| /* |
| ****************************************************************************** |
| * |
| * Copyright (C) 1999-2003, International Business Machines |
| * Corporation and others. All Rights Reserved. |
| * |
| ****************************************************************************** |
| * file name: ubidiln.c |
| * encoding: US-ASCII |
| * tab size: 8 (not used) |
| * indentation:4 |
| * |
| * created on: 1999aug06 |
| * created by: Markus W. Scherer |
| */ |
| |
| /* set import/export definitions */ |
| #ifndef U_COMMON_IMPLEMENTATION |
| # define U_COMMON_IMPLEMENTATION |
| #endif |
| |
| #include "cmemory.h" |
| #include "unicode/utypes.h" |
| #include "unicode/ustring.h" |
| #include "unicode/uchar.h" |
| #include "unicode/ubidi.h" |
| #include "ubidiimp.h" |
| |
| /* |
| * General remarks about the functions in this file: |
| * |
| * These functions deal with the aspects of potentially mixed-directional |
| * text in a single paragraph or in a line of a single paragraph |
| * which has already been processed according to |
| * the Unicode 3.0 BiDi algorithm as defined in |
| * http://www.unicode.org/unicode/reports/tr9/ , version 5, |
| * also described in The Unicode Standard, Version 3.0 . |
| * |
| * This means that there is a UBiDi object with a levels |
| * and a dirProps array. |
| * paraLevel and direction are also set. |
| * Only if the length of the text is zero, then levels==dirProps==NULL. |
| * |
| * The overall directionality of the paragraph |
| * or line is used to bypass the reordering steps if possible. |
| * Even purely RTL text does not need reordering there because |
| * the ubidi_getLogical/VisualIndex() functions can compute the |
| * index on the fly in such a case. |
| * |
| * The implementation of the access to same-level-runs and of the reordering |
| * do attempt to provide better performance and less memory usage compared to |
| * a direct implementation of especially rule (L2) with an array of |
| * one (32-bit) integer per text character. |
| * |
| * Here, the levels array is scanned as soon as necessary, and a vector of |
| * same-level-runs is created. Reordering then is done on this vector. |
| * For each run of text positions that were resolved to the same level, |
| * only 8 bytes are stored: the first text position of the run and the visual |
| * position behind the run after reordering. |
| * One sign bit is used to hold the directionality of the run. |
| * This is inefficient if there are many very short runs. If the average run |
| * length is <2, then this uses more memory. |
| * |
| * In a further attempt to save memory, the levels array is never changed |
| * after all the resolution rules (Xn, Wn, Nn, In). |
| * Many functions have to consider the field trailingWSStart: |
| * if it is less than length, then there is an implicit trailing run |
| * at the paraLevel, |
| * which is not reflected in the levels array. |
| * This allows a line UBiDi object to use the same levels array as |
| * its paragraph parent object. |
| * |
| * When a UBiDi object is created for a line of a paragraph, then the |
| * paragraph's levels and dirProps arrays are reused by way of setting |
| * a pointer into them, not by copying. This again saves memory and forbids to |
| * change the now shared levels for (L1). |
| */ |
| |
| /* handle trailing WS (L1) -------------------------------------------------- */ |
| |
| /* |
| * setTrailingWSStart() sets the start index for a trailing |
| * run of WS in the line. This is necessary because we do not modify |
| * the paragraph's levels array that we just point into. |
| * Using trailingWSStart is another form of performing (L1). |
| * |
