1 /* 2 * Copyright (c) 2009, 2021, 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 /* 27 ******************************************************************************* 28 * Copyright (C) 2001-2014, International Business Machines 29 * Corporation and others. All Rights Reserved. 30 ******************************************************************************* 31 */ 32 /* Written by Simon Montagu, Matitiahu Allouche 33 * (ported from C code written by Markus W. Scherer) 34 */ 35 36 package jdk.internal.icu.text; 37 38 import java.text.Bidi; 39 import java.util.Arrays; 40 41 final class BidiLine { 42 43 /* 44 * General remarks about the functions in this file: 45 * 46 * These functions deal with the aspects of potentially mixed-directional 47 * text in a single paragraph or in a line of a single paragraph 48 * which has already been processed according to 49 * the Unicode 3.0 Bidi algorithm as defined in 50 * <a href="http://www.unicode.org/reports/tr9/">Unicode Standard Annex #9: 51 * Unicode Bidirectional Algorithm</a>, version 13, 52 * also described in The Unicode Standard, Version 4.0.1 . 53 * 54 * This means that there is a Bidi object with a levels 55 * and a dirProps array. 56 * paraLevel and direction are also set. 57 * Only if the length of the text is zero, then levels==dirProps==NULL. 58 * 59 * The overall directionality of the paragraph 60 * or line is used to bypass the reordering steps if possible. 61 * Even purely RTL text does not need reordering there because 62 * the getLogical/VisualIndex() methods can compute the 63 * index on the fly in such a case. 64 * 65 * The implementation of the access to same-level-runs and of the reordering 66 * do attempt to provide better performance and less memory usage compared to 67 * a direct implementation of especially rule (L2) with an array of 68 * one (32-bit) integer per text character. 69 * 70 * Here, the levels array is scanned as soon as necessary, and a vector of 71 * same-level-runs is created. Reordering then is done on this vector. 72 * For each run of text positions that were resolved to the same level, 73 * only 8 bytes are stored: the first text position of the run and the visual 74 * position behind the run after reordering. 75 * One sign bit is used to hold the directionality of the run. 76 * This is inefficient if there are many very short runs. If the average run 77 * length is <2, then this uses more memory. 78 * 79 * In a further attempt to save memory, the levels array is never changed 80 * after all the resolution rules (Xn, Wn, Nn, In). 81 * Many methods have to consider the field trailingWSStart: 82 * if it is less than length, then there is an implicit trailing run 83 * at the paraLevel, 84 * which is not reflected in the levels array. 85 * This allows a line Bidi object to use the same levels array as 86 * its paragraph parent object. 87 * 88 * When a Bidi object is created for a line of a paragraph, then the 89 * paragraph's levels and dirProps arrays are reused by way of setting 90 * a pointer into them, not by copying. This again saves memory and forbids to 91 * change the now shared levels for (L1). 92 */ 93 94 /* handle trailing WS (L1) -------------------------------------------------- */ 95 96 /* 97 * setTrailingWSStart() sets the start index for a trailing 98 * run of WS in the line. This is necessary because we do not modify 99 * the paragraph's levels array that we just point into. 100 * Using trailingWSStart is another form of performing (L1). 