |
| 679 | double dy = ly - sy; |
| 680 | m = dy / dx; |
| 681 | } |
| 682 | } |
| 683 | |
| 684 | void set(LineInfo rhs) { |
| 685 | this.sx = rhs.sx; |
| 686 | this.sy = rhs.sy; |
| 687 | this.lx = rhs.lx; |
| 688 | this.ly = rhs.ly; |
| 689 | this.m = rhs.m; |
| 690 | } |
| 691 | |
| 692 | /** |
| 693 | * Return true if we intersect the infinitely tall rectangle with |
| 694 | * lo <= x < hi. If we do, also return the pinned portion of ourselves in |
| 695 | * result. |
| 696 | */ |
| 697 | boolean pin(double lo, double hi, LineInfo result) { |
| 698 | result.set(this); |
| 699 | if (lx >= sx) { |
| 700 | if (sx < hi && lx >= lo) { |
| 701 | if (sx < lo) { |
| 702 | if (m != 0) result.sy = sy + m * (lo - sx); |
| 703 | result.sx = lo; |
| 704 | } |
| 705 | if (lx > hi) { |
| 706 | if (m != 0) result.ly = ly + m * (hi - lx); |
| 707 | result.lx = hi; |
| 708 | } |
| 709 | return true; |
| 710 | } |
| 711 | } else { |
| 712 | if (lx < hi && sx >= lo) { |
| 713 | if (lx < lo) { |
| 714 | if (m != 0) result.ly = ly + m * (lo - lx); |
| 715 | result.lx = lo; |
| 716 | } |
| 717 | if (sx > hi) { |
| 718 | if (m != 0) result.sy = sy + m * (hi - sx); |
| 719 | result.sx = hi; |
| 720 | } |
| 721 | return true; |
| 722 | } |
| 723 | } |
| 724 | return false; |
| 725 | } |
| 726 | |
| 727 | /** |
| 728 | * Return true if we intersect the segment at ix. This takes |
| 729 | * the path end type into account and computes the relevant |
| 730 | * parameters to pass to pin(double, double, LineInfo). |
| 731 | */ |
| 732 | boolean pin(int ix, LineInfo result) { |
| 733 | double lo = data[ix-1]; |
| 734 | double hi = data[ix+2]; |
| 735 | switch (SegmentPath.this.etype) { |
| 736 | case PINNED: |
| 737 | break; |
| 738 | case EXTENDED: |
| 739 | if (ix == 3) lo = Double.NEGATIVE_INFINITY; |
| 740 | if (ix == data.length - 3) hi = Double.POSITIVE_INFINITY; |
| 741 | break; |
| 742 | case CLOSED: |
| 743 | // not implemented |
| 744 | break; |
| 745 | } |
| 746 | |
| 747 | return pin(lo, hi, result); |
| 748 | } |
| 749 | } |
| 750 | |
| 751 | /** |
| 752 | * Each segment will construct its own general path, mapping the provided lines |
| 753 | * into its own simple space. |
| 754 | */ |
| 755 | class Segment { |
| 756 | final int ix; // index into data array for this segment |
| 757 | final double ux, uy; // unit vector |
| 758 | |
| 759 | final LineInfo temp; // working line info |
| 760 | |
| 761 | boolean broken; // true if a moveto has occurred since we last added to our path |
| 762 | double cx, cy; // last point in gp |
| 763 | GeneralPath gp; // path built for this segment |
| 764 | |
| 765 | Segment(int ix) { |
| 766 | this.ix = ix; |
| 767 | double len = data[ix+2] - data[ix-1]; |
| 768 | this.ux = (data[ix] - data[ix-3]) / len; |
| 769 | this.uy = (data[ix+1] - data[ix-2]) / len; |
| 770 | this.temp = new LineInfo(); |
| 771 | } |
| 772 | |
| 773 | void init() { |
| 774 | if (LOGMAP) LOG.format("s(%d) init\n", ix); |
| 775 | broken = true; |
| 776 | cx = cy = Double.MIN_VALUE; |
| 777 | this.gp = new GeneralPath(); |
| 778 | } |
| 779 | |
| 780 | void move() { |
| 781 | if (LOGMAP) LOG.format("s(%d) move\n", ix); |
| 782 | broken = true; |
