1 // © 2016 and later: Unicode, Inc. and others. 2 // License & terms of use: http://www.unicode.org/copyright.html#License 3 /* 4 ******************************************************************************* 5 * Copyright (C) 2001-2014, International Business Machines 6 * Corporation and others. All Rights Reserved. 7 ******************************************************************************* 8 */ 9 /* Written by Simon Montagu, Matitiahu Allouche 10 * (ported from C code written by Markus W. Scherer) 11 */ 12 13 package com.ibm.icu.text; 14 15 16 import java.util.Arrays; 17 18 final class BidiLine { 19 20 /* 21 * General remarks about the functions in this file: 22 * 23 * These functions deal with the aspects of potentially mixed-directional 24 * text in a single paragraph or in a line of a single paragraph 25 * which has already been processed according to 26 * the Unicode 3.0 Bidi algorithm as defined in 27 * http://www.unicode.org/unicode/reports/tr9/ , version 13, 28 * also described in The Unicode Standard, Version 4.0.1 . 29 * 30 * This means that there is a Bidi object with a levels 31 * and a dirProps array. 32 * paraLevel and direction are also set. 33 * Only if the length of the text is zero, then levels==dirProps==NULL. 34 * 35 * The overall directionality of the paragraph 36 * or line is used to bypass the reordering steps if possible. 37 * Even purely RTL text does not need reordering there because 38 * the getLogical/VisualIndex() methods can compute the 39 * index on the fly in such a case. 40 * 41 * The implementation of the access to same-level-runs and of the reordering 42 * do attempt to provide better performance and less memory usage compared to 43 * a direct implementation of especially rule (L2) with an array of 44 * one (32-bit) integer per text character. 45 * 46 * Here, the levels array is scanned as soon as necessary, and a vector of 47 * same-level-runs is created. Reordering then is done on this vector. 48 * For each run of text positions that were resolved to the same level, 49 * only 8 bytes are stored: the first text position of the run and the visual 50 * position behind the run after reordering. 51 * One sign bit is used to hold the directionality of the run. 52 * This is inefficient if there are many very short runs. If the average run 53 * length is <2, then this uses more memory. 54 * 55 * In a further attempt to save memory, the levels array is never changed 56 * after all the resolution rules (Xn, Wn, Nn, In). 57 * Many methods have to consider the field trailingWSStart: 58 * if it is less than length, then there is an implicit trailing run 59 * at the paraLevel, 60 * which is not reflected in the levels array. 61 * This allows a line Bidi object to use the same levels array as 62 * its paragraph parent object. 63 * 64 * When a Bidi object is created for a line of a paragraph, then the 65 * paragraph's levels and dirProps arrays are reused by way of setting 66 * a pointer into them, not by copying. This again saves memory and forbids to 67 * change the now shared levels for (L1). 68 */ 69 70 /* handle trailing WS (L1) -------------------------------------------------- */ 71 72 /* 73 * setTrailingWSStart() sets the start index for a trailing 74 * run of WS in the line. This is necessary because we do not modify 75 * the paragraph's levels array that we just point into. 76 * Using trailingWSStart is another form of performing (L1). 77 * 78 * To make subsequent operations easier, we also include the run 79 * before the WS if it is at the paraLevel - we merge the two here. 80 * 81 * This method is called only from setLine(), so paraLevel is 82 * set correctly for the line even when contextual multiple paragraphs. 83 */ 84 setTrailingWSStart(Bidi bidi)85 static void setTrailingWSStart(Bidi bidi) 86 { 87 byte[] dirProps = bidi.dirProps; 88 byte[] levels = bidi.levels; 89 int start = bidi.length; 90 byte paraLevel = bidi.paraLevel; 91 92 /* If the line is terminated by a block separator, all preceding WS etc... 93 are already set to paragraph level. 94 Setting trailingWSStart to pBidi->length will avoid changing the 95 level of B chars from 0 to paraLevel in getLevels when 96 orderParagraphsLTR==TRUE 97 */ 98 if (dirProps[start - 1] == Bidi.B) { 99 bidi.trailingWSStart = start; /* currently == bidi.length */ 100 return; 101 } 102 /* go backwards across all WS, BN, explicit codes */ 103 while (start > 0 && 104 (Bidi.DirPropFlag(dirProps[start - 1]) & Bidi.MASK_WS) != 0) { 105 --start; 106 } 107 108 /* if the WS run can be merged with the previous run then do so here */ 109 while (start > 0 && levels[start - 1] == paraLevel) { 110 --start; 111 } 112 113 bidi.trailingWSStart=start; 114 } 115 setLine(Bidi paraBidi, int start, int limit)116 static Bidi setLine(Bidi paraBidi, int start, int limit) { 117 int length; 118 119 Bidi lineBidi = new Bidi(); 120 121 /* set the values in lineBidi from its paraBidi parent */ 122 /* class members are