957 lines
33 KiB
C
957 lines
33 KiB
C
/*
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******************************************************************************
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*
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* Copyright (C) 1999-2001, International Business Machines
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* Corporation and others. All Rights Reserved.
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*
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******************************************************************************
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* file name: ubidiln.c
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* encoding: US-ASCII
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* tab size: 8 (not used)
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* indentation:4
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*
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* created on: 1999aug06
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* created by: Markus W. Scherer
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*/
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/* set import/export definitions */
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#ifndef U_COMMON_IMPLEMENTATION
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# define U_COMMON_IMPLEMENTATION
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#endif
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#include "cmemory.h"
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#include "unicode/utypes.h"
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#include "unicode/ustring.h"
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#include "unicode/uchar.h"
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#include "unicode/ubidi.h"
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#include "ubidiimp.h"
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/*
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* General remarks about the functions in this file:
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*
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* These functions deal with the aspects of potentially mixed-directional
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* text in a single paragraph or in a line of a single paragraph
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* which has already been processed according to
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* the Unicode 3.0 BiDi algorithm as defined in
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* http://www.unicode.org/unicode/reports/tr9/ , version 5,
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* also described in The Unicode Standard, Version 3.0 .
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*
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* This means that there is a UBiDi object with a levels
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* and a dirProps array.
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* paraLevel and direction are also set.
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* Only if the length of the text is zero, then levels==dirProps==NULL.
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*
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* The overall directionality of the paragraph
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* or line is used to bypass the reordering steps if possible.
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* Even purely RTL text does not need reordering there because
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* the ubidi_getLogical/VisualIndex() functions can compute the
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* index on the fly in such a case.
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*
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* The implementation of the access to same-level-runs and of the reordering
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* do attempt to provide better performance and less memory usage compared to
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* a direct implementation of especially rule (L2) with an array of
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* one (32-bit) integer per text character.
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*
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* Here, the levels array is scanned as soon as necessary, and a vector of
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* same-level-runs is created. Reordering then is done on this vector.
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* For each run of text positions that were resolved to the same level,
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* only 8 bytes are stored: the first text position of the run and the visual
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* position behind the run after reordering.
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* One sign bit is used to hold the directionality of the run.
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* This is inefficient if there are many very short runs. If the average run
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* length is <2, then this uses more memory.
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*
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* In a further attempt to save memory, the levels array is never changed
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* after all the resolution rules (Xn, Wn, Nn, In).
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* Many functions have to consider the field trailingWSStart:
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* if it is less than length, then there is an implicit trailing run
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* at the paraLevel,
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* which is not reflected in the levels array.
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* This allows a line UBiDi object to use the same levels array as
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* its paragraph parent object.
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*
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* When a UBiDi object is created for a line of a paragraph, then the
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* paragraph's levels and dirProps arrays are reused by way of setting
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* a pointer into them, not by copying. This again saves memory and forbids to
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* change the now shared levels for (L1).
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*/
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/* handle trailing WS (L1) -------------------------------------------------- */
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/*
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* setTrailingWSStart() sets the start index for a trailing
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* run of WS in the line. This is necessary because we do not modify
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* the paragraph's levels array that we just point into.
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* Using trailingWSStart is another form of performing (L1).
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*
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* To make subsequent operations easier, we also include the run
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* before the WS if it is at the paraLevel - we merge the two here.
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*/
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static void
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setTrailingWSStart(UBiDi *pBiDi) {
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/* pBiDi->direction!=UBIDI_MIXED */
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const DirProp *dirProps=pBiDi->dirProps;
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UBiDiLevel *levels=pBiDi->levels;
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int32_t start=pBiDi->length;
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UBiDiLevel paraLevel=pBiDi->paraLevel;
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/* go backwards across all WS, BN, explicit codes */
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while(start>0 && DIRPROP_FLAG(dirProps[start-1])&MASK_WS) {
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--start;
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}
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/* if the WS run can be merged with the previous run then do so here */
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while(start>0 && levels[start-1]==paraLevel) {
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--start;
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}
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pBiDi->trailingWSStart=start;
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}
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/* ubidi_setLine ------------------------------------------------------------ */
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U_CAPI void U_EXPORT2
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ubidi_setLine(const UBiDi *pParaBiDi,
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int32_t start, int32_t limit,
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UBiDi *pLineBiDi,
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UErrorCode *pErrorCode) {
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int32_t length;
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/* check the argument values */
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if(pErrorCode==NULL || U_FAILURE(*pErrorCode)) {
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return;
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} else if(pParaBiDi==NULL || pLineBiDi==NULL) {
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*pErrorCode=U_ILLEGAL_ARGUMENT_ERROR;
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return;
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} else if(start<0 || start>limit || limit>pParaBiDi->length) {
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*pErrorCode=U_INDEX_OUTOFBOUNDS_ERROR;
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return;
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}
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/* set the values in pLineBiDi from its pParaBiDi parent */
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pLineBiDi->text=pParaBiDi->text+start;
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length=pLineBiDi->length=limit-start;
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pLineBiDi->paraLevel=pParaBiDi->paraLevel;
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pLineBiDi->runs=NULL;
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pLineBiDi->flags=0;
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if(length>0) {
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pLineBiDi->dirProps=pParaBiDi->dirProps+start;
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pLineBiDi->levels=pParaBiDi->levels+start;
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pLineBiDi->runCount=-1;
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if(pParaBiDi->direction!=UBIDI_MIXED) {
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/* the parent is already trivial */
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pLineBiDi->direction=pParaBiDi->direction;
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/*
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* The parent's levels are all either
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* implicitly or explicitly ==paraLevel;
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* do the same here.
