| /* |
| ****************************************************************************** |
| * |
| * Copyright (C) 2000-2001, International Business Machines |
| * Corporation and others. All Rights Reserved. |
| * |
| ****************************************************************************** |
| * file name: ubidiwrt.c |
| * encoding: US-ASCII |
| * tab size: 8 (not used) |
| * indentation:4 |
| * |
| * created on: 1999aug06 |
| * created by: Markus W. Scherer |
| * |
| * This file contains implementations for BiDi functions that use |
| * the core algorithm and core API to write reordered text. |
| */ |
| |
| /* set import/export definitions */ |
| #ifndef U_COMMON_IMPLEMENTATION |
| # define U_COMMON_IMPLEMENTATION |
| #endif |
| |
| #include "unicode/utypes.h" |
| #include "unicode/ustring.h" |
| #include "unicode/uchar.h" |
| #include "unicode/ubidi.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 |
| |
| /** BiDi control code points */ |
| enum { |
| LRM_CHAR=0x200e, |
| RLM_CHAR, |
| LRE_CHAR=0x202a, |
| RLE_CHAR, |
| PDF_CHAR, |
| LRO_CHAR, |
| RLO_CHAR |
| }; |
| |
| #define IS_BIDI_CONTROL_CHAR(c) (((uint32_t)(c)&0xfffffffe)==LRM_CHAR || (uint32_t)((c)-LRE_CHAR)<5) |
| #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 UTextOffset |
| 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 */ |
| UTextOffset i=0, j=0; |
| UChar32 c; |
| |
| if(destSize<srcLength) { |
| *pErrorCode=U_BUFFER_OVERFLOW_ERROR; |
| return srcLength; |
| } |
| do { |
| UTF_NEXT_CHAR(src, i, srcLength, c); |
| c=u_charMirror(c); |
| UTF_APPEND_CHAR_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; |
| UTextOffset i, j=0; |
| UChar32 c; |
| do { |
| i=0; |
| UTF_NEXT_CHAR(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); |
| UTF_APPEND_CHAR_UNSAFE(dest, j, c); |
| } |
| } while(srcLength>0); |
| return j; |
| } |
| } /* end of switch */ |
| } |
| |
| static UTextOffset |
| 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. |
| */ |
| UTextOffset 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 */ |
| UTF_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 { |
| UTF_PREV_CHAR(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 */ |
| UTF_PREV_CHAR(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))) { |
| UTF_PREV_CHAR(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 */ |
| UTextOffset k=0; |
| c=u_charMirror(c); |
| UTF_APPEND_CHAR_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 UTextOffset 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); |
| } |
| |
| #define MASK_R_AL (1UL<<U_RIGHT_TO_LEFT|1UL<<U_RIGHT_TO_LEFT_ARABIC) |
| |
| U_CAPI UTextOffset U_EXPORT2 |
| ubidi_writeReordered(UBiDi *pBiDi, |
| UChar *dest, int32_t destSize, |
| uint16_t options, |
| UErrorCode *pErrorCode) { |
| const UChar *text; |
| int32_t length, destCapacity; |
| UTextOffset run, runCount, logicalStart, runLength; |
| |
| if(pErrorCode==NULL || U_FAILURE(*pErrorCode)) { |
| return 0; |
| } |
| |
| /* more error checking */ |
| if( pBiDi==NULL || |
| (text=ubidi_getText(pBiDi))==NULL || (length=ubidi_getLength(pBiDi))<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+length))) |
| { |
| *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 */ |
| destCapacity=destSize; |
| |
| /* |
| * 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(!ubidi_isInverse(pBiDi)) { |
| 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); |
| } |
| dest+=runLength; |
| destSize-=runLength; |
| } |
| } else { |
| /* insert BiDi controls for "inverse BiDi" */ |
| const UChar *src; |
| UBiDiDirection dir; |
| |
| for(run=0; run<runCount; ++run) { |
| dir=ubidi_getVisualRun(pBiDi, run, &logicalStart, &runLength); |
| src=text+logicalStart; |
| |
| if(UBIDI_LTR==dir) { |
| if(/*run>0 &&*/ u_charDirection(*src)!=U_LEFT_TO_RIGHT) { |
| if(destSize>0) { |
| *dest++=LRM_CHAR; |
| } |
| --destSize; |
| } |
| |
| runLength=doWriteForward(src, runLength, |
| dest, destSize, |
| (uint16_t)(options&~UBIDI_DO_MIRRORING), pErrorCode); |
| dest+=runLength; |
| destSize-=runLength; |
| |
| if(/*run<runCount-1 &&*/ u_charDirection(src[runLength-1])!=U_LEFT_TO_RIGHT) { |
| if(destSize>0) { |
| *dest++=LRM_CHAR; |
| } |
| --destSize; |
| } |
| } else { |
| if(/*run>0 &&*/ !(MASK_R_AL&1UL<<u_charDirection(src[runLength-1]))) { |
| if(destSize>0) { |
| *dest++=RLM_CHAR; |
| } |
| --destSize; |
| } |
| |
| runLength=doWriteReverse(src, runLength, |
| dest, destSize, |
| options, pErrorCode); |
| dest+=runLength; |
| destSize-=runLength; |
| |
| if(/*run<runCount-1 &&*/ !(MASK_R_AL&1UL<<u_charDirection(*src))) { |
| if(destSize>0) { |
| *dest++=RLM_CHAR; |
| } |
| --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); |
| } |
| dest+=runLength; |
| destSize-=runLength; |
| } |
| } else { |
| /* insert BiDi controls for "inverse BiDi" */ |
| 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 &&*/ u_charDirection(src[runLength-1])!=U_LEFT_TO_RIGHT) { |
| if(destSize>0) { |
| *dest++=LRM_CHAR; |
| } |
| --destSize; |
| } |
| |
| runLength=doWriteReverse(src, runLength, |
| dest, destSize, |
| (uint16_t)(options&~UBIDI_DO_MIRRORING), pErrorCode); |
| dest+=runLength; |
| destSize-=runLength; |
| |
| if(/*run>0 &&*/ u_charDirection(*src)!=U_LEFT_TO_RIGHT) { |
| if(destSize>0) { |
| *dest++=LRM_CHAR; |
| } |
| --destSize; |
| } |
| } else { |
| if(/*run<runCount-1 &&*/ !(MASK_R_AL&1UL<<u_charDirection(*src))) { |
| if(destSize>0) { |
| *dest++=RLM_CHAR; |
| } |
| --destSize; |
| } |
| |
| runLength=doWriteForward(src, runLength, |
| dest, destSize, |
| options, pErrorCode); |
| dest+=runLength; |
| destSize-=runLength; |
| |
| if(/*run>0 &&*/ !(MASK_R_AL&1UL<<u_charDirection(src[runLength-1]))) { |
| if(destSize>0) { |
| *dest++=RLM_CHAR; |
| } |
| --destSize; |
| } |
| } |
| } |
| } |
| } |
| |
| return u_terminateUChars(dest, destCapacity, destCapacity-destSize, pErrorCode); |
| } |
