lib/taglobal.c

   1 /* taglobal.c */
   2
   3 /*
   4  * Copyright (C) 2011-2012 by Werner Lemberg.
   5  *
   6  * This file is part of the ttfautohint library, and may only be used,
   7  * modified, and distributed under the terms given in `COPYING'.  By
   8  * continuing to use, modify, or distribute this file you indicate that you
   9  * have read `COPYING' and understand and accept it fully.
  10  *
  11  * The file `COPYING' mentioned in the previous paragraph is distributed
  12  * with the ttfautohint library.
  13  */
  14
  15
  16 /* originally file `afglobal.c' (2011-Mar-28) from FreeType */
  17
  18 /* heavily modified 2011 by Werner Lemberg <wl@gnu.org> */
  19
  20 #include <stdlib.h>
  21
  22 #include "taglobal.h"
  23
  24 #include "tadummy.h"
  25 #include "talatin.h"
  26
  27 #if 0
  28 #include "tacjk.h"
  29 #include "taindic.h"
  30
  31 #ifdef FT_OPTION_AUTOFIT2
  32 #include "talatin2.h"
  33 #endif
  34 #endif /* 0 */
  35
  36 /* populate this list when you add new scripts */
  37 static TA_ScriptClass const ta_script_classes[] =
  38 {
  39   &ta_dummy_script_class,
  40 #ifdef FT_OPTION_AUTOFIT2
  41   &ta_latin2_script_class,
  42 #endif
  43   &ta_latin_script_class,
  44 #if 0
  45   &ta_cjk_script_class,
  46   &ta_indic_script_class,
  47 #endif
  48   NULL /* do not remove */
  49 };
  50
  51
  52 /* Compute the script index of each glyph within a given face. */
  53
  54 static FT_Error
  55 ta_face_globals_compute_script_coverage(TA_FaceGlobals globals,
  56                                         FT_UInt fallback_script)
  57 {
  58   FT_Error error = FT_Err_Ok;
  59   FT_Face face = globals->face;
  60   FT_CharMap old_charmap = face->charmap;
  61   FT_Byte* gscripts = globals->glyph_scripts;
  62   FT_UInt ss;
  63   FT_UInt i;
  64
  65
  66   /* the value TA_SCRIPT_NONE means `uncovered glyph' */
  67   memset(globals->glyph_scripts, TA_SCRIPT_NONE, globals->glyph_count);
  68
  69   error = FT_Select_Charmap(face, FT_ENCODING_UNICODE);
  70   if (error)
  71   {
  72     /* ignore this error; we simply use the fallback script */
  73     /* XXX: Shouldn't we rather disable hinting? */
  74     error = FT_Err_Ok;
  75     goto Exit;
  76   }
  77
  78   /* scan each script in a Unicode charmap */
  79   for (ss = 0; ta_script_classes[ss]; ss++)
  80   {
  81     TA_ScriptClass clazz = ta_script_classes[ss];
  82     TA_Script_UniRange range;
  83
  84
  85     if (clazz->script_uni_ranges == NULL)
  86       continue;
  87
  88     /* scan all Unicode points in the range and */
  89     /* set the corresponding glyph script index */
  90     for (range = clazz->script_uni_ranges; range->first != 0; range++)
  91     {
  92       FT_ULong charcode = range->first;
  93       FT_UInt gindex;
  94
  95
  96       gindex = FT_Get_Char_Index(face, charcode);
  97
  98       if (gindex != 0
  99           && gindex < (FT_ULong)globals->glyph_count
 100           && gscripts[gindex] == TA_SCRIPT_NONE)
 101         gscripts[gindex] = (FT_Byte)ss;
 102
 103       for (;;)
 104       {
 105         charcode = FT_Get_Next_Char(face, charcode, &gindex);
 106
 107         if (gindex == 0 || charcode > range->last)
 108           break;
 109
 110         if (gindex < (FT_ULong)globals->glyph_count
 111             && gscripts[gindex] == TA_SCRIPT_NONE)
 112           gscripts[gindex] = (FT_Byte)ss;
 113       }
 114     }
 115   }
 116
 117   /* mark ASCII digits */
 118   for (i = 0x30; i <= 0x39; i++)
 119   {
 120     FT_UInt gindex = FT_Get_Char_Index(face, i);
 121
 122
 123     if (gindex != 0
 124         && gindex < (FT_ULong)globals->glyph_count)
 125       gscripts[gindex] |= TA_DIGIT;
 126   }
 127
 128 Exit:
 129   /* by default, all uncovered glyphs are set to the fallback script */
 130   /* XXX: Shouldn't we disable hinting or do something similar? */
 131   {
 132     FT_Long nn;
 133
 134
 135     for (nn = 0; nn < globals->glyph_count; nn++)
 136     {
 137       if ((gscripts[nn] & ~TA_DIGIT) == TA_SCRIPT_NONE)
 138       {