| 783 | } |
| 784 | |
| 785 | void close() { |
| 786 | if (!broken) { |
| 787 | if (LOGMAP) LOG.format("s(%d) close\n[cp]\n", ix); |
| 788 | gp.closePath(); |
| 789 | } |
| 790 | } |
| 791 | |
| 792 | void line(LineInfo li) { |
| 793 | if (LOGMAP) LOG.format("s(%d) line %g, %g to %g, %g\n", ix, li.sx, li.sy, li.lx, li.ly); |
| 794 | |
| 795 | if (li.pin(ix, temp)) { |
| 796 | if (LOGMAP) LOG.format("pin: %g, %g to %g, %g\n", temp.sx, temp.sy, temp.lx, temp.ly); |
| 797 | |
| 798 | temp.sx -= data[ix-1]; |
| 799 | double sx = data[ix-3] + temp.sx * ux - temp.sy * uy; |
| 800 | double sy = data[ix-2] + temp.sx * uy + temp.sy * ux; |
| 801 | temp.lx -= data[ix-1]; |
| 802 | double lx = data[ix-3] + temp.lx * ux - temp.ly * uy; |
| 803 | double ly = data[ix-2] + temp.lx * uy + temp.ly * ux; |
| 804 | |
| 805 | if (LOGMAP) LOG.format("points: %g, %g to %g, %g\n", sx, sy, lx, ly); |
| 806 | |
| 807 | if (sx != cx || sy != cy) { |
| 808 | if (broken) { |
| 809 | if (LOGMAP) LOG.format("[mt %g, %g]\n", sx, sy); |
| 810 | gp.moveTo((float)sx, (float)sy); |
| 811 | } else { |
| 812 | if (LOGMAP) LOG.format("[lt %g, %g]\n", sx, sy); |
| 813 | gp.lineTo((float)sx, (float)sy); |
| 814 | } |
| 815 | } |
| 816 | if (LOGMAP) LOG.format("[lt %g, %g]\n", lx, ly); |
| 817 | gp.lineTo((float)lx, (float)ly); |
| 818 | |
| 819 | broken = false; |
| 820 | cx = lx; |
| 821 | cy = ly; |
| 822 | } |
| 823 | } |
| 824 | } |
| 825 | |
| 826 | class Mapper { |
| 827 | final LineInfo li; // working line info |
| 828 | final ArrayList<Segment> segments; // cache additional data on segments, working objects |
| 829 | final Point2D.Double mpt; // last moveto source point |
| 830 | final Point2D.Double cpt; // current source point |
| 831 | boolean haveMT; // true when last op was a moveto |
| 832 | |
| 833 | Mapper() { |
| 834 | li = new LineInfo(); |
| 835 | segments = new ArrayList<Segment>(); |
| 836 | for (int i = 3; i < data.length; i += 3) { |
| 837 | if (data[i+2] != data[i-1]) { // a new segment |
| 838 | segments.add(new Segment(i)); |
| 839 | } |
| 840 | } |
| 841 | |
| 842 | mpt = new Point2D.Double(); |
| 843 | cpt = new Point2D.Double(); |
| 844 | } |
| 845 | |
| 846 | void init() { |
| 847 | if (LOGMAP) LOG.format("init\n"); |
| 848 | haveMT = false; |
| 849 | for (Segment s: segments) { |
| 850 | s.init(); |
| 851 | } |
| 852 | } |
| 853 | |
| 854 | void moveTo(double x, double y) { |
| 855 | if (LOGMAP) LOG.format("moveto %g, %g\n", x, y); |
| 856 | mpt.x = x; |
| 857 | mpt.y = y; |
| 858 | haveMT = true; |
| 859 | } |
| 860 | |
| 861 | void lineTo(double x, double y) { |
| 862 | if (LOGMAP) LOG.format("lineto %g, %g\n", x, y); |
| 863 | |
| 864 | if (haveMT) { |
| 865 | // prepare previous point for no-op check |
| 866 | cpt.x = mpt.x; |
| 867 | cpt.y = mpt.y; |
| 868 | } |
| 869 | |
| 870 | if (x == cpt.x && y == cpt.y) { |
| 871 | // lineto is a no-op |
| 872 | return; |
| 873 | } |
| 874 | |
| 875 | if (haveMT) { |
| 876 | // current point is the most recent moveto point |
| 877 | haveMT = false; |
| 878 | for (Segment s: segments) { |
| 879 | s.move(); |
| 880 | } |
| 881 | } |
| 882 | |
| 883 | li.set(cpt.x, cpt.y, x, y); |
