1 /* 2 * Copyright (c) 2007, 2018, Oracle and/or its affiliates. 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. Oracle designates this 8 * particular file as subject to the "Classpath" exception as provided 9 * by Oracle 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 22 * or visit www.oracle.com if you need additional information or have any 23 * questions. 24 */ 25 26 package com.sun.marlin; 27 28 import java.util.Arrays; 29 import com.sun.marlin.DTransformingPathConsumer2D.CurveBasicMonotonizer; 30 import com.sun.marlin.DTransformingPathConsumer2D.CurveClipSplitter; 31 32 /** 33 * The <code>DDasher</code> class takes a series of linear commands 34 * (<code>moveTo</code>, <code>lineTo</code>, <code>close</code> and 35 * <code>end</code>) and breaks them into smaller segments according to a 36 * dash pattern array and a starting dash phase. 37 * 38 * <p> Issues: in J2Se, a zero length dash segment as drawn as a very 39 * short dash, whereas Pisces does not draw anything. The PostScript 40 * semantics are unclear. 41 * 42 */ 43 public final class DDasher implements DPathConsumer2D, MarlinConst { 44 45 /* huge circle with radius ~ 2E9 only needs 12 subdivision levels */ 46 static final int REC_LIMIT = 16; 47 static final double CURVE_LEN_ERR = MarlinProperties.getCurveLengthError(); // 0.01 initial 48 static final double MIN_T_INC = 1.0d / (1 << REC_LIMIT); 49 50 // More than 24 bits of mantissa means we can no longer accurately 51 // measure the number of times cycled through the dash array so we 52 // punt and override the phase to just be 0 past that point. 53 static final double MAX_CYCLES = 16000000.0d; 54 55 private DPathConsumer2D out; 56 private double[] dash; 57 private int dashLen; 58 private double startPhase; 59 private boolean startDashOn; 60 private int startIdx; 61 62 private boolean starting; 63 private boolean needsMoveTo; 64 65 private int idx; 66 private boolean dashOn; 67 private double phase; 68 69 // The starting point of the path 70 private double sx0, sy0; 71 // the current point 72 private double cx0, cy0; 73 74 // temporary storage for the current curve 75 private final double[] curCurvepts; 76 77 // per-thread renderer context 78 final DRendererContext rdrCtx; 79 80 // flag to recycle dash array copy 81 boolean recycleDashes; 82 83 // We don't emit the first dash right away. If we did, caps would be 84 // drawn on it, but we need joins to be drawn if there's a closePath() 85 // So, we store the path elements that make up the first dash in the 86 // buffer below. 87 private double[] firstSegmentsBuffer; // dynamic array 88 private int firstSegidx; 89 90 // dashes ref (dirty) 91 final DoubleArrayCache.Reference dashes_ref; 92 // firstSegmentsBuffer ref (dirty) 93 final DoubleArrayCache.Reference firstSegmentsBuffer_ref; 94 95 // Bounds of the drawing region, at pixel precision. 96 private double[] clipRect; 97 98 // the outcode of the current point 99 private int cOutCode = 0; 100 101 private boolean subdivide = DO_CLIP_SUBDIVIDER; 102 103 private final LengthIterator li = new LengthIterator(); 104 105 private final CurveClipSplitter curveSplitter; 106 107 private double cycleLen; 108 private boolean outside; 109 private double totalSkipLen; 110 111 /** 112 * Constructs a <code>DDasher</code>. 113 * @param rdrCtx per-thread renderer context 114 */ 115 DDasher(final DRendererContext rdrCtx) { 116 this.rdrCtx = rdrCtx; 117 118 dashes_ref = rdrCtx.newDirtyDoubleArrayRef(INITIAL_ARRAY); // 1K 119 120 firstSegmentsBuffer_ref = rdrCtx.newDirtyDoubleArrayRef(INITIAL_ARRAY); // 1K 121 firstSegmentsBuffer = firstSegmentsBuffer_ref.initial; 122 123 // we need curCurvepts to be able to contain 2 curves because when 124 // dashing curves, we need to subdivide it 125 curCurvepts = new double[8 * 2]; 126 127 this.curveSplitter = rdrCtx.curveClipSplitter; 128 } 129 130 /** 131 * Initialize the <code>DDasher</code>. 132 * 133 * @param out an output <code>DPathConsumer2D</code>. 