1 /*
2 * Copyright (c) 2009, 2020, 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 * http://www.unicode.org/unicode/reports/tr9/ , version 13,
51 * also described in The Unicode Standard, Version 4.0.1 .
52 *
53 * This means that there is a Bidi object with a levels
54 * and a dirProps array.
55 * paraLevel and direction are also set.
56 * Only if the length of the text is zero, then levels==dirProps==NULL.
57 *
58 * The overall directionality of the paragraph
59 * or line is used to bypass the reordering steps if possible.
60 * Even purely RTL text does not need reordering there because
61 * the getLogical/VisualIndex() methods can compute the
62 * index on the fly in such a case.
63 *
64 * The implementation of the access to same-level-runs and of the reordering
65 * do attempt to provide better performance and less memory usage compared to
66 * a direct implementation of especially rule (L2) with an array of
67 * one (32-bit) integer per text character.
68 *
69 * Here, the levels array is scanned as soon as necessary, and a vector of
70 * same-level-runs is created. Reordering then is done on this vector.
71 * For each run of text positions that were resolved to the same level,
72 * only 8 bytes are stored: the first text position of the run and the visual
73 * position behind the run after reordering.
74 * One sign bit is used to hold the directionality of the run.
75 * This is inefficient if there are many very short runs. If the average run
76 * length is <2, then this uses more memory.
77 *
78 * In a further attempt to save memory, the levels array is never changed
79 * after all the resolution rules (Xn, Wn, Nn, In).
80 * Many methods have to consider the field trailingWSStart:
81 * if it is less than length, then there is an implicit trailing run
82 * at the paraLevel,
83 * which is not reflected in the levels array.
84 * This allows a line Bidi object to use the same levels array as
85 * its paragraph parent object.
86 *
87 * When a Bidi object is created for a line of a paragraph, then the
88 * paragraph's levels and dirProps arrays are reused by way of setting
89 * a pointer into them, not by copying. This again saves memory and forbids to
90 * change the now shared levels for (L1).
91 */
92
93 /* handle trailing WS (L1) -------------------------------------------------- */
94
95 /*
96 * setTrailingWSStart() sets the start index for a trailing
97 * run of WS in the line. This is necessary because we do not modify
98 * the paragraph's levels array that we just point into.
99 * Using trailingWSStart is another form of performing (L1).
100 *
101 * To make subsequent operations easier, we also include the run
102 * before the WS if it is at the paraLevel - we merge the two here.
103 *
104 * This method is called only from setLine(), so paraLevel is
105 * set correctly for the line even when contextual multiple paragraphs.
106 */
107
108 static void setTrailingWSStart(BidiBase bidiBase)
109 {
110 byte[] dirProps = bidiBase.dirProps;
111 byte[] levels = bidiBase.levels;
112 int start = bidiBase.length;
113 byte paraLevel = bidiBase.paraLevel;
114
115 /* If the line is terminated by a block separator, all preceding WS etc...
116 are already set to paragraph level.
117 Setting trailingWSStart to pBidi->length will avoid changing the
118 level of B chars from 0 to paraLevel in getLevels when
119 orderParagraphsLTR==TRUE
120 */
121 if (dirProps[start - 1] == BidiBase.B) {
122 bidiBase.trailingWSStart = start; /* currently == bidiBase.length */
123 return;
124 }
125 /* go backwards across all WS, BN, explicit codes */
126 while (start > 0 &&
127 (BidiBase.DirPropFlag(dirProps[start - 1]) & BidiBase.MASK_WS) != 0) {
128 --start;
129 }
130
131 /* if the WS run can be merged with the previous run then do so here */
132 while (start > 0 && levels[start - 1] == paraLevel) {
133 --start;
134 }
135
136 bidiBase.trailingWSStart=start;
137 }
138
139 static Bidi setLine(BidiBase paraBidi,
140 Bidi newBidi, BidiBase lineBidi,
141 int start, int limit) {
142 int length;
143
144 /* set the values in lineBidi from its paraBidi parent */
145 /* class members are already initialized to 0 */
146 // lineBidi.paraBidi = null; /* mark unfinished setLine */
147 // lineBidi.flags = 0;
