shapearabic.c

linux下开源浏览器WebKit的源码,市面上的很多商用浏览器都是移植自WebKit

/*
******************************************************************************
*
*   Copyright (C) 2000-2004, International Business Machines
*   Corporation and others. All Rights Reserved.
*   Copyright (C) 2007 Apple Inc. All rights reserved.
*
*   Permission is hereby granted, free of charge, to any person obtaining a copy of this
*   software and associated documentation files (the "Software"), to deal in the Software
*   without restriction, including without limitation the rights to use, copy, modify,
*   merge, publish, distribute, and/or sell copies of the Software, and to permit persons
*   to whom the Software is furnished to do so, provided that the above copyright notice(s)
*   and this permission notice appear in all copies of the Software and that both the above
*   copyright notice(s) and this permission notice appear in supporting documentation.
*
*   THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
*   INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
*   PURPOSE AND NONINFRINGEMENT OF THIRD PARTY RIGHTS. IN NO EVENT SHALL THE COPYRIGHT HOLDER
*   OR HOLDERS INCLUDED IN THIS NOTICE BE LIABLE FOR ANY CLAIM, OR ANY SPECIAL INDIRECT OR
*   CONSEQUENTIAL DAMAGES, OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
*   PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
*   OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*
*   Except as contained in this notice, the name of a copyright holder shall not be used in
*   advertising or otherwise to promote the sale, use or other dealings in this Software
*   without prior written authorization of the copyright holder.
*
******************************************************************************
*
*   Arabic letter shaping implemented by Ayman Roshdy
*/

#include "config.h"

#if USE(ATSUI)

#include "ShapeArabic.h"

#include <unicode/utypes.h>
#include <unicode/uchar.h>
#include <unicode/ustring.h>
#include <unicode/ushape.h>
#include <wtf/Assertions.h>

/*
 * ### 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;