/* ****************************************************************************** * * Copyright (C) 2000-2004, International Business Machines * Corporation and others. All Rights Reserved. * Copyright (C) 2007 Apple Inc. All rights reserved. * ****************************************************************************** * * Arabic letter shaping implemented by Ayman Roshdy */ #include "config.h" #include "ShapeArabic.h" #include #include #include #include #include /* * ### TODO in general for letter shaping: * - the letter shaping code is UTF-16-unaware; needs update * + especially invertBuffer()?! * - needs to handle the "Arabic Tail" that is used in some legacy codepages * as a glyph fragment of wide-glyph letters * + IBM Unicode conversion tables map it to U+200B (ZWSP) * + IBM Egypt has proposed to encode the tail in Unicode among Arabic Presentation Forms */ /* definitions for Arabic letter shaping ------------------------------------ */ #define IRRELEVANT 4 #define LAMTYPE 16 #define ALEFTYPE 32 #define LINKR 1 #define LINKL 2 static const UChar IrrelevantPos[] = { 0x0, 0x2, 0x4, 0x6, 0x8, 0xA, 0xC, 0xE, }; static const UChar araLink[178]= { 1 + 32 + 256 * 0x11,/*0x0622*/ 1 + 32 + 256 * 0x13,/*0x0623*/ 1 + 256 * 0x15,/*0x0624*/ 1 + 32 + 256 * 0x17,/*0x0625*/ 1 + 2 + 256 * 0x19,/*0x0626*/ 1 + 32 + 256 * 0x1D,/*0x0627*/ 1 + 2 + 256 * 0x1F,/*0x0628*/ 1 + 256 * 0x23,/*0x0629*/ 1 + 2 + 256 * 0x25,/*0x062A*/ 1 + 2 + 256 * 0x29,/*0x062B*/ 1 + 2 + 256 * 0x2D,/*0x062C*/ 1 + 2 + 256 * 0x31,/*0x062D*/ 1 + 2 + 256 * 0x35,/*0x062E*/ 1 + 256 * 0x39,/*0x062F*/ 1 + 256 * 0x3B,/*0x0630*/ 1 + 256 * 0x3D,/*0x0631*/ 1 + 256 * 0x3F,/*0x0632*/ 1 + 2 + 256 * 0x41,/*0x0633*/ 1 + 2 + 256 * 0x45,/*0x0634*/ 1 + 2 + 256 * 0x49,/*0x0635*/ 1 + 2 + 256 * 0x4D,/*0x0636*/ 1 + 2 + 256 * 0x51,/*0x0637*/ 1 + 2 + 256 * 0x55,/*0x0638*/ 1 + 2 + 256 * 0x59,/*0x0639*/ 1 + 2 + 256 * 0x5D,/*0x063A*/ 0, 0, 0, 0, 0, /*0x063B-0x063F*/ 1 + 2, /*0x0640*/ 1 + 2 + 256 * 0x61,/*0x0641*/ 1 + 2 + 256 * 0x65,/*0x0642*/ 1 + 2 + 256 * 0x69,/*0x0643*/ 1 + 2 + 16 + 256 * 0x6D,/*0x0644*/ 1 + 2 + 256 * 0x71,/*0x0645*/ 1 + 2 + 256 * 0x75,/*0x0646*/ 1 + 2 + 256 * 0x79,/*0x0647*/ 1 + 256 * 0x7D,/*0x0648*/ 1 + 256 * 0x7F,/*0x0649*/ 1 + 2 + 256 * 0x81,/*0x064A*/ 4, 4, 4, 4, /*0x064B-0x064E*/ 4, 4, 4, 4, /*0x064F-0x0652*/ 4, 4, 4, 0, 0, /*0x0653-0x0657*/ 0, 0, 0, 0, /*0x0658-0x065B*/ 1 + 256 * 0x85,/*0x065C*/ 1 + 256 * 0x87,/*0x065D*/ 1 + 256 * 0x89,/*0x065E*/ 1 + 256 * 0x8B,/*0x065F*/ 0, 0, 0, 0, 0, /*0x0660-0x0664*/ 0, 0, 0, 0, 0, /*0x0665-0x0669*/ 0, 0, 0, 0, 0, 0, /*0x066A-0x066F*/ 4, /*0x0670*/ 0, /*0x0671*/ 1 + 32, /*0x0672*/ 1 + 32, /*0x0673*/ 0, /*0x0674*/ 1 + 32, /*0x0675*/ 1, 1, /*0x0676-0x0677*/ 