148 // lineBidi.controlCount = 0;
149
150 length = lineBidi.length = lineBidi.originalLength =
151 lineBidi.resultLength = limit - start;
152
153 lineBidi.text = new char[length];
154 System.arraycopy(paraBidi.text, start, lineBidi.text, 0, length);
155 lineBidi.paraLevel = paraBidi.GetParaLevelAt(start);
156 lineBidi.paraCount = paraBidi.paraCount;
157 lineBidi.runs = new BidiRun[0];
158 lineBidi.reorderingMode = paraBidi.reorderingMode;
159 lineBidi.reorderingOptions = paraBidi.reorderingOptions;
160 if (paraBidi.controlCount > 0) {
161 int j;
162 for (j = start; j < limit; j++) {
163 if (BidiBase.IsBidiControlChar(paraBidi.text[j])) {
164 lineBidi.controlCount++;
165 }
166 }
167 lineBidi.resultLength -= lineBidi.controlCount;
168 }
169 /* copy proper subset of DirProps */
170 lineBidi.getDirPropsMemory(length);
171 lineBidi.dirProps = lineBidi.dirPropsMemory;
172 System.arraycopy(paraBidi.dirProps, start, lineBidi.dirProps, 0,
173 length);
174 /* copy proper subset of Levels */
175 lineBidi.getLevelsMemory(length);
176 lineBidi.levels = lineBidi.levelsMemory;
177 System.arraycopy(paraBidi.levels, start, lineBidi.levels, 0,
178 length);
179 lineBidi.runCount = -1;
180
181 if (paraBidi.direction != BidiBase.MIXED) {
182 /* the parent is already trivial */
183 lineBidi.direction = paraBidi.direction;
184
185 /*
186 * The parent's levels are all either
187 * implicitly or explicitly ==paraLevel;
188 * do the same here.
189 */
190 if (paraBidi.trailingWSStart <= start) {
191 lineBidi.trailingWSStart = 0;
192 } else if (paraBidi.trailingWSStart < limit) {
193 lineBidi.trailingWSStart = paraBidi.trailingWSStart - start;
194 } else {
195 lineBidi.trailingWSStart = length;
196 }
197 } else {
198 byte[] levels = lineBidi.levels;
199 int i, trailingWSStart;
200 byte level;
201
202 setTrailingWSStart(lineBidi);
203 trailingWSStart = lineBidi.trailingWSStart;
204
205 /* recalculate lineBidiBase.direction */
206 if (trailingWSStart == 0) {
207 /* all levels are at paraLevel */
208 lineBidi.direction = (byte)(lineBidi.paraLevel & 1);
209 } else {
210 /* get the level of the first character */
211 level = (byte)(levels[0] & 1);
212
213 /* if there is anything of a different level, then the line
214 is mixed */
215 if (trailingWSStart < length &&
216 (lineBidi.paraLevel & 1) != level) {
217 /* the trailing WS is at paraLevel, which differs from
218 levels[0] */
219 lineBidi.direction = BidiBase.MIXED;
220 } else {
221 /* see if levels[1..trailingWSStart-1] have the same
222 direction as levels[0] and paraLevel */
223 for (i = 1; ; i++) {
224 if (i == trailingWSStart) {
225 /* the direction values match those in level */
226 lineBidi.direction = level;
227 break;
228 } else if ((levels[i] & 1) != level) {
229 lineBidi.direction = BidiBase.MIXED;
230 break;
231 }
232 }
233 }
234 }
235
236 switch(lineBidi.direction) {
237 case Bidi.DIRECTION_LEFT_TO_RIGHT:
238 /* make sure paraLevel is even */
239 lineBidi.paraLevel = (byte)
240 ((lineBidi.paraLevel + 1) & ~1);
241
242 /* all levels are implicitly at paraLevel (important for
243 getLevels()) */
244 lineBidi.trailingWSStart = 0;
245 break;
246 case Bidi.DIRECTION_RIGHT_TO_LEFT:
247 /* make sure paraLevel is odd */
248 lineBidi.paraLevel |= 1;
249
250 /* all levels are implicitly at paraLevel (important for
251 getLevels()) */
252 lineBidi.trailingWSStart = 0;
253 break;
254 default:
255 break;
256 }
257 }
258
259 lineBidi.paraBidi = paraBidi; /* mark successful setLine */
260
261 return newBidi;
262 }
263
264 static byte getLevelAt(BidiBase bidiBase, int charIndex)
265 {
266 /* return paraLevel if in the trailing WS run, otherwise the real level */
267 if (bidiBase.direction != BidiBase.MIXED || charIndex >= bidiBase.trailingWSStart) {
268 return bidiBase.GetParaLevelAt(charIndex);
269 } else {
270 return bidiBase.levels[charIndex];
271 }
272 }
273
274 static byte[] getLevels(BidiBase bidiBase)
275 {
276 int start = bidiBase.trailingWSStart;
277 int length = bidiBase.length;
278
279 if (start != length) {
280 /* the current levels array does not reflect the WS run */
281 /*
282 * After the previous if(), we know that the levels array
283 * has an implicit trailing WS run and therefore does not fully
284 * reflect itself all the levels.