| * To make subsequent operations easier, we also include the run |
| * before the WS if it is at the paraLevel - we merge the two here. |
| */ |
| static void |
| setTrailingWSStart(UBiDi *pBiDi) { |
| /* pBiDi->direction!=UBIDI_MIXED */ |
| |
| const DirProp *dirProps=pBiDi->dirProps; |
| UBiDiLevel *levels=pBiDi->levels; |
| int32_t start=pBiDi->length; |
| UBiDiLevel paraLevel=pBiDi->paraLevel; |
| |
| /* go backwards across all WS, BN, explicit codes */ |
| while(start>0 && DIRPROP_FLAG(dirProps[start-1])&MASK_WS) { |
| --start; |
| } |
| |
| /* if the WS run can be merged with the previous run then do so here */ |
| while(start>0 && levels[start-1]==paraLevel) { |
| --start; |
| } |
| |
| pBiDi->trailingWSStart=start; |
| } |
| |
| /* ubidi_setLine ------------------------------------------------------------ */ |
| |
| U_CAPI void U_EXPORT2 |
| ubidi_setLine(const UBiDi *pParaBiDi, |
| int32_t start, int32_t limit, |
| UBiDi *pLineBiDi, |
| UErrorCode *pErrorCode) { |
| int32_t length; |
| |
| /* check the argument values */ |
| if(pErrorCode==NULL || U_FAILURE(*pErrorCode)) { |
| return; |
| } else if(pParaBiDi==NULL || pLineBiDi==NULL) { |
| *pErrorCode=U_ILLEGAL_ARGUMENT_ERROR; |
| return; |
| } else if(start<0 || start>limit || limit>pParaBiDi->length) { |
| *pErrorCode=U_INDEX_OUTOFBOUNDS_ERROR; |
| return; |
| } |
| |
| /* set the values in pLineBiDi from its pParaBiDi parent */ |
| pLineBiDi->text=pParaBiDi->text+start; |
| length=pLineBiDi->length=limit-start; |
| pLineBiDi->paraLevel=pParaBiDi->paraLevel; |
| |
| pLineBiDi->runs=NULL; |
| pLineBiDi->flags=0; |
| |
| if(length>0) { |
| pLineBiDi->dirProps=pParaBiDi->dirProps+start; |
| pLineBiDi->levels=pParaBiDi->levels+start; |
| pLineBiDi->runCount=-1; |
| |
| if(pParaBiDi->direction!=UBIDI_MIXED) { |
| /* the parent is already trivial */ |
| pLineBiDi->direction=pParaBiDi->direction; |
| |
| /* |
| * The parent's levels are all either |
| * implicitly or explicitly ==paraLevel; |
| * do the same here. |
| */ |
| if(pParaBiDi->trailingWSStart<=start) { |
| pLineBiDi->trailingWSStart=0; |
| } else if(pParaBiDi->trailingWSStart<limit) { |
| pLineBiDi->trailingWSStart=pParaBiDi->trailingWSStart-start; |
| } else { |
| pLineBiDi->trailingWSStart=length; |
| } |
| } else { |
| const UBiDiLevel *levels=pLineBiDi->levels; |
| int32_t i, trailingWSStart; |
| UBiDiLevel level; |
| |
| setTrailingWSStart(pLineBiDi); |
| trailingWSStart=pLineBiDi->trailingWSStart; |
| |
| /* recalculate pLineBiDi->direction */ |
| if(trailingWSStart==0) { |
| /* all levels are at paraLevel */ |
| pLineBiDi->direction=(UBiDiDirection)(pLineBiDi->paraLevel&1); |
| } else { |
| /* get the level of the first character */ |
| level=(UBiDiLevel)(levels[0]&1); |
| |
| /* if there is anything of a different level, then the line is mixed */ |
| if(trailingWSStart<length && (pLineBiDi->paraLevel&1)!=level) { |
| /* the trailing WS is at paraLevel, which differs from levels[0] */ |
| pLineBiDi->direction=UBIDI_MIXED; |
| } else { |
| /* see if levels[1..trailingWSStart-1] have the same direction as levels[0] and paraLevel */ |
| i=1; |
| for(;;) { |
| if(i==trailingWSStart) { |
| /* the direction values match those in level */ |
| pLineBiDi->direction=(UBiDiDirection)level; |
| break; |
| } else if((levels[i]&1)!=level) { |
| pLineBiDi->direction=UBIDI_MIXED; |
| break; |
| } |
| ++i; |
| } |
| } |
| } |
| |
| switch(pLineBiDi->direction) { |
| case UBIDI_LTR: |
| /* make sure paraLevel is even */ |
| pLineBiDi->paraLevel=(UBiDiLevel)((pLineBiDi->paraLevel+1)&~1); |
| |
| /* all levels are implicitly at paraLevel (important for ubidi_getLevels()) */ |
| pLineBiDi->trailingWSStart=0; |
| break; |
| case UBIDI_RTL: |
| /* make sure paraLevel is odd */ |
