--- /dev/null
+// © 2016 and later: Unicode, Inc. and others.
+// License & terms of use: http://www.unicode.org/copyright.html
+/*
+******************************************************************************
+*
+* Copyright (C) 2000-2015, International Business Machines
+* Corporation and others. All Rights Reserved.
+*
+******************************************************************************
+* file name: ubidiwrt.c
+* encoding: UTF-8
+* tab size: 8 (not used)
+* indentation:4
+*
+* created on: 1999aug06
+* created by: Markus W. Scherer, updated by Matitiahu Allouche
+*
+* This file contains implementations for BiDi functions that use
+* the core algorithm and core API to write reordered text.
+*/
+
+#include "unicode/utypes.h"
+#include "unicode/ustring.h"
+#include "unicode/uchar.h"
+#include "unicode/ubidi.h"
+#include "unicode/utf16.h"
+#include "cmemory.h"
+#include "ustr_imp.h"
+#include "ubidiimp.h"
+
+/*
+ * The function implementations in this file are designed
+ * for UTF-16 and UTF-32, not for UTF-8.
+ *
+ * Assumptions that are not true for UTF-8:
+ * - Any code point always needs the same number of code units
+ * ("minimum-length-problem" of UTF-8)
+ * - The BiDi control characters need only one code unit each
+ *
+ * Further assumptions for all UTFs:
+ * - u_charMirror(c) needs the same number of code units as c
+ */
+#if UTF_SIZE==8
+# error reimplement ubidi_writeReordered() for UTF-8, see comment above
+#endif
+
+#define IS_COMBINING(type) ((1UL<<(type))&(1UL<<U_NON_SPACING_MARK|1UL<<U_COMBINING_SPACING_MARK|1UL<<U_ENCLOSING_MARK))
+
+/*
+ * When we have UBIDI_OUTPUT_REVERSE set on ubidi_writeReordered(), then we
+ * semantically write RTL runs in reverse and later reverse them again.
+ * Instead, we actually write them in forward order to begin with.
+ * However, if the RTL run was to be mirrored, we need to mirror here now
+ * since the implicit second reversal must not do it.
+ * It looks strange to do mirroring in LTR output, but it is only because
+ * we are writing RTL output in reverse.
+ */
+static int32_t
+doWriteForward(const UChar *src, int32_t srcLength,
+ UChar *dest, int32_t destSize,
+ uint16_t options,
+ UErrorCode *pErrorCode) {
+ /* optimize for several combinations of options */
+ switch(options&(UBIDI_REMOVE_BIDI_CONTROLS|UBIDI_DO_MIRRORING)) {
+ case 0: {
+ /* simply copy the LTR run to the destination */
+ int32_t length=srcLength;
+ if(destSize<length) {
+ *pErrorCode=U_BUFFER_OVERFLOW_ERROR;
+ return srcLength;
+ }
+ do {
+ *dest++=*src++;
+ } while(--length>0);
+ return srcLength;
+ }
+ case UBIDI_DO_MIRRORING: {
+ /* do mirroring */
+ int32_t i=0, j=0;
+ UChar32 c;
+
+ if(destSize<srcLength) {
+ *pErrorCode=U_BUFFER_OVERFLOW_ERROR;
+ return srcLength;
+ }
+ do {
+ U16_NEXT(src, i, srcLength, c);
+ c=u_charMirror(c);
+ U16_APPEND_UNSAFE(dest, j, c);
+ } while(i<srcLength);
+ return srcLength;
+ }
+ case UBIDI_REMOVE_BIDI_CONTROLS: {
+ /* copy the LTR run and remove any BiDi control characters */
+ int32_t remaining=destSize;
+ UChar c;
+ do {
+ c=*src++;
+ if(!IS_BIDI_CONTROL_CHAR(c)) {
+ if(--remaining<0) {
+ *pErrorCode=U_BUFFER_OVERFLOW_ERROR;
+
+ /* preflight the length */
+ while(--srcLength>0) {
+ c=*src++;
+ if(!IS_BIDI_CONTROL_CHAR(c)) {
+ --remaining;
+ }
+ }
+ return destSize-remaining;
+ }
+ *dest++=c;
+ }
+ } while(--srcLength>0);
+ return destSize-remaining;
+ }
+ default: {
+ /* remove BiDi control characters and do mirroring */
+ int32_t remaining=destSize;
+ int32_t i, j=0;
+ UChar32 c;
+ do {
+ i=0;
+ U16_NEXT(src, i, srcLength, c);
+ src+=i;
+ srcLength-=i;
+ if(!IS_BIDI_CONTROL_CHAR(c)) {
+ remaining-=i;
+ if(remaining<0) {
+ *pErrorCode=U_BUFFER_OVERFLOW_ERROR;
+
+ /* preflight the length */
+ while(srcLength>0) {
+ c=*src++;
+ if(!IS_BIDI_CONTROL_CHAR(c)) {
+ --remaining;
+ }
+ --srcLength;
+ }
+ return destSize-remaining;
+ }
+ c=u_charMirror(c);
+ U16_APPEND_UNSAFE(dest, j, c);
+ }
+ } while(srcLength>0);
+ return j;
+ }
+ } /* end of switch */
+}
+
+static int32_t
+doWriteReverse(const UChar *src, int32_t srcLength,
+ UChar *dest, int32_t destSize,
+ uint16_t options,
+ UErrorCode *pErrorCode) {
+ /*
+ * RTL run -
+ *
+ * RTL runs need to be copied to the destination in reverse order
+ * of code points, not code units, to keep Unicode characters intact.