285 * This must be a Bidi object for a line, and
286 * we need to create a new levels array.
287 */
288 /* bidiBase.paraLevel is ok even if contextual multiple paragraphs,
289 since bidiBase is a line object */
290 Arrays.fill(bidiBase.levels, start, length, bidiBase.paraLevel);
291
292 /* this new levels array is set for the line and reflects the WS run */
293 bidiBase.trailingWSStart = length;
294 }
295 if (length < bidiBase.levels.length) {
296 byte[] levels = new byte[length];
297 System.arraycopy(bidiBase.levels, 0, levels, 0, length);
298 return levels;
299 }
300 return bidiBase.levels;
301 }
302
303 static BidiRun getVisualRun(BidiBase bidiBase, int runIndex) {
304 int start = bidiBase.runs[runIndex].start;
305 int limit;
306 byte level = bidiBase.runs[runIndex].level;
307
308 if (runIndex > 0) {
309 limit = start +
310 bidiBase.runs[runIndex].limit -
311 bidiBase.runs[runIndex - 1].limit;
312 } else {
313 limit = start + bidiBase.runs[0].limit;
314 }
315 return new BidiRun(start, limit, level);
316 }
317
318 /* in trivial cases there is only one trivial run; called by getRuns() */
319 private static void getSingleRun(BidiBase bidiBase, byte level) {
320 /* simple, single-run case */
321 bidiBase.runs = bidiBase.simpleRuns;
322 bidiBase.runCount = 1;
323
324 /* fill and reorder the single run */
325 bidiBase.runs[0] = new BidiRun(0, bidiBase.length, level);
326 }
327
328 /* reorder the runs array (L2) ---------------------------------------------- */
329
330 /*
331 * Reorder the same-level runs in the runs array.
332 * Here, runCount>1 and maxLevel>=minLevel>=paraLevel.
333 * All the visualStart fields=logical start before reordering.
334 * The "odd" bits are not set yet.
335 *
336 * Reordering with this data structure lends itself to some handy shortcuts:
337 *
338 * Since each run is moved but not modified, and since at the initial maxLevel
339 * each sequence of same-level runs consists of only one run each, we
340 * don't need to do anything there and can predecrement maxLevel.
341 * In many simple cases, the reordering is thus done entirely in the
342 * index mapping.
343 * Also, reordering occurs only down to the lowest odd level that occurs,
344 * which is minLevel|1. However, if the lowest level itself is odd, then
345 * in the last reordering the sequence of the runs at this level or higher
346 * will be all runs, and we don't need the elaborate loop to search for them.
347 * This is covered by ++minLevel instead of minLevel|=1 followed
348 * by an extra reorder-all after the reorder-some loop.
349 * About a trailing WS run:
350 * Such a run would need special treatment because its level is not
351 * reflected in levels[] if this is not a paragraph object.
352 * Instead, all characters from trailingWSStart on are implicitly at
353 * paraLevel.
354 * However, for all maxLevel>paraLevel, this run will never be reordered
355 * and does not need to be taken into account. maxLevel==paraLevel is only reordered
356 * if minLevel==paraLevel is odd, which is done in the extra segment.
357 * This means that for the main reordering loop we don't need to consider
358 * this run and can --runCount. If it is later part of the all-runs
359 * reordering, then runCount is adjusted accordingly.