1+2, /*0x0678*/ 1+2 + 256 * 0x16,/*0x0679*/ 1+2 + 256 * 0x0E,/*0x067A*/ 1+2 + 256 * 0x02,/*0x067B*/ 1+2, 1+2, /*0x067C-0x067D*/ 1+2 + 256 * 0x06,/*0x067E*/ 1+2 + 256 * 0x12,/*0x067F*/ 1+2 + 256 * 0x0A,/*0x0680*/ 1+2, 1+2, /*0x0681-0x0682*/ 1+2 + 256 * 0x26,/*0x0683*/ 1+2 + 256 * 0x22,/*0x0684*/ 1+2, /*0x0685*/ 1+2 + 256 * 0x2A,/*0x0686*/ 1+2 + 256 * 0x2E,/*0x0687*/ 1 + 256 * 0x38,/*0x0688*/ 1, 1, 1, /*0x0689-0x068B*/ 1 + 256 * 0x34,/*0x068C*/ 1 + 256 * 0x32,/*0x068D*/ 1 + 256 * 0x36,/*0x068E*/ 1, 1, /*0x068F-0x0690*/ 1 + 256 * 0x3C,/*0x0691*/ 1, 1, 1, 1, 1, 1, /*0x0692-0x0697*/ 1 + 256 * 0x3A,/*0x0698*/ 1, /*0x0699*/ 1+2, 1+2, 1+2, 1+2, 1+2, 1+2, /*0x069A-0x069F*/ 1+2, 1+2, 1+2, 1+2, /*0x06A0-0x06A3*/ 1+2 + 256 * 0x2E,/*0x06A4*/ 1+2, /*0x06A5*/ 1+2 + 256 * 0x1E,/*0x06A6*/ 1+2, 1+2, /*0x06A7-0x06A8*/ 1+2 + 256 * 0x3E,/*0x06A9*/ 1+2, 1+2, 1+2, /*0x06AA-0x06AC*/ 1+2 + 256 * 0x83,/*0x06AD*/ 1+2, /*0x06AE*/ 1+2 + 256 * 0x42,/*0x06AF*/ 1+2, /*0x06B0*/ 1+2 + 256 * 0x4A,/*0x06B1*/ 1+2, /*0x06B2*/ 1+2 + 256 * 0x46,/*0x06B3*/ 1+2, 1+2, 1+2, 1+2, 1+2, 1+2, /*0x06B4-0x06B9*/ 1+2, /*0x06BA*/ // FIXME: Seems to have a final form 1+2 + 256 * 0x50,/*0x06BB*/ 1+2, 1+2, /*0x06BC-0x06BD*/ 1+2 + 256 * 0x5A,/*0x06BE*/ 1+2, /*0x06BF*/ 1, /*0x06C0*/ 1+2 + 256 * 0x56,/*0x06C1*/ 1+2, /*0x06C2*/ 1, 1, /*0x06C3-0x06C4*/ 1 + 256 * 0x90,/*0x06C5*/ 1 + 256 * 0x89,/*0x06C6*/ 1 + 256 * 0x87,/*0x06C7*/ 1 + 256 * 0x8B,/*0x06C8*/ 1 + 256 * 0x92,/*0x06C9*/ 1, /*0x06CA*/ 1 + 256 * 0x8E,/*0x06CB*/ 1+2 + 256 * 0xAC,/*0x06CC*/ 1, /*0x06CD*/ 1+2, /*0x06CE*/ 1, /*0x06CF*/ 1+2 + 256 * 0x94,/*0x06D0*/ 1+2, /*0x06D1*/ 1 + 256 * 0x5E,/*0x06D2*/ 1 + 256 * 0x60 /*0x06D3*/ }; static const UChar presLink[141]= { 1 + 2, /*0xFE70*/ 1 + 2, /*0xFE71*/ 1 + 2, 0, 1+ 2, 0, 1+ 2, /*0xFE72-0xFE76*/ 1 + 2, /*0xFE77*/ 1+ 2, 1 + 2, 1+2, 1 + 2, /*0xFE78-0xFE81*/ 1+ 2, 1 + 2, 1+2, 1 + 2, /*0xFE82-0xFE85*/ 0, 0 + 32, 1 + 32, 0 + 32, /*0xFE86-0xFE89*/ 1 + 32, 0, 1, 0 + 32, /*0xFE8A-0xFE8D*/ 1 + 32, 0, 2, 1 + 2, /*0xFE8E-0xFE91*/ 1, 0 + 32, 1 + 32, 0, /*0xFE92-0xFE95*/ 2, 1 + 2, 1, 0, /*0xFE96-0xFE99*/ 1, 0, 2, 1 + 2, /*0xFE9A-0xFE9D*/ 1, 0, 2, 1 + 2, /*0xFE9E-0xFEA1*/ 1, 0, 2, 1 + 2, /*0xFEA2-0xFEA5*/ 1, 0, 2, 1 + 2, /*0xFEA6-0xFEA9*/ 1, 0, 2, 1 + 2, /*0xFEAA-0xFEAD*/ 1, 0, 1, 0, /*0xFEAE-0xFEB1*/ 1, 0, 1, 0, /*0xFEB2-0xFEB5*/ 1, 0, 2, 1+2, /*0xFEB6-0xFEB9*/ 1, 0, 2, 1+2, /*0xFEBA-0xFEBD*/ 1, 0, 2, 1+2, /*0xFEBE-0xFEC1*/ 1, 0, 2, 1+2, /*0xFEC2-0xFEC5*/ 1, 0, 2, 1+2, /*0xFEC6-0xFEC9*/ 1, 0, 2, 1+2, /*0xFECA-0xFECD*/ 1, 0, 2, 1+2, /*0xFECE-0xFED1*/ 1, 0, 2, 1+2, /*0xFED2-0xFED5*/ 1, 0, 2, 1+2, /*0xFED6-0xFED9*/ 1, 0, 2, 1+2, /*0xFEDA-0xFEDD*/ 1, 0, 2, 1+2, /*0xFEDE-0xFEE1*/ 1, 0 + 16, 2 + 16, 1 + 2 +16, /*0xFEE2-0xFEE5*/ 