101 * 102 * To make subsequent operations easier, we also include the run 103 * before the WS if it is at the paraLevel - we merge the two here. 104 * 105 * This method is called only from setLine(), so paraLevel is 106 * set correctly for the line even when contextual multiple paragraphs. 107 */ 108 setTrailingWSStart(BidiBase bidiBase)109 static void setTrailingWSStart(BidiBase bidiBase) 110 { 111 byte[] dirProps = bidiBase.dirProps; 112 byte[] levels = bidiBase.levels; 113 int start = bidiBase.length; 114 byte paraLevel = bidiBase.paraLevel; 115 116 /* If the line is terminated by a block separator, all preceding WS etc... 117 are already set to paragraph level. 118 Setting trailingWSStart to pBidi->length will avoid changing the 119 level of B chars from 0 to paraLevel in getLevels when 120 orderParagraphsLTR==TRUE 121 */ 122 if (dirProps[start - 1] == BidiBase.B) { 123 bidiBase.trailingWSStart = start; /* currently == bidiBase.length */ 124 return; 125 } 126 /* go backwards across all WS, BN, explicit codes */ 127 while (start > 0 && 128 (BidiBase.DirPropFlag(dirProps[start - 1]) & BidiBase.MASK_WS) != 0) { 129 --start; 130 } 131 132 /* if the WS run can be merged with the previous run then do so here */ 133 while (start > 0 && levels[start - 1] == paraLevel) { 134 --start; 135 } 136 137 bidiBase.trailingWSStart=start; 138 } 139 setLine(BidiBase paraBidi, Bidi newBidi, BidiBase lineBidi, int start, int limit)140 static Bidi setLine(BidiBase paraBidi, 141 Bidi newBidi, BidiBase lineBidi, 142 int start, int limit) { 143 int length; 144 145 /* set the values in lineBidi from its paraBidi parent */ 146 /* class members are already initialized to 0 */ 147 // lineBidi.paraBidi = null; /* mark unfinished setLine */ 148 // lineBidi.flags = 0; 149 // lineBidi.controlCount = 0; 150 151 length = lineBidi.length = lineBidi.originalLength = 152 lineBidi.resultLength = limit - start; 153 154 lineBidi.text = new char[length]; 155 System.arraycopy(paraBidi.text, start, lineBidi.text, 0, length); 156 lineBidi.paraLevel = paraBidi.GetParaLevelAt(start); 157 lineBidi.paraCount = paraBidi.paraCount; 158 lineBidi.runs = new BidiRun[0]; 159 lineBidi.reorderingMode = paraBidi.reorderingMode; 160 lineBidi.reorderingOptions = paraBidi.reorderingOptions; 161 if (paraBidi.controlCount > 0) { 162 int j; 163 for (j = start; j < limit; j++) { 164 if (BidiBase.IsBidiControlChar(paraBidi.text[j])) { 165 lineBidi.controlCount++; 166 } 167 } 168 lineBidi.resultLength -= lineBidi.controlCount; 169 } 170 /* copy proper subset of DirProps */ 171 lineBidi.getDirPropsMemory(length); 172 lineBidi.dirProps = lineBidi.dirPropsMemory; 173 System.arraycopy(paraBidi.dirProps, start, lineBidi.dirProps, 0, 174 length); 175 /* copy proper subset of Levels */ 176 lineBidi.getLevelsMemory(length); 177 lineBidi.levels = lineBidi.levelsMemory; 178 System.arraycopy(paraBidi.levels, start, lineBidi.levels, 0, 179 length); 180 lineBidi.runCount = -1; 181 182 if (paraBidi.direction != BidiBase.MIXED) { 183 /* the parent is already trivial */ 184 lineBidi.direction = paraBidi.direction; 185 186 /* 187 * The parent's levels are all either 188 * implicitly or explicitly ==paraLevel; 189 * do the same here. 190 */ 191 if (paraBidi.trailingWSStart <= start) { 192 lineBidi.trailingWSStart = 0; 193 } else if (paraBidi.trailingWSStart < limit) { 194 lineBidi.trailingWSStart = paraBidi.trailingWSStart - start; 195 } else { 196 lineBidi.trailingWSStart = length; 197 } 198 } else { 199 byte[] levels = lineBidi.levels; 200 int i, trailingWSStart; 201 byte level; 202 203 setTrailingWSStart(lineBidi); 204 trailingWSStart = lineBidi.trailingWSStart; 205 206 /* recalculate lineBidiBase.direction */ 207 if (trailingWSStart == 0) { 208 /* all levels are at paraLevel */ 209 lineBidi.direction = (byte)(lineBidi.paraLevel & 1); 210 } else { 211 /* get the level of the first character */ 212 level = (byte)(levels[0] & 1); 213 214 /* if there is anything of a different level, then the line 215 is mixed */ 216 if (trailingWSStart < length && 217 (lineBidi.paraLevel & 1) != level) { 218 /* the trailing WS is at paraLevel, which differs from 219 levels[0] */ 220 lineBidi.direction = BidiBase.MIXED; 221 } else { 222 /* see if levels[1..trailingWSStart-1] have the same 223 direction as levels[0] and paraLevel */ 224 for (i = 1; ; i++) { 225 if (i == trailingWSStart) { 226 /* the direction values match those in level */ 227 lineBidi.direction = level; 228 break; 229 } else if ((levels[i] & 1) != level) { 230 lineBidi.direction = BidiBase.MIXED; 231 break; 232 } 233 } 234 } 235 } 236 237 switch(lineBidi.direction) { 238 case Bidi.DIRECTION_LEFT_TO_RIGHT: 239 /* make sure paraLevel is even */ 240 lineBidi.paraLevel = (byte) 241 ((lineBidi.paraLevel + 1) & ~1); 242 243 /* all levels are implicitly at paraLevel (important for 244 getLevels()) */ 245 lineBidi.trailingWSStart = 0; 246 break; 247 case Bidi.DIRECTION_RIGHT_TO_LEFT: 248 /* make sure paraLevel is odd */ 249 lineBidi.paraLevel |= 1; 250 251 /* all levels are implicitly at paraLevel (important for 252 getLevels()) */ 253 lineBidi.trailingWSStart = 0; 254 break; 255 default: 256 break; 257 } 258 } 259 260 lineBidi.paraBidi = paraBidi; /* mark successful setLine */ 261 262 return newBidi; 263 } 264 getLevelAt(BidiBase bidiBase, int charIndex)265 static byte getLevelAt(BidiBase bidiBase, int charIndex) 266 { 267 /* return paraLevel if in the trailing WS run, otherwise the real level */ 268 if (bidiBase.direction != BidiBase.MIXED || charIndex >= bidiBase.trailingWSStart) { 269 return bidiBase.GetParaLevelAt(charIndex); 270 } else { 271 return bidiBase.levels[charIndex]; 272 } 273 } 274 getLevels(BidiBase bidiBase)275 static byte[] getLevels(BidiBase bidiBase) 276 { 277 int start = bidiBase.trailingWSStart; 278 int length = bidiBase.length; 279 280 if (start != length) { 281 /* the current levels array does not reflect the WS run */ 282 /* 283 * After the previous if(), we know that the levels array 284 * has an implicit trailing WS run and therefore does not fully 285 * reflect itself all the levels. 286 * This must be a Bidi object for a line, and 287 * we need to create a new levels array. 288 */ 289 /* bidiBase.paraLevel is ok even if contextual multiple paragraphs, 290 since bidiBase is a line object */ 291 Arrays.fill(bidiBase.levels, start, length, bidiBase.paraLevel); 292 293 /* this new levels array is set for the line and reflects the WS run */ 294 bidiBase.trailingWSStart = length; 295 } 296 if (length < bidiBase.levels.length) { 297 byte[] levels = new byte[length]; 298 System.arraycopy(bidiBase.levels, 0, levels, 0, length); 299 return levels; 300 } 301 return bidiBase.levels; 302 } 303 getVisualRun(BidiBase bidiBase, int runIndex)304 static BidiRun getVisualRun(BidiBase bidiBase, int runIndex) { 305 int start = bidiBase.runs[runIndex].start; 306 int limit; 307 byte level = bidiBase.runs[runIndex].level; 308 309 if (runIndex > 0) { 310 limit = start + 311 bidiBase.runs[runIndex].limit - 312 bidiBase.runs[runIndex - 1].limit; 313 } else { 314 limit = start + bidiBase.runs[0].limit; 315 } 316 return new BidiRun(start, limit, level); 317 } 318 319 /* in trivial cases there is only one trivial run; called by getRuns() */ getSingleRun(BidiBase bidiBase, byte level)320 private static void getSingleRun(BidiBase bidiBase, byte level) { 321 /* simple, single-run case */ 322 bidiBase.runs = bidiBase.simpleRuns; 323 bidiBase.runCount = 1; 324 325 /* fill and reorder the single run */ 326 bidiBase.runs[0] = new BidiRun(0, bidiBase.length, level); 327 } 328 329 /* reorder the runs array (L2) ---------------------------------------------- */ 330 331 /* 332 * Reorder the same-level runs in the runs array. 333 * Here, runCount>1 and maxLevel>=minLevel>=paraLevel. 334 * All the visualStart fields=logical start before reordering. 335 * The "odd" bits are not set yet. 336 * 337 * Reordering with this data structure lends itself to some handy shortcuts: 338 * 339 * Since each run is moved but not modified, and since at the initial maxLevel 340 * each sequence of same-level runs consists of only one run each, we 341 * don't need to do anything there and can predecrement maxLevel. 342 * In many simple cases, the reordering is thus done entirely in the 343 * index mapping. 344 * Also, reordering occurs only down to the lowest odd level that occurs, 345 * which is minLevel|1. However, if the lowest level itself is odd, then 346 * in the last reordering the sequence of the runs at this level or higher 347 * will be all runs, and we don't need the elaborate loop to search for them. 348 * This is covered by ++minLevel instead of minLevel|=1 followed 349 * by an extra reorder-all after the reorder-some loop. 350 * About a trailing WS run: 351 * Such a run would need special treatment because its level is not 352 * reflected in levels[] if this is not a paragraph object. 353 * Instead, all characters from trailingWSStart on are implicitly at 354 * paraLevel. 355 * However, for all maxLevel>paraLevel, this run will never be reordered 356 * and does not need to be taken into account. maxLevel==paraLevel is only reordered 357 * if minLevel==paraLevel is odd, which is done in the extra segment. 358 * This means that for the main reordering loop we don't need to consider 359 * this run and can --runCount. If it is later part of the all-runs 360 * reordering, then runCount is adjusted accordingly. 361 */ reorderLine(BidiBase bidiBase, byte minLevel, byte maxLevel)362 private static void reorderLine(BidiBase bidiBase, byte minLevel, byte maxLevel) { 363 364 /* nothing to do? */ 365 if (maxLevel<=(minLevel|1)) { 366 return; 367 } 368 369 BidiRun[] runs; 370 BidiRun tempRun; 371 byte[] levels; 372 int firstRun, endRun, limitRun, runCount; 373 374 /* 375 * Reorder only down to the lowest odd level 376 * and reorder at an odd minLevel in a separate, simpler loop. 377 * See comments above for why minLevel is always incremented. 