134 * @param dash an array of <code>double</code>s containing the dash pattern 135 * @param dashLen length of the given dash array 136 * @param phase a <code>double</code> containing the dash phase 137 * @param recycleDashes true to indicate to recycle the given dash array 138 * @return this instance 139 */ 140 public DDasher init(final DPathConsumer2D out, final double[] dash, final int dashLen, 141 double phase, final boolean recycleDashes) 142 { 143 this.out = out; 144 145 // Normalize so 0 <= phase < dash[0] 146 int sidx = 0; 147 dashOn = true; 148 149 // note: BasicStroke constructor checks dash elements and sum > 0 150 double sum = 0.0d; 151 for (int i = 0; i < dashLen; i++) { 152 sum += dash[i]; 153 } 154 this.cycleLen = sum; 155 156 double cycles = phase / sum; 157 if (phase < 0.0d) { 158 if (-cycles >= MAX_CYCLES) { 159 phase = 0.0d; 160 } else { 161 int fullcycles = FloatMath.floor_int(-cycles); 162 if ((fullcycles & dashLen & 1) != 0) { 163 dashOn = !dashOn; 164 } 165 phase += fullcycles * sum; 166 while (phase < 0.0d) { 167 if (--sidx < 0) { 168 sidx = dashLen - 1; 169 } 170 phase += dash[sidx]; 171 dashOn = !dashOn; 172 } 173 } 174 } else if (phase > 0.0d) { 175 if (cycles >= MAX_CYCLES) { 176 phase = 0.0d; 177 } else { 178 int fullcycles = FloatMath.floor_int(cycles); 179 if ((fullcycles & dashLen & 1) != 0) { 180 dashOn = !dashOn; 181 } 182 phase -= fullcycles * sum; 183 double d; 184 while (phase >= (d = dash[sidx])) { 185 phase -= d; 186 sidx = (sidx + 1) % dashLen; 187 dashOn = !dashOn; 188 } 189 } 190 } 191 192 this.dash = dash; 193 this.dashLen = dashLen; 194 this.phase = phase; 195 this.startPhase = phase; 196 this.startDashOn = dashOn; 197 this.startIdx = sidx; 198 this.starting = true; 199 this.needsMoveTo = false; 200 this.firstSegidx = 0; 201 202 this.recycleDashes = recycleDashes; 203 204 if (rdrCtx.doClip) { 205 this.clipRect = rdrCtx.clipRect; 206 } else { 207 this.clipRect = null; 208 this.cOutCode = 0; 209 } 210 return this; // fluent API 211 } 212 213 /** 214 * Disposes this dasher: 215 * clean up before reusing this instance 216 */ 217 void dispose() { 218 if (DO_CLEAN_DIRTY) { 219 // Force zero-fill dirty arrays: 220 Arrays.fill(curCurvepts, 0.0d); 221 } 222 // Return arrays: 223 if (recycleDashes) { 224 dash = dashes_ref.putArray(dash); 225 } 226 firstSegmentsBuffer = firstSegmentsBuffer_ref.putArray(firstSegmentsBuffer); 227 } 228 229 public double[] copyDashArray(final float[] dashes) { 230 final int len = dashes.length; 231 final double[] newDashes; 232 if (len <= MarlinConst.INITIAL_ARRAY) { 233 newDashes = dashes_ref.initial; 234 } else { 235 if (DO_STATS) { 236 rdrCtx.stats.stat_array_dasher_dasher.add(len); 237 } 238 newDashes = dashes_ref.getArray(len); 239 } 240 for (int i = 0; i < len; i++) { newDashes[i] = dashes[i]; } 241 return newDashes; 242 } 243 244 @Override 245 public void moveTo(final double x0, final double y0) { 246 if (firstSegidx != 0) { 247 out.moveTo(sx0, sy0); 248 emitFirstSegments(); 249 } 250 this.needsMoveTo = true; 251 this.idx = startIdx; 252 this.dashOn = this.startDashOn; 253 this.phase = this.startPhase; 254 this.cx0 = x0; 255 this.cy0 = y0; 256 257 // update starting point: 258 this.sx0 = x0; 259 this.sy0 = y0; 260 this.starting = true; 261 262 if (clipRect != null) { 263 final int outcode = DHelpers.outcode(x0, y0, clipRect); 264 this.cOutCode = outcode; 265 this.outside = false; 266 this.totalSkipLen = 0.0d; 267 } 268 } 269 270 private void emitSeg(double[] buf, int off, int type) { 271 switch (type) { 272 case 4: 273 out.lineTo(buf[off], buf[off + 1]); 274 return; 275 case 8: 276 out.curveTo(buf[off ], buf[off + 1], 277 buf[off + 2], buf[off + 3], 278 buf[off + 4], buf[off + 5]); 279 return; 280 case 6: 281 out.quadTo(buf[off ], buf[off + 1], 282 buf[off + 2], buf[off + 3]); 283 return; 284 default: 285 } 286 } 287 288 private void emitFirstSegments() { 289 final double[] fSegBuf = firstSegmentsBuffer; 290 291 for (int i = 0, len = firstSegidx; i < len; ) { 