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*/
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if(pParaBiDi->trailingWSStart<=start) {
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pLineBiDi->trailingWSStart=0;
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} else if(pParaBiDi->trailingWSStart<limit) {
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pLineBiDi->trailingWSStart=pParaBiDi->trailingWSStart-start;
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} else {
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pLineBiDi->trailingWSStart=length;
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}
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} else {
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const UBiDiLevel *levels=pLineBiDi->levels;
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int32_t i, trailingWSStart;
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UBiDiLevel level;
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setTrailingWSStart(pLineBiDi);
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trailingWSStart=pLineBiDi->trailingWSStart;
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/* recalculate pLineBiDi->direction */
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if(trailingWSStart==0) {
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/* all levels are at paraLevel */
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pLineBiDi->direction=(UBiDiDirection)(pLineBiDi->paraLevel&1);
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} else {
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/* get the level of the first character */
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level=(UBiDiLevel)(levels[0]&1);
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/* if there is anything of a different level, then the line is mixed */
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if(trailingWSStart<length && (pLineBiDi->paraLevel&1)!=level) {
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/* the trailing WS is at paraLevel, which differs from levels[0] */
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pLineBiDi->direction=UBIDI_MIXED;
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} else {
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/* see if levels[1..trailingWSStart-1] have the same direction as levels[0] and paraLevel */
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i=1;
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for(;;) {
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if(i==trailingWSStart) {
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/* the direction values match those in level */
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pLineBiDi->direction=(UBiDiDirection)level;
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break;
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} else if((levels[i]&1)!=level) {
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pLineBiDi->direction=UBIDI_MIXED;
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break;
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}
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++i;
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}
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}
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}
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switch(pLineBiDi->direction) {
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case UBIDI_LTR:
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/* make sure paraLevel is even */
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pLineBiDi->paraLevel=(UBiDiLevel)((pLineBiDi->paraLevel+1)&~1);
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/* all levels are implicitly at paraLevel (important for ubidi_getLevels()) */
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pLineBiDi->trailingWSStart=0;
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break;
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case UBIDI_RTL:
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/* make sure paraLevel is odd */
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pLineBiDi->paraLevel|=1;
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/* all levels are implicitly at paraLevel (important for ubidi_getLevels()) */
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pLineBiDi->trailingWSStart=0;
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break;
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default:
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break;
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}
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}
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} else {
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/* create an object for a zero-length line */
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pLineBiDi->direction=pLineBiDi->paraLevel&1 ? UBIDI_RTL : UBIDI_LTR;
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pLineBiDi->trailingWSStart=pLineBiDi->runCount=0;
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pLineBiDi->dirProps=NULL;
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pLineBiDi->levels=NULL;
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}
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return;
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}
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U_CAPI UBiDiLevel U_EXPORT2
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ubidi_getLevelAt(const UBiDi *pBiDi, int32_t charIndex) {
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/* return paraLevel if in the trailing WS run, otherwise the real level */
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if(pBiDi==NULL || charIndex<0 || pBiDi->length<=charIndex) {
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return 0;
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} else if(pBiDi->direction!=UBIDI_MIXED || charIndex>=pBiDi->trailingWSStart) {
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return pBiDi->paraLevel;
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} else {
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return pBiDi->levels[charIndex];
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}
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}
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U_CAPI const UBiDiLevel * U_EXPORT2
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ubidi_getLevels(UBiDi *pBiDi, UErrorCode *pErrorCode) {
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int32_t start, length;
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if(pErrorCode==NULL || U_FAILURE(*pErrorCode)) {
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return NULL;
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} else if(pBiDi==NULL || (length=pBiDi->length)<=0) {
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*pErrorCode=U_ILLEGAL_ARGUMENT_ERROR;
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return NULL;
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}
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if((start=pBiDi->trailingWSStart)==length) {
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/* the current levels array reflects the WS run */
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return pBiDi->levels;
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}
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/*
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* After the previous if(), we know that the levels array
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* has an implicit trailing WS run and therefore does not fully
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* reflect itself all the levels.