378 */ 379 ++minLevel; 380 381 runs = bidiBase.runs; 382 levels = bidiBase.levels; 383 runCount = bidiBase.runCount; 384 385 /* do not include the WS run at paraLevel<=old minLevel except in the simple loop */ 386 if (bidiBase.trailingWSStart < bidiBase.length) { 387 --runCount; 388 } 389 390 while (--maxLevel >= minLevel) { 391 firstRun = 0; 392 393 /* loop for all sequences of runs */ 394 for ( ; ; ) { 395 /* look for a sequence of runs that are all at >=maxLevel */ 396 /* look for the first run of such a sequence */ 397 while (firstRun < runCount && levels[runs[firstRun].start] < maxLevel) { 398 ++firstRun; 399 } 400 if (firstRun >= runCount) { 401 break; /* no more such runs */ 402 } 403 404 /* look for the limit run of such a sequence (the run behind it) */ 405 for (limitRun = firstRun; ++limitRun < runCount && 406 levels[runs[limitRun].start]>=maxLevel; ) {} 407 408 /* Swap the entire sequence of runs from firstRun to limitRun-1. */ 409 endRun = limitRun - 1; 410 while (firstRun < endRun) { 411 tempRun = runs[firstRun]; 412 runs[firstRun] = runs[endRun]; 413 runs[endRun] = tempRun; 414 ++firstRun; 415 --endRun; 416 } 417 418 if (limitRun == runCount) { 419 break; /* no more such runs */ 420 } else { 421 firstRun = limitRun + 1; 422 } 423 } 424 } 425 426 /* now do maxLevel==old minLevel (==odd!), see above */ 427 if ((minLevel & 1) == 0) { 428 firstRun = 0; 429 430 /* include the trailing WS run in this complete reordering */ 431 if (bidiBase.trailingWSStart == bidiBase.length) { 432 --runCount; 433 } 434 435 /* Swap the entire sequence of all runs. (endRun==runCount) */ 436 while (firstRun < runCount) { 437 tempRun = runs[firstRun]; 438 runs[firstRun] = runs[runCount]; 439 runs[runCount] = tempRun; 440 ++firstRun; 441 --runCount; 442 } 443 } 444 } 445 446 /* compute the runs array --------------------------------------------------- */ 447 getRunFromLogicalIndex(BidiBase bidiBase, int logicalIndex)448 static int getRunFromLogicalIndex(BidiBase bidiBase, int logicalIndex) { 449 BidiRun[] runs = bidiBase.runs; 450 int runCount = bidiBase.runCount, visualStart = 0, i, length, logicalStart; 451 452 for (i = 0; i < runCount; i++) { 453 length = runs[i].limit - visualStart; 454 logicalStart = runs[i].start; 455 if ((logicalIndex >= logicalStart) && (logicalIndex < (logicalStart+length))) { 456 return i; 457 } 458 visualStart += length; 459 } 460 /* we should never get here */ 461 throw new IllegalStateException("Internal ICU error in getRunFromLogicalIndex"); 462 } 463 464 /* 465 * Compute the runs array from the levels array. 466 * After getRuns() returns true, runCount is guaranteed to be >0 467 * and the runs are reordered. 468 * Odd-level runs have visualStart on their visual right edge and 469 * they progress visually to the left. 470 * If option OPTION_INSERT_MARKS is set, insertRemove will contain the 471 * sum of appropriate LRM/RLM_BEFORE/AFTER flags. 472 * If option OPTION_REMOVE_CONTROLS is set, insertRemove will contain the 473 * negative number of BiDi control characters within this run. 474 */ getRuns(BidiBase bidiBase)475 static void getRuns(BidiBase bidiBase) { 476 /* 477 * This method returns immediately if the runs are already set. This 478 * includes the case of length==0 (handled in setPara).. 479 */ 480 if (bidiBase.runCount >= 0) { 481 return; 482 } 483 if (bidiBase.direction != BidiBase.MIXED) { 484 /* simple, single-run case - this covers length==0 */ 485 /* bidiBase.paraLevel is ok even for contextual multiple paragraphs */ 486 getSingleRun(bidiBase, bidiBase.paraLevel); 487 } else /* BidiBase.MIXED, length>0 */ { 488 /* mixed directionality */ 489 int length = bidiBase.length, limit; 490 byte[] levels = bidiBase.levels; 491 int i, runCount; 492 byte level = -1; /* initialize with no valid level */ 493 /* 494 * If there are WS characters at the end of the line 495 * and the run preceding them has a level different from 496 * paraLevel, then they will form their own run at paraLevel (L1). 