+ *
+ * The general strategy for this is to read the source text
+ * in backward order, collect all code units for a code point
+ * (and optionally following combining characters, see below),
+ * and copy all these code units in ascending order
+ * to the destination for this run.
+ *
+ * Several options request whether combining characters
+ * should be kept after their base characters,
+ * whether BiDi control characters should be removed, and
+ * whether characters should be replaced by their mirror-image
+ * equivalent Unicode characters.
+ */
+ int32_t i, j;
+ UChar32 c;
+
+ /* optimize for several combinations of options */
+ switch(options&(UBIDI_REMOVE_BIDI_CONTROLS|UBIDI_DO_MIRRORING|UBIDI_KEEP_BASE_COMBINING)) {
+ case 0:
+ /*
+ * With none of the "complicated" options set, the destination
+ * run will have the same length as the source run,
+ * and there is no mirroring and no keeping combining characters
+ * with their base characters.
+ */
+ if(destSize<srcLength) {
+ *pErrorCode=U_BUFFER_OVERFLOW_ERROR;
+ return srcLength;
+ }
+ destSize=srcLength;
+
+ /* preserve character integrity */
+ do {
+ /* i is always after the last code unit known to need to be kept in this segment */
+ i=srcLength;
+
+ /* collect code units for one base character */
+ U16_BACK_1(src, 0, srcLength);
+
+ /* copy this base character */
+ j=srcLength;
+ do {
+ *dest++=src[j++];
+ } while(j<i);
+ } while(srcLength>0);
+ break;
+ case UBIDI_KEEP_BASE_COMBINING:
+ /*
+ * Here, too, the destination
+ * run will have the same length as the source run,
+ * and there is no mirroring.
+ * We do need to keep combining characters with their base characters.
+ */
+ if(destSize<srcLength) {
+ *pErrorCode=U_BUFFER_OVERFLOW_ERROR;
+ return srcLength;
+ }
+ destSize=srcLength;
+
+ /* preserve character integrity */
+ do {
+ /* i is always after the last code unit known to need to be kept in this segment */
+ i=srcLength;
+
+ /* collect code units and modifier letters for one base character */
+ do {
+ U16_PREV(src, 0, srcLength, c);
+ } while(srcLength>0 && IS_COMBINING(u_charType(c)));
+
+ /* copy this "user character" */
+ j=srcLength;
+ do {
+ *dest++=src[j++];
+ } while(j<i);
+ } while(srcLength>0);
+ break;
+ default:
+ /*
+ * With several "complicated" options set, this is the most
+ * general and the slowest copying of an RTL run.
+ * We will do mirroring, remove BiDi controls, and
+ * keep combining characters with their base characters
+ * as requested.