292 int type = (int)fSegBuf[i]; 293 emitSeg(fSegBuf, i + 1, type); 294 i += (type - 1); 295 } 296 firstSegidx = 0; 297 } 298 299 // precondition: pts must be in relative coordinates (relative to x0,y0) 300 private void goTo(final double[] pts, final int off, final int type, 301 final boolean on) 302 { 303 final int index = off + type; 304 final double x = pts[index - 4]; 305 final double y = pts[index - 3]; 306 307 if (on) { 308 if (starting) { 309 goTo_starting(pts, off, type); 310 } else { 311 if (needsMoveTo) { 312 needsMoveTo = false; 313 out.moveTo(cx0, cy0); 314 } 315 emitSeg(pts, off, type); 316 } 317 } else { 318 if (starting) { 319 // low probability test (hotspot) 320 starting = false; 321 } 322 needsMoveTo = true; 323 } 324 this.cx0 = x; 325 this.cy0 = y; 326 } 327 328 private void goTo_starting(final double[] pts, final int off, final int type) { 329 int len = type - 1; // - 2 + 1 330 int segIdx = firstSegidx; 331 double[] buf = firstSegmentsBuffer; 332 333 if (segIdx + len > buf.length) { 334 if (DO_STATS) { 335 rdrCtx.stats.stat_array_dasher_firstSegmentsBuffer 336 .add(segIdx + len); 337 } 338 firstSegmentsBuffer = buf 339 = firstSegmentsBuffer_ref.widenArray(buf, segIdx, 340 segIdx + len); 341 } 342 buf[segIdx++] = type; 343 len--; 344 // small arraycopy (2, 4 or 6) but with offset: 345 System.arraycopy(pts, off, buf, segIdx, len); 346 firstSegidx = segIdx + len; 347 } 348 349 @Override 350 public void lineTo(final double x1, final double y1) { 351 final int outcode0 = this.cOutCode; 352 353 if (clipRect != null) { 354 final int outcode1 = DHelpers.outcode(x1, y1, clipRect); 355 356 // Should clip 357 final int orCode = (outcode0 | outcode1); 358 359 if (orCode != 0) { 360 final int sideCode = outcode0 & outcode1; 361 362 // basic rejection criteria: 363 if (sideCode == 0) { 364 // ovelap clip: 365 if (subdivide) { 366 // avoid reentrance 367 subdivide = false; 368 // subdivide curve => callback with subdivided parts: 369 boolean ret = curveSplitter.splitLine(cx0, cy0, x1, y1, 370 orCode, this); 371 // reentrance is done: 372 subdivide = true; 373 if (ret) { 374 return; 375 } 376 } 377 // already subdivided so render it 378 } else { 379 this.cOutCode = outcode1; 380 skipLineTo(x1, y1); 381 return; 382 } 383 } 384 385 this.cOutCode = outcode1; 386 387 if (this.outside) { 388 this.outside = false; 389 // Adjust current index, phase & dash: 390 skipLen(); 391 } 392 } 393 _lineTo(x1, y1); 394 } 395 396 private void _lineTo(final double x1, final double y1) { 397 final double dx = x1 - cx0; 398 final double dy = y1 - cy0; 399 400 double len = dx * dx + dy * dy; 401 if (len == 0.0d) { 402 return; 403 } 404 len = Math.sqrt(len); 405 406 // The scaling factors needed to get the dx and dy of the 407 // transformed dash segments. 408 final double cx = dx / len; 409 final double cy = dy / len; 410 411 final double[] _curCurvepts = curCurvepts; 412 final double[] _dash = dash; 413 final int _dashLen = this.dashLen; 414 415 int _idx = idx; 416 boolean _dashOn = dashOn; 417 double _phase = phase; 418 419 double leftInThisDashSegment, d; 420 421 while (true) { 422 d = _dash[_idx]; 423 leftInThisDashSegment = d - _phase; 424 425 if (len <= leftInThisDashSegment) { 426 _curCurvepts[0] = x1; 427 _curCurvepts[1] = y1; 428 429 goTo(_curCurvepts, 0, 4, _dashOn); 430 431 // Advance phase within current dash segment 432 _phase += len; 433 434 // TODO: compare double values using epsilon: 435 if (len == leftInThisDashSegment) { 436 _phase = 0.0d; 437 _idx = (_idx + 1) % _dashLen; 438 _dashOn = !_dashOn; 439 } 440 break; 441 } 442 443 if (_phase == 0.0d) { 444 _curCurvepts[0] = cx0 + d * cx; 445 _curCurvepts[1] = cy0 + d * cy; 446 } else { 447 _curCurvepts[0] = cx0 + leftInThisDashSegment * cx; 448 _curCurvepts[1] = cy0 + leftInThisDashSegment * cy; 449 } 450 451 goTo(_curCurvepts, 0, 4, _dashOn); 452 453 len -= leftInThisDashSegment; 454 // Advance to next dash segment 455 _idx = (_idx + 1) % _dashLen; 456 _dashOn = !