497 * Count them separately. 498 * We need some special treatment for this in order to not 499 * modify the levels array which a line Bidi object shares 500 * with its paragraph parent and its other line siblings. 501 * In other words, for the trailing WS, it may be 502 * levels[]!=paraLevel but we have to treat it like it were so. 503 */ 504 limit = bidiBase.trailingWSStart; 505 /* count the runs, there is at least one non-WS run, and limit>0 */ 506 runCount = 0; 507 for (i = 0; i < limit; ++i) { 508 /* increment runCount at the start of each run */ 509 if (levels[i] != level) { 510 ++runCount; 511 level = levels[i]; 512 } 513 } 514 515 /* 516 * We don't need to see if the last run can be merged with a trailing 517 * WS run because setTrailingWSStart() would have done that. 518 */ 519 if (runCount == 1 && limit == length) { 520 /* There is only one non-WS run and no trailing WS-run. */ 521 getSingleRun(bidiBase, levels[0]); 522 } else /* runCount>1 || limit<length */ { 523 /* allocate and set the runs */ 524 BidiRun[] runs; 525 int runIndex, start; 526 byte minLevel = BidiBase.MAX_EXPLICIT_LEVEL + 1; 527 byte maxLevel=0; 528 529 /* now, count a (non-mergeable) WS run */ 530 if (limit < length) { 531 ++runCount; 532 } 533 534 /* runCount > 1 */ 535 bidiBase.getRunsMemory(runCount); 536 runs = bidiBase.runsMemory; 537 538 /* set the runs */ 539 /* FOOD FOR THOUGHT: this could be optimized, e.g.: 540 * 464->444, 484->444, 575->555, 595->555 541 * However, that would take longer. Check also how it would 542 * interact with BiDi control removal and inserting Marks. 543 */ 544 runIndex = 0; 545 546 /* search for the run limits and initialize visualLimit values with the run lengths */ 547 i = 0; 548 do { 549 /* prepare this run */ 550 start = i; 551 level = levels[i]; 552 if (level < minLevel) { 553 minLevel = level; 554 } 555 if (level > maxLevel) { 556 maxLevel = level; 557 } 558 559 /* look for the run limit */ 560 while (++i < limit && levels[i] == level) {} 561 562 /* i is another run limit */ 563 runs[runIndex] = new BidiRun(start, i - start, level); 564 ++runIndex; 565 } while (i < limit); 566 567 if (limit < length) { 568 /* there is a separate WS run */ 569 runs[runIndex] = new BidiRun(limit, length - limit, bidiBase.paraLevel); 570 /* For the trailing WS run, bidiBase.paraLevel is ok even 571 if contextual multiple paragraphs. */ 572 if (bidiBase.paraLevel < minLevel) { 573 minLevel = bidiBase.paraLevel; 574 } 575 } 576 577 /* set the object fields */ 578 bidiBase.runs = runs; 579 bidiBase.runCount = runCount; 580 581 reorderLine(bidiBase, minLevel, maxLevel); 582 583 /* now add the direction flags and adjust the visualLimit's to be just that */ 584 /* this loop will also handle the trailing WS run */ 585 limit = 0; 586 for (i = 0; i < runCount; ++i) { 587 runs[i].level = levels[runs[i].start]; 588 limit = (runs[i].limit += limit); 589 } 590 591 /* Set the embedding level for the trailing WS run. */ 592 /* For a RTL paragraph, it will be the *first* run in visual order. */ 593 /* For the trailing WS run, bidiBase.paraLevel is ok even if 594 contextual multiple paragraphs. */ 595 if (runIndex < runCount) { 596 int trailingRun = ((bidiBase.paraLevel & 1) != 0)? 