 139         gscripts[nn] &= ~TA_SCRIPT_NONE;
 140         gscripts[nn] |= fallback_script;
 141       }
 142     }
 143   }
 144
 145   FT_Set_Charmap(face, old_charmap);
 146   return error;
 147 }
 148
 149
 150 FT_Error
 151 ta_face_globals_new(FT_Face face,
 152                     TA_FaceGlobals *aglobals,
 153                     FT_UInt fallback_script)
 154 {
 155   FT_Error error;
 156   TA_FaceGlobals globals;
 157
 158
 159   globals = (TA_FaceGlobals)calloc(1, sizeof (TA_FaceGlobalsRec) +
 160                                       face->num_glyphs * sizeof (FT_Byte));
 161   if (!globals)
 162   {
 163     error = FT_Err_Out_Of_Memory;
 164     goto Err;
 165   }
 166
 167   globals->face = face;
 168   globals->glyph_count = face->num_glyphs;
 169   globals->glyph_scripts = (FT_Byte*)(globals + 1);
 170
 171   error = ta_face_globals_compute_script_coverage(globals, fallback_script);
 172   if (error)
 173   {
 174     ta_face_globals_free(globals);
 175     globals = NULL;
 176   }
 177
 178 Err:
 179   *aglobals = globals;
 180   return error;
 181 }
 182
 183
 184 void
 185 ta_face_globals_free(TA_FaceGlobals globals)
 186 {
 187   if (globals)
 188   {
 189     FT_UInt nn;
 190
 191
 192     for (nn = 0; nn < TA_SCRIPT_MAX; nn++)
 193     {
 194       if (globals->metrics[nn])
 195       {
 196         TA_ScriptClass clazz = ta_script_classes[nn];
 197
 198
 199 #if 0
 200         FT_ASSERT(globals->metrics[nn]->clazz == clazz);
 201 #endif
 202
 203         if (clazz->script_metrics_done)
 204           clazz->script_metrics_done(globals->metrics[nn]);
 205
 206         free(globals->metrics[nn]);
 207         globals->metrics[nn] = NULL;
 208       }
 209     }
 210
 211     globals->glyph_count = 0;
 212     globals->glyph_scripts = NULL; /* no need to free this one! */
 213     globals->face = NULL;
 214
 215     free(globals);
 216     globals = NULL;
 217   }
 218 }
 219
 220
 221 FT_Error
 222 ta_face_globals_get_metrics(TA_FaceGlobals globals,
 223                             FT_UInt gindex,
 224                             FT_UInt options,
 225                             TA_ScriptMetrics *ametrics)
 226 {
 227   TA_ScriptMetrics metrics = NULL;
 228   FT_UInt gidx;
 229   TA_ScriptClass clazz;
 230   FT_UInt script = options & 15;
 231   const FT_Offset script_max = sizeof (ta_script_classes)
 232                                / sizeof (ta_script_classes[0]);
 233   FT_Error error = FT_Err_Ok;
 234
 235
 236   if (gindex >= (FT_ULong)globals->glyph_count)
 237   {
 238     error = FT_Err_Invalid_Argument;
 239     goto Exit;
 240   }
 241
 242   gidx = script;
 243   if (gidx == 0
 244       || gidx + 1 >= script_max)
 245     gidx = globals->glyph_scripts[gindex] & TA_SCRIPT_NONE;
 246
 247   clazz = ta_script_classes[gidx];
 248   if (script == 0)
 249     script = clazz->script;
 250
 251   metrics = globals->metrics[clazz->script];
 252   if (metrics == NULL)
 253   {
 254     /* create the global metrics object if necessary */
 255     metrics = (TA_ScriptMetrics)calloc(1, clazz->script_metrics_size);
 256     if (!metrics)
 257     {
 258       error = FT_Err_Out_Of_Memory;
 259       goto Exit;
 260     }
 261
 262     metrics->clazz = clazz;
 263
 264     if (clazz->script_metrics_init)
 265     {
 266       error = clazz->script_metrics_init(metrics, globals->face);
 267       if (error)
 268       {
 269         if (clazz->script_metrics_done)
 270           clazz->script_metrics_done(metrics);
 271
 272         free(metrics);
 273         metrics = NULL;
 274         goto Exit;
 275       }
 276     }
 277
 278     globals->metrics[clazz->script] = metrics;
 279   }
 280
 281 Exit:
 282   *ametrics = metrics;
 283
 284   return error;
 285 }
 286
 287
 288 FT_Bool
 289 ta_face_globals_is_digit(TA_FaceGlobals globals,
 290                          FT_UInt gindex)
 291 {
 292   if (gindex < (FT_ULong)globals->glyph_count)
 293     return (FT_Bool)(globals->glyph_scripts[gindex] & TA_DIGIT);
 294
 295   return (FT_Bool)0;
 296 }
 297
 298 /* end of taglobal.c */