wine/dlls/gdi32/bidi.c

/*
 * GDI BiDirectional handling
 *
 * Copyright 2003 Shachar Shemesh
 * Copyright 2007 Maarten Lankhorst
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
 *
 * Code derived from the modified reference implementation
 * that was found in revision 17 of http://unicode.org/reports/tr9/
 * "Unicode Standard Annex #9: THE BIDIRECTIONAL ALGORITHM"
 *
 * -- Copyright (C) 1999-2005, ASMUS, Inc.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of the Unicode data files and any associated documentation (the
 * "Data Files") or Unicode software and any associated documentation (the
 * "Software") to deal in the Data Files or Software without restriction,
 * including without limitation the rights to use, copy, modify, merge,
 * publish, distribute, and/or sell copies of the Data Files or Software,
 * and to permit persons to whom the Data Files or Software are furnished
 * to do so, provided that (a) the above copyright notice(s) and this
 * permission notice appear with all copies of the Data Files or Software,
 * (b) both the above copyright notice(s) and this permission notice appear
 * in associated documentation, and (c) there is clear notice in each
 * modified Data File or in the Software as well as in the documentation
 * associated with the Data File(s) or Software that the data or software
 * has been modified.
 */

#include "config.h"

#include <stdarg.h>
#include "windef.h"
#include "winbase.h"
#include "wingdi.h"
#include "wine/debug.h"
#include "gdi_private.h"

WINE_DEFAULT_DEBUG_CHANNEL(bidi);

#define ASSERT(x) do { if (!(x)) FIXME("assert failed: %s\n", #x); } while(0)

/* HELPER FUNCTIONS AND DECLARATIONS */

#define odd(x) ((x) & 1)

/*------------------------------------------------------------------------
    Bidirectional Character Types

    as defined by the Unicode Bidirectional Algorithm Table 3-7.

    Note:

      The list of bidirectional character types here is not grouped the
      same way as the table 3-7, since the numberic values for the types
      are chosen to keep the state and action tables compact.
------------------------------------------------------------------------*/
enum directions
{
    /* input types */
             /* ON MUST be zero, code relies on ON = N = 0 */
    ON = 0,  /* Other Neutral */
    L,       /* Left Letter */
    R,       /* Right Letter */
    AN,      /* Arabic Number */
    EN,      /* European Number */
    AL,      /* Arabic Letter (Right-to-left) */
    NSM,     /* Non-spacing Mark */
    CS,      /* Common Separator */
    ES,      /* European Separator */
    ET,      /* European Terminator (post/prefix e.g. $ and %) */

    /* resolved types */
    BN,      /* Boundary neutral (type of RLE etc after explicit levels) */

    /* input types, */
    S,       /* Segment Separator (TAB)        // used only in L1 */
    WS,      /* White space                    // used only in L1 */
    B,       /* Paragraph Separator (aka as PS) */

    /* types for explicit controls */
    RLO,     /* these are used only in X1-X9 */
    RLE,
    LRO,
    LRE,
    PDF,

    /* resolved types, also resolved directions */
    N = ON,  /* alias, where ON, WS and S are treated the same */
};

/* HELPER FUNCTIONS */

/* grep -r ';BN;' data.txt  | grep -v [0-9A-F][0-9A-F][0-9A-F][0-9A-F][0-9A-F] | sed -e s@\;.*@@ -e s/^..../0x\&,\ / | xargs echo */
static const WCHAR BNs[] = {
    0x0000, 0x0001, 0x0002, 0x0003, 0x0004, 0x0005, 0x0006, 0x0007, 0x0008,
    0x000E, 0x000F, 0x0010, 0x0011, 0x0012, 0x0013, 0x0014, 0x0015, 0x0016,
    0x0017, 0x0018, 0x0019, 0x001A, 0x001B, 0x007F, 0x0080, 0x0081, 0x0082,
    0x0083, 0x0084, 0x0086, 0x0087, 0x0088, 0x0089, 0x008A, 0x008B, 0x008C,
    0x008D, 0x008E, 0x008F, 0x0090, 0x0091, 0x0092, 0x0093, 0x0094, 0x0095,
    0x0096, 0x0097, 0x0098, 0x0099, 0x009A, 0x009B, 0x009C, 0x009D, 0x009E,
    0x009F, 0x00AD, 0x070F, 0x200B, 0x200C, 0x200D, 0x2060, 0x2061, 0x2062,
    0x2063, 0x206A, 0x206B, 0x206C, 0x206D, 0x206E, 0x206F, 0xFEFF
};