+ */
+ if(!(options&UBIDI_REMOVE_BIDI_CONTROLS)) {
+ i=srcLength;
+ } else {
+ /* we need to find out the destination length of the run,
+ which will not include the BiDi control characters */
+ int32_t length=srcLength;
+ UChar ch;
+
+ i=0;
+ do {
+ ch=*src++;
+ if(!IS_BIDI_CONTROL_CHAR(ch)) {
+ ++i;
+ }
+ } while(--length>0);
+ src-=srcLength;
+ }
+
+ if(destSize<i) {
+ *pErrorCode=U_BUFFER_OVERFLOW_ERROR;
+ return i;
+ }
+ destSize=i;
+
+ /* preserve character integrity */
+ do {
+ /* i is always after the last code unit known to need to be kept in this segment */
+ i=srcLength;
+
+ /* collect code units for one base character */
+ U16_PREV(src, 0, srcLength, c);
+ if(options&UBIDI_KEEP_BASE_COMBINING) {
+ /* collect modifier letters for this base character */
+ while(srcLength>0 && IS_COMBINING(u_charType(c))) {
+ U16_PREV(src, 0, srcLength, c);
+ }
+ }
+
+ if(options&UBIDI_REMOVE_BIDI_CONTROLS && IS_BIDI_CONTROL_CHAR(c)) {
+ /* do not copy this BiDi control character */
+ continue;
+ }
+
+ /* copy this "user character" */
+ j=srcLength;
+ if(options&UBIDI_DO_MIRRORING) {
+ /* mirror only the base character */
+ int32_t k=0;
+ c=u_charMirror(c);
+ U16_APPEND_UNSAFE(dest, k, c);
+ dest+=k;
+ j+=k;
+ }
+ while(j<i) {
+ *dest++=src[j++];
+ }
+ } while(srcLength>0);
+ break;
+ } /* end of switch */
+
+ return destSize;
+}
+
+U_CAPI int32_t U_EXPORT2
+ubidi_writeReverse(const UChar *src, int32_t srcLength,
+ UChar *dest, int32_t destSize,
+ uint16_t options,
+ UErrorCode *pErrorCode) {
+ int32_t destLength;
+
+ if(pErrorCode==NULL || U_FAILURE(*pErrorCode)) {
+ return 0;
+ }
+
+ /* more error checking */
+ if( src==NULL || srcLength<-1 ||
+ destSize<0 || (destSize>0 && dest==NULL))
+ {
+ *pErrorCode=U_ILLEGAL_ARGUMENT_ERROR;
+ return 0;
+ }
+
+ /* do input and output overlap? */
+ if( dest!=NULL &&
+ ((src>=dest && src<dest+destSize) ||
+ (dest>=src && dest<src+srcLength)))
+ {
+ *pErrorCode=U_ILLEGAL_ARGUMENT_ERROR;
+ return 0;
+ }
+
+ if(srcLength==-1) {
+ srcLength=u_strlen(src);
+ }
+ if(srcLength>0) {
+ destLength=doWriteReverse(src, srcLength, dest, destSize, options, pErrorCode);
+ } else {
+ /* nothing to do */
+ destLength=0;
+ }
+
+ return u_terminateUChars(dest, destSize, destLength, pErrorCode);
+}
+
+U_CAPI int32_t U_EXPORT2
+ubidi_writeReordered(UBiDi *pBiDi,
+ UChar *dest, int32_t destSize,
+ uint16_t options,
+ UErrorCode *pErrorCode) {
+ const UChar *text;
+ UChar *saveDest;
+ int32_t length, destCapacity;
+ int32_t run, runCount, logicalStart, runLength;
+
+ if(pErrorCode==NULL || U_FAILURE(*pErrorCode)) {
+ return 0;
+ }
+
+ /* more error checking */
+ if( pBiDi==NULL ||
+ (text=pBiDi->text)==NULL || (length=pBiDi->length)<0 ||
+ destSize<0 || (destSize>0 && dest==NULL))
+ {
+ *pErrorCode=U_ILLEGAL_ARGUMENT_ERROR;
+ return 0;
+ }
+
+ /* do input and output overlap? */
+ if( dest!=NULL &&
+ ((text>=dest && text<dest+destSize) ||
+ (dest>=text && dest<text+pBiDi->originalLength)))
+ {
+ *pErrorCode=U_ILLEGAL_ARGUMENT_ERROR;
+ return 0;
+ }
+
+ if(length==0) {
+ /* nothing to do */
+ return u_terminateUChars(dest, destSize, 0, pErrorCode);
+ }
+
+ runCount=ubidi_countRuns(pBiDi, pErrorCode);
+ if(U_FAILURE(*pErrorCode)) {
+ return 0;
+ }
+
+ /* destSize shrinks, later destination length=destCapacity-destSize */
+ saveDest=dest;
+ destCapacity=destSize;
+
+ /*
+ * Option "insert marks" implies UBIDI_INSERT_LRM_FOR_NUMERIC if the
+ * reordering mode (checked below) is appropriate.