already initialized to 0 */ 123 // lineBidi.paraBidi = null; /* mark unfinished setLine */ 124 // lineBidi.flags = 0; 125 // lineBidi.controlCount = 0; 126 127 length = lineBidi.length = lineBidi.originalLength = 128 lineBidi.resultLength = limit - start; 129 130 lineBidi.text = new char[length]; 131 System.arraycopy(paraBidi.text, start, lineBidi.text, 0, length); 132 lineBidi.paraLevel = paraBidi.GetParaLevelAt(start); 133 lineBidi.paraCount = paraBidi.paraCount; 134 lineBidi.runs = new BidiRun[0]; 135 lineBidi.reorderingMode = paraBidi.reorderingMode; 136 lineBidi.reorderingOptions = paraBidi.reorderingOptions; 137 if (paraBidi.controlCount > 0) { 138 int j; 139 for (j = start; j < limit; j++) { 140 if (Bidi.IsBidiControlChar(paraBidi.text[j])) { 141 lineBidi.controlCount++; 142 } 143 } 144 lineBidi.resultLength -= lineBidi.controlCount; 145 } 146 /* copy proper subset of DirProps */ 147 lineBidi.getDirPropsMemory(length); 148 lineBidi.dirProps = lineBidi.dirPropsMemory; 149 System.arraycopy(paraBidi.dirProps, start, lineBidi.dirProps, 0, 150 length); 151 /* copy proper subset of Levels */ 152 lineBidi.getLevelsMemory(length); 153 lineBidi.levels = lineBidi.levelsMemory; 154 System.arraycopy(paraBidi.levels, start, lineBidi.levels, 0, 155 length); 156 lineBidi.runCount = -1; 157 158 if (paraBidi.direction != Bidi.MIXED) { 159 /* the parent is already trivial */ 160 lineBidi.direction = paraBidi.direction; 161 162 /* 163 * The parent's levels are all either 164 * implicitly or explicitly ==paraLevel; 165 * do the same here. 166 */ 167 if (paraBidi.trailingWSStart <= start) { 168 lineBidi.trailingWSStart = 0; 169 } else if (paraBidi.trailingWSStart < limit) { 170 lineBidi.trailingWSStart = paraBidi.trailingWSStart - start; 171 } else { 172 lineBidi.trailingWSStart = length; 173 } 174 } else { 175 byte[] levels = lineBidi.levels; 176 int i, trailingWSStart; 177 byte level; 178 179 setTrailingWSStart(lineBidi); 180 trailingWSStart = lineBidi.trailingWSStart; 181 182 /* recalculate lineBidi.direction */ 183 if (trailingWSStart == 0) { 184 /* all levels are at paraLevel */ 185 lineBidi.direction = (byte)(lineBidi.paraLevel & 1); 186 } else { 187 /* get the level of the first character */ 188 level = (byte)(levels[0] & 1); 189 190 /* if there is anything of a different level, then the line 191 is mixed */ 192 if (trailingWSStart < length && 193 (lineBidi.paraLevel & 1) != level) { 194 /* the trailing WS is at paraLevel, which differs from 195 levels[0] */ 196 lineBidi.direction = Bidi.MIXED; 197 } else { 198 /* see if levels[1..trailingWSStart-1] have the same 199 direction as levels[0] and paraLevel */ 200 for (i = 1; ; i++) { 201 if (i == trailingWSStart) { 202 /* the direction values match those in level */ 203 lineBidi.direction = level; 204 break; 205 } else if ((levels[i] & 1) != level) { 206 lineBidi.direction = Bidi.MIXED; 207 break; 208 } 209 } 210 } 211 } 212 213 switch(lineBidi.direction) { 214 case Bidi.DIRECTION_LEFT_TO_RIGHT: 215 /* make sure paraLevel is even */ 216 lineBidi.paraLevel = (byte) 217 ((lineBidi.paraLevel + 1) & ~1); 218 219 /* all levels are implicitly at paraLevel (important for 220 getLevels()) */ 221 lineBidi.trailingWSStart = 0; 222 break; 223 case Bidi.DIRECTION_RIGHT_TO_LEFT: 224 /* make sure paraLevel is odd */ 225 lineBidi.paraLevel |= 1; 226 227 /* all levels are implicitly at paraLevel (important for 228 getLevels()) */ 229 lineBidi.trailingWSStart = 0; 230 break; 231 default: 232 break; 233 } 234 } 235 lineBidi.paraBidi = paraBidi; /* mark successful setLine */ 236 return lineBidi; 237 } 238 getLevelAt(Bidi bidi, int charIndex)239 static byte getLevelAt(Bidi bidi, int charIndex) 240 { 241 /* return paraLevel if in the trailing WS run, otherwise the real level */ 242 if (bidi.direction != Bidi.MIXED || charIndex >= bidi.trailingWSStart) { 243 return bidi.GetParaLevelAt(charIndex); 244 } else { 245 return bidi.levels[charIndex]; 246 } 247 } 248 getLevels(Bidi bidi)249 static byte[] getLevels(Bidi bidi) 250 { 251 int start = bidi.trailingWSStart; 252 int length = bidi.length; 253 254 if (start != length) { 255 /* the current levels array does not reflect the WS run */ 256 /* 257 * After the previous if(), we know that the levels array 258 * has an implicit trailing WS run and therefore does not fully 259 * reflect itself all the levels. 260 * This must be a Bidi object for a line, and 261 * we need to create a new levels array. 