/* fribidi-arabic.c - Arabic shaping

 *

 * Copyright (C) 2005  Behdad Esfahbod

 *

 * This file is part of GNU FriBidi.

 * 

 * GNU FriBidi 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.

 * 

 * GNU FriBidi 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 GNU FriBidi; if not, write to the Free Software

 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA

 * 

 * For licensing issues, contact <fribidi.license@gmail.com> or write to

 * Sharif FarsiWeb, Inc., PO Box 13445-389, Tehran, Iran.

 *

 * Author(s):

 *   Behdad Esfahbod, 2005

 */

#include "common.h"

#ifdef HAVE_CONFIG_H

# include <config.h>

#endif

#ifdef HAVE_STDLIB_H

# include <stdlib.h>

#endif

#include <fribidi-arabic.h>

#include <fribidi-unicode.h>

typedef struct _PairMap {

  FriBidiChar pair[2], to;

} PairMap;

#define FRIBIDI_ACCESS_SHAPE_TABLE(table,min,max,x,shape) (table), (min), (max)

# define FRIBIDI_ACCESS_SHAPE_TABLE_REAL(table,min,max,x,shape) \

  (((x)<(min)||(x)>(max))?(x):(table)[(x)-(min)][(shape)])

#include "arabic-shaping.tab.i"

#include "arabic-misc.tab.i"

static void

fribidi_shape_arabic_joining (

  /* input */

  const FriBidiChar table[][4],

  FriBidiChar min,

  FriBidiChar max,

  const FriBidiStrIndex len,

  const FriBidiArabicProp *ar_props,

  /* input and output */

  FriBidiChar *str

)

{

  register FriBidiStrIndex i;

  for (i = 0; i < len; i++)

    if (FRIBIDI_ARAB_SHAPES(ar_props[i]))

      str[i] = FRIBIDI_ACCESS_SHAPE_TABLE_REAL (table, min, max, str[i], FRIBIDI_JOIN_SHAPE (ar_props[i]));

}

static int

comp_PairMap (const void *pa, const void *pb)

{

  PairMap *a = (PairMap *)pa;

  PairMap *b = (PairMap *)pb;

  if (a->pair[0] != b->pair[0])

    return a->pair[0] < b->pair[0] ? -1 : +1;

  else

    return a->pair[1] < b->pair[1] ? -1 :

           a->pair[1] > b->pair[1] ? +1 :

     0;

}

static void *

fribidi_bsearch (const void *key, const void *base,

                 unsigned int nmemb, unsigned int size,

                 int (*compar)(const void *_key, const void *_item))

{

  int min = 0, max = (int) nmemb - 1;

  while (min <= max)

  {

    int mid = ((unsigned int) min + (unsigned int) max) / 2;

    const void *p = (const void *) (((const char *) base) + (mid * size));

    int c = compar (key, p);

    if (c < 0)

      max = mid - 1;

    else if (c > 0)

      min = mid + 1;

    else

      return (void *) p;

  }

  return NULL;

}

static FriBidiChar

find_pair_match (const PairMap *table, int size, FriBidiChar first, FriBidiChar second)

{

  PairMap *match;

  PairMap x;

  x.pair[0] = first;

  x.pair[1] = second;

  x.to = 0;

  match = fribidi_bsearch (&x, table, size, sizeof (table[0]), comp_PairMap);

  return match ? match->to : 0;

}

#define PAIR_MATCH(table,len,first,second) \

  ((first)<(table[0].pair[0])||(first)>(table[len-1].pair[0])?0: \

   find_pair_match(table, len, first, second))

static void

fribidi_shape_arabic_ligature (

  /* input */

  const PairMap *table,

  int size,

  const FriBidiLevel *embedding_levels,

  const FriBidiStrIndex len,

  /* input and output */

  FriBidiArabicProp *ar_props,

  FriBidiChar *str

)

{

  /* TODO: This doesn't form ligatures for even-level Arabic text.

   * no big problem though. */

  register FriBidiStrIndex i;

  for (i = 0; i < len - 1; i++) {

    register FriBidiChar c;

    if (FRIBIDI_LEVEL_IS_RTL(embedding_levels[i]) &&

  embedding_levels[i] == embedding_levels[i+1] &&

  (c = PAIR_MATCH(table, size, str[i], str[i+1])))

      {

  str[i] = FRIBIDI_CHAR_FILL;

  FRIBIDI_SET_BITS(ar_props[i], FRIBIDI_MASK_LIGATURED);

  str[i+1] = c;

      }

  }

}

#define DO_LIGATURING(table, levels, len, ar_props, str) \

  fribidi_shape_arabic_ligature ((table), sizeof(table)/sizeof((table)[0]), levels, len, ar_props, str)

#define DO_SHAPING(tablemacro, len, ar_props, str) \

  fribidi_shape_arabic_joining (tablemacro(,), len, ar_props, str);

FRIBIDI_ENTRY void

fribidi_shape_arabic (

  /* input */

  FriBidiFlags flags,

  const FriBidiLevel *embedding_levels,

  const FriBidiStrIndex len,

  /* input and output */

  FriBidiArabicProp *ar_props,

  FriBidiChar *str

)

{

  DBG ("in fribidi_shape_arabic");

  if UNLIKELY

    (len == 0 || !str) return;

  DBG ("in fribidi_shape");

  fribidi_assert (ar_props);

  if (FRIBIDI_TEST_BITS (flags, FRIBIDI_FLAG_SHAPE_ARAB_PRES))

    {

      DO_SHAPING (FRIBIDI_GET_ARABIC_SHAPE_PRES, len, ar_props, str);

    }

  if (FRIBIDI_TEST_BITS (flags, FRIBIDI_FLAG_SHAPE_ARAB_LIGA))

    {

      DO_LIGATURING (mandatory_liga_table, embedding_levels, len, ar_props, str);

    }

  if (FRIBIDI_TEST_BITS (flags, FRIBIDI_FLAG_SHAPE_ARAB_CONSOLE))

    {

      DO_LIGATURING (console_liga_table, embedding_levels, len, ar_props, str);

      DO_SHAPING (FRIBIDI_GET_ARABIC_SHAPE_NSM, len, ar_props, str);

    }

}

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 */