_dashOn; 457 _phase = 0.0d; 458 } 459 // Save local state: 460 idx = _idx; 461 dashOn = _dashOn; 462 phase = _phase; 463 } 464 465 private void skipLineTo(final double x1, final double y1) { 466 final double dx = x1 - cx0; 467 final double dy = y1 - cy0; 468 469 double len = dx * dx + dy * dy; 470 if (len != 0.0d) { 471 len = Math.sqrt(len); 472 } 473 474 // Accumulate skipped length: 475 this.outside = true; 476 this.totalSkipLen += len; 477 478 // Fix initial move: 479 this.needsMoveTo = true; 480 this.starting = false; 481 482 this.cx0 = x1; 483 this.cy0 = y1; 484 } 485 486 public void skipLen() { 487 double len = this.totalSkipLen; 488 this.totalSkipLen = 0.0d; 489 490 final double[] _dash = dash; 491 final int _dashLen = this.dashLen; 492 493 int _idx = idx; 494 boolean _dashOn = dashOn; 495 double _phase = phase; 496 497 // -2 to ensure having 2 iterations of the post-loop 498 // to compensate the remaining phase 499 final long fullcycles = (long)Math.floor(len / cycleLen) - 2L; 500 501 if (fullcycles > 0L) { 502 len -= cycleLen * fullcycles; 503 504 final long iterations = fullcycles * _dashLen; 505 _idx = (int) (iterations + _idx) % _dashLen; 506 _dashOn = (iterations + (_dashOn ? 1L : 0L) & 1L) == 1L; 507 } 508 509 double leftInThisDashSegment, d; 510 511 while (true) { 512 d = _dash[_idx]; 513 leftInThisDashSegment = d - _phase; 514 515 if (len <= leftInThisDashSegment) { 516 // Advance phase within current dash segment 517 _phase += len; 518 519 // TODO: compare double values using epsilon: 520 if (len == leftInThisDashSegment) { 521 _phase = 0.0d; 522 _idx = (_idx + 1) % _dashLen; 523 _dashOn = !_dashOn; 524 } 525 break; 526 } 527 528 len -= leftInThisDashSegment; 529 // Advance to next dash segment 530 _idx = (_idx + 1) % _dashLen; 531 _dashOn = !_dashOn; 532 _phase = 0.0d; 533 } 534 // Save local state: 535 idx = _idx; 536 dashOn = _dashOn; 537 phase = _phase; 538 } 539 540 // preconditions: curCurvepts must be an array of length at least 2 * type, 541 // that contains the curve we want to dash in the first type elements 542 private void somethingTo(final int type) { 543 final double[] _curCurvepts = curCurvepts; 544 if (pointCurve(_curCurvepts, type)) { 545 return; 546 } 547 final LengthIterator _li = li; 548 final double[] _dash = dash; 549 final int _dashLen = this.dashLen; 550 551 _li.initializeIterationOnCurve(_curCurvepts, type); 552 553 int _idx = idx; 554 boolean _dashOn = dashOn; 555 double _phase = phase; 556 557 // initially the current curve is at curCurvepts[0...type] 558 int curCurveoff = 0; 559 double prevT = 0.0d; 560 double t; 561 double leftInThisDashSegment = _dash[_idx] - _phase; 562 563 while ((t = _li.next(leftInThisDashSegment)) < 1.0d) { 564 if (t != 0.0d) { 565 DHelpers.subdivideAt((t - prevT) / (1.0d - prevT), 566 _curCurvepts, curCurveoff, 567 _curCurvepts, 0, type); 568 prevT = t; 569 goTo(_curCurvepts, 2, type, _dashOn); 570 curCurveoff = type; 571 } 572 // Advance to next dash segment 573 _idx = (_idx + 1) % _dashLen; 574 _dashOn = !_dashOn; 575 _phase = 0.0d; 576 leftInThisDashSegment = _dash[_idx]; 577 } 578 579 goTo(_curCurvepts, curCurveoff + 2, type, _dashOn); 580 581 _phase += _li.lastSegLen(); 582 if (_phase >= _dash[_idx]) { 583 _phase = 0.0d; 584 _idx = (_idx + 1) % _dashLen; 585 _dashOn = !_dashOn; 586 } 587 // Save local state: 588 idx = _idx; 589 dashOn = _dashOn; 590 phase = _phase; 591 592 // reset LengthIterator: 593 _li.reset(); 594 } 595 596 private void skipSomethingTo(final int type) { 597 final double[] _curCurvepts = curCurvepts; 598 if (pointCurve(_curCurvepts, type)) { 599 return; 600 } 601 final LengthIterator _li = li; 602 603 _li.initializeIterationOnCurve(_curCurvepts, type); 604 605 // In contrary to somethingTo(), 606 // just estimate properly the curve length: 607 final double len = _li.totalLength(); 608 609 // Accumulate skipped length: 610 this.outside = true; 611 this.totalSkipLen += len; 612 613 // Fix initial move: 614 this.needsMoveTo = true; 615 this.starting = false; 616 } 617 618 private static boolean pointCurve(final double[] curve, final int type) { 619 for (int i = 2; i < type; i++) { 620 if (curve[i] != curve[i-2]) { 621 return false; 622 } 623 } 624 return true; 625 } 626 627 // Objects of this class are used to iterate through curves. They return 628 // t values where the left side of the curve has a specified length. 