262 */ 263 /* bidi.paraLevel is ok even if contextual multiple paragraphs, 264 since bidi is a line object */ 265 Arrays.fill(bidi.levels, start, length, bidi.paraLevel); 266 267 /* this new levels array is set for the line and reflects the WS run */ 268 bidi.trailingWSStart = length; 269 } 270 if (length < bidi.levels.length) { 271 byte[] levels = new byte[length]; 272 System.arraycopy(bidi.levels, 0, levels, 0, length); 273 return levels; 274 } 275 return bidi.levels; 276 } 277 getLogicalRun(Bidi bidi, int logicalPosition)278 static BidiRun getLogicalRun(Bidi bidi, int logicalPosition) 279 { 280 /* this is done based on runs rather than on levels since levels have 281 a special interpretation when REORDER_RUNS_ONLY 282 */ 283 BidiRun newRun = new BidiRun(), iRun; 284 getRuns(bidi); 285 int runCount = bidi.runCount; 286 int visualStart = 0, logicalLimit = 0; 287 iRun = bidi.runs[0]; 288 289 for (int i = 0; i < runCount; i++) { 290 iRun = bidi.runs[i]; 291 logicalLimit = iRun.start + iRun.limit - visualStart; 292 if ((logicalPosition >= iRun.start) && 293 (logicalPosition < logicalLimit)) { 294 break; 295 } 296 visualStart = iRun.limit; 297 } 298 newRun.start = iRun.start; 299 newRun.limit = logicalLimit; 300 newRun.level = iRun.level; 301 return newRun; 302 } 303 getVisualRun(Bidi bidi, int runIndex)304 static BidiRun getVisualRun(Bidi bidi, int runIndex) 305 { 306 int start = bidi.runs[runIndex].start; 307 int limit; 308 byte level = bidi.runs[runIndex].level; 309 310 if (runIndex > 0) { 311 limit = start + 312 bidi.runs[runIndex].limit - 313 bidi.runs[runIndex - 1].limit; 314 } else { 315 limit = start + bidi.runs[0].limit; 316 } 317 return new BidiRun(start, limit, level); 318 } 319 320 /* in trivial cases there is only one trivial run; called by getRuns() */ getSingleRun(Bidi bidi, byte level)321 static void getSingleRun(Bidi bidi, byte level) { 322 /* simple, single-run case */ 323 bidi.runs = bidi.simpleRuns; 324 bidi.runCount = 1; 325 326 /* fill and reorder the single run */ 327 bidi.runs[0] = new BidiRun(0, bidi.length, level); 328 } 329 330 /* reorder the runs array (L2) ---------------------------------------------- */ 331 332 /* 333 * Reorder the same-level runs in the runs array. 334 * Here, runCount>1 and maxLevel>=minLevel>=paraLevel. 335 * All the visualStart fields=logical start before reordering. 336 * The "odd" bits are not set yet. 337 * 338 * Reordering with this data structure lends itself to some handy shortcuts: 339 * 340 * Since each run is moved but not modified, and since at the initial maxLevel 341 * each sequence of same-level runs consists of only one run each, we 342 * don't need to do anything there and can predecrement maxLevel. 343 * In many simple cases, the reordering is thus done entirely in the 344 * index mapping. 345 * Also, reordering occurs only down to the lowest odd level that occurs, 346 * which is minLevel|1. However, if the lowest level itself is odd, then 347 * in the last reordering the sequence of the runs at this level or higher 348 * will be all runs, and we don't need the elaborate loop to search for them. 349 * This is covered by ++minLevel instead of minLevel|=1 followed 350 * by an extra reorder-all after the reorder-some loop. 351 * About a trailing WS run: 352 * Such a run would need special treatment because its level is not 353 * reflected in levels[] if this is not a paragraph object. 354 * Instead, all characters from trailingWSStart on are implicitly at 355 * paraLevel. 356 * However, for all maxLevel>paraLevel, this run will never be reordered 357 * and does not need to be taken into account. maxLevel==paraLevel is only reordered 358 * if minLevel==paraLevel is odd, which is done in the extra segment. 359 * This means that for the main reordering loop we don't need to consider 360 * this run and can --runCount. If it is later part of the all-runs 361 * reordering, then runCount is adjusted accordingly. 362 */ reorderLine(Bidi bidi, byte minLevel, byte maxLevel)363 private static void reorderLine(Bidi bidi, byte minLevel, byte maxLevel) { 364 365 /* nothing to do? */ 366 if (maxLevel<=(minLevel|1)) { 367 return; 368 } 369 370 BidiRun[] runs; 371 BidiRun tempRun; 372 byte[] levels; 373 int firstRun, endRun, limitRun, runCount; 374 375 /* 376 * Reorder only down to the lowest odd level 377 * and reorder at an odd minLevel in a separate, simpler loop. 378 * See comments above for why minLevel is always incremented. 379 */ 380 ++minLevel; 381 382 runs = bidi.runs; 383 levels = bidi.levels; 384 runCount = bidi.runCount; 385 386 /* do not include the WS run at paraLevel<=old minLevel except in the simple loop */ 387 if (bidi.trailingWSStart < bidi.length) { 388 --runCount; 389 } 390 391 while (--maxLevel >= minLevel) { 392 firstRun = 0; 393 394 /* loop for all sequences of runs */ 395 for ( ; ; ) { 396 /* look for a sequence of runs that are all at >=maxLevel */ 397 /* look for the first run of such a sequence */ 398 while (firstRun < runCount && levels[runs[firstRun].start] < maxLevel) { 399 ++firstRun; 400 } 401 if (firstRun >= runCount) { 402 break; /* no more such runs */ 403 } 404 405 /* look for the limit run of such a sequence (the run behind it) */ 406 for (limitRun = firstRun; ++limitRun < runCount && 407 levels[runs[limitRun].start]>=maxLevel; ) {} 408 409 /* Swap the entire sequence of runs from firstRun to limitRun-1. */ 410 endRun = limitRun - 1; 411 while (firstRun < endRun) { 412 tempRun = runs[firstRun]; 413 