360 */
361 private static void reorderLine(BidiBase bidiBase, byte minLevel, byte maxLevel) {
362
363 /* nothing to do? */
364 if (maxLevel<=(minLevel|1)) {
365 return;
366 }
367
368 BidiRun[] runs;
369 BidiRun tempRun;
370 byte[] levels;
371 int firstRun, endRun, limitRun, runCount;
372
373 /*
374 * Reorder only down to the lowest odd level
375 * and reorder at an odd minLevel in a separate, simpler loop.
376 * See comments above for why minLevel is always incremented.
377 */
378 ++minLevel;
379
380 runs = bidiBase.runs;
381 levels = bidiBase.levels;
382 runCount = bidiBase.runCount;
383
384 /* do not include the WS run at paraLevel<=old minLevel except in the simple loop */
385 if (bidiBase.trailingWSStart < bidiBase.length) {
386 --runCount;
387 }
388
389 while (--maxLevel >= minLevel) {
390 firstRun = 0;
391
392 /* loop for all sequences of runs */
393 for ( ; ; ) {
394 /* look for a sequence of runs that are all at >=maxLevel */
395 /* look for the first run of such a sequence */
396 while (firstRun < runCount && levels[runs[firstRun].start] < maxLevel) {
397 ++firstRun;
398 }
399 if (firstRun >= runCount) {
400 break; /* no more such runs */
401 }
402
403 /* look for the limit run of such a sequence (the run behind it) */
404 for (limitRun = firstRun; ++limitRun < runCount &&
405 levels[runs[limitRun].start]>=maxLevel; ) {}
406
407 /* Swap the entire sequence of runs from firstRun to limitRun-1. */
408 endRun = limitRun - 1;
409 while (firstRun < endRun) {
410 tempRun = runs[firstRun];
411 runs[firstRun] = runs[endRun];
412 runs[endRun] = tempRun;
413 ++firstRun;
414 --endRun;
415 }
416
417 if (limitRun == runCount) {
418 break; /* no more such runs */
419 } else {
420 firstRun = limitRun + 1;
421 }
422 }
423 }
424
425 /* now do maxLevel==old minLevel (==odd!), see above */
426 if ((minLevel & 1) == 0) {
427 firstRun = 0;
428
429 /* include the trailing WS run in this complete reordering */
430 if (bidiBase.trailingWSStart == bidiBase.length) {
431 --runCount;
432 }
433
434 /* Swap the entire sequence of all runs. (endRun==runCount) */
435 while (firstRun < runCount) {
436 tempRun = runs[firstRun];
437 runs[firstRun] = runs[runCount];
438 runs[runCount] = tempRun;
439 ++firstRun;
440 --runCount;
441 }
442 }
443 }
444
445 /* compute the runs array --------------------------------------------------- */
446
447 static int getRunFromLogicalIndex(BidiBase bidiBase, int logicalIndex) {
448 BidiRun[] runs = bidiBase.runs;
449 int runCount = bidiBase.runCount, visualStart = 0, i, length, logicalStart;
450
451 for (i = 0; i < runCount; i++) {
452 length = runs[i].limit - visualStart;
453 logicalStart = runs[i].start;
454 if ((logicalIndex >= logicalStart) && (logicalIndex < (logicalStart+length))) {
455 return i;
456 }
457 visualStart += length;
458 }
459 /* we should never get here */
460 throw new IllegalStateException("Internal ICU error in getRunFromLogicalIndex");
461 }
462
463 /*
464 * Compute the runs array from the levels array.
465 * After getRuns() returns true, runCount is guaranteed to be >0
466 * and the runs are reordered.
467 * Odd-level runs have visualStart on their visual right edge and
468 * they progress visually to the left.
469 * If option OPTION_INSERT_MARKS is set, insertRemove will contain the
470 * sum of appropriate LRM/RLM_BEFORE/AFTER flags.
471 * If option OPTION_REMOVE_CONTROLS is set, insertRemove will contain the
472 * negative number of BiDi control characters within this run.
473 */
474 static void getRuns(BidiBase bidiBase) {
475 /*
476 * This method returns immediately if the runs are already set. This
477 * includes the case of length==0 (handled in setPara)..