629 // It does this by subdividing the input curve until a certain error 630 // condition has been met. A recursive subdivision procedure would 631 // return as many as 1<<limit curves, but this is an iterator and we 632 // don't need all the curves all at once, so what we carry out a 633 // lazy inorder traversal of the recursion tree (meaning we only move 634 // through the tree when we need the next subdivided curve). This saves 635 // us a lot of memory because at any one time we only need to store 636 // limit+1 curves - one for each level of the tree + 1. 637 // NOTE: the way we do things here is not enough to traverse a general 638 // tree; however, the trees we are interested in have the property that 639 // every non leaf node has exactly 2 children 640 static final class LengthIterator { 641 // Holds the curves at various levels of the recursion. The root 642 // (i.e. the original curve) is at recCurveStack[0] (but then it 643 // gets subdivided, the left half is put at 1, so most of the time 644 // only the right half of the original curve is at 0) 645 private final double[][] recCurveStack; // dirty 646 // sidesRight[i] indicates whether the node at level i+1 in the path from 647 // the root to the current leaf is a left or right child of its parent. 648 private final boolean[] sidesRight; // dirty 649 private int curveType; 650 // lastT and nextT delimit the current leaf. 651 private double nextT; 652 private double lenAtNextT; 653 private double lastT; 654 private double lenAtLastT; 655 private double lenAtLastSplit; 656 private double lastSegLen; 657 // the current level in the recursion tree. 0 is the root. limit 658 // is the deepest possible leaf. 659 private int recLevel; 660 private boolean done; 661 662 // the lengths of the lines of the control polygon. Only its first 663 // curveType/2 - 1 elements are valid. This is an optimization. See 664 // next() for more detail. 665 private final double[] curLeafCtrlPolyLengths = new double[3]; 666 667 LengthIterator() { 668 this.recCurveStack = new double[REC_LIMIT + 1][8]; 669 this.sidesRight = new boolean[REC_LIMIT]; 670 // if any methods are called without first initializing this object 671 // on a curve, we want it to fail ASAP. 672 this.nextT = Double.MAX_VALUE; 673 this.lenAtNextT = Double.MAX_VALUE; 674 this.lenAtLastSplit = Double.MIN_VALUE; 675 this.recLevel = Integer.MIN_VALUE; 676 this.lastSegLen = Double.MAX_VALUE; 677 this.done = true; 678 } 679 680 /** 681 * Reset this LengthIterator. 682 */ 683 void reset() { 684 // keep data dirty 685 // as it appears not useful to reset data: 686 if (DO_CLEAN_DIRTY) { 687 final int recLimit = recCurveStack.length - 1; 688 for (int i = recLimit; i >= 0; i--) { 689 Arrays.fill(recCurveStack[i], 0.0d); 690 } 691 Arrays.fill(sidesRight, false); 692 Arrays.fill(curLeafCtrlPolyLengths, 0.0d); 693 Arrays.fill(nextRoots, 0.0d); 694 Arrays.fill(flatLeafCoefCache, 0.0d); 695 flatLeafCoefCache[2] = -1.0d; 696 } 697 } 698 699 void initializeIterationOnCurve(final double[] pts, final int type) { 700 // optimize arraycopy (8 values faster than 6 = type): 701 System.arraycopy(pts, 0, recCurveStack[0], 0, 8); 702 this.curveType = type; 703 this.recLevel = 0; 704 this.lastT = 0.0d; 705 this.lenAtLastT = 0.0d; 706 this.nextT = 0.0d; 707 this.lenAtNextT = 0.0d; 708 goLeft(); // initializes nextT and lenAtNextT properly 709 this.lenAtLastSplit = 0.0d; 710 if (recLevel > 0) { 711 this.sidesRight[0] = false; 712 this.done = false; 713 } else { 714 // the root of the tree is a leaf so we're done. 715 this.sidesRight[0] = true; 716 this.done = true; 717 } 718 this.lastSegLen = 0.0d; 719 } 720 721 // 0 == false, 1 == true, -1 == invalid cached value. 