+ */
+ if(pBiDi->reorderingOptions & UBIDI_OPTION_INSERT_MARKS) {
+ options|=UBIDI_INSERT_LRM_FOR_NUMERIC;
+ options&=~UBIDI_REMOVE_BIDI_CONTROLS;
+ }
+ /*
+ * Option "remove controls" implies UBIDI_REMOVE_BIDI_CONTROLS
+ * and cancels UBIDI_INSERT_LRM_FOR_NUMERIC.
+ */
+ if(pBiDi->reorderingOptions & UBIDI_OPTION_REMOVE_CONTROLS) {
+ options|=UBIDI_REMOVE_BIDI_CONTROLS;
+ options&=~UBIDI_INSERT_LRM_FOR_NUMERIC;
+ }
+ /*
+ * If we do not perform the "inverse BiDi" algorithm, then we
+ * don't need to insert any LRMs, and don't need to test for it.
+ */
+ if((pBiDi->reorderingMode != UBIDI_REORDER_INVERSE_NUMBERS_AS_L) &&
+ (pBiDi->reorderingMode != UBIDI_REORDER_INVERSE_LIKE_DIRECT) &&
+ (pBiDi->reorderingMode != UBIDI_REORDER_INVERSE_FOR_NUMBERS_SPECIAL) &&
+ (pBiDi->reorderingMode != UBIDI_REORDER_RUNS_ONLY)) {
+ options&=~UBIDI_INSERT_LRM_FOR_NUMERIC;
+ }
+ /*
+ * Iterate through all visual runs and copy the run text segments to
+ * the destination, according to the options.
+ *
+ * The tests for where to insert LRMs ignore the fact that there may be
+ * BN codes or non-BMP code points at the beginning and end of a run;
+ * they may insert LRMs unnecessarily but the tests are faster this way
+ * (this would have to be improved for UTF-8).
+ *
+ * Note that the only errors that are set by doWriteXY() are buffer overflow
+ * errors. Ignore them until the end, and continue for preflighting.
+ */
+ if(!(options&UBIDI_OUTPUT_REVERSE)) {
+ /* forward output */
+ if(!(options&UBIDI_INSERT_LRM_FOR_NUMERIC)) {
+ /* do not insert BiDi controls */
+ for(run=0; run<runCount; ++run) {
+ if(UBIDI_LTR==ubidi_getVisualRun(pBiDi, run, &logicalStart, &runLength)) {
+ runLength=doWriteForward(text+logicalStart, runLength,
+ dest, destSize,
+ (uint16_t)(options&~UBIDI_DO_MIRRORING), pErrorCode);
+ } else {
+ runLength=doWriteReverse(text+logicalStart, runLength,
+ dest, destSize,
+ options, pErrorCode);
+ }
+ if(dest!=NULL) {
+ dest+=runLength;
+ }
+ destSize-=runLength;
+ }
+ } else {
+ /* insert BiDi controls for "inverse BiDi" */
+ const DirProp *dirProps=pBiDi->dirProps;
+ const UChar *src;
+ UChar uc;
+ UBiDiDirection dir;
+ int32_t markFlag;
+
+ for(run=0; run<runCount; ++run) {
+ dir=ubidi_getVisualRun(pBiDi, run, &logicalStart, &runLength);
+ src=text+logicalStart;
+ /* check if something relevant in insertPoints */
+ markFlag=pBiDi->runs[run].insertRemove;
+ if(markFlag<0) { /* BiDi controls count */
+ markFlag=0;
+ }
+
+ if(UBIDI_LTR==dir) {
+ if((pBiDi->isInverse) &&
+ (/*run>0 &&*/ dirProps[logicalStart]!=L)) {
+ markFlag |= LRM_BEFORE;
+ }
+ if (markFlag & LRM_BEFORE) {
+ uc=LRM_CHAR;
+ }
+ else if (markFlag & RLM_BEFORE) {
+ uc=RLM_CHAR;
+ }
+ else uc=0;
+ if(uc) {
+ if(destSize>0) {
+ *dest++=uc;
+ }
+ --destSize;
+ }
+
+ runLength=doWriteForward(src, runLength,
+ dest, destSize,
+ (uint16_t)(options&~UBIDI_DO_MIRRORING), pErrorCode);
+ if(dest!=NULL) {
+ dest+=runLength;
+ }
+ destSize-=runLength;
+
+ if((pBiDi->isInverse) &&