| pLineBiDi->paraLevel|=1; |
| |
| /* all levels are implicitly at paraLevel (important for ubidi_getLevels()) */ |
| pLineBiDi->trailingWSStart=0; |
| break; |
| default: |
| break; |
| } |
| } |
| } else { |
| /* create an object for a zero-length line */ |
| pLineBiDi->direction=pLineBiDi->paraLevel&1 ? UBIDI_RTL : UBIDI_LTR; |
| pLineBiDi->trailingWSStart=pLineBiDi->runCount=0; |
| |
| pLineBiDi->dirProps=NULL; |
| pLineBiDi->levels=NULL; |
| } |
| return; |
| } |
| |
| U_CAPI UBiDiLevel U_EXPORT2 |
| ubidi_getLevelAt(const UBiDi *pBiDi, int32_t charIndex) { |
| /* return paraLevel if in the trailing WS run, otherwise the real level */ |
| if(pBiDi==NULL || charIndex<0 || pBiDi->length<=charIndex) { |
| return 0; |
| } else if(pBiDi->direction!=UBIDI_MIXED || charIndex>=pBiDi->trailingWSStart) { |
| return pBiDi->paraLevel; |
| } else { |
| return pBiDi->levels[charIndex]; |
| } |
| } |
| |
| U_CAPI const UBiDiLevel * U_EXPORT2 |
| ubidi_getLevels(UBiDi *pBiDi, UErrorCode *pErrorCode) { |
| int32_t start, length; |
| |
| if(pErrorCode==NULL || U_FAILURE(*pErrorCode)) { |
| return NULL; |
| } else if(pBiDi==NULL || (length=pBiDi->length)<=0) { |
| *pErrorCode=U_ILLEGAL_ARGUMENT_ERROR; |
| return NULL; |
| } |
| |
| if((start=pBiDi->trailingWSStart)==length) { |
| /* the current levels array reflects the WS run */ |
| return pBiDi->levels; |
| } |
| |
| /* |
| * After the previous if(), we know that the levels array |
| * has an implicit trailing WS run and therefore does not fully |
| * reflect itself all the levels. |
| * This must be a UBiDi object for a line, and |
| * we need to create a new levels array. |
| */ |
| |
| if(getLevelsMemory(pBiDi, length)) { |
| UBiDiLevel *levels=pBiDi->levelsMemory; |
| |
| if(start>0 && levels!=pBiDi->levels) { |
| uprv_memcpy(levels, pBiDi->levels, start); |
| } |
| uprv_memset(levels+start, pBiDi->paraLevel, length-start); |
| |
| /* this new levels array is set for the line and reflects the WS run */ |
| pBiDi->trailingWSStart=length; |
| return pBiDi->levels=levels; |
| } else { |
| /* out of memory */ |
| *pErrorCode=U_MEMORY_ALLOCATION_ERROR; |
| return NULL; |
| } |
| } |
| |
| U_CAPI void U_EXPORT2 |
| ubidi_getLogicalRun(const UBiDi *pBiDi, int32_t logicalStart, |
| int32_t *pLogicalLimit, UBiDiLevel *pLevel) { |
| int32_t length; |
| |
| if(pBiDi==NULL || logicalStart<0 || (length=pBiDi->length)<=logicalStart) { |
| return; |
| } |
| |
| if(pBiDi->direction!=UBIDI_MIXED || logicalStart>=pBiDi->trailingWSStart) { |
| if(pLogicalLimit!=NULL) { |
| *pLogicalLimit=length; |
| } |
| if(pLevel!=NULL) { |
| *pLevel=pBiDi->paraLevel; |
| } |
| } else { |
| UBiDiLevel *levels=pBiDi->levels; |
| UBiDiLevel level=levels[logicalStart]; |
| |
| /* search for the end of the run */ |
| length=pBiDi->trailingWSStart; |
| while(++logicalStart<length && level==levels[logicalStart]) {} |
| |
| if(pLogicalLimit!=NULL) { |
| *pLogicalLimit=logicalStart; |
| } |
| if(pLevel!=NULL) { |
| *pLevel=level; |
| } |
| } |
| } |
| |
| /* runs API functions ------------------------------------------------------- */ |
| |
| U_CAPI int32_t U_EXPORT2 |
| ubidi_countRuns(UBiDi *pBiDi, UErrorCode *pErrorCode) { |
| if(pErrorCode==NULL || U_FAILURE(*pErrorCode)) { |
| return -1; |
| } else if(pBiDi==NULL || (pBiDi->runCount<0 && !ubidi_getRuns(pBiDi))) { |
| *pErrorCode=U_MEMORY_ALLOCATION_ERROR; |
| return -1; |
| } else { |
| return pBiDi->runCount; |
| } |
| } |
| |
| U_CAPI UBiDiDirection U_EXPORT2 |
| ubidi_getVisualRun(UBiDi *pBiDi, int32_t runIndex, |
| int32_t *pLogicalStart, int32_t *pLength) { |
| if( pBiDi==NULL || runIndex<0 || |
| (pBiDi->runCount==-1 && !ubidi_getRuns(pBiDi)) || |
| runIndex>=pBiDi->runCount |
| ) { |