0 : runIndex; 597 runs[trailingRun].level = bidiBase.paraLevel; 598 } 599 } 600 } 601 602 /* handle insert LRM/RLM BEFORE/AFTER run */ 603 if (bidiBase.insertPoints.size > 0) { 604 BidiBase.Point point; 605 int runIndex, ip; 606 for (ip = 0; ip < bidiBase.insertPoints.size; ip++) { 607 point = bidiBase.insertPoints.points[ip]; 608 runIndex = getRunFromLogicalIndex(bidiBase, point.pos); 609 bidiBase.runs[runIndex].insertRemove |= point.flag; 610 } 611 } 612 613 /* handle remove BiDi control characters */ 614 if (bidiBase.controlCount > 0) { 615 int runIndex, ic; 616 char c; 617 for (ic = 0; ic < bidiBase.length; ic++) { 618 c = bidiBase.text[ic]; 619 if (BidiBase.IsBidiControlChar(c)) { 620 runIndex = getRunFromLogicalIndex(bidiBase, ic); 621 bidiBase.runs[runIndex].insertRemove--; 622 } 623 } 624 } 625 } 626 prepareReorder(byte[] levels, byte[] pMinLevel, byte[] pMaxLevel)627 static int[] prepareReorder(byte[] levels, byte[] pMinLevel, byte[] pMaxLevel) 628 { 629 int start; 630 byte level, minLevel, maxLevel; 631 632 if (levels == null || levels.length <= 0) { 633 return null; 634 } 635 636 /* determine minLevel and maxLevel */ 637 minLevel = BidiBase.MAX_EXPLICIT_LEVEL + 1; 638 maxLevel = 0; 639 for (start = levels.length; start>0; ) { 640 level = levels[--start]; 641 if (level < 0 || level > (BidiBase.MAX_EXPLICIT_LEVEL + 1)) { 642 return null; 643 } 644 if (level < minLevel) { 645 minLevel = level; 646 } 647 if (level > maxLevel) { 648 maxLevel = level; 649 } 650 } 651 pMinLevel[0] = minLevel; 652 pMaxLevel[0] = maxLevel; 653 654 /* initialize the index map */ 655 int[] indexMap = new int[levels.length]; 656 for (start = levels.length; start > 0; ) { 657 --start; 658 indexMap[start] = start; 659 } 660 661 return indexMap; 662 } 663 reorderVisual(byte[] levels)664 static int[] reorderVisual(byte[] levels) 665 { 666 byte[] aMinLevel = new byte[1]; 667 byte[] aMaxLevel = new byte[1]; 668 int start, end, limit, temp; 669 byte minLevel, maxLevel; 670 671 int[] indexMap = prepareReorder(levels, aMinLevel, aMaxLevel); 672 if (indexMap == null) { 673 return null; 674 } 675 676 minLevel = aMinLevel[0]; 677 maxLevel = aMaxLevel[0]; 678 679 /* nothing to do? */ 680 if (minLevel == maxLevel && (minLevel & 1) == 0) { 681 return indexMap; 682 } 683 684 /* reorder only down to the lowest odd level */ 685 minLevel |= 1; 686 687 /* loop maxLevel..minLevel */ 688 do { 689 start = 0; 690 691 /* loop for all sequences of levels to reorder at the current maxLevel */ 692 for ( ; ; ) { 693 /* look for a sequence of levels that are all at >=maxLevel */ 694 /* look for the first index of such a sequence */ 695 while (start < levels.length && levels[start] < maxLevel) { 696 ++start; 697 } 698 if (start >= levels.length) { 699 break; /* no more such runs */ 700 } 701 702 /* look for the limit of such a sequence (the index behind it) */ 703 for (limit = start; ++limit < levels.length && levels[limit] >= maxLevel; ) {} 704 705 /* 706 * Swap the entire interval of indexes from start to limit-1. 707 * We don't need to swap the levels for the purpose of this 708 * algorithm: the sequence of levels that we look at does not 709 * move anyway. 