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* This must be a UBiDi object for a line, and
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* we need to create a new levels array.
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*/
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if(getLevelsMemory(pBiDi, length)) {
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UBiDiLevel *levels=pBiDi->levelsMemory;
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if(start>0 && levels!=pBiDi->levels) {
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uprv_memcpy(levels, pBiDi->levels, start);
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}
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uprv_memset(levels+start, pBiDi->paraLevel, length-start);
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/* this new levels array is set for the line and reflects the WS run */
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pBiDi->trailingWSStart=length;
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return pBiDi->levels=levels;
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} else {
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/* out of memory */
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*pErrorCode=U_MEMORY_ALLOCATION_ERROR;
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return NULL;
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}
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}
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U_CAPI void U_EXPORT2
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ubidi_getLogicalRun(const UBiDi *pBiDi, int32_t logicalStart,
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int32_t *pLogicalLimit, UBiDiLevel *pLevel) {
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int32_t length;
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if(pBiDi==NULL || logicalStart<0 || (length=pBiDi->length)<=logicalStart) {
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return;
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}
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if(pBiDi->direction!=UBIDI_MIXED || logicalStart>=pBiDi->trailingWSStart) {
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if(pLogicalLimit!=NULL) {
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*pLogicalLimit=length;
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}
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if(pLevel!=NULL) {
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*pLevel=pBiDi->paraLevel;
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}
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} else {
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UBiDiLevel *levels=pBiDi->levels;
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UBiDiLevel level=levels[logicalStart];
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/* search for the end of the run */
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length=pBiDi->trailingWSStart;
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while(++logicalStart<length && level==levels[logicalStart]) {}
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if(pLogicalLimit!=NULL) {
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*pLogicalLimit=logicalStart;
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}
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if(pLevel!=NULL) {
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*pLevel=level;
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}
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}
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}
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/* runs API functions ------------------------------------------------------- */
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U_CAPI int32_t U_EXPORT2
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ubidi_countRuns(UBiDi *pBiDi, UErrorCode *pErrorCode) {
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if(pErrorCode==NULL || U_FAILURE(*pErrorCode)) {
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return -1;
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} else if(pBiDi==NULL || (pBiDi->runCount<0 && !ubidi_getRuns(pBiDi))) {
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*pErrorCode=U_MEMORY_ALLOCATION_ERROR;
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return -1;
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} else {
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return pBiDi->runCount;
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}
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}
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U_CAPI UBiDiDirection U_EXPORT2
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ubidi_getVisualRun(UBiDi *pBiDi, int32_t runIndex,
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int32_t *pLogicalStart, int32_t *pLength) {
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if( pBiDi==NULL || runIndex<0 ||
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(pBiDi->runCount==-1 && !ubidi_getRuns(pBiDi)) ||
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runIndex>=pBiDi->runCount
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) {
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return UBIDI_LTR;
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} else {
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int32_t start=pBiDi->runs[runIndex].logicalStart;
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if(pLogicalStart!=NULL) {
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*pLogicalStart=GET_INDEX(start);
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}
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if(pLength!=NULL) {
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if(runIndex>0) {
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*pLength=pBiDi->runs[runIndex].visualLimit-
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pBiDi->runs[runIndex-1].visualLimit;
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} else {
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*pLength=pBiDi->runs[0].visualLimit;
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}
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}
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return (UBiDiDirection)GET_ODD_BIT(start);
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}
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}
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/* in trivial cases there is only one trivial run; called by ubidi_getRuns() */
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static void
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getSingleRun(UBiDi *pBiDi, UBiDiLevel level) {
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/* simple, single-run case */
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pBiDi->runs=pBiDi->simpleRuns;
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pBiDi->runCount=1;
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/* fill and reorder the single run */
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pBiDi->runs[0].logicalStart=MAKE_INDEX_ODD_PAIR(0, level);
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pBiDi->runs[0].visualLimit=pBiDi->length;
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}
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/* reorder the runs array (L2) ---------------------------------------------- */
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/*
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* Reorder the same-level runs in the runs array.
