modules/freetype2/src/autofit/afglobal.c

   1 /***************************************************************************/
   2 /*                                                                         */
   3 /*  afglobal.c                                                             */
   4 /*                                                                         */
   5 /*    Auto-fitter routines to compute global hinting values (body).        */
   6 /*                                                                         */
   7 /*  Copyright 2003, 2004, 2005, 2006, 2007, 2008 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 "afglobal.h"
  20 #include "afdummy.h"
  21 #include "aflatin.h"
  22 #include "afcjk.h"
  23 #include "afindic.h"
  24
  25 #include "aferrors.h"
  26
  27 #ifdef FT_OPTION_AUTOFIT2
  28 #include "aflatin2.h"
  29 #endif
  30
  31   /* populate this list when you add new scripts */
  32   static AF_ScriptClass const  af_script_classes[] =
  33   {
  34     &af_dummy_script_class,
  35 #ifdef FT_OPTION_AUTOFIT2
  36     &af_latin2_script_class,
  37 #endif
  38     &af_latin_script_class,
  39     &af_cjk_script_class,
  40     &af_indic_script_class,
  41     NULL  /* do not remove */
  42   };
  43
  44   /* index of default script in `af_script_classes' */
  45 #define AF_SCRIPT_LIST_DEFAULT  2
  46   /* indicates an uncovered glyph                   */
  47 #define AF_SCRIPT_LIST_NONE   255
  48
  49
  50   /*
  51    *  Note that glyph_scripts[] is used to map each glyph into
  52    *  an index into the `af_script_classes' array.
  53    *
  54    */
  55   typedef struct  AF_FaceGlobalsRec_
  56   {
  57     FT_Face           face;
  58     FT_UInt           glyph_count;    /* same as face->num_glyphs */
  59     FT_Byte*          glyph_scripts;
  60
  61     AF_ScriptMetrics  metrics[AF_SCRIPT_MAX];
  62
  63   } AF_FaceGlobalsRec;
  64
  65
  66   /* Compute the script index of each glyph within a given face. */
  67
  68   static FT_Error
  69   af_face_globals_compute_script_coverage( AF_FaceGlobals  globals )
  70   {
  71     FT_Error    error       = AF_Err_Ok;
  72     FT_Face     face        = globals->face;
  73     FT_CharMap  old_charmap = face->charmap;
  74     FT_Byte*    gscripts    = globals->glyph_scripts;
  75     FT_UInt     ss;
  76
  77
  78     /* the value 255 means `uncovered glyph' */
  79     FT_MEM_SET( globals->glyph_scripts,
  80                 AF_SCRIPT_LIST_NONE,
  81                 globals->glyph_count );
  82
  83     error = FT_Select_Charmap( face, FT_ENCODING_UNICODE );
  84     if ( error )
  85     {
  86      /*
  87       *  Ignore this error; we simply use the default script.
  88       *  XXX: Shouldn't we rather disable hinting?
  89       */
  90       error = AF_Err_Ok;
  91       goto Exit;
  92     }
  93
  94     /* scan each script in a Unicode charmap */
  95     for ( ss = 0; af_script_classes[ss]; ss++ )
  96     {
  97       AF_ScriptClass      clazz = af_script_classes[ss];
  98       AF_Script_UniRange  range;
  99
 100
 101       if ( clazz->script_uni_ranges == NULL )
 102         continue;
 103
 104       /*
 105        *  Scan all unicode points in the range and set the corresponding
 106        *  glyph script index.
 107        */
 108       for ( range = clazz->script_uni_ranges; range->first != 0; range++ )
 109       {
 110         FT_ULong  charcode = range->first;
 111         FT_UInt   gindex;
 112
 113
 114         gindex = FT_Get_Char_Index( face, charcode );
 115
 116         if ( gindex != 0                             &&
 117              gindex < globals->glyph_count           &&
 118              gscripts[gindex] == AF_SCRIPT_LIST_NONE )
 119         {
 120           gscripts[gindex] = (FT_Byte)ss;
 121         }
 122
 123         for (;;)
 124         {
 125           charcode = FT_Get_Next_Char( face, charcode, &gindex );
 126
 127           if ( gindex == 0 || charcode > range->last )
 128             break;
 129
 130           if ( gindex < globals->glyph_count           &&
 131                gscripts[gindex] == AF_SCRIPT_LIST_NONE )
 132           {
 133             gscripts[gindex] = (FT_Byte)ss;
 134           }
 135         }
 136       }
 137     }
 138
 139   Exit:
 140     /*
 141      *  By default, all uncovered glyphs are set to the latin script.