| return UBIDI_LTR; |
| } else { |
| int32_t start=pBiDi->runs[runIndex].logicalStart; |
| if(pLogicalStart!=NULL) { |
| *pLogicalStart=GET_INDEX(start); |
| } |
| if(pLength!=NULL) { |
| if(runIndex>0) { |
| *pLength=pBiDi->runs[runIndex].visualLimit- |
| pBiDi->runs[runIndex-1].visualLimit; |
| } else { |
| *pLength=pBiDi->runs[0].visualLimit; |
| } |
| } |
| return (UBiDiDirection)GET_ODD_BIT(start); |
| } |
| } |
| |
| /* in trivial cases there is only one trivial run; called by ubidi_getRuns() */ |
| static void |
| getSingleRun(UBiDi *pBiDi, UBiDiLevel level) { |
| /* simple, single-run case */ |
| pBiDi->runs=pBiDi->simpleRuns; |
| pBiDi->runCount=1; |
| |
| /* fill and reorder the single run */ |
| pBiDi->runs[0].logicalStart=MAKE_INDEX_ODD_PAIR(0, level); |
| pBiDi->runs[0].visualLimit=pBiDi->length; |
| } |
| |
| /* reorder the runs array (L2) ---------------------------------------------- */ |
| |
| /* |
| * Reorder the same-level runs in the runs array. |
| * Here, runCount>1 and maxLevel>=minLevel>=paraLevel. |
| * All the visualStart fields=logical start before reordering. |
| * The "odd" bits are not set yet. |
| * |
| * Reordering with this data structure lends itself to some handy shortcuts: |
| * |
| * Since each run is moved but not modified, and since at the initial maxLevel |
| * each sequence of same-level runs consists of only one run each, we |
| * don't need to do anything there and can predecrement maxLevel. |
| * In many simple cases, the reordering is thus done entirely in the |
| * index mapping. |
| * Also, reordering occurs only down to the lowest odd level that occurs, |
| * which is minLevel|1. However, if the lowest level itself is odd, then |
| * in the last reordering the sequence of the runs at this level or higher |
| * will be all runs, and we don't need the elaborate loop to search for them. |
| * This is covered by ++minLevel instead of minLevel|=1 followed |
| * by an extra reorder-all after the reorder-some loop. |
| * About a trailing WS run: |
| * Such a run would need special treatment because its level is not |
| * reflected in levels[] if this is not a paragraph object. |
| * Instead, all characters from trailingWSStart on are implicitly at |
| * paraLevel. |
| * However, for all maxLevel>paraLevel, this run will never be reordered |
| * and does not need to be taken into account. maxLevel==paraLevel is only reordered |
| * if minLevel==paraLevel is odd, which is done in the extra segment. |
| * This means that for the main reordering loop we don't need to consider |
| * this run and can --runCount. If it is later part of the all-runs |
| * reordering, then runCount is adjusted accordingly. |
| */ |
| static void |
| reorderLine(UBiDi *pBiDi, UBiDiLevel minLevel, UBiDiLevel maxLevel) { |
| Run *runs; |
| UBiDiLevel *levels; |
| int32_t firstRun, endRun, limitRun, runCount, |
| temp; |
| |
| /* nothing to do? */ |
| if(maxLevel<=(minLevel|1)) { |
| return; |
| } |
| |
| /* |
| * Reorder only down to the lowest odd level |
| * and reorder at an odd minLevel in a separate, simpler loop. |
| * See comments above for why minLevel is always incremented. |
| */ |
| ++minLevel; |
| |
| runs=pBiDi->runs; |
| levels=pBiDi->levels; |
| runCount=pBiDi->runCount; |
| |
| /* do not include the WS run at paraLevel<=old minLevel except in the simple loop */ |
| if(pBiDi->trailingWSStart<pBiDi->length) { |
| --runCount; |
| } |
| |
| while(--maxLevel>=minLevel) { |
| firstRun=0; |
| |
| /* loop for all sequences of runs */ |
| for(;;) { |
| /* look for a sequence of runs that are all at >=maxLevel */ |
| /* look for the first run of such a sequence */ |
| while(firstRun<runCount && levels[runs[firstRun].logicalStart]<maxLevel) { |