710 */ 711 end = limit - 1; 712 while (start < end) { 713 temp = indexMap[start]; 714 indexMap[start] = indexMap[end]; 715 indexMap[end] = temp; 716 717 ++start; 718 --end; 719 } 720 721 if (limit == levels.length) { 722 break; /* no more such sequences */ 723 } else { 724 start = limit + 1; 725 } 726 } 727 } while (--maxLevel >= minLevel); 728 729 return indexMap; 730 } 731 getVisualMap(BidiBase bidiBase)732 static int[] getVisualMap(BidiBase bidiBase) 733 { 734 /* fill a visual-to-logical index map using the runs[] */ 735 BidiRun[] runs = bidiBase.runs; 736 int logicalStart, visualStart, visualLimit; 737 int allocLength = bidiBase.length > bidiBase.resultLength ? bidiBase.length 738 : bidiBase.resultLength; 739 int[] indexMap = new int[allocLength]; 740 741 visualStart = 0; 742 int idx = 0; 743 for (int j = 0; j < bidiBase.runCount; ++j) { 744 logicalStart = runs[j].start; 745 visualLimit = runs[j].limit; 746 if (runs[j].isEvenRun()) { 747 do { /* LTR */ 748 indexMap[idx++] = logicalStart++; 749 } while (++visualStart < visualLimit); 750 } else { 751 logicalStart += visualLimit - visualStart; /* logicalLimit */ 752 do { /* RTL */ 753 indexMap[idx++] = --logicalStart; 754 } while (++visualStart < visualLimit); 755 } 756 /* visualStart==visualLimit; */ 757 } 758 759 if (bidiBase.insertPoints.size > 0) { 760 int markFound = 0, runCount = bidiBase.runCount; 761 int insertRemove, i, j, k; 762 runs = bidiBase.runs; 763 /* count all inserted marks */ 764 for (i = 0; i < runCount; i++) { 765 insertRemove = runs[i].insertRemove; 766 if ((insertRemove & (BidiBase.LRM_BEFORE|BidiBase.RLM_BEFORE)) > 0) { 767 markFound++; 768 } 769 if ((insertRemove & (BidiBase.LRM_AFTER|BidiBase.RLM_AFTER)) > 0) { 770 markFound++; 771 } 772 } 773 /* move back indexes by number of preceding marks */ 774 k = bidiBase.resultLength; 775 for (i = runCount - 1; i >= 0 && markFound > 0; i--) { 776 insertRemove = runs[i].insertRemove; 777 if ((insertRemove & (BidiBase.LRM_AFTER|BidiBase.RLM_AFTER)) > 0) { 778 indexMap[--k] = BidiBase.MAP_NOWHERE; 779 markFound--; 780 } 781 visualStart = i > 0 ? runs[i-1].limit : 0; 782 for (j = runs[i].limit - 1; j >= visualStart && markFound > 0; j--) { 783 indexMap[--k] = indexMap[j]; 784 } 785 if ((insertRemove & (BidiBase.LRM_BEFORE|BidiBase.RLM_BEFORE)) > 0) { 786 indexMap[--k] = BidiBase.MAP_NOWHERE; 787 markFound--; 788 } 789 } 790 } 791 else if (bidiBase.controlCount > 0) { 792 int runCount = bidiBase.runCount, logicalEnd; 793 int insertRemove, length, i, j, k, m; 794 char uchar; 795 boolean evenRun; 796 runs = bidiBase.runs; 797 visualStart = 0; 798 /* move forward indexes by number of preceding controls */ 799 k = 0; 800 for (i = 0; i < runCount; i++, visualStart += length) { 801 length = runs[i].limit - visualStart; 802 insertRemove = runs[i].insertRemove; 803 /* if no control found yet, nothing to do in this run */ 804 if ((insertRemove == 0) && (k == visualStart)) { 805 k += length; 806 continue; 807 } 808 /* if no control in this run */ 809 if (insertRemove == 0) { 810 visualLimit = runs[i].limit; 811 for (j = visualStart; j < visualLimit; j++) { 812 indexMap[k++] = indexMap[j]; 813 } 814 continue; 815 } 816 logicalStart = runs[i].start; 817 evenRun = runs[i].isEvenRun(); 818 logicalEnd = logicalStart + length - 1; 819 for (j = 0; j < length; j++) { 820 m = evenRun ? logicalStart + j : logicalEnd - j; 821 uchar = bidiBase.text[m]; 822 if (!BidiBase.IsBidiControlChar(uchar)) { 823 indexMap[k++] = m; 824 } 825 } 826 } 827 } 828 if (allocLength == bidiBase.resultLength) { 829 return indexMap; 830 } 831 int[] newMap = new int[bidiBase.resultLength]; 832 System.arraycopy(indexMap, 0, newMap, 0, bidiBase.resultLength); 833 return newMap; 834 } 835 836 } 837