| 884 | for (Segment s: segments) { |
| 885 | s.line(li); |
| 886 | } |
| 887 | |
| 888 | cpt.x = x; |
| 889 | cpt.y = y; |
| 890 | } |
| 891 | |
| 892 | void close() { |
| 893 | if (LOGMAP) LOG.format("close\n"); |
| 894 | lineTo(mpt.x, mpt.y); |
| 895 | for (Segment s: segments) { |
| 896 | s.close(); |
| 897 | } |
| 898 | } |
| 899 | |
| 900 | public Shape mapShape(Shape s) { |
| 901 | if (LOGMAP) LOG.format("mapshape on path: %s\n", LayoutPathImpl.SegmentPath.this); |
| 902 | PathIterator pi = s.getPathIterator(null, 1); // cheap way to handle curves. |
| 903 | |
| 904 | if (LOGMAP) LOG.format("start\n"); |
| 905 | init(); |
| 906 | |
| 907 | final double[] coords = new double[2]; |
| 908 | while (!pi.isDone()) { |
| 909 | switch (pi.currentSegment(coords)) { |
| 910 | case SEG_CLOSE: close(); break; |
| 911 | case SEG_MOVETO: moveTo(coords[0], coords[1]); break; |
| 912 | case SEG_LINETO: lineTo(coords[0], coords[1]); break; |
| 913 | default: break; |
| 914 | } |
| 915 | |
| 916 | pi.next(); |
| 917 | } |
| 918 | if (LOGMAP) LOG.format("finish\n\n"); |
| 919 | |
| 920 | GeneralPath gp = new GeneralPath(); |
| 921 | for (Segment seg: segments) { |
| 922 | gp.append(seg.gp, false); |
| 923 | } |
| 924 | return gp; |
| 925 | } |
| 926 | } |
| 927 | |
| 928 | // |
| 929 | // for debugging |
| 930 | // |
| 931 | |
| 932 | public String toString() { |
| 933 | StringBuilder b = new StringBuilder(); |
| 934 | b.append("{"); |
| 935 | b.append(etype.toString()); |
| 936 | b.append(" "); |
| 937 | for (int i = 0; i < data.length; i += 3) { |
| 938 | if (i > 0) { |
| 939 | b.append(","); |
| 940 | } |
| 941 | float x = ((int)(data[i] * 100))/100.0f; |
| 942 | float y = ((int)(data[i+1] * 100))/100.0f; |
| 943 | float l = ((int)(data[i+2] * 10))/10.0f; |
| 944 | b.append("{"); |
| 945 | b.append(x); |
| 946 | b.append(","); |
| 947 | b.append(y); |
| 948 | b.append(","); |
| 949 | b.append(l); |
| 950 | b.append("}"); |
| 951 | } |
| 952 | b.append("}"); |
| 953 | return b.toString(); |
| 954 | } |
| 955 | } |
| 956 | |
| 957 | |
| 958 | public static class EmptyPath extends LayoutPathImpl { |
| 959 | private AffineTransform tx; |
| 960 | |
| 961 | public EmptyPath(AffineTransform tx) { |
| 962 | this.tx = tx; |
| 963 | } |
| 964 | |
| 965 | public void pathToPoint(Point2D location, boolean preceding, Point2D point) { |
| 966 | if (tx != null) { |
| 967 | tx.transform(location, point); |
| 968 | } else { |
| 969 | point.setLocation(location); |
| 970 | } |
| 971 | } |
| 972 | |
| 973 | public boolean pointToPath(Point2D pt, Point2D result) { |
| 974 | result.setLocation(pt); |
| 975 | if (tx != null) { |
| 976 | try { |
| 977 | tx.inverseTransform(pt, result); |
| 978 | } |
| 979 | catch (NoninvertibleTransformException ex) { |
| 980 | } |
| 981 | } |
| 982 | return result.getX() > 0; |
| 983 | } |
| 984 | |
| 985 | public double start() { return 0; } |
| 986 | |
| 987 | public double end() { return 0; } |
| 988 | |
| 989 | public double length() { return 0; } |
| 990 | |
| 991 | public Shape mapShape(Shape s) { |
| 992 | if (tx != null) { |
| 993 | return tx.createTransformedShape(s); |
| 994 | } |
| 995 | return s; |
| 996 | } |
| 997 | } |
| 998 | } |