478 */
479 if (bidiBase.runCount >= 0) {
480 return;
481 }
482 if (bidiBase.direction != BidiBase.MIXED) {
483 /* simple, single-run case - this covers length==0 */
484 /* bidiBase.paraLevel is ok even for contextual multiple paragraphs */
485 getSingleRun(bidiBase, bidiBase.paraLevel);
486 } else /* BidiBase.MIXED, length>0 */ {
487 /* mixed directionality */
488 int length = bidiBase.length, limit;
489 byte[] levels = bidiBase.levels;
490 int i, runCount;
491 byte level = -1; /* initialize with no valid level */
492 /*
493 * If there are WS characters at the end of the line
494 * and the run preceding them has a level different from
495 * paraLevel, then they will form their own run at paraLevel (L1).
496 * Count them separately.
497 * We need some special treatment for this in order to not
498 * modify the levels array which a line Bidi object shares
499 * with its paragraph parent and its other line siblings.
500 * In other words, for the trailing WS, it may be
501 * levels[]!=paraLevel but we have to treat it like it were so.
502 */
503 limit = bidiBase.trailingWSStart;
504 /* count the runs, there is at least one non-WS run, and limit>0 */
505 runCount = 0;
506 for (i = 0; i < limit; ++i) {
507 /* increment runCount at the start of each run */
508 if (levels[i] != level) {
509 ++runCount;
510 level = levels[i];
511 }
512 }
513
514 /*
515 * We don't need to see if the last run can be merged with a trailing
516 * WS run because setTrailingWSStart() would have done that.
517 */
518 if (runCount == 1 && limit == length) {
519 /* There is only one non-WS run and no trailing WS-run. */
520 getSingleRun(bidiBase, levels[0]);
521 } else /* runCount>1 || limit<length */ {
522 /* allocate and set the runs */
523 BidiRun[] runs;
524 int runIndex, start;
525 byte minLevel = BidiBase.MAX_EXPLICIT_LEVEL + 1;
526 byte maxLevel=0;
527
528 /* now, count a (non-mergeable) WS run */
529 if (limit < length) {
530 ++runCount;
531 }
532
533 /* runCount > 1 */
534 bidiBase.getRunsMemory(runCount);
535 runs = bidiBase.runsMemory;
536
537 /* set the runs */
538 /* FOOD FOR THOUGHT: this could be optimized, e.g.:
539 * 464->444, 484->444, 575->555, 595->555
540 * However, that would take longer. Check also how it would
541 * interact with BiDi control removal and inserting Marks.
542 */
543 runIndex = 0;
544
545 /* search for the run limits and initialize visualLimit values with the run lengths */
546 i = 0;
547 do {
548 /* prepare this run */
549 start = i;
550 level = levels[i];
551 if (level < minLevel) {
552 minLevel = level;
553 }
554 if (level > maxLevel) {
555 maxLevel = level;
556 }
557
558 /* look for the run limit */
559 while (++i < limit && levels[i] == level) {}
560
561 /* i is another run limit */
562 runs[runIndex] = new BidiRun(start, i - start, level);
563 ++runIndex;
564 } while (i < limit);
565
566 if (limit < length) {
567 /* there is a separate WS run */
568 runs[runIndex] = new BidiRun(limit, length - limit, bidiBase.paraLevel);
569 /* For the trailing WS run, bidiBase.paraLevel is ok even
570 if contextual multiple paragraphs. */
571 if (bidiBase.paraLevel < minLevel) {
572 minLevel = bidiBase.paraLevel;
573 }
574 }
575
576 /* set the object fields */
577 bidiBase.runs = runs;
578 bidiBase.runCount = runCount;
579
580 reorderLine(bidiBase, minLevel, maxLevel);
581
582 /* now add the direction flags and adjust the visualLimit's to be just that */
583 /* this loop will also handle the trailing WS run */
584 limit = 0;
585 for (i = 0; i < runCount; ++i) {
