thirdparty/freetype-2.3.12/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, 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 "afglobal.h"
  20 #include "afdummy.h"
  21 #include "aflatin.h"
  22 #include "afcjk.h"
  23 #include "afindic.h"
  24 #include "afpic.h"
  25
  26 #include "aferrors.h"
  27
  28 #ifdef FT_OPTION_AUTOFIT2
  29 #include "aflatin2.h"
  30 #endif
  31
  32 #ifndef FT_CONFIG_OPTION_PIC
  33
  34 /* when updating this table, don't forget to update
  35   AF_SCRIPT_CLASSES_COUNT and autofit_module_class_pic_init */
  36
  37   /* populate this list when you add new scripts */
  38   static AF_ScriptClass const  af_script_classes[] =
  39   {
  40     &af_dummy_script_class,
  41 #ifdef FT_OPTION_AUTOFIT2
  42     &af_latin2_script_class,
  43 #endif
  44     &af_latin_script_class,
  45     &af_cjk_script_class,
  46     &af_indic_script_class,
  47     NULL  /* do not remove */
  48   };
  49
  50 #endif /* FT_CONFIG_OPTION_PIC */
  51
  52   /* index of default script in `af_script_classes' */
  53 #define AF_SCRIPT_LIST_DEFAULT  2
  54   /* a bit mask indicating an uncovered glyph       */
  55 #define AF_SCRIPT_LIST_NONE     0x7F
  56   /* if this flag is set, we have an ASCII digit    */
  57 #define AF_DIGIT                0x80
  58
  59
  60   /*
  61    *  Note that glyph_scripts[] is used to map each glyph into
  62    *  an index into the `af_script_classes' array.
  63    *
  64    */
  65   typedef struct  AF_FaceGlobalsRec_
  66   {
  67     FT_Face           face;
  68     FT_Long           glyph_count;    /* same as face->num_glyphs */
  69     FT_Byte*          glyph_scripts;
  70
  71     AF_ScriptMetrics  metrics[AF_SCRIPT_MAX];
  72
  73   } AF_FaceGlobalsRec;
  74
  75
  76   /* Compute the script index of each glyph within a given face. */
  77
  78   static FT_Error
  79   af_face_globals_compute_script_coverage( AF_FaceGlobals  globals )
  80   {
  81     FT_Error    error       = AF_Err_Ok;
  82     FT_Face     face        = globals->face;
  83     FT_CharMap  old_charmap = face->charmap;
  84     FT_Byte*    gscripts    = globals->glyph_scripts;
  85     FT_UInt     ss, i;
  86
  87
  88     /* the value 255 means `uncovered glyph' */
  89     FT_MEM_SET( globals->glyph_scripts,
  90                 AF_SCRIPT_LIST_NONE,
  91                 globals->glyph_count );
  92
  93     error = FT_Select_Charmap( face, FT_ENCODING_UNICODE );
  94     if ( error )
  95     {
  96      /*
  97       *  Ignore this error; we simply use the default script.
  98       *  XXX: Shouldn't we rather disable hinting?
  99       */
 100       error = AF_Err_Ok;
 101       goto Exit;
 102     }
 103
 104     /* scan each script in a Unicode charmap */
 105     for ( ss = 0; AF_SCRIPT_CLASSES_GET[ss]; ss++ )
 106     {
 107       AF_ScriptClass      clazz = AF_SCRIPT_CLASSES_GET[ss];
 108       AF_Script_UniRange  range;
 109
 110
 111       if ( clazz->script_uni_ranges == NULL )
 112         continue;
 113
 114       /*
 115        *  Scan all unicode points in the range and set the corresponding
 116        *  glyph script index.
 117        */
 118       for ( range = clazz->script_uni_ranges; range->first != 0; range++ )
 119       {
 120         FT_ULong  charcode = range->first;
 121         FT_UInt   gindex;
 122
 123
 124         gindex = FT_Get_Char_Index( face, charcode );
 125
 126         if ( gindex != 0                             &&
 127              gindex < (FT_ULong)globals->glyph_count &&
 128              gscripts[gindex] == AF_SCRIPT_LIST_NONE )
 129         {
 130           gscripts[gindex] = (FT_Byte)ss;
 131         }
 132
 133         for (;;)
 134         {
 135           charcode = FT_Get_Next_Char( face, charcode, &gindex );
 136
 137           if ( gindex == 0 || charcode > range->last )
 138             break;
 139
 140           if ( gindex < (FT_ULong)globals->glyph_count &&
 141                gscripts[gindex] == AF_SCRIPT_LIST_NONE )
 142           {
 143             gscripts[gindex] = (FT_Byte)ss;
 144           }
 145         }
 146       }
 147     }
 148
 149     /* mark ASCII digits */
 150     for ( i = 0x30; i <= 0x39; i++ )
 151     {
 152       FT_UInt  gindex = FT_Get_Char_Index( face, i );
 153
 154
 155       if ( gindex != 0 && gindex < (FT_ULong)globals->glyph_count )
 156         gscripts[gindex] |= AF_DIGIT;
 157     }
 158
 159   Exit:
 160     /*
 161      *  By default, all uncovered glyphs are set to the latin script.