 142      *  XXX: Shouldn't we disable hinting or do something similar?
 143      */
 144     {
 145       FT_UInt  nn;
 146
 147
 148       for ( nn = 0; nn < globals->glyph_count; nn++ )
 149       {
 150         if ( gscripts[nn] == AF_SCRIPT_LIST_NONE )
 151           gscripts[nn] = AF_SCRIPT_LIST_DEFAULT;
 152       }
 153     }
 154
 155     FT_Set_Charmap( face, old_charmap );
 156     return error;
 157   }
 158
 159
 160   FT_LOCAL_DEF( FT_Error )
 161   af_face_globals_new( FT_Face          face,
 162                        AF_FaceGlobals  *aglobals )
 163   {
 164     FT_Error        error;
 165     FT_Memory       memory;
 166     AF_FaceGlobals  globals;
 167
 168
 169     memory = face->memory;
 170
 171     if ( !FT_ALLOC( globals, sizeof ( *globals ) +
 172                              face->num_glyphs * sizeof ( FT_Byte ) ) )
 173     {
 174       globals->face          = face;
 175       globals->glyph_count   = face->num_glyphs;
 176       globals->glyph_scripts = (FT_Byte*)( globals + 1 );
 177
 178       error = af_face_globals_compute_script_coverage( globals );
 179       if ( error )
 180       {
 181         af_face_globals_free( globals );
 182         globals = NULL;
 183       }
 184     }
 185
 186     *aglobals = globals;
 187     return error;
 188   }
 189
 190
 191   FT_LOCAL_DEF( void )
 192   af_face_globals_free( AF_FaceGlobals  globals )
 193   {
 194     if ( globals )
 195     {
 196       FT_Memory  memory = globals->face->memory;
 197       FT_UInt    nn;
 198
 199
 200       for ( nn = 0; nn < AF_SCRIPT_MAX; nn++ )
 201       {
 202         if ( globals->metrics[nn] )
 203         {
 204           AF_ScriptClass  clazz = af_script_classes[nn];
 205
 206
 207           FT_ASSERT( globals->metrics[nn]->clazz == clazz );
 208
 209           if ( clazz->script_metrics_done )
 210             clazz->script_metrics_done( globals->metrics[nn] );
 211
 212           FT_FREE( globals->metrics[nn] );
 213         }
 214       }
 215
 216       globals->glyph_count   = 0;
 217       globals->glyph_scripts = NULL;  /* no need to free this one! */
 218       globals->face          = NULL;
 219
 220       FT_FREE( globals );
 221     }
 222   }
 223
 224
 225   FT_LOCAL_DEF( FT_Error )
 226   af_face_globals_get_metrics( AF_FaceGlobals     globals,
 227                                FT_UInt            gindex,
 228                                FT_UInt            options,
 229                                AF_ScriptMetrics  *ametrics )
 230   {
 231     AF_ScriptMetrics  metrics = NULL;
 232     FT_UInt           gidx;
 233     AF_ScriptClass    clazz;
 234     FT_UInt           script     = options & 15;
 235     const FT_UInt     script_max = sizeof ( af_script_classes ) /
 236                                      sizeof ( af_script_classes[0] );
 237     FT_Error          error      = AF_Err_Ok;
 238
 239
 240     if ( gindex >= globals->glyph_count )
 241     {
 242       error = AF_Err_Invalid_Argument;
 243       goto Exit;
 244     }
 245
 246     gidx = script;
 247     if ( gidx == 0 || gidx + 1 >= script_max )
 248       gidx = globals->glyph_scripts[gindex];
 249
 250     clazz = af_script_classes[gidx];
 251     if ( script == 0 )
 252       script = clazz->script;
 253
 254     metrics = globals->metrics[clazz->script];
 255     if ( metrics == NULL )
 256     {
 257       /* create the global metrics object when needed */
 258       FT_Memory  memory = globals->face->memory;
 259
 260
 261       if ( FT_ALLOC( metrics, clazz->script_metrics_size ) )
 262         goto Exit;
 263
 264       metrics->clazz = clazz;
 265
 266       if ( clazz->script_metrics_init )
 267       {
 268         error = clazz->script_metrics_init( metrics, globals->face );
 269         if ( error )
 270         {
 271           if ( clazz->script_metrics_done )
 272             clazz->script_metrics_done( metrics );
 273
 274           FT_FREE( metrics );
 275           goto Exit;
 276         }
 277       }
 278
 279       globals->metrics[clazz->script] = metrics;
 280     }
 281
 282   Exit:
 283     *ametrics = metrics;
 284
 285     return error;
 286   }
 287
 288
 289 /* END */