/* Idem, but with ';R;' instead of ';BN;' */
static const WCHAR Rs[] = {
    0x05BE, 0x05C0, 0x05C3, 0x05C6, 0x05D0, 0x05D1, 0x05D2, 0x05D3, 0x05D4,
    0x05D5, 0x05D6, 0x05D7, 0x05D8, 0x05D9, 0x05DA, 0x05DB, 0x05DC, 0x05DD,
    0x05DE, 0x05DF, 0x05E0, 0x05E1, 0x05E2, 0x05E3, 0x05E4, 0x05E5, 0x05E6,
    0x05E7, 0x05E8, 0x05E9, 0x05EA, 0x05F0, 0x05F1, 0x05F2, 0x05F3, 0x05F4,
    0x07C0, 0x07C1, 0x07C2, 0x07C3, 0x07C4, 0x07C5, 0x07C6, 0x07C7, 0x07C8,
    0x07C9, 0x07CA, 0x07CB, 0x07CC, 0x07CD, 0x07CE, 0x07CF, 0x07D0, 0x07D1,
    0x07D2, 0x07D3, 0x07D4, 0x07D5, 0x07D6, 0x07D7, 0x07D8, 0x07D9, 0x07DA,
    0x07DB, 0x07DC, 0x07DD, 0x07DE, 0x07DF, 0x07E0, 0x07E1, 0x07E2, 0x07E3,
    0x07E4, 0x07E5, 0x07E6, 0x07E7, 0x07E8, 0x07E9, 0x07EA, 0x07F4, 0x07F5,
    0x07FA, 0x200F, 0xFB1D, 0xFB1F, 0xFB20, 0xFB21, 0xFB22, 0xFB23, 0xFB24,
    0xFB25, 0xFB26, 0xFB27, 0xFB28, 0xFB2A, 0xFB2B, 0xFB2C, 0xFB2D, 0xFB2E,
    0xFB2F, 0xFB30, 0xFB31, 0xFB32, 0xFB33, 0xFB34, 0xFB35, 0xFB36, 0xFB38,
    0xFB39, 0xFB3A, 0xFB3B, 0xFB3C, 0xFB3E, 0xFB40, 0xFB41, 0xFB43, 0xFB44,
    0xFB46, 0xFB47, 0xFB48, 0xFB49, 0xFB4A, 0xFB4B, 0xFB4C, 0xFB4D, 0xFB4E,
    0xFB4F
};

/* Convert the incomplete win32 table to some slightly more useful data */
static void classify(LPCWSTR lpString, WORD *chartype, DWORD uCount)
{
    unsigned i, j;
    GetStringTypeW(CT_CTYPE2, lpString, uCount, chartype);
    for (i = 0; i < uCount; ++i)
        switch (chartype[i])
        {
            case C2_LEFTTORIGHT: chartype[i] = L; break;
            case C2_RIGHTTOLEFT:
                chartype[i] = AL;
                for (j = 0; j < sizeof(Rs)/sizeof(WCHAR); ++j)
                    if (Rs[j] == lpString[i])
                    {
                        chartype[i] = R;
                        break;
                    }
                break;

            case C2_EUROPENUMBER: chartype[i] = EN; break;
            case C2_EUROPESEPARATOR: chartype[i] = ES; break;
            case C2_EUROPETERMINATOR: chartype[i] = ET; break;
            case C2_ARABICNUMBER: chartype[i] = AN; break;
            case C2_COMMONSEPARATOR: chartype[i] = CS; break;
            case C2_BLOCKSEPARATOR: chartype[i] = B; break;
            case C2_SEGMENTSEPARATOR: chartype[i] = S; break;
            case C2_WHITESPACE: chartype[i] = WS; break;
            case C2_OTHERNEUTRAL:
                switch (lpString[i])
                {
                    case 0x202A: chartype[i] = LRE; break;
                    case 0x202B: chartype[i] = RLE; break;
                    case 0x202C: chartype[i] = PDF; break;
                    case 0x202D: chartype[i] = LRO; break;
                    case 0x202E: chartype[i] = RLO; break;
                    default: chartype[i] = ON; break;
                }
                break;
            case C2_NOTAPPLICABLE:
                chartype[i] = NSM;
                for (j = 0; j < sizeof(BNs)/sizeof(WCHAR); ++j)
                    if (BNs[j] == lpString[i])
                    {
                        chartype[i] = BN;
                        break;
                    }
                break;

            default:
                /* According to BiDi spec, unassigned characters default to L */
                FIXME("Unhandled character type: %04x\n", chartype[i]);
                chartype[i] = L;
                break;
        }
}

/* reverse cch characters */
static void reverse(LPWSTR psz, int cch)
{
    WCHAR chTemp;
    int ich = 0;
    for (; ich < --cch; ich++)
    {
        chTemp = psz[ich];
        psz[ich] = psz[cch];
        psz[cch] = chTemp;
    }
}

/* THE PARAGRAPH LEVEL */

/*------------------------------------------------------------------------
    Function: resolveParagraphs

    Resolves the input strings into blocks over which the algorithm
    is then applied.