1 + 16, 0, 2, 1+2, /*0xFEE6-0xFEE9*/ 1, 0, 2, 1+2, /*0xFEEA-0xFEED*/ 1, 0, 2, 1+2, /*0xFEEE-0xFEF1*/ 1, 0, 1, 0, /*0xFEF2-0xFEF5*/ 1, 0, 2, 1+2, /*0xFEF6-0xFEF9*/ 1, 0, 1, 0, /*0xFEFA-0xFEFD*/ 1, 0, 1, 0, 1 }; static const UChar convertFEto06[] = { /***********0******1******2******3******4******5******6******7******8******9******A******B******C******D******E******F***/ /*FE7*/ 0x64B, 0x64B, 0x64C, 0x64C, 0x64D, 0x64D, 0x64E, 0x64E, 0x64F, 0x64F, 0x650, 0x650, 0x651, 0x651, 0x652, 0x652, /*FE8*/ 0x621, 0x622, 0x622, 0x623, 0x623, 0x624, 0x624, 0x625, 0x625, 0x626, 0x626, 0x626, 0x626, 0x627, 0x627, 0x628, /*FE9*/ 0x628, 0x628, 0x628, 0x629, 0x629, 0x62A, 0x62A, 0x62A, 0x62A, 0x62B, 0x62B, 0x62B, 0x62B, 0x62C, 0x62C, 0x62C, /*FEA*/ 0x62C, 0x62D, 0x62D, 0x62D, 0x62D, 0x62E, 0x62E, 0x62E, 0x62E, 0x62F, 0x62F, 0x630, 0x630, 0x631, 0x631, 0x632, /*FEB*/ 0x632, 0x633, 0x633, 0x633, 0x633, 0x634, 0x634, 0x634, 0x634, 0x635, 0x635, 0x635, 0x635, 0x636, 0x636, 0x636, /*FEC*/ 0x636, 0x637, 0x637, 0x637, 0x637, 0x638, 0x638, 0x638, 0x638, 0x639, 0x639, 0x639, 0x639, 0x63A, 0x63A, 0x63A, /*FED*/ 0x63A, 0x641, 0x641, 0x641, 0x641, 0x642, 0x642, 0x642, 0x642, 0x643, 0x643, 0x643, 0x643, 0x644, 0x644, 0x644, /*FEE*/ 0x644, 0x645, 0x645, 0x645, 0x645, 0x646, 0x646, 0x646, 0x646, 0x647, 0x647, 0x647, 0x647, 0x648, 0x648, 0x649, /*FEF*/ 0x649, 0x64A, 0x64A, 0x64A, 0x64A, 0x65C, 0x65C, 0x65D, 0x65D, 0x65E, 0x65E, 0x65F, 0x65F }; static const UChar shapeTable[4][4][4]= { { {0,0,0,0}, {0,0,0,0}, {0,1,0,3}, {0,1,0,1} }, { {0,0,2,2}, {0,0,1,2}, {0,1,1,2}, {0,1,1,3} }, { {0,0,0,0}, {0,0,0,0}, {0,1,0,3}, {0,1,0,3} }, { {0,0,1,2}, {0,0,1,2}, {0,1,1,2}, {0,1,1,3} } }; /* *Name : changeLamAlef *Function : Converts the Alef characters into an equivalent * LamAlef location in the 0x06xx Range, this is an * intermediate stage in the operation of the program * later it'll be converted into the 0xFExx LamAlefs * in the shaping function. */ static UChar changeLamAlef(UChar ch) { switch(ch) { case 0x0622 : return(0x065C); break; case 0x0623 : return(0x065D); break; case 0x0625 : return(0x065E); break; case 0x0627 : return(0x065F); break; default : return(0); break; } } /* *Name : specialChar *Function : Special Arabic characters need special handling in the shapeUnicode * function, this function returns 1 or 2 for these special characters */ static int32_t specialChar(UChar ch) { if( (ch>0x0621 && ch<0x0626)||(ch==0x0627)||(ch>0x062e && ch<0x0633)|| (ch>0x0647 && ch<0x064a)||(ch==0x0629) ) { return (1); } else if( ch>=0x064B && ch<= 0x0652 ) return (2); else if( (ch>=0x0653 && ch<= 0x0655) || ch == 0x0670 || (ch>=0xFE70 && ch<= 0xFE7F) ) return (3); else return (0); } /* *Name : getLink *Function : Resolves the link between the characters as * Arabic characters have four forms : * Isolated, Initial, Middle and Final Form */ static UChar getLink(UChar ch) { if(ch >= 0x0622 && ch <= 0x06D3) { return(araLink[ch-0x0622]); } else if(ch == 0x200D) { return(3); } else if(ch >= 0x206D && ch <= 0x206F) { return(4); } else if(ch >= 0xFE70 && ch <= 0xFEFC) { return(presLink[ch-0xFE70]); } else { return(0); } } /* *Name : isTashkeelChar *Function : Returns 1 for Tashkeel characters else return 0 */ static int32_t isTashkeelChar(UChar ch) { if( ch>=0x064B && ch<= 0x0652 ) return (1); else return (0); } /* *Name : shapeUnicode *Function : Converts an Arabic Unicode buffer in 06xx Range into a shaped * arabic Unicode buffer in FExx Range */ static int32_t shapeUnicode(UChar *dest, int32_t sourceLength, int32_t destSize,uint32_t options, UErrorCode *pErrorCode, int tashkeelFlag) { int32_t i, iend; int32_t prevPos, lastPos,Nx, Nw; unsigned int Shape; int32_t flag; int32_t lamalef_found = 0; UChar prevLink = 0, lastLink = 0, currLink, nextLink = 0; UChar wLamalef; /* * Converts the input buffer from FExx Range into 06xx Range * to make sure that all characters are in the 06xx range * even the lamalef is converted to the special region in * the 06xx range */ for (i = 0; i < sourceLength; i++) { UChar inputChar = dest[i]; if ( (inputChar >= 0xFE70) && (inputChar <= 0xFEFC)) { dest[i] = convertFEto06 [ (inputChar - 0xFE70) ] ; } } /* sets the index to the end of the buffer, together with the step point to -1 */ i = 0; iend = sourceLength; /* * This function resolves the link between the characters . * Arabic characters have four forms : * Isolated Form, Initial Form, Middle Form and Final Form */ currLink = getLink(dest[i]); prevPos = i; lastPos = i; Nx = sourceLength + 2, Nw = 0; while (i != iend) { /* If high byte of currLink > 0 then more than one shape */ if ((currLink & 0xFF00) > 0 || isTashkeelChar(dest[i])) { Nw = i + 1; while (Nx >= sourceLength) { /* we need to know about next char */ if(Nw == iend) { nextLink = 0; Nx = -1; } else { nextLink = getLink(dest[Nw]); if((nextLink & IRRELEVANT) == 0) { Nx = Nw; } else { Nw = Nw + 1; } } } if ( ((currLink & ALEFTYPE) > 0) && ((lastLink & LAMTYPE) > 0) ) { lamalef_found = 1; wLamalef = changeLamAlef(dest[i]); /*get from 0x065C-0x065f */ if ( wLamalef != 0) { dest[i] = ' '; /* The default case is to drop the Alef and replace */ dest[lastPos] =wLamalef; /* it by a space. */ i=lastPos; } lastLink = prevLink; currLink = getLink(wLamalef); } /* * get the proper shape according to link ability of neighbors * and of character; depends on the order of the shapes * (isolated, initial, middle, final) in the compatibility area */ flag = specialChar(dest[i]); Shape = shapeTable[nextLink & (LINKR + LINKL)] [lastLink & (LINKR + LINKL)] [currLink & (LINKR + LINKL)]; if (flag == 1) { Shape = (Shape == 1 || Shape == 3) ? 