thirdparty/freetype-2.3.12/src/pfr/pfrcmap.c

   1 /***************************************************************************/
   2 /*                                                                         */
   3 /*  pfrcmap.c                                                              */
   4 /*                                                                         */
   5 /*    FreeType PFR cmap handling (body).                                   */
   6 /*                                                                         */
   7 /*  Copyright 2002, 2007, 2009 by                                          */
   8 /*  David Turner, Robert Wilhelm, and Werner Lemberg.                      */
   9 /*                                                                         */
  10 /*  This file is part of the FreeType project, and may only be used,       */
  11 /*  modified, and distributed under the terms of the FreeType project      */
  12 /*  license, LICENSE.TXT.  By continuing to use, modify, or distribute     */
  13 /*  this file you indicate that you have read the license and              */
  14 /*  understand and accept it fully.                                        */
  15 /*                                                                         */
  16 /***************************************************************************/
  17
  18
  19 #include "pfrcmap.h"
  20 #include "pfrobjs.h"
  21
  22 #include "pfrerror.h"
  23
  24
  25   FT_CALLBACK_DEF( FT_Error )
  26   pfr_cmap_init( PFR_CMap  cmap )
  27   {
  28     FT_Error  error = PFR_Err_Ok;
  29     PFR_Face  face  = (PFR_Face)FT_CMAP_FACE( cmap );
  30
  31
  32     cmap->num_chars = face->phy_font.num_chars;
  33     cmap->chars     = face->phy_font.chars;
  34
  35     /* just for safety, check that the character entries are correctly */
  36     /* sorted in increasing character code order                       */
  37     {
  38       FT_UInt  n;
  39
  40
  41       for ( n = 1; n < cmap->num_chars; n++ )
  42       {
  43         if ( cmap->chars[n - 1].char_code >= cmap->chars[n].char_code )
  44         {
  45           error = PFR_Err_Invalid_Table;
  46           goto Exit;
  47         }
  48       }
  49     }
  50
  51   Exit:
  52     return error;
  53   }
  54
  55
  56   FT_CALLBACK_DEF( void )
  57   pfr_cmap_done( PFR_CMap  cmap )
  58   {
  59     cmap->chars     = NULL;
  60     cmap->num_chars = 0;
  61   }
  62
  63
  64   FT_CALLBACK_DEF( FT_UInt )
  65   pfr_cmap_char_index( PFR_CMap   cmap,
  66                        FT_UInt32  char_code )
  67   {
  68     FT_UInt   min = 0;
  69     FT_UInt   max = cmap->num_chars;
  70     FT_UInt   mid;
  71     PFR_Char  gchar;
  72
  73
  74     while ( min < max )
  75     {
  76       mid   = min + ( max - min ) / 2;
  77       gchar = cmap->chars + mid;
  78
  79       if ( gchar->char_code == char_code )
  80         return mid + 1;
  81
  82       if ( gchar->char_code < char_code )
  83         min = mid + 1;
  84       else
  85         max = mid;
  86     }
  87     return 0;
  88   }
  89
  90
  91   FT_CALLBACK_DEF( FT_UInt32 )
  92   pfr_cmap_char_next( PFR_CMap    cmap,
  93                       FT_UInt32  *pchar_code )
  94   {
  95     FT_UInt    result    = 0;
  96     FT_UInt32  char_code = *pchar_code + 1;
  97
  98
  99   Restart:
 100     {
 101       FT_UInt   min = 0;
 102       FT_UInt   max = cmap->num_chars;
 103       FT_UInt   mid;
 104       PFR_Char  gchar;
 105
 106
 107       while ( min < max )
 108       {
 109         mid   = min + ( ( max - min ) >> 1 );
 110         gchar = cmap->chars + mid;
 111
 112         if ( gchar->char_code == char_code )
 113         {
 114           result = mid;
 115           if ( result != 0 )
 116           {
 117             result++;
 118             goto Exit;
 119           }
 120
 121           char_code++;
 122           goto Restart;
 123         }
 124
 125         if ( gchar->char_code < char_code )
 126           min = mid+1;
 127         else
 128           max = mid;
 129       }
 130
 131       /* we didn't find it, but we have a pair just above it */
 132       char_code = 0;
 133
 134       if ( min < cmap->num_chars )
 135       {
 136         gchar  = cmap->chars + min;
 137         result = min;
 138         if ( result != 0 )
 139         {
 140           result++;
 141           char_code = gchar->char_code;
 142         }
 143       }
 144     }
 145
 146   Exit:
 147     *pchar_code = char_code;
 148     return result;
 149   }
 150
 151
 152   FT_CALLBACK_TABLE_DEF const FT_CMap_ClassRec
 153   pfr_cmap_class_rec =
 154   {
 155     sizeof ( PFR_CMapRec ),
 156
 157     (FT_CMap_InitFunc)     pfr_cmap_init,
 158     (FT_CMap_DoneFunc)     pfr_cmap_done,
 159     (FT_CMap_CharIndexFunc)pfr_cmap_char_index,
 160     (FT_CMap_CharNextFunc) pfr_cmap_char_next,
 161
 162     NULL, NULL, NULL, NULL, NULL
 163   };
 164
 165
 166 /* END */