| ++firstRun; |
| } |
| if(firstRun>=runCount) { |
| break; /* no more such runs */ |
| } |
| |
| /* look for the limit run of such a sequence (the run behind it) */ |
| for(limitRun=firstRun; ++limitRun<runCount && levels[runs[limitRun].logicalStart]>=maxLevel;) {} |
| |
| /* Swap the entire sequence of runs from firstRun to limitRun-1. */ |
| endRun=limitRun-1; |
| while(firstRun<endRun) { |
| temp=runs[firstRun].logicalStart; |
| runs[firstRun].logicalStart=runs[endRun].logicalStart; |
| runs[endRun].logicalStart=temp; |
| |
| temp=runs[firstRun].visualLimit; |
| runs[firstRun].visualLimit=runs[endRun].visualLimit; |
| runs[endRun].visualLimit=temp; |
| |
| ++firstRun; |
| --endRun; |
| } |
| |
| if(limitRun==runCount) { |
| break; /* no more such runs */ |
| } else { |
| firstRun=limitRun+1; |
| } |
| } |
| } |
| |
| /* now do maxLevel==old minLevel (==odd!), see above */ |
| if(!(minLevel&1)) { |
| firstRun=0; |
| |
| /* include the trailing WS run in this complete reordering */ |
| if(pBiDi->trailingWSStart==pBiDi->length) { |
| --runCount; |
| } |
| |
| /* Swap the entire sequence of all runs. (endRun==runCount) */ |
| while(firstRun<runCount) { |
| temp=runs[firstRun].logicalStart; |
| runs[firstRun].logicalStart=runs[runCount].logicalStart; |
| runs[runCount].logicalStart=temp; |
| |
| temp=runs[firstRun].visualLimit; |
| runs[firstRun].visualLimit=runs[runCount].visualLimit; |
| runs[runCount].visualLimit=temp; |
| |
| ++firstRun; |
| --runCount; |
| } |
| } |
| } |
| |
| /* compute the runs array --------------------------------------------------- */ |
| |
| /* |
| * Compute the runs array from the levels array. |
| * After ubidi_getRuns() returns TRUE, runCount is guaranteed to be >0 |
| * and the runs are reordered. |
| * Odd-level runs have visualStart on their visual right edge and |
| * they progress visually to the left. |
| */ |
| U_CFUNC UBool |
| ubidi_getRuns(UBiDi *pBiDi) { |
| if(pBiDi->direction!=UBIDI_MIXED) { |
| /* simple, single-run case - this covers length==0 */ |
| getSingleRun(pBiDi, pBiDi->paraLevel); |
| } else /* UBIDI_MIXED, length>0 */ { |
| /* mixed directionality */ |
| int32_t length=pBiDi->length, limit; |
| |
| /* |
| * If there are WS characters at the end of the line |
| * and the run preceding them has a level different from |
| * paraLevel, then they will form their own run at paraLevel (L1). |
| * Count them separately. |
| * We need some special treatment for this in order to not |
| * modify the levels array which a line UBiDi object shares |
| * with its paragraph parent and its other line siblings. |
| * In other words, for the trailing WS, it may be |
| * levels[]!=paraLevel but we have to treat it like it were so. |
| */ |
| limit=pBiDi->trailingWSStart; |
| if(limit==0) { |
| /* there is only WS on this line */ |
| getSingleRun(pBiDi, pBiDi->paraLevel); |
| } else { |
| UBiDiLevel *levels=pBiDi->levels; |
| int32_t i, runCount; |
| UBiDiLevel level=UBIDI_DEFAULT_LTR; /* initialize with no valid level */ |
| |
| /* count the runs, there is at least one non-WS run, and limit>0 */ |
| runCount=0; |
| for(i=0; i<limit; ++i) { |
| /* increment runCount at the start of each run */ |
| if(levels[i]!=level) { |
| ++runCount; |
| level=levels[i]; |
| } |
| } |
| |
| /* |
| * We don't need to see if the last run can be merged with a trailing |
| * WS run because setTrailingWSStart() would have done that. |
| */ |
| if(runCount==1 && limit==length) { |
| /* There is only one non-WS run and no trailing WS-run. */ |
| getSingleRun(pBiDi, levels[0]); |
| } else /* runCount>1 || limit<length */ { |
| /* allocate and set the runs */ |
| Run *runs; |
| int32_t runIndex, start; |