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* Here, runCount>1 and maxLevel>=minLevel>=paraLevel.
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* All the visualStart fields=logical start before reordering.
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* The "odd" bits are not set yet.
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*
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* Reordering with this data structure lends itself to some handy shortcuts:
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*
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* Since each run is moved but not modified, and since at the initial maxLevel
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* each sequence of same-level runs consists of only one run each, we
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* don't need to do anything there and can predecrement maxLevel.
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* In many simple cases, the reordering is thus done entirely in the
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* index mapping.
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* Also, reordering occurs only down to the lowest odd level that occurs,
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* which is minLevel|1. However, if the lowest level itself is odd, then
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* in the last reordering the sequence of the runs at this level or higher
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* will be all runs, and we don't need the elaborate loop to search for them.
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* This is covered by ++minLevel instead of minLevel|=1 followed
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* by an extra reorder-all after the reorder-some loop.
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* About a trailing WS run:
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* Such a run would need special treatment because its level is not
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* reflected in levels[] if this is not a paragraph object.
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* Instead, all characters from trailingWSStart on are implicitly at
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* paraLevel.
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* However, for all maxLevel>paraLevel, this run will never be reordered
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* and does not need to be taken into account. maxLevel==paraLevel is only reordered
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* if minLevel==paraLevel is odd, which is done in the extra segment.
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* This means that for the main reordering loop we don't need to consider
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* this run and can --runCount. If it is later part of the all-runs
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* reordering, then runCount is adjusted accordingly.
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*/
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static void
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reorderLine(UBiDi *pBiDi, UBiDiLevel minLevel, UBiDiLevel maxLevel) {
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Run *runs;
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UBiDiLevel *levels;
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int32_t firstRun, endRun, limitRun, runCount,
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temp;
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/* nothing to do? */
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if(maxLevel<=(minLevel|1)) {
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return;
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}
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/*
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* Reorder only down to the lowest odd level
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* and reorder at an odd minLevel in a separate, simpler loop.
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* See comments above for why minLevel is always incremented.
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*/
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++minLevel;
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runs=pBiDi->runs;
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levels=pBiDi->levels;
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runCount=pBiDi->runCount;
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/* do not include the WS run at paraLevel<=old minLevel except in the simple loop */
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if(pBiDi->trailingWSStart<pBiDi->length) {
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--runCount;
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}
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while(--maxLevel>=minLevel) {
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firstRun=0;
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/* loop for all sequences of runs */
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for(;;) {
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/* look for a sequence of runs that are all at >=maxLevel */
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/* look for the first run of such a sequence */
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while(firstRun<runCount && levels[runs[firstRun].logicalStart]<maxLevel) {
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++firstRun;
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}
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if(firstRun>=runCount) {
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break; /* no more such runs */
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}
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/* look for the limit run of such a sequence (the run behind it) */
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for(limitRun=firstRun; ++limitRun<runCount && levels[runs[limitRun].logicalStart]>=maxLevel;) {}
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/* Swap the entire sequence of runs from firstRun to limitRun-1. */
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endRun=limitRun-1;
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while(firstRun<endRun) {
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temp=runs[firstRun].logicalStart;
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runs[firstRun].logicalStart=runs[endRun].logicalStart;
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runs[endRun].logicalStart=temp;
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temp=runs[firstRun].visualLimit;
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runs[firstRun].visualLimit=runs[endRun].visualLimit;
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runs[endRun].visualLimit=temp;
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++firstRun;
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--endRun;
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}
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if(limitRun==runCount) {
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break; /* no more such runs */
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} else {
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firstRun=limitRun+1;
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}
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}
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}
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/* now do maxLevel==old minLevel (==odd!), see above */
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if(!(minLevel&1)) {
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firstRun=0;
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/* include the trailing WS run in this complete reordering */
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if(pBiDi->trailingWSStart==pBiDi->length) {
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--runCount;
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}
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/* Swap the entire sequence of all runs. (endRun==runCount) */
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while(firstRun<runCount) {
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temp=runs[firstRun].logicalStart;
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runs[firstRun].logicalStart=runs[runCount].logicalStart;
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runs[runCount].logicalStart=temp;
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temp=runs[firstRun].visualLimit;
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runs[firstRun].visualLimit=runs[runCount].visualLimit;
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runs[runCount].visualLimit=temp;
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++firstRun;
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--runCount;
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}
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}
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}
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/* compute the runs array --------------------------------------------------- */
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|
|
|
/*
|
|
* 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;
|
|
}
|
|
}
|
|
}
|