runs[firstRun] = runs[endRun]; 414 runs[endRun] = tempRun; 415 ++firstRun; 416 --endRun; 417 } 418 419 if (limitRun == runCount) { 420 break; /* no more such runs */ 421 } else { 422 firstRun = limitRun + 1; 423 } 424 } 425 } 426 427 /* now do maxLevel==old minLevel (==odd!), see above */ 428 if ((minLevel & 1) == 0) { 429 firstRun = 0; 430 431 /* include the trailing WS run in this complete reordering */ 432 if (bidi.trailingWSStart == bidi.length) { 433 --runCount; 434 } 435 436 /* Swap the entire sequence of all runs. (endRun==runCount) */ 437 while (firstRun < runCount) { 438 tempRun = runs[firstRun]; 439 runs[firstRun] = runs[runCount]; 440 runs[runCount] = tempRun; 441 ++firstRun; 442 --runCount; 443 } 444 } 445 } 446 447 /* compute the runs array --------------------------------------------------- */ 448 getRunFromLogicalIndex(Bidi bidi, int logicalIndex)449 static int getRunFromLogicalIndex(Bidi bidi, int logicalIndex) { 450 BidiRun[] runs = bidi.runs; 451 int runCount = bidi.runCount, visualStart = 0, i, length, logicalStart; 452 453 for (i = 0; i < runCount; i++) { 454 length = runs[i].limit - visualStart; 455 logicalStart = runs[i].start; 456 if ((logicalIndex >= logicalStart) && (logicalIndex < (logicalStart+length))) { 457 return i; 458 } 459 visualStart += length; 460 } 461 ///CLOVER:OFF 462 /* we should never get here */ 463 throw new IllegalStateException("Internal ICU error in getRunFromLogicalIndex"); 464 ///CLOVER:ON 465 } 466 467 /* 468 * Compute the runs array from the levels array. 469 * After getRuns() returns true, runCount is guaranteed to be >0 470 * and the runs are reordered. 471 * Odd-level runs have visualStart on their visual right edge and 472 * they progress visually to the left. 473 * If option OPTION_INSERT_MARKS is set, insertRemove will contain the 474 * sum of appropriate LRM/RLM_BEFORE/AFTER flags. 475 * If option OPTION_REMOVE_CONTROLS is set, insertRemove will contain the 476 * negative number of BiDi control characters within this run. 477 */ getRuns(Bidi bidi)478 static void getRuns(Bidi bidi) { 479 /* 480 * This method returns immediately if the runs are already set. This 481 * includes the case of length==0 (handled in setPara).. 482 */ 483 if (bidi.runCount >= 0) { 484 return; 485 } 486 if (bidi.direction != Bidi.MIXED) { 487 /* simple, single-run case - this covers length==0 */ 488 /* bidi.paraLevel is ok even for contextual multiple paragraphs */ 489 getSingleRun(bidi, bidi.paraLevel); 490 } else /* Bidi.MIXED, length>0 */ { 491 /* mixed directionality */ 492 int length = bidi.length, limit; 493 byte[] levels = bidi.levels; 494 int i, runCount; 495 byte level = -1; /* initialize with no valid level */ 496 /* 497 * If there are WS characters at the end of the line 498 * and the run preceding them has a level different from 499 * paraLevel, then they will form their own run at paraLevel (L1). 500 * Count them separately. 501 * We need some special treatment for this in order to not 502 * modify the levels array which a line Bidi object shares 503 * with its paragraph parent and its other line siblings. 504 * In other words, for the trailing WS, it may be 505 * levels[]!=paraLevel but we have to treat it like it were so. 506 */ 507 limit = bidi.trailingWSStart; 508 /* count the runs, there is at least one non-WS run, and limit>0 */ 509 runCount = 0; 510 for (i = 0; i < limit; ++i) { 511 /* increment runCount at the start of each run */ 512 if (levels[i] != level) { 513 ++runCount; 514 level = levels[i]; 515 } 516 } 517 518 /* 519 * We don't need to see if the last run can be merged with a trailing 520 * WS run because setTrailingWSStart() would have done that. 521 */ 522 if (runCount == 1 && limit == length) { 523 /* There is only one non-WS run and no trailing WS-run. */ 524 getSingleRun(bidi, levels[0]); 525 } else /* runCount>1 || limit<length */ { 526 /* allocate and set the runs */ 527 BidiRun[] runs; 528 int runIndex, start; 529 byte minLevel = Bidi.MAX_EXPLICIT_LEVEL + 1; 530 byte maxLevel=0; 531 532 /* now, count a (non-mergeable) WS run */ 533 if (limit < length) { 534 ++runCount; 535 } 536 537 /* runCount > 1 */ 538 bidi.getRunsMemory(runCount); 539 runs = bidi.runsMemory; 540 541 /* set the runs */ 542 /* FOOD FOR THOUGHT: this could be optimized, e.g.: 543 * 464->444, 484->444, 575->555, 595->555 544 * However, that would take longer. Check also how it would 545 * interact with BiDi control removal and inserting Marks. 