| UBiDiLevel minLevel=UBIDI_MAX_EXPLICIT_LEVEL+1, maxLevel=0; |
| |
| /* now, count a (non-mergable) WS run */ |
| if(limit<length) { |
| ++runCount; |
| } |
| |
| /* runCount>1 */ |
| if(getRunsMemory(pBiDi, runCount)) { |
| runs=pBiDi->runsMemory; |
| } else { |
| return FALSE; |
| } |
| |
| /* set the runs */ |
| /* this could be optimized, e.g.: 464->444, 484->444, 575->555, 595->555 */ |
| /* however, that would take longer and make other functions more complicated */ |
| runIndex=0; |
| |
| /* search for the run limits and initialize visualLimit values with the run lengths */ |
| i=0; |
| do { |
| /* prepare this run */ |
| start=i; |
| level=levels[i]; |
| if(level<minLevel) { |
| minLevel=level; |
| } |
| if(level>maxLevel) { |
| maxLevel=level; |
| } |
| |
| /* look for the run limit */ |
| while(++i<limit && levels[i]==level) {} |
| |
| /* i is another run limit */ |
| runs[runIndex].logicalStart=start; |
| runs[runIndex].visualLimit=i-start; |
| ++runIndex; |
| } while(i<limit); |
| |
| if(limit<length) { |
| /* there is a separate WS run */ |
| runs[runIndex].logicalStart=limit; |
| runs[runIndex].visualLimit=length-limit; |
| if(pBiDi->paraLevel<minLevel) { |
| minLevel=pBiDi->paraLevel; |
| } |
| } |
| |
| /* set the object fields */ |
| pBiDi->runs=runs; |
| pBiDi->runCount=runCount; |
| |
| reorderLine(pBiDi, minLevel, maxLevel); |
| |
| /* now add the direction flags and adjust the visualLimit's to be just that */ |
| ADD_ODD_BIT_FROM_LEVEL(runs[0].logicalStart, levels[runs[0].logicalStart]); |
| limit=runs[0].visualLimit; |
| |
| /* this loop will also handle the trailing WS run */ |
| for(i=1; i<runCount; ++i) { |
| ADD_ODD_BIT_FROM_LEVEL(runs[i].logicalStart, levels[runs[i].logicalStart]); |
| limit=runs[i].visualLimit+=limit; |
| } |
| |
| /* Set the "odd" bit for the trailing WS run. */ |
| /* For a RTL paragraph, it will be the *first* run in visual order. */ |
| if(runIndex<runCount) { |
| int32_t trailingRun = ((pBiDi->paraLevel & 1) != 0)? 0 : runIndex; |
| |
| ADD_ODD_BIT_FROM_LEVEL(runs[trailingRun].logicalStart, pBiDi->paraLevel); |
| } |
| } |
| } |
| } |
| return TRUE; |
| } |
| |
| static UBool |
| prepareReorder(const UBiDiLevel *levels, int32_t length, |
| int32_t *indexMap, |
| UBiDiLevel *pMinLevel, UBiDiLevel *pMaxLevel) { |
| int32_t start; |
| UBiDiLevel level, minLevel, maxLevel; |
| |
| if(levels==NULL || length<=0) { |
| return FALSE; |
| } |
| |
| /* determine minLevel and maxLevel */ |
| minLevel=UBIDI_MAX_EXPLICIT_LEVEL+1; |
| maxLevel=0; |
| for(start=length; start>0;) { |
| level=levels[--start]; |
| if(level>UBIDI_MAX_EXPLICIT_LEVEL+1) { |
| return FALSE; |
| } |
| if(level<minLevel) { |
| minLevel=level; |
| } |
| if(level>maxLevel) { |
| maxLevel=level; |
| } |
| } |
| *pMinLevel=minLevel; |
| *pMaxLevel=maxLevel; |
| |
| /* initialize the index map */ |
| for(start=length; start>0;) { |
| --start; |
| indexMap[start]=start; |
| } |
| |
| return TRUE; |
| } |
| |
| /* reorder a line based on a levels array (L2) ------------------------------ */ |
| |
| U_CAPI void U_EXPORT2 |
| ubidi_reorderLogical(const UBiDiLevel *levels, int32_t length, int32_t *indexMap) { |
| int32_t start, limit, sumOfSosEos; |
| UBiDiLevel minLevel, maxLevel; |
| |
| if(indexMap==NULL || !prepareReorder(levels, length, indexMap, &minLevel, &maxLevel)) { |
| return; |
| } |
| |
| /* nothing to do? */ |
| if(minLevel==maxLevel && (minLevel&1)==0) { |
| return; |
| } |
| |
| /* reorder only down to the lowest odd level */ |
| minLevel|=1; |
| |
| /* loop maxLevel..minLevel */ |
| do { |
| start=0; |
| |
| /* loop for all sequences of levels to reorder at the current maxLevel */ |
| for(;;) { |
| /* look for a sequence of levels that are all at >=maxLevel */ |