586 runs[i].level = levels[runs[i].start];
587 limit = (runs[i].limit += limit);
588 }
589
590 /* Set the embedding level for the trailing WS run. */
591 /* For a RTL paragraph, it will be the *first* run in visual order. */
592 /* For the trailing WS run, bidiBase.paraLevel is ok even if
593 contextual multiple paragraphs. */
594 if (runIndex < runCount) {
595 int trailingRun = ((bidiBase.paraLevel & 1) != 0)? 0 : runIndex;
596 runs[trailingRun].level = bidiBase.paraLevel;
597 }
598 }
599 }
600
601 /* handle insert LRM/RLM BEFORE/AFTER run */
602 if (bidiBase.insertPoints.size > 0) {
603 BidiBase.Point point;
604 int runIndex, ip;
605 for (ip = 0; ip < bidiBase.insertPoints.size; ip++) {
606 point = bidiBase.insertPoints.points[ip];
607 runIndex = getRunFromLogicalIndex(bidiBase, point.pos);
608 bidiBase.runs[runIndex].insertRemove |= point.flag;
609 }
610 }
611
612 /* handle remove BiDi control characters */
613 if (bidiBase.controlCount > 0) {
614 int runIndex, ic;
615 char c;
616 for (ic = 0; ic < bidiBase.length; ic++) {
617 c = bidiBase.text[ic];
618 if (BidiBase.IsBidiControlChar(c)) {
619 runIndex = getRunFromLogicalIndex(bidiBase, ic);
620 bidiBase.runs[runIndex].insertRemove--;
621 }
622 }
623 }
624 }
625
626 static int[] prepareReorder(byte[] levels, byte[] pMinLevel, byte[] pMaxLevel)
627 {
628 int start;
629 byte level, minLevel, maxLevel;
630
631 if (levels == null || levels.length <= 0) {
632 return null;
633 }
634
635 /* determine minLevel and maxLevel */
636 minLevel = BidiBase.MAX_EXPLICIT_LEVEL + 1;
637 maxLevel = 0;
638 for (start = levels.length; start>0; ) {
639 level = levels[--start];
640 if (level < 0 || level > (BidiBase.MAX_EXPLICIT_LEVEL + 1)) {
641 return null;
642 }
643 if (level < minLevel) {
644 minLevel = level;
645 }
646 if (level > maxLevel) {
647 maxLevel = level;
648 }
649 }
650 pMinLevel[0] = minLevel;
651 pMaxLevel[0] = maxLevel;
652
653 /* initialize the index map */
654 int[] indexMap = new int[levels.length];
655 for (start = levels.length; start > 0; ) {
656 --start;
657 indexMap[start] = start;
658 }
659
660 return indexMap;
661 }
662
663 static int[] reorderVisual(byte[] levels)
664 {
665 byte[] aMinLevel = new byte[1];
666 byte[] aMaxLevel = new byte[1];
667 int start, end, limit, temp;
668 byte minLevel, maxLevel;
669
670 int[] indexMap = prepareReorder(levels, aMinLevel, aMaxLevel);
671 if (indexMap == null) {
672 return null;
673 }
674
675 minLevel = aMinLevel[0];
676 maxLevel = aMaxLevel[0];
677
678 /* nothing to do? */
679 if (minLevel == maxLevel && (minLevel & 1) == 0) {
680 return indexMap;
681 }
682
683 /* reorder only down to the lowest odd level */
684 minLevel |= 1;
685
686 /* loop maxLevel..minLevel */
687 do {
688 start = 0;
689
690 /* loop for all sequences of levels to reorder at the current maxLevel */
691 for ( ; ; ) {
692 /* look for a sequence of levels that are all at >=maxLevel */
693 /* look for the first index of such a sequence */
694 while (start < levels.length && levels[start] < maxLevel) {
695 ++start;
696 }
697 if (start >= levels.length) {
698 break; /* no more such runs */
699 }
700
701 /* look for the limit of such a sequence (the index behind it) */
702 for (limit = start; ++limit < levels.length && levels[limit] >= maxLevel; ) {}
703
704 /*
705 * Swap the entire interval of indexes from start to limit-1.
706 * We don't need to swap the levels for the purpose of this
707 * algorithm: the sequence of levels that we look at does not
708 * move anyway.