546 */ 547 runIndex = 0; 548 549 /* search for the run limits and initialize visualLimit values with the run lengths */ 550 i = 0; 551 do { 552 /* prepare this run */ 553 start = i; 554 level = levels[i]; 555 if (level < minLevel) { 556 minLevel = level; 557 } 558 if (level > maxLevel) { 559 maxLevel = level; 560 } 561 562 /* look for the run limit */ 563 while (++i < limit && levels[i] == level) {} 564 565 /* i is another run limit */ 566 runs[runIndex] = new BidiRun(start, i - start, level); 567 ++runIndex; 568 } while (i < limit); 569 570 if (limit < length) { 571 /* there is a separate WS run */ 572 runs[runIndex] = new BidiRun(limit, length - limit, bidi.paraLevel); 573 /* For the trailing WS run, bidi.paraLevel is ok even 574 if contextual multiple paragraphs. */ 575 if (bidi.paraLevel < minLevel) { 576 minLevel = bidi.paraLevel; 577 } 578 } 579 580 /* set the object fields */ 581 bidi.runs = runs; 582 bidi.runCount = runCount; 583 584 reorderLine(bidi, minLevel, maxLevel); 585 586 /* now add the direction flags and adjust the visualLimit's to be just that */ 587 /* this loop will also handle the trailing WS run */ 588 limit = 0; 589 for (i = 0; i < runCount; ++i) { 590 runs[i].level = levels[runs[i].start]; 591 limit = (runs[i].limit += limit); 592 } 593 594 /* Set the embedding level for the trailing WS run. */ 595 /* For a RTL paragraph, it will be the *first* run in visual order. */ 596 /* For the trailing WS run, bidi.paraLevel is ok even if 597 contextual multiple paragraphs. */ 598 if (runIndex < runCount) { 599 int trailingRun = ((bidi.paraLevel & 1) != 0)? 0 : runIndex; 600 runs[trailingRun].level = bidi.paraLevel; 601 } 602 } 603 } 604 605 /* handle insert LRM/RLM BEFORE/AFTER run */ 606 if (bidi.insertPoints.size > 0) { 607 Bidi.Point point; 608 int runIndex, ip; 609 for (ip = 0; ip < bidi.insertPoints.size; ip++) { 610 point = bidi.insertPoints.points[ip]; 611 runIndex = getRunFromLogicalIndex(bidi, point.pos); 612 bidi.runs[runIndex].insertRemove |= point.flag; 613 } 614 } 615 616 /* handle remove BiDi control characters */ 617 if (bidi.controlCount > 0) { 618 int runIndex, ic; 619 char c; 620 for (ic = 0; ic < bidi.length; ic++) { 621 c = bidi.text[ic]; 622 if (Bidi.IsBidiControlChar(c)) { 623 runIndex = getRunFromLogicalIndex(bidi, ic); 624 bidi.runs[runIndex].insertRemove--; 625 } 626 } 627 } 628 } 629 prepareReorder(byte[] levels, byte[] pMinLevel, byte[] pMaxLevel)630 static int[] prepareReorder(byte[] levels, byte[] pMinLevel, byte[] pMaxLevel) 631 { 632 int start; 633 byte level, minLevel, maxLevel; 634 635 if (levels == null || levels.length <= 0) { 636 return null; 637 } 638 639 /* determine minLevel and maxLevel */ 640 minLevel = Bidi.MAX_EXPLICIT_LEVEL + 1; 641 maxLevel = 0; 642 for (start = levels.length; start>0; ) { 643 level = levels[--start]; 644 if (level < 0) { 645 return null; 646 } 647 if (level > (Bidi.MAX_EXPLICIT_LEVEL + 1)) { 648 return null; 649 } 650 if (level < minLevel) { 651 minLevel = level; 652 } 653 if (level > maxLevel) { 654 maxLevel = level; 655 } 656 } 657 pMinLevel[0] = minLevel; 658 pMaxLevel[0] = maxLevel; 659 660 /* initialize the index map */ 661 int[] indexMap = new int[levels.length]; 662 for (start = levels.length; start > 0; ) { 663 --start; 664 indexMap[start] = start; 665 } 666 667 return indexMap; 668 } 669 reorderLogical(byte[] levels)670 static int[] reorderLogical(byte[] levels) 671 { 672 byte[] aMinLevel = new byte[1]; 673 byte[] aMaxLevel = new byte[1]; 674 int start, limit, sumOfSosEos; 675 byte minLevel, maxLevel; 676 int[] indexMap = prepareReorder(levels, aMinLevel, aMaxLevel); 677 if (indexMap == null) { 678 return null; 679 } 680 681 minLevel = aMinLevel[0]; 682 maxLevel = aMaxLevel[0]; 683 684 /* nothing to do? */ 685 if (minLevel == maxLevel && (minLevel & 1) == 0) { 686 return indexMap; 687 } 688 689 /* reorder only down to the lowest odd level */ 690 minLevel |= 1; 691 692 /* loop maxLevel..minLevel */ 693 do { 694 start = 0; 695 696 /* loop for all sequences of levels to reorder at the current maxLevel */ 697 for ( ; ; ) { 698 /* look for a sequence of levels that are all at >=maxLevel */ 699 /* look for the first index of such a sequence */ 700 while (start < levels.length && levels[start] < maxLevel) { 701 ++start; 702 } 703 if (start >= levels.length) { 704 break; /* no more such sequences */ 705 } 706 707 /* look for the limit of such a sequence (the index behind it) */ 708 for (limit = start; ++limit < levels.length && levels[limit] >= maxLevel; ) {} 709 710 /* 711 * sos=start of sequence, eos=end of sequence 712 * 713 * The closed (inclusive) interval from sos to eos includes all the logical 714 * and visual indexes within this sequence. They are logically and 715 * visually contiguous and in the same range. 