| /* look for the first index of such a sequence */ |
| while(start<length && levels[start]<maxLevel) { |
| ++start; |
| } |
| if(start>=length) { |
| break; /* no more such sequences */ |
| } |
| |
| /* look for the limit of such a sequence (the index behind it) */ |
| for(limit=start; ++limit<length && levels[limit]>=maxLevel;) {} |
| |
| /* |
| * sos=start of sequence, eos=end of sequence |
| * |
| * The closed (inclusive) interval from sos to eos includes all the logical |
| * and visual indexes within this sequence. They are logically and |
| * visually contiguous and in the same range. |
| * |
| * For each run, the new visual index=sos+eos-old visual index; |
| * we pre-add sos+eos into sumOfSosEos -> |
| * new visual index=sumOfSosEos-old visual index; |
| */ |
| sumOfSosEos=start+limit-1; |
| |
| /* reorder each index in the sequence */ |
| do { |
| indexMap[start]=sumOfSosEos-indexMap[start]; |
| } while(++start<limit); |
| |
| /* start==limit */ |
| if(limit==length) { |
| break; /* no more such sequences */ |
| } else { |
| start=limit+1; |
| } |
| } |
| } while(--maxLevel>=minLevel); |
| } |
| |
| U_CAPI void U_EXPORT2 |
| ubidi_reorderVisual(const UBiDiLevel *levels, int32_t length, int32_t *indexMap) { |
| int32_t start, end, limit, temp; |
| UBiDiLevel minLevel, maxLevel; |
| |
| if(indexMap==NULL || !prepareReorder(levels, length, indexMap, &minLevel, &maxLevel)) { |
| return; |
| } |
| |
| /* nothing to do? */ |
| if(minLevel==maxLevel && (minLevel&1)==0) { |
| return; |
| } |
| |
| /* reorder only down to the lowest odd level */ |
| minLevel|=1; |
| |
| /* loop maxLevel..minLevel */ |
| do { |
| start=0; |
| |
| /* loop for all sequences of levels to reorder at the current maxLevel */ |
| for(;;) { |
| /* look for a sequence of levels that are all at >=maxLevel */ |
| /* look for the first index of such a sequence */ |
| while(start<length && levels[start]<maxLevel) { |
| ++start; |
| } |
| if(start>=length) { |
| break; /* no more such runs */ |
| } |
| |
| /* look for the limit of such a sequence (the index behind it) */ |
| for(limit=start; ++limit<length && levels[limit]>=maxLevel;) {} |
| |
| /* |
| * Swap the entire interval of indexes from start to limit-1. |
| * We don't need to swap the levels for the purpose of this |
| * algorithm: the sequence of levels that we look at does not |
| * move anyway. |
| */ |
| end=limit-1; |
| while(start<end) { |
| temp=indexMap[start]; |
| indexMap[start]=indexMap[end]; |
| indexMap[end]=temp; |
| |
| ++start; |
| --end; |
| } |
| |
| if(limit==length) { |
| break; /* no more such sequences */ |
| } else { |
| start=limit+1; |
| } |
| } |
| } while(--maxLevel>=minLevel); |
| } |
| |
| /* API functions for logical<->visual mapping ------------------------------- */ |
| |
| U_CAPI int32_t U_EXPORT2 |
| ubidi_getVisualIndex(UBiDi *pBiDi, int32_t logicalIndex, UErrorCode *pErrorCode) { |
| if(pErrorCode==NULL || U_FAILURE(*pErrorCode)) { |
| return 0; |
| } else if(pBiDi==NULL) { |
| *pErrorCode=U_ILLEGAL_ARGUMENT_ERROR; |
| return 0; |
| } else if(logicalIndex<0 || pBiDi->length<=logicalIndex) { |
| *pErrorCode=U_INDEX_OUTOFBOUNDS_ERROR; |
| return 0; |
| } else { |
| /* we can do the trivial cases without the runs array */ |
| switch(pBiDi->direction) { |
| case UBIDI_LTR: |
| return logicalIndex; |
| case UBIDI_RTL: |
| return pBiDi->length-logicalIndex-1; |
| default: |
| if(pBiDi->runCount<0 && !ubidi_getRuns(pBiDi)) { |
| *pErrorCode=U_MEMORY_ALLOCATION_ERROR; |
| return 0; |
| } else { |
| Run *runs=pBiDi->runs; |
| int32_t i, visualStart=0, offset, length; |
| |
| /* linear search for the run, search on the visual runs */ |
| for(i=0;; ++i) { |
| length=runs[i].visualLimit-visualStart; |