709 */
710 end = limit - 1;
711 while (start < end) {
712 temp = indexMap[start];
713 indexMap[start] = indexMap[end];
714 indexMap[end] = temp;
715
716 ++start;
717 --end;
718 }
719
720 if (limit == levels.length) {
721 break; /* no more such sequences */
722 } else {
723 start = limit + 1;
724 }
725 }
726 } while (--maxLevel >= minLevel);
727
728 return indexMap;
729 }
730
731 static int[] getVisualMap(BidiBase bidiBase)
732 {
733 /* fill a visual-to-logical index map using the runs[] */
734 BidiRun[] runs = bidiBase.runs;
735 int logicalStart, visualStart, visualLimit;
736 int allocLength = bidiBase.length > bidiBase.resultLength ? bidiBase.length
737 : bidiBase.resultLength;
738 int[] indexMap = new int[allocLength];
739
740 visualStart = 0;
741 int idx = 0;
742 for (int j = 0; j < bidiBase.runCount; ++j) {
743 logicalStart = runs[j].start;
744 visualLimit = runs[j].limit;
745 if (runs[j].isEvenRun()) {
746 do { /* LTR */
747 indexMap[idx++] = logicalStart++;
748 } while (++visualStart < visualLimit);
749 } else {
750 logicalStart += visualLimit - visualStart; /* logicalLimit */
751 do { /* RTL */
752 indexMap[idx++] = --logicalStart;
753 } while (++visualStart < visualLimit);
754 }
755 /* visualStart==visualLimit; */
756 }
757
758 if (bidiBase.insertPoints.size > 0) {
759 int markFound = 0, runCount = bidiBase.runCount;
760 int insertRemove, i, j, k;
761 runs = bidiBase.runs;
762 /* count all inserted marks */
763 for (i = 0; i < runCount; i++) {
764 insertRemove = runs[i].insertRemove;
765 if ((insertRemove & (BidiBase.LRM_BEFORE|BidiBase.RLM_BEFORE)) > 0) {
766 markFound++;
767 }
768 if ((insertRemove & (BidiBase.LRM_AFTER|BidiBase.RLM_AFTER)) > 0) {
769 markFound++;
770 }
771 }
772 /* move back indexes by number of preceding marks */
773 k = bidiBase.resultLength;
774 for (i = runCount - 1; i >= 0 && markFound > 0; i--) {
775 insertRemove = runs[i].insertRemove;
776 if ((insertRemove & (BidiBase.LRM_AFTER|BidiBase.RLM_AFTER)) > 0) {
777 indexMap[--k] = BidiBase.MAP_NOWHERE;
778 markFound--;
779 }
780 visualStart = i > 0 ? runs[i-1].limit : 0;
781 for (j = runs[i].limit - 1; j >= visualStart && markFound > 0; j--) {
782 indexMap[--k] = indexMap[j];
783 }
784 if ((insertRemove & (BidiBase.LRM_BEFORE|BidiBase.RLM_BEFORE)) > 0) {
785 indexMap[--k] = BidiBase.MAP_NOWHERE;
786 markFound--;
787 }
788 }
789 }
790 else if (bidiBase.controlCount > 0) {
791 int runCount = bidiBase.runCount, logicalEnd;
792 int insertRemove, length, i, j, k, m;
793 char uchar;
794 boolean evenRun;
795 runs = bidiBase.runs;
796 visualStart = 0;
797 /* move forward indexes by number of preceding controls */
798 k = 0;
799 for (i = 0; i < runCount; i++, visualStart += length) {
800 length = runs[i].limit - visualStart;
801 insertRemove = runs[i].insertRemove;
802 /* if no control found yet, nothing to do in this run */
803 if ((insertRemove == 0) && (k == visualStart)) {
804 k += length;
805 continue;
806 }
807 /* if no control in this run */
808 if (insertRemove == 0) {
809 visualLimit = runs[i].limit;
810 for (j = visualStart; j < visualLimit; j++) {
811 indexMap[k++] = indexMap[j];
812 }
813 continue;
814 }
815 logicalStart = runs[i].start;
816 evenRun = runs[i].isEvenRun();
817 logicalEnd = logicalStart + length - 1;
818 for (j = 0; j < length; j++) {
819 m = evenRun ? logicalStart + j : logicalEnd - j;
820 uchar = bidiBase.text[m];
821 if (!BidiBase.IsBidiControlChar(uchar)) {
822 indexMap[k++] = m;
823 }
824 }
825 }
826 }
827 if (allocLength == bidiBase.resultLength) {
828 return indexMap;
829 }
830 int[] newMap = new int[bidiBase.resultLength];
831 System.arraycopy(indexMap, 0, newMap, 0, bidiBase.resultLength);
832 return newMap;
833 }
834
835 }