722 private int cachedHaveLowAcceleration = -1; 723 724 private boolean haveLowAcceleration(final double err) { 725 if (cachedHaveLowAcceleration == -1) { 726 final double len1 = curLeafCtrlPolyLengths[0]; 727 final double len2 = curLeafCtrlPolyLengths[1]; 728 // the test below is equivalent to !within(len1/len2, 1, err). 729 // It is using a multiplication instead of a division, so it 730 // should be a bit faster. 731 if (!DHelpers.within(len1, len2, err * len2)) { 732 cachedHaveLowAcceleration = 0; 733 return false; 734 } 735 if (curveType == 8) { 736 final double len3 = curLeafCtrlPolyLengths[2]; 737 // if len1 is close to 2 and 2 is close to 3, that probably 738 // means 1 is close to 3 so the second part of this test might 739 // not be needed, but it doesn't hurt to include it. 740 final double errLen3 = err * len3; 741 if (!(DHelpers.within(len2, len3, errLen3) && 742 DHelpers.within(len1, len3, errLen3))) { 743 cachedHaveLowAcceleration = 0; 744 return false; 745 } 746 } 747 cachedHaveLowAcceleration = 1; 748 return true; 749 } 750 751 return (cachedHaveLowAcceleration == 1); 752 } 753 754 // we want to avoid allocations/gc so we keep this array so we 755 // can put roots in it, 756 private final double[] nextRoots = new double[4]; 757 758 // caches the coefficients of the current leaf in its flattened 759 // form (see inside next() for what that means). The cache is 760 // invalid when it's third element is negative, since in any 761 // valid flattened curve, this would be >= 0. 762 private final double[] flatLeafCoefCache = new double[]{0.0d, 0.0d, -1.0d, 0.0d}; 763 764 // returns the t value where the remaining curve should be split in 765 // order for the left subdivided curve to have length len. If len 766 // is >= than the length of the uniterated curve, it returns 1. 767 double next(final double len) { 768 final double targetLength = lenAtLastSplit + len; 769 while (lenAtNextT < targetLength) { 770 if (done) { 771 lastSegLen = lenAtNextT - lenAtLastSplit; 772 return 1.0d; 773 } 774 goToNextLeaf(); 775 } 776 lenAtLastSplit = targetLength; 777 final double leaflen = lenAtNextT - lenAtLastT; 778 double t = (targetLength - lenAtLastT) / leaflen; 779 780 // cubicRootsInAB is a fairly expensive call, so we just don't do it 781 // if the acceleration in this section of the curve is small enough. 782 if (!haveLowAcceleration(0.05d)) { 783 // We flatten the current leaf along the x axis, so that we're 784 // left with a, b, c which define a 1D Bezier curve. We then 785 // solve this to get the parameter of the original leaf that 786 // gives us the desired length. 787 final double[] _flatLeafCoefCache = flatLeafCoefCache; 788 789 if (_flatLeafCoefCache[2] < 0.0d) { 790 double x = curLeafCtrlPolyLengths[0], 791 y = x + curLeafCtrlPolyLengths[1]; 792 if (curveType == 8) { 793 double z = y + curLeafCtrlPolyLengths[2]; 794 _flatLeafCoefCache[0] = 3.0d * (x - y) + z; 795 _flatLeafCoefCache[1] = 3.0d * (y - 2.0d * x); 796 _flatLeafCoefCache[2] = 3.0d * x; 797 _flatLeafCoefCache[3] = -z; 798 } else if (curveType == 6) { 799 _flatLeafCoefCache[0] = 0.0d; 800 _flatLeafCoefCache[1] = y - 2.0d * x; 801 _flatLeafCoefCache[2] = 2.0d * x; 802 _flatLeafCoefCache[3] = -y; 803 } 804 } 805 double a = _flatLeafCoefCache[0]; 806 double b = _flatLeafCoefCache[1]; 807 double c = _flatLeafCoefCache[2]; 808 double d = t * _flatLeafCoefCache[3]; 809 810 // we use cubicRootsInAB here, because we want only roots in 0, 1, 811 // and our quadratic root finder doesn't filter, so it's just a 812 // matter of convenience. 813 final int n = DHelpers.cubicRootsInAB(a, b, c, d, nextRoots, 0, 0.0d, 1.0d); 814 if (n == 1 && !Double.isNaN(nextRoots[0])) { 815 t = nextRoots[0]; 816 } 817 } 818 // t is relative to the current leaf, so we must make it a valid parameter 819 // of the original curve. 