 162      *  XXX: Shouldn't we disable hinting or do something similar?
 163      */
 164     {
 165       FT_Long  nn;
 166
 167
 168       for ( nn = 0; nn < globals->glyph_count; nn++ )
 169       {
 170         if ( gscripts[nn] == AF_SCRIPT_LIST_NONE )
 171           gscripts[nn] = AF_SCRIPT_LIST_DEFAULT;
 172       }
 173     }
 174
 175     FT_Set_Charmap( face, old_charmap );
 176     return error;
 177   }
 178
 179
 180   FT_LOCAL_DEF( FT_Error )
 181   af_face_globals_new( FT_Face          face,
 182                        AF_FaceGlobals  *aglobals )
 183   {
 184     FT_Error        error;
 185     FT_Memory       memory;
 186     AF_FaceGlobals  globals;
 187
 188
 189     memory = face->memory;
 190
 191     if ( !FT_ALLOC( globals, sizeof ( *globals ) +
 192                              face->num_glyphs * sizeof ( FT_Byte ) ) )
 193     {
 194       globals->face          = face;
 195       globals->glyph_count   = face->num_glyphs;
 196       globals->glyph_scripts = (FT_Byte*)( globals + 1 );
 197
 198       error = af_face_globals_compute_script_coverage( globals );
 199       if ( error )
 200       {
 201         af_face_globals_free( globals );
 202         globals = NULL;
 203       }
 204     }
 205
 206     *aglobals = globals;
 207     return error;
 208   }
 209
 210
 211   FT_LOCAL_DEF( void )
 212   af_face_globals_free( AF_FaceGlobals  globals )
 213   {
 214     if ( globals )
 215     {
 216       FT_Memory  memory = globals->face->memory;
 217       FT_UInt    nn;
 218
 219
 220       for ( nn = 0; nn < AF_SCRIPT_MAX; nn++ )
 221       {
 222         if ( globals->metrics[nn] )
 223         {
 224           AF_ScriptClass  clazz = AF_SCRIPT_CLASSES_GET[nn];
 225
 226
 227           FT_ASSERT( globals->metrics[nn]->clazz == clazz );
 228
 229           if ( clazz->script_metrics_done )
 230             clazz->script_metrics_done( globals->metrics[nn] );
 231
 232           FT_FREE( globals->metrics[nn] );
 233         }
 234       }
 235
 236       globals->glyph_count   = 0;
 237       globals->glyph_scripts = NULL;  /* no need to free this one! */
 238       globals->face          = NULL;
 239
 240       FT_FREE( globals );
 241     }
 242   }
 243
 244
 245   FT_LOCAL_DEF( FT_Error )
 246   af_face_globals_get_metrics( AF_FaceGlobals     globals,
 247                                FT_UInt            gindex,
 248                                FT_UInt            options,
 249                                AF_ScriptMetrics  *ametrics )
 250   {
 251     AF_ScriptMetrics  metrics = NULL;
 252     FT_UInt           gidx;
 253     AF_ScriptClass    clazz;
 254     FT_UInt           script     = options & 15;
 255     const FT_Offset   script_max = sizeof ( AF_SCRIPT_CLASSES_GET ) /
 256                                      sizeof ( AF_SCRIPT_CLASSES_GET[0] );
 257     FT_Error          error      = AF_Err_Ok;
 258
 259
 260     if ( gindex >= (FT_ULong)globals->glyph_count )
 261     {
 262       error = AF_Err_Invalid_Argument;
 263       goto Exit;
 264     }
 265
 266     gidx = script;
 267     if ( gidx == 0 || gidx + 1 >= script_max )
 268       gidx = globals->glyph_scripts[gindex] & AF_SCRIPT_LIST_NONE;
 269
 270     clazz = AF_SCRIPT_CLASSES_GET[gidx];
 271     if ( script == 0 )
 272       script = clazz->script;
 273
 274     metrics = globals->metrics[clazz->script];
 275     if ( metrics == NULL )
 276     {
 277       /* create the global metrics object when needed */
 278       FT_Memory  memory = globals->face->memory;
 279
 280
 281       if ( FT_ALLOC( metrics, clazz->script_metrics_size ) )
 282         goto Exit;
 283
 284       metrics->clazz = clazz;
 285
 286       if ( clazz->script_metrics_init )
 287       {
 288         error = clazz->script_metrics_init( metrics, globals->face );
 289         if ( error )
 290         {
 291           if ( clazz->script_metrics_done )
 292             clazz->script_metrics_done( metrics );
 293
 294           FT_FREE( metrics );
 295           goto Exit;
 296         }
 297       }
 298
 299       globals->metrics[clazz->script] = metrics;
 300     }
 301
 302   Exit:
 303     *ametrics = metrics;
 304
 305     return error;
 306   }
 307
 308
 309   FT_LOCAL_DEF( FT_Bool )
 310   af_face_globals_is_digit( AF_FaceGlobals  globals,
 311                             FT_UInt         gindex )
 312   {
 313     if ( gindex < (FT_ULong)globals->glyph_count )
 314       return (FT_Bool)( globals->glyph_scripts[gindex] & AF_DIGIT );
 315
 316     return (FT_Bool)0;
 317   }
 318
 319
 320 /* END */