1 : 0; } else if(flag == 2) { if( (lastLink & LINKL) && (nextLink & LINKR) && (tashkeelFlag == 1) && dest[i] != 0x064C && dest[i] != 0x064D ) { Shape = 1; if( (nextLink&ALEFTYPE) == ALEFTYPE && (lastLink&LAMTYPE) == LAMTYPE ) Shape = 0; } else { Shape = 0; } } if(flag == 2) { dest[i] = 0xFE70 + IrrelevantPos[(dest[i] - 0x064B)] + Shape; } else dest[i] = (UChar)((dest[i] < 0x0670 ? 0xFE70 : 0xFB50) + (currLink >> 8) + Shape); } /* move one notch forward */ if ((currLink & IRRELEVANT) == 0) { prevLink = lastLink; lastLink = currLink; prevPos = lastPos; lastPos = i; } i++; if (i == Nx) { currLink = nextLink; Nx = sourceLength + 2; } else if(i != iend) { currLink = getLink(dest[i]); } } destSize = sourceLength; return destSize; } int32_t shapeArabic(const UChar *source, int32_t sourceLength, UChar *dest, int32_t destCapacity, uint32_t options, UErrorCode *pErrorCode) { int32_t destLength; /* usual error checking */ if(pErrorCode==NULL || U_FAILURE(*pErrorCode)) { return 0; } /* make sure that no reserved options values are used; allow dest==NULL only for preflighting */ if( source==NULL || sourceLength<-1 || (dest==NULL && destCapacity!=0) || destCapacity<0 || options>=U_SHAPE_DIGIT_TYPE_RESERVED || (options&U_SHAPE_DIGITS_MASK)>=U_SHAPE_DIGITS_RESERVED ) { *pErrorCode=U_ILLEGAL_ARGUMENT_ERROR; return 0; } /* determine the source length */ if(sourceLength==-1) { sourceLength=u_strlen(source); } if(sourceLength==0) { return 0; } /* check that source and destination do not overlap */ if( dest!=NULL && ((source<=dest && destdestCapacity) { *pErrorCode=U_BUFFER_OVERFLOW_ERROR; return outputSize; } /* Start of Arabic letter shaping part */ memcpy(dest, source, sourceLength*U_SIZEOF_UCHAR); ASSERT((options&U_SHAPE_TEXT_DIRECTION_MASK) == U_SHAPE_TEXT_DIRECTION_LOGICAL); switch(options&U_SHAPE_LETTERS_MASK) { case U_SHAPE_LETTERS_SHAPE : /* Call the shaping function with tashkeel flag == 1 */ destLength = shapeUnicode(dest,sourceLength,destCapacity,options,pErrorCode,1); break; case U_SHAPE_LETTERS_SHAPE_TASHKEEL_ISOLATED : /* Call the shaping function with tashkeel flag == 0 */ destLength = shapeUnicode(dest,sourceLength,destCapacity,options,pErrorCode,0); break; case U_SHAPE_LETTERS_UNSHAPE : ASSERT_NOT_REACHED(); break; default : /* will never occur because of validity checks above */ destLength = 0; break; } /* End of Arabic letter shaping part */ } else ASSERT_NOT_REACHED(); ASSERT((options & U_SHAPE_DIGITS_MASK) == U_SHAPE_DIGITS_NOOP); return sourceLength; }