| offset=logicalIndex-GET_INDEX(runs[i].logicalStart); |
| if(offset>=0 && offset<length) { |
| if(IS_EVEN_RUN(runs[i].logicalStart)) { |
| /* LTR */ |
| return visualStart+offset; |
| } else { |
| /* RTL */ |
| return visualStart+length-offset-1; |
| } |
| } |
| visualStart+=length; |
| } |
| } |
| } |
| } |
| } |
| |
| U_CAPI int32_t U_EXPORT2 |
| ubidi_getLogicalIndex(UBiDi *pBiDi, int32_t visualIndex, UErrorCode *pErrorCode) { |
| if(pErrorCode==NULL || U_FAILURE(*pErrorCode)) { |
| return 0; |
| } else if(pBiDi==NULL) { |
| *pErrorCode=U_ILLEGAL_ARGUMENT_ERROR; |
| return 0; |
| } else if(visualIndex<0 || pBiDi->length<=visualIndex) { |
| *pErrorCode=U_INDEX_OUTOFBOUNDS_ERROR; |
| return 0; |
| } else { |
| /* we can do the trivial cases without the runs array */ |
| switch(pBiDi->direction) { |
| case UBIDI_LTR: |
| return visualIndex; |
| case UBIDI_RTL: |
| return pBiDi->length-visualIndex-1; |
| default: |
| if(pBiDi->runCount<0 && !ubidi_getRuns(pBiDi)) { |
| *pErrorCode=U_MEMORY_ALLOCATION_ERROR; |
| return 0; |
| } else { |
| Run *runs=pBiDi->runs; |
| int32_t i, runCount=pBiDi->runCount, start; |
| |
| if(runCount<=10) { |
| /* linear search for the run */ |
| for(i=0; visualIndex>=runs[i].visualLimit; ++i) {} |
| } else { |
| /* binary search for the run */ |
| int32_t begin=0, limit=runCount; |
| |
| /* the middle if() will guaranteed find the run, we don't need a loop limit */ |
| for(;;) { |
| i=(begin+limit)/2; |
| if(visualIndex>=runs[i].visualLimit) { |
| begin=i+1; |
| } else if(i==0 || visualIndex>=runs[i-1].visualLimit) { |
| break; |
| } else { |
| limit=i; |
| } |
| } |
| } |
| |
| start=runs[i].logicalStart; |
| if(IS_EVEN_RUN(start)) { |
| /* LTR */ |
| /* the offset in runs[i] is visualIndex-runs[i-1].visualLimit */ |
| if(i>0) { |
| visualIndex-=runs[i-1].visualLimit; |
| } |
| return GET_INDEX(start)+visualIndex; |
| } else { |
| /* RTL */ |
| return GET_INDEX(start)+runs[i].visualLimit-visualIndex-1; |
| } |
| } |
| } |
| } |
| } |
| |
| U_CAPI void U_EXPORT2 |
| ubidi_getLogicalMap(UBiDi *pBiDi, int32_t *indexMap, UErrorCode *pErrorCode) { |
| UBiDiLevel *levels; |
| |
| /* ubidi_getLevels() checks all of its and our arguments */ |
| if((levels=(UBiDiLevel *)ubidi_getLevels(pBiDi, pErrorCode))==NULL) { |
| /* no op */ |
| } else if(indexMap==NULL) { |
| *pErrorCode=U_ILLEGAL_ARGUMENT_ERROR; |
| } else { |
| ubidi_reorderLogical(levels, pBiDi->length, indexMap); |
| } |
| } |
| |
| U_CAPI void U_EXPORT2 |
| ubidi_getVisualMap(UBiDi *pBiDi, int32_t *indexMap, UErrorCode *pErrorCode) { |
| /* ubidi_countRuns() checks all of its and our arguments */ |
| if(ubidi_countRuns(pBiDi, pErrorCode)<=0) { |
| /* no op */ |
| } else if(indexMap==NULL) { |
| *pErrorCode=U_ILLEGAL_ARGUMENT_ERROR; |
| } else { |
| /* fill a visual-to-logical index map using the runs[] */ |
| Run *runs=pBiDi->runs, *runsLimit=runs+pBiDi->runCount; |
| int32_t logicalStart, visualStart, visualLimit; |
| |
| visualStart=0; |
| for(; runs<runsLimit; ++runs) { |
| logicalStart=runs->logicalStart; |
| visualLimit=runs->visualLimit; |
| if(IS_EVEN_RUN(logicalStart)) { |
| do { /* LTR */ |
| *indexMap++ = logicalStart++; |
| } while(++visualStart<visualLimit); |
| } else { |
| REMOVE_ODD_BIT(logicalStart); |
| logicalStart+=visualLimit-visualStart; /* logicalLimit */ |
| do { /* RTL */ |
| *indexMap++ = --logicalStart; |
| } while(++visualStart<visualLimit); |
| } |
| /* visualStart==visualLimit; */ |
| } |
| } |
| } |
| |
| U_CAPI void U_EXPORT2 |
| ubidi_invertMap(const int32_t *srcMap, int32_t *destMap, int32_t length) { |
| if(srcMap!=NULL && destMap!=NULL) { |
| srcMap+=length; |
| while(length>0) { |
| destMap[*--srcMap]=--length; |
| } |
| } |
| } |