+ (/*run<runCount-1 &&*/ dirProps[logicalStart+runLength-1]!=L)) {
+ markFlag |= LRM_AFTER;
+ }
+ if (markFlag & LRM_AFTER) {
+ uc=LRM_CHAR;
+ }
+ else if (markFlag & RLM_AFTER) {
+ uc=RLM_CHAR;
+ }
+ else uc=0;
+ if(uc) {
+ if(destSize>0) {
+ *dest++=uc;
+ }
+ --destSize;
+ }
+ } else { /* RTL run */
+ if((pBiDi->isInverse) &&
+ (/*run>0 &&*/ !(MASK_R_AL&DIRPROP_FLAG(dirProps[logicalStart+runLength-1])))) {
+ markFlag |= RLM_BEFORE;
+ }
+ if (markFlag & LRM_BEFORE) {
+ uc=LRM_CHAR;
+ }
+ else if (markFlag & RLM_BEFORE) {
+ uc=RLM_CHAR;
+ }
+ else uc=0;
+ if(uc) {
+ if(destSize>0) {
+ *dest++=uc;
+ }
+ --destSize;
+ }
+
+ runLength=doWriteReverse(src, runLength,
+ dest, destSize,
+ options, pErrorCode);
+ if(dest!=NULL) {
+ dest+=runLength;
+ }
+ destSize-=runLength;
+
+ if((pBiDi->isInverse) &&
+ (/*run<runCount-1 &&*/ !(MASK_R_AL&DIRPROP_FLAG(dirProps[logicalStart])))) {
+ markFlag |= RLM_AFTER;
+ }
+ if (markFlag & LRM_AFTER) {
+ uc=LRM_CHAR;
+ }
+ else if (markFlag & RLM_AFTER) {
+ uc=RLM_CHAR;
+ }
+ else uc=0;
+ if(uc) {
+ if(destSize>0) {
+ *dest++=uc;
+ }
+ --destSize;
+ }
+ }
+ }
+ }
+ } else {
+ /* reverse output */
+ if(!(options&UBIDI_INSERT_LRM_FOR_NUMERIC)) {
+ /* do not insert BiDi controls */
+ for(run=runCount; --run>=0;) {
+ if(UBIDI_LTR==ubidi_getVisualRun(pBiDi, run, &logicalStart, &runLength)) {
+ runLength=doWriteReverse(text+logicalStart, runLength,
+ dest, destSize,
+ (uint16_t)(options&~UBIDI_DO_MIRRORING), pErrorCode);
+ } else {
+ runLength=doWriteForward(text+logicalStart, runLength,
+ dest, destSize,
+ options, pErrorCode);
+ }
+ if(dest!=NULL) {
+ dest+=runLength;
+ }
+ destSize-=runLength;
+ }
+ } else {
+ /* insert BiDi controls for "inverse BiDi" */
+ const DirProp *dirProps=pBiDi->dirProps;
+ const UChar *src;
+ UBiDiDirection dir;
+
+ for(run=runCount; --run>=0;) {
+ /* reverse output */
+ dir=ubidi_getVisualRun(pBiDi, run, &logicalStart, &runLength);
+ src=text+logicalStart;
+
+ if(UBIDI_LTR==dir) {
+ if(/*run<runCount-1 &&*/ dirProps[logicalStart+runLength-1]!=L) {
+ if(destSize>0) {
+ *dest++=LRM_CHAR;
+ }
+ --destSize;
+ }
+
+ runLength=doWriteReverse(src, runLength,
+ dest, destSize,
+ (uint16_t)(options&~UBIDI_DO_MIRRORING), pErrorCode);
+ if(dest!=NULL) {
+ dest+=runLength;
+ }
+ destSize-=runLength;
+
+ if(/*run>0 &&*/ dirProps[logicalStart]!=L) {
+ if(destSize>0) {
+ *dest++=LRM_CHAR;
+ }
+ --destSize;
+ }
+ } else {
+ if(/*run<runCount-1 &&*/ !(MASK_R_AL&DIRPROP_FLAG(dirProps[logicalStart]))) {
+ if(destSize>0) {
+ *dest++=RLM_CHAR;
+ }
+ --destSize;
+ }
+
+ runLength=doWriteForward(src, runLength,
+ dest, destSize,
+ options, pErrorCode);
+ if(dest!=NULL) {
+ dest+=runLength;
+ }
+ destSize-=runLength;
+
+ if(/*run>0 &&*/ !(MASK_R_AL&DIRPROP_FLAG(dirProps[logicalStart+runLength-1]))) {
+ if(destSize>0) {
+ *dest++=RLM_CHAR;
+ }
+ --destSize;
+ }
+ }
+ }
+ }
+ }
+
+ return u_terminateUChars(saveDest, destCapacity, destCapacity-destSize, pErrorCode);
+}
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