    Implements Rule P1 of the Unicode Bidi Algorithm

    Input: Text string
           Character count

    Output: revised character count

    Note:    This is a very simplfistic function. In effect it restricts
            the action of the algorithm to the first paragraph in the input
            where a paragraph ends at the end of the first block separator
            or at the end of the input text.

------------------------------------------------------------------------*/

static int resolveParagraphs(WORD *types, int cch)
{
    /* skip characters not of type B */
    int ich = 0;
    for(; ich < cch && types[ich] != B; ich++);
    /* stop after first B, make it a BN for use in the next steps */
    if (ich < cch && types[ich] == B)
        types[ich++] = BN;
    return ich;
}

/*************************************************************
 *    BIDI_Reorder
 */
BOOL BIDI_Reorder(
                LPCWSTR lpString,       /* [in] The string for which information is to be returned */
                INT uCount,     /* [in] Number of WCHARs in string. */
                DWORD dwFlags,  /* [in] GetCharacterPlacement compatible flags specifying how to process the string */
                DWORD dwWineGCP_Flags,       /* [in] Wine internal flags - Force paragraph direction */
                LPWSTR lpOutString, /* [out] Reordered string */
                INT uCountOut,  /* [in] Size of output buffer */
                UINT *lpOrder /* [out] Logical -> Visual order map */
    )
{
    WORD *levels;
    WORD *chartype;
    unsigned i, baselevel = 0, forcedir = 0, done;
    TRACE("%s, %d, 0x%08x lpOutString=%p, lpOrder=%p\n",
          debugstr_wn(lpString, uCount), uCount, dwFlags,
          lpOutString, lpOrder);

    if (!(dwFlags & GCP_REORDER))
    {
        FIXME("Asked to reorder without reorder flag set\n");
        return FALSE;
    }

    if (uCountOut < uCount)
    {
        FIXME("lpOutString too small");
        return FALSE;
    }

    chartype = HeapAlloc(GetProcessHeap(), 0, uCount * 2 * sizeof(WORD));
    levels = chartype + uCount;
    if (!chartype)
    {
        WARN("Out of memory\n");
        return FALSE;
    }

    memcpy(lpOutString, lpString, uCount * sizeof(WCHAR));

    switch (dwWineGCP_Flags&WINE_GCPW_DIR_MASK)
    {
    /* force means initial level is set directly,
     * loose means initial level is determined by first character that has a direction */
    case WINE_GCPW_FORCE_LTR: forcedir = L; break;
    case WINE_GCPW_FORCE_RTL: forcedir = R; baselevel = 1; break;
    default: break;
    }

    i = done = 0;
    while (done < uCount)
    {
        unsigned j, lastgood;
        classify(lpOutString + done, chartype, uCount - done);
        /* limit text to first block */
        i = resolveParagraphs(chartype, uCount - done);
        for (j = 0; j < i - 1; ++j)
            switch(chartype[j])
            {
                case B:
                case S:
                case WS:
                case ON: chartype[i] = N;
                default: continue;
            }

        if (!forcedir)
        {
            if ((dwWineGCP_Flags&WINE_GCPW_DIR_MASK) == WINE_GCPW_LOOSE_RTL)
                baselevel = 1;
            else baselevel = 0;

            for (j = 0; j < i; ++j)
            {
                if (chartype[j] == L)
                {
                    baselevel = 0;
                    break;
                }
                if (chartype[j] == R)
                {
                    baselevel = 1;
                    break;
                }
            }
        }

        /* Temporary stub: Assume everything is in the direction we want */
        memset(levels, baselevel, i * sizeof(WORD));
        if (baselevel)
            reverse(lpOutString, i);

        if (lpOrder)
        {
            unsigned k;
            for (j = lastgood = 0; j < i; ++j)
                if (levels[j] != levels[lastgood])
                {
                    --j;
                    if (odd(levels[lastgood]))
                        for (k = j; k >= lastgood; --k)
                            lpOrder[done + k] = done + j - k;
                    else
                        for (k = lastgood; k <= j; ++k)
                            lpOrder[done + k] = done + k;
                    lastgood = ++j;
                }
            if (odd(levels[lastgood]))
                for (k = j - 1; k >= lastgood; --k)
                    lpOrder[done + k] = done + j - 1 - k;
            else
                for (k = lastgood; k <= j; ++k)
                    lpOrder[done + k] = done + k;
        }
        done += i;
    }

    HeapFree(GetProcessHeap(), 0, chartype);
    return TRUE;
}