716 * 717 * For each run, the new visual index=sos+eos-old visual index; 718 * we pre-add sos+eos into sumOfSosEos -> 719 * new visual index=sumOfSosEos-old visual index; 720 */ 721 sumOfSosEos = start + limit - 1; 722 723 /* reorder each index in the sequence */ 724 do { 725 indexMap[start] = sumOfSosEos - indexMap[start]; 726 } while (++start < limit); 727 728 /* start==limit */ 729 if (limit == levels.length) { 730 break; /* no more such sequences */ 731 } else { 732 start = limit + 1; 733 } 734 } 735 } while (--maxLevel >= minLevel); 736 return indexMap; 737 } 738 reorderVisual(byte[] levels)739 static int[] reorderVisual(byte[] levels) 740 { 741 byte[] aMinLevel = new byte[1]; 742 byte[] aMaxLevel = new byte[1]; 743 int start, end, limit, temp; 744 byte minLevel, maxLevel; 745 746 int[] indexMap = prepareReorder(levels, aMinLevel, aMaxLevel); 747 if (indexMap == null) { 748 return null; 749 } 750 751 minLevel = aMinLevel[0]; 752 maxLevel = aMaxLevel[0]; 753 754 /* nothing to do? */ 755 if (minLevel == maxLevel && (minLevel & 1) == 0) { 756 return indexMap; 757 } 758 759 /* reorder only down to the lowest odd level */ 760 minLevel |= 1; 761 762 /* loop maxLevel..minLevel */ 763 do { 764 start = 0; 765 766 /* loop for all sequences of levels to reorder at the current maxLevel */ 767 for ( ; ; ) { 768 /* look for a sequence of levels that are all at >=maxLevel */ 769 /* look for the first index of such a sequence */ 770 while (start < levels.length && levels[start] < maxLevel) { 771 ++start; 772 } 773 if (start >= levels.length) { 774 break; /* no more such runs */ 775 } 776 777 /* look for the limit of such a sequence (the index behind it) */ 778 for (limit = start; ++limit < levels.length && levels[limit] >= maxLevel; ) {} 779 780 /* 781 * Swap the entire interval of indexes from start to limit-1. 782 * We don't need to swap the levels for the purpose of this 783 * algorithm: the sequence of levels that we look at does not 784 * move anyway. 785 */ 786 end = limit - 1; 787 while (start < end) { 788 temp = indexMap[start]; 789 indexMap[start] = indexMap[end]; 790 indexMap[end] = temp; 791 792 ++start; 793 --end; 794 } 795 796 if (limit == levels.length) { 797 break; /* no more such sequences */ 798 } else { 799 start = limit + 1; 800 } 801 } 802 } while (--maxLevel >= minLevel); 803 804 return indexMap; 805 } 806 getVisualIndex(Bidi bidi, int logicalIndex)807 static int getVisualIndex(Bidi bidi, int logicalIndex) 808 { 809 int visualIndex = Bidi.MAP_NOWHERE; 810 811 /* we can do the trivial cases without the runs array */ 812 switch(bidi.direction) { 813 case Bidi.LTR: 814 visualIndex = logicalIndex; 815 break; 816 case Bidi.RTL: 817 visualIndex = bidi.length - logicalIndex - 1; 818 break; 819 default: 820 getRuns(bidi); 821 BidiRun[] runs = bidi.runs; 822 int i, visualStart = 0, offset, length; 823 824 /* linear search for the run, search on the visual runs */ 825 for (i = 0; i < bidi.runCount; ++i) { 826 length = runs[i].limit - visualStart; 827 offset = logicalIndex - runs[i].start; 828 if (offset >= 0 && offset < length) { 829 if (runs[i].isEvenRun()) { 830 /* LTR */ 831 visualIndex = visualStart + offset; 832 } else { 833 /* RTL */ 834 visualIndex = visualStart + length - offset - 1; 835 } 836 break; /* exit for loop */ 837 } 838 visualStart += length; 839 } 840 if (i >= bidi.runCount) { 841 return Bidi.MAP_NOWHERE; 842 } 843 } 844 845 if (bidi.insertPoints.size > 0) { 846 /* add the number of added marks until the calculated visual index */ 847 BidiRun runs[] = bidi.runs; 848 int i, length, insertRemove; 849 int visualStart = 0, markFound = 0; 850 for (i = 0; ; i++, visualStart += length) { 851 length = runs[i].limit - visualStart; 852 insertRemove = runs[i].insertRemove; 853 if ((insertRemove & (Bidi.LRM_BEFORE|Bidi.RLM_BEFORE)) > 0) { 854 markFound++; 855 } 856 /* is it the run containing the visual index? */ 857 if (visualIndex < runs[i].limit) { 858 return visualIndex + markFound; 859 } 860 if ((insertRemove & (Bidi.LRM_AFTER|Bidi.RLM_AFTER)) > 0) { 861 markFound++; 862 } 863 } 864 } 865 else if (bidi.controlCount > 0) { 866 /* subtract the number of controls until the calculated visual index */ 867 BidiRun[] runs = bidi.runs; 868 int i, j, start, limit, length, insertRemove; 869 int visualStart = 0, controlFound = 0; 870 char uchar = bidi.text[logicalIndex]; 871 /* is the logical index pointing to a control ? */ 872 if (Bidi.IsBidiControlChar(uchar)) { 873 return Bidi.MAP_NOWHERE; 874 } 875 /* loop on runs */ 876 for (i = 0; ; i++, visualStart += length) { 877 length = runs[i].limit - visualStart; 878 insertRemove = runs[i].insertRemove; 879 /* calculated visual index is beyond this run? */ 880 if (visualIndex >= runs[i].limit) { 881 controlFound -= insertRemove; 882 continue; 883 } 884 /* calculated visual index must be within current run */ 885 if (insertRemove == 0) { 886 return visualIndex - controlFound; 887 } 888 if (runs[i].isEvenRun()) { 889 /* LTR: check from run start to logical index */ 890 start = runs[i].start; 891 limit = logicalIndex; 892 } else { 893 /* RTL: check from logical index to run end */ 894 start = logicalIndex + 1; 895 limit = runs[i].start + length; 896 } 897 for (j = start; j < limit; j++) { 898 uchar = bidi.text[j]; 899 if (Bidi.IsBidiControlChar(uchar)) { 900 controlFound++; 901 } 902 } 903 return visualIndex - controlFound; 904 } 905 } 906 907 return visualIndex; 908 } 909 getLogicalIndex(Bidi bidi, int visualIndex)910 static int getLogicalIndex(Bidi bidi, int visualIndex) 911 { 912 BidiRun[] runs; 913 int i, runCount, start; 914 915 runs = bidi.runs; 916 runCount = bidi.runCount; 917 if (bidi.insertPoints.size > 0) { 918 /* handle inserted LRM/RLM */ 919 int markFound = 0, insertRemove; 920 int visualStart = 0, length; 921 /* subtract number of marks until visual index */ 922 for (i = 0; ; i++, visualStart += length) { 923 length = runs[i].limit - visualStart; 924 insertRemove = runs[i].insertRemove; 925 if ((insertRemove & (Bidi.LRM_BEFORE|Bidi.RLM_BEFORE)) > 0) { 926 if (visualIndex <= (visualStart+markFound)) { 927 return Bidi.MAP_NOWHERE; 928 } 929 markFound++; 930 } 931 /* is adjusted visual index within this run? */ 932 if (visualIndex < (runs[i].limit + markFound)) { 933 visualIndex -= markFound; 934 break; 935 } 936 if ((insertRemove & (Bidi.LRM_AFTER|Bidi.RLM_AFTER)) > 0) { 937 if (visualIndex == (visualStart + length + markFound)) { 938 return Bidi.MAP_NOWHERE; 939 } 940 markFound++; 941 } 942 } 943 } 944 else if (bidi.controlCount > 0) { 945 /* handle removed BiDi control characters */ 946 int controlFound = 0, insertRemove, length; 947 int logicalStart, logicalEnd, visualStart = 0, j, k; 948 char uchar; 949 boolean evenRun; 950 /* add number of controls until visual index */ 951 for (i = 0; ; i++, visualStart += length) { 952 length = runs[i].limit - visualStart; 953 insertRemove = runs[i].insertRemove; 954 /* is adjusted visual index beyond current run? */ 955 if (visualIndex >= (runs[i].limit - controlFound + insertRemove)) { 956 controlFound -= insertRemove; 957 continue; 958 } 959 /* adjusted visual index is within current run */ 960 if (insertRemove == 0) { 961 visualIndex += controlFound; 962 break; 963 } 964 /* count non-control chars until visualIndex */ 965 logicalStart = runs[i].start; 966 evenRun = runs[i].isEvenRun(); 967 logicalEnd = logicalStart + length - 1; 968 for (j = 0; j < length; j++) { 969 k= evenRun ? logicalStart+j : logicalEnd-j; 970 uchar = bidi.text[k]; 971 if (Bidi.IsBidiControlChar(uchar)) { 972 controlFound++; 973 } 974 if ((visualIndex + controlFound) == (visualStart + j)) { 975 break; 976 } 977 } 978 visualIndex += controlFound; 979 break; 980 } 981 } 982 /* handle all cases */ 983 if (runCount <= 10) { 984 /* linear search for the run */ 985 for (i = 0; visualIndex >= runs[i].limit; ++i) {} 986 } else { 987 /* binary search for the run */ 988 int begin = 0, limit = runCount; 989 990 /* the middle if() is guaranteed to find the run, we don't need a loop limit */ 991 for ( ; ; ) { 992 i = (begin + limit) >>> 1; 993 if (visualIndex >= runs[i].limit) { 994 begin = i + 1; 995 } else if (i==0 || visualIndex >= runs[i-1].limit) { 996 break; 997 } else { 998 limit = i; 999 } 1000 } 1001 } 1002 1003 start= runs[i].start; 1004 if (runs[i].isEvenRun()) { 1005 /* LTR */ 1006 /* the offset in runs[i] is visualIndex-runs[i-1].visualLimit */ 1007 if (i > 0) { 1008 visualIndex -= runs[i - 1].limit; 1009 } 1010 return start + visualIndex; 1011 } else { 1012 /* RTL */ 1013 return start + runs[i].limit - visualIndex - 1; 1014 } 1015 } 1016 getLogicalMap(Bidi bidi)1017 static int[] getLogicalMap(Bidi bidi) 1018 { 1019 /* fill a logical-to-visual index map using the runs[] */ 1020 BidiRun[] runs = bidi.runs; 1021 int logicalStart, visualStart, logicalLimit, visualLimit; 1022 int[] indexMap = new int[bidi.length]; 1023 if (bidi.length > bidi.resultLength) { 1024 Arrays.fill(indexMap, Bidi.MAP_NOWHERE); 1025 } 1026 1027 visualStart = 0; 1028 for (int j = 0; j < bidi.runCount; ++j) { 1029 logicalStart = runs[j].start; 1030 visualLimit = runs[j].limit; 1031 if (runs[j].isEvenRun()) { 1032 do { /* LTR */ 1033 indexMap[logicalStart++] = visualStart++; 1034 } while (visualStart < visualLimit); 1035 } else { 1036 logicalStart += visualLimit - visualStart; /* logicalLimit */ 1037 do { /* RTL */ 1038 indexMap[--logicalStart] = visualStart++; 1039 } while (visualStart < visualLimit); 1040 } 1041 /* visualStart==visualLimit; */ 1042 } 1043 1044 if (bidi.insertPoints.size > 0) { 1045 int markFound = 0, runCount = bidi.runCount; 1046 int length, insertRemove, i, j; 1047 runs = bidi.runs; 1048 visualStart = 0; 1049 /* add number of marks found until each index */ 1050 for (i = 0; i < runCount; i++, visualStart += length) { 1051 length = runs[i].limit - visualStart; 1052 insertRemove = runs[i].insertRemove; 1053 if ((insertRemove & (Bidi.LRM_BEFORE|Bidi.RLM_BEFORE)) > 0) { 1054 markFound++; 1055 } 1056 if (markFound > 0) { 1057 logicalStart = runs[i].start; 1058 logicalLimit = logicalStart + length; 1059 for (j = logicalStart; j < logicalLimit; j++) { 1060 indexMap[j] += markFound; 1061 } 1062 } 1063 if ((insertRemove & (Bidi.LRM_AFTER|Bidi.RLM_AFTER)) > 0) { 1064 markFound++; 1065 } 1066 } 1067 } 1068 else if (bidi.controlCount > 0) { 1069 int controlFound = 0, runCount = bidi.runCount; 1070 int length, insertRemove, i, j, k; 1071 boolean evenRun; 1072 char uchar; 1073 runs = bidi.runs; 1074 visualStart = 0; 1075 /* subtract number of controls found until each index */ 1076 for (i = 0; i < runCount; i++, visualStart += length) { 1077 length = runs[i].limit - visualStart; 1078 insertRemove = runs[i].insertRemove; 1079 /* no control found within previous runs nor within this run */ 1080 if ((controlFound - insertRemove) == 0) { 1081 continue; 1082 } 1083 logicalStart = runs[i].start; 1084 evenRun = runs[i].isEvenRun(); 1085 logicalLimit = logicalStart + length; 1086 /* if no control within this run */ 1087 if (insertRemove == 0) { 1088 for (j = logicalStart; j < logicalLimit; j++) { 1089 indexMap[j] -= controlFound; 1090 } 1091 continue; 1092 } 1093 for (j = 0; j < length; j++) { 1094 k = evenRun ? logicalStart + j : logicalLimit - j - 1; 1095 uchar = bidi.text[k]; 1096 if (Bidi.IsBidiControlChar(uchar)) { 1097 controlFound++; 1098 indexMap[k] = Bidi.MAP_NOWHERE; 1099 continue; 1100 } 1101 indexMap[k] -= controlFound; 1102 } 1103 } 1104 } 1105 return indexMap; 1106 } 1107 getVisualMap(Bidi bidi)1108 static int[] getVisualMap(Bidi bidi) 1109 { 1110 /* fill a visual-to-logical index map using the runs[] */ 1111 BidiRun[] runs = bidi.runs; 1112 int logicalStart, visualStart, visualLimit; 1113 int allocLength = bidi.length > bidi.resultLength ? bidi.length 1114 : bidi.resultLength; 1115 int[] indexMap = new int[allocLength]; 1116 1117 visualStart = 0; 1118 int idx = 0; 1119 for (int j = 0; j < bidi.runCount; ++j) { 1120 logicalStart = runs[j].start; 1121 visualLimit = runs[j].limit; 1122 if (runs[j].isEvenRun()) { 1123 do { /* LTR */ 1124 indexMap[idx++] = logicalStart++; 1125 } while (++visualStart < visualLimit); 1126 } else { 1127 logicalStart += visualLimit - visualStart; /* logicalLimit */ 1128 do { /* RTL */ 1129 indexMap[idx++] = --logicalStart; 1130 } while (++visualStart < visualLimit); 1131 } 1132 /* visualStart==visualLimit; */ 1133 } 1134 1135 if (bidi.insertPoints.size > 0) { 1136 int markFound = 0, runCount = bidi.runCount; 1137 int insertRemove, i, j, k; 1138 runs = bidi.runs; 1139 /* count all inserted marks */ 1140 for (i = 0; i < runCount; i++) { 1141 insertRemove = runs[i].insertRemove; 1142 if ((insertRemove & (Bidi.LRM_BEFORE|Bidi.RLM_BEFORE)) > 0) { 1143 markFound++; 1144 } 1145 if ((insertRemove & (Bidi.LRM_AFTER|Bidi.RLM_AFTER)) > 0) { 1146 markFound++; 1147 } 1148 } 1149 /* move back indexes by number of preceding marks */ 1150 k = bidi.resultLength; 1151 for (i = runCount - 1; i >= 0 && markFound > 0; i--) { 1152 insertRemove = runs[i].insertRemove; 1153 if ((insertRemove & (Bidi.LRM_AFTER|Bidi.RLM_AFTER)) > 0) { 1154 indexMap[--k] = Bidi.MAP_NOWHERE; 1155 markFound--; 1156 } 1157 visualStart = i > 0 ? runs[i-1].limit : 0; 1158 for (j = runs[i].limit - 1; j >= visualStart && markFound > 0; j--) { 1159 indexMap[--k] = indexMap[j]; 1160 } 1161 if ((insertRemove & (Bidi.LRM_BEFORE|Bidi.RLM_BEFORE)) > 0) { 1162 indexMap[--k] = Bidi.MAP_NOWHERE; 1163 markFound--; 1164 } 1165 } 1166 } 1167 else if (bidi.controlCount > 0) { 1168 int runCount = bidi.runCount, logicalEnd; 1169 int insertRemove, length, i, j, k, m; 1170 char uchar; 1171 boolean evenRun; 1172 runs = bidi.runs; 1173 visualStart = 0; 1174 /* move forward indexes by number of preceding controls */ 1175 k = 0; 1176 for (i = 0; i < runCount; i++, visualStart += length) { 1177 length = runs[i].limit - visualStart; 1178 insertRemove = runs[i].insertRemove; 1179 /* if no control found yet, nothing to do in this run */ 1180 if ((insertRemove == 0) && (k == visualStart)) { 1181 k += length; 1182 continue; 1183 } 1184 /* if no control in this run */ 1185 if (insertRemove == 0) { 1186 visualLimit = runs[i].limit; 1187 for (j = visualStart; j < visualLimit; j++) { 1188 indexMap[k++] = indexMap[j]; 1189 } 1190 continue; 1191 } 1192 logicalStart = runs[i].start; 1193 evenRun = runs[i].isEvenRun(); 1194 logicalEnd = logicalStart + length - 1; 1195 for (j = 0; j < length; j++) { 1196 m = evenRun ? logicalStart + j : logicalEnd - j; 1197 uchar = bidi.text[m]; 1198 if (!Bidi.IsBidiControlChar(uchar)) { 1199 indexMap[k++] = m; 1200 } 1201 } 1202 } 1203 } 1204 if (allocLength == bidi.resultLength) { 1205 return indexMap; 1206 } 1207 int[] newMap = new int[bidi.resultLength]; 1208 System.arraycopy(indexMap, 0, newMap, 0, bidi.resultLength); 1209 return newMap; 1210 } 1211 invertMap(int[] srcMap)1212 static int[] invertMap(int[] srcMap) 1213 { 1214 int srcLength = srcMap.length; 1215 int destLength = -1, count = 0, i, srcEntry; 1216 1217 /* find highest value and count positive indexes in srcMap */ 1218 for (i = 0; i < srcLength; i++) { 1219 srcEntry = srcMap[i]; 1220 if (srcEntry > destLength) { 1221 destLength = srcEntry; 1222 } 1223 if (srcEntry >= 0) { 1224 count++; 1225 } 1226 } 1227 destLength++; /* add 1 for origin 0 */ 1228 int[] destMap = new int[destLength]; 1229 if (count < destLength) { 1230 /* we must fill unmatched destMap entries with -1 */ 1231 Arrays.fill(destMap, Bidi.MAP_NOWHERE); 1232 } 1233 for (i = 0; i < srcLength; i++) { 1234 srcEntry = srcMap[i]; 1235 if (srcEntry >= 0) { 1236 destMap[srcEntry] = i; 1237 } 1238 } 1239 return destMap; 1240 } 1241 } 1242