820 t = t * (nextT - lastT) + lastT; 821 if (t >= 1.0d) { 822 t = 1.0d; 823 done = true; 824 } 825 // even if done = true, if we're here, that means targetLength 826 // is equal to, or very, very close to the total length of the 827 // curve, so lastSegLen won't be too high. In cases where len 828 // overshoots the curve, this method will exit in the while 829 // loop, and lastSegLen will still be set to the right value. 830 lastSegLen = len; 831 return t; 832 } 833 834 double totalLength() { 835 while (!done) { 836 goToNextLeaf(); 837 } 838 // reset LengthIterator: 839 reset(); 840 841 return lenAtNextT; 842 } 843 844 double lastSegLen() { 845 return lastSegLen; 846 } 847 848 // go to the next leaf (in an inorder traversal) in the recursion tree 849 // preconditions: must be on a leaf, and that leaf must not be the root. 850 private void goToNextLeaf() { 851 // We must go to the first ancestor node that has an unvisited 852 // right child. 853 final boolean[] _sides = sidesRight; 854 int _recLevel = recLevel; 855 _recLevel--; 856 857 while(_sides[_recLevel]) { 858 if (_recLevel == 0) { 859 recLevel = 0; 860 done = true; 861 return; 862 } 863 _recLevel--; 864 } 865 866 _sides[_recLevel] = true; 867 // optimize arraycopy (8 values faster than 6 = type): 868 System.arraycopy(recCurveStack[_recLevel++], 0, 869 recCurveStack[_recLevel], 0, 8); 870 recLevel = _recLevel; 871 goLeft(); 872 } 873 874 // go to the leftmost node from the current node. Return its length. 875 private void goLeft() { 876 final double len = onLeaf(); 877 if (len >= 0.0d) { 878 lastT = nextT; 879 lenAtLastT = lenAtNextT; 880 nextT += (1 << (REC_LIMIT - recLevel)) * MIN_T_INC; 881 lenAtNextT += len; 882 // invalidate caches 883 flatLeafCoefCache[2] = -1.0d; 884 cachedHaveLowAcceleration = -1; 885 } else { 886 DHelpers.subdivide(recCurveStack[recLevel], 887 recCurveStack[recLevel + 1], 888 recCurveStack[recLevel], curveType); 889 890 sidesRight[recLevel] = false; 891 recLevel++; 892 goLeft(); 893 } 894 } 895 896 // this is a bit of a hack. It returns -1 if we're not on a leaf, and 897 // the length of the leaf if we are on a leaf. 898 private double onLeaf() { 899 final double[] curve = recCurveStack[recLevel]; 900 final int _curveType = curveType; 901 double polyLen = 0.0d; 902 903 double x0 = curve[0], y0 = curve[1]; 904 for (int i = 2; i < _curveType; i += 2) { 905 final double x1 = curve[i], y1 = curve[i + 1]; 906 final double len = DHelpers.linelen(x0, y0, x1, y1); 907 polyLen += len; 908 curLeafCtrlPolyLengths[(i >> 1) - 1] = len; 909 x0 = x1; 910 y0 = y1; 911 } 912 913 final double lineLen = DHelpers.linelen(curve[0], curve[1], x0, y0); 914 915 if ((polyLen - lineLen) < CURVE_LEN_ERR || recLevel == REC_LIMIT) { 916 return (polyLen + lineLen) / 2.0d; 917 } 918 return -1.0d; 919 } 920 } 921 922 @Override 923 public void curveTo(final double x1, final double y1, 924 final double x2, final double y2, 925 final double x3, final double y3) 926 { 927 final int outcode0 = this.cOutCode; 928 929 if (clipRect != null) { 930 final int outcode1 = DHelpers.outcode(x1, y1, clipRect); 931 final int outcode2 = DHelpers.outcode(x2, y2, clipRect); 932 final int outcode3 = DHelpers.outcode(x3, y3, clipRect); 933 934 // Should clip 935 final int orCode = (outcode0 | outcode1 | outcode2 | outcode3); 936 if (orCode != 0) { 937 final int sideCode = outcode0 & outcode1 & outcode2 & outcode3; 938 939 // basic rejection criteria: 940 if (sideCode == 0) { 941 // ovelap clip: 942 if (subdivide) { 943 // avoid reentrance 944 subdivide = false; 945 // subdivide curve => callback with subdivided parts: 946 boolean ret = curveSplitter.splitCurve(cx0, cy0, x1, y1, x2, y2, x3, y3, 947 orCode, this); 948 // reentrance is done: 949 subdivide = true; 950 if (ret) { 951 return; 952 } 953 } 954 // already subdivided so render it 955 } else { 956 this.cOutCode = outcode3; 957 skipCurveTo(x1, y1, x2, y2, x3, y3); 958 return; 959 } 960 } 961 962 this.cOutCode = outcode3; 963 964 if (this.outside) { 965 this.outside = false; 966 // Adjust current index, phase & dash: 967 skipLen(); 968 } 969 } 970 _curveTo(x1, y1, x2, y2, x3, y3); 971 } 972 973 private void _curveTo(final double x1, final double y1, 974 final double x2, final double y2, 975 final double x3, final double y3) 976 { 977 final double[] _curCurvepts = curCurvepts; 978 979 // monotonize curve: 980 final CurveBasicMonotonizer monotonizer 981 = rdrCtx.monotonizer.curve(cx0, cy0, x1, y1, x2, y2, x3, y3); 982 983 final int nSplits = monotonizer.nbSplits; 984 final double[] mid = monotonizer.middle; 985 986 for (int i = 0, off = 0; i <= nSplits; i++, off += 6) { 987 // optimize arraycopy (8 values faster than 6 = type): 988 System.arraycopy(mid, off, _curCurvepts, 0, 8); 989 990 somethingTo(8); 991 } 992 } 993 994 private void skipCurveTo(final double x1, final double y1, 995 final double x2, final double y2, 996 final double x3, final double y3) 997 { 998 final double[] _curCurvepts = curCurvepts; 999 _curCurvepts[0] = cx0; _curCurvepts[1] = cy0; 1000 _curCurvepts[2] = x1; _curCurvepts[3] = y1; 1001 _curCurvepts[4] = x2; _curCurvepts[5] = y2; 1002 _curCurvepts[6] = x3; _curCurvepts[7] = y3; 1003 1004 skipSomethingTo(8); 1005 1006 this.cx0 = x3; 1007 this.cy0 = y3; 1008 } 1009 1010 @Override 1011 public void quadTo(final double x1, final double y1, 1012 final double x2, final double y2) 1013 { 1014 final int outcode0 = this.cOutCode; 1015 1016 if (clipRect != null) { 1017 final int outcode1 = DHelpers.outcode(x1, y1, clipRect); 1018 final int outcode2 = DHelpers.outcode(x2, y2, clipRect); 1019 1020 // Should clip 1021 final int orCode = (outcode0 | outcode1 | outcode2); 1022 if (orCode != 0) { 1023 final int sideCode = outcode0 & outcode1 & outcode2; 1024 1025 // basic rejection criteria: 1026 if (sideCode == 0) { 1027 // ovelap clip: 1028 if (subdivide) { 1029 // avoid reentrance 1030 subdivide = false; 1031 // subdivide curve => call lineTo() with subdivided curves: 1032 boolean ret = curveSplitter.splitQuad(cx0, cy0, x1, y1, 1033 x2, y2, orCode, this); 1034 // reentrance is done: 1035 subdivide = true; 1036 if (ret) { 1037 return; 1038 } 1039 } 1040 // already subdivided so render it 1041 } else { 1042 this.cOutCode = outcode2; 1043 skipQuadTo(x1, y1, x2, y2); 1044 return; 1045 } 1046 } 1047 1048 this.cOutCode = outcode2; 1049 1050 if (this.outside) { 1051 this.outside = false; 1052 // Adjust current index, phase & dash: 1053 skipLen(); 1054 } 1055 } 1056 _quadTo(x1, y1, x2, y2); 1057 } 1058 1059 private void _quadTo(final double x1, final double y1, 1060 final double x2, final double y2) 1061 { 1062 final double[] _curCurvepts = curCurvepts; 1063 1064 // monotonize quad: 1065 final CurveBasicMonotonizer monotonizer 1066 = rdrCtx.monotonizer.quad(cx0, cy0, x1, y1, x2, y2); 1067 1068 final int nSplits = monotonizer.nbSplits; 1069 final double[] mid = monotonizer.middle; 1070 1071 for (int i = 0, off = 0; i <= nSplits; i++, off += 4) { 1072 // optimize arraycopy (8 values faster than 6 = type): 1073 System.arraycopy(mid, off, _curCurvepts, 0, 8); 1074 1075 somethingTo(6); 1076 } 1077 } 1078 1079 private void skipQuadTo(final double x1, final double y1, 1080 final double x2, final double y2) 1081 { 1082 final double[] _curCurvepts = curCurvepts; 1083 _curCurvepts[0] = cx0; _curCurvepts[1] = cy0; 1084 _curCurvepts[2] = x1; _curCurvepts[3] = y1; 1085 _curCurvepts[4] = x2; _curCurvepts[5] = y2; 1086 1087 skipSomethingTo(6); 1088 1089 this.cx0 = x2; 1090 this.cy0 = y2; 1091 } 1092 1093 @Override 1094 public void closePath() { 1095 if (cx0 != sx0 || cy0 != sy0) { 1096 lineTo(sx0, sy0); 1097 } 1098 if (firstSegidx != 0) { 1099 if (!dashOn || needsMoveTo) { 1100 out.moveTo(sx0, sy0); 1101 } 1102 emitFirstSegments(); 1103 } 1104 moveTo(sx0, sy0); 1105 } 1106 1107 @Override 1108 public void pathDone() { 1109 if (firstSegidx != 0) { 1110 out.moveTo(sx0, sy0); 1111 emitFirstSegments(); 1112 } 1113 out.pathDone(); 1114 1115 // Dispose this instance: 1116 dispose(); 1117 } 1118 } 1119