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 {
  57   FT_Error error = FT_Err_Ok;
  58   FT_Face face = globals->face;
  59   FT_CharMap old_charmap = face->charmap;
  60   FT_Byte* gscripts = globals->glyph_scripts;
  61   FT_UInt ss;
  62   FT_UInt i;
  63
  64
  65   /* the value TA_SCRIPT_NONE means `uncovered glyph' */
  66   memset(globals->glyph_scripts, TA_SCRIPT_NONE, globals->glyph_count);
  67
  68   error = FT_Select_Charmap(face, FT_ENCODING_UNICODE);
  69   if (error)
  70   {
  71     /* ignore this error; we simply use the fallback script */
  72     /* XXX: Shouldn't we rather disable hinting? */
  73     error = FT_Err_Ok;
  74     goto Exit;
  75   }
  76
  77   /* scan each script in a Unicode charmap */
  78   for (ss = 0; ta_script_classes[ss]; ss++)
  79   {
  80     TA_ScriptClass clazz = ta_script_classes[ss];
  81     TA_Script_UniRange range;
  82
  83
  84     if (clazz->script_uni_ranges == NULL)
  85       continue;
  86
  87     /* scan all Unicode points in the range and */
  88     /* set the corresponding glyph script index */
  89     for (range = clazz->script_uni_ranges; range->first != 0; range++)
  90     {
  91       FT_ULong charcode = range->first;
  92       FT_UInt gindex;
  93
  94
  95       gindex = FT_Get_Char_Index(face, charcode);
  96
  97       if (gindex != 0
  98           && gindex < (FT_ULong)globals->glyph_count
  99           && gscripts[gindex] == TA_SCRIPT_NONE)
 100         gscripts[gindex] = (FT_Byte)ss;
 101
 102       for (;;)
 103       {
 104         charcode = FT_Get_Next_Char(face, charcode, &gindex);
 105
 106         if (gindex == 0 || charcode > range->last)
 107           break;
 108
 109         if (gindex < (FT_ULong)globals->glyph_count
 110             && gscripts[gindex] == TA_SCRIPT_NONE)
 111           gscripts[gindex] = (FT_Byte)ss;
 112       }
 113     }
 114   }
 115
 116   /* mark ASCII digits */
 117   for (i = 0x30; i <= 0x39; i++)
 118   {
 119     FT_UInt gindex = FT_Get_Char_Index(face, i);
 120
 121
 122     if (gindex != 0
 123         && gindex < (FT_ULong)globals->glyph_count)
 124       gscripts[gindex] |= TA_DIGIT;
 125   }
 126
 127 Exit:
 128   /* by default, all uncovered glyphs are set to the fallback script */
 129   /* XXX: Shouldn't we disable hinting or do something similar? */
 130   if (globals->font->fallback_script != TA_SCRIPT_NONE)
 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] |= globals->font->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                     FONT* font)
 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   globals->font = font;
 171
 172   error = ta_face_globals_compute_script_coverage(globals);
 173   if (error)
 174   {
 175     ta_face_globals_free(globals);
 176     globals = NULL;
 177   }
 178
 179   globals->increase_x_height = TA_PROP_INCREASE_X_HEIGHT_MAX;
 180
 181 Err:
 182   *aglobals = globals;
 183   return error;
 184 }
 185
 186
 187 void
 188 ta_face_globals_free(TA_FaceGlobals globals)
 189 {
 190   if (globals)
 191   {
 192     FT_UInt nn;
 193
 194
 195     for (nn = 0; nn < TA_SCRIPT_MAX; nn++)
 196     {
 197       if (globals->metrics[nn])
 198       {
 199         TA_ScriptClass clazz = ta_script_classes[nn];
 200
 201
 202 #if 0
 203         FT_ASSERT(globals->metrics[nn]->clazz == clazz);
 204 #endif
 205
 206         if (clazz->script_metrics_done)
 207           clazz->script_metrics_done(globals->metrics[nn]);
 208
 209         free(globals->metrics[nn]);
 210         globals->metrics[nn] = NULL;
 211       }
 212     }
 213
 214     globals->glyph_count = 0;
 215     globals->glyph_scripts = NULL; /* no need to free this one! */
 216     globals->face = NULL;
 217
 218     free(globals);
 219     globals = NULL;
 220   }
 221 }
 222
 223
 224 FT_Error
 225 ta_face_globals_get_metrics(TA_FaceGlobals globals,
 226                             FT_UInt gindex,
 227                             FT_UInt options,
 228                             TA_ScriptMetrics *ametrics)
 229 {
 230   TA_ScriptMetrics metrics = NULL;
 231   FT_UInt gidx;
 232   TA_ScriptClass clazz;
 233   FT_UInt script = options & 15;
 234   const FT_Offset script_max = sizeof (ta_script_classes)
 235                                / sizeof (ta_script_classes[0]);
 236   FT_Error error = FT_Err_Ok;
 237
 238
 239   if (gindex >= (FT_ULong)globals->glyph_count)
 240   {
 241     error = FT_Err_Invalid_Argument;
 242     goto Exit;
 243   }
 244
 245   gidx = script;
 246   if (gidx == 0
 247       || gidx + 1 >= script_max)
 248     gidx = globals->glyph_scripts[gindex] & TA_SCRIPT_NONE;
 249
 250   clazz = ta_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 if necessary */
 258     metrics = (TA_ScriptMetrics)calloc(1, clazz->script_metrics_size);
 259     if (!metrics)
 260     {
 261       error = FT_Err_Out_Of_Memory;
 262       goto Exit;
 263     }
 264
 265     metrics->clazz = clazz;
 266     metrics->globals = globals;
 267
 268     if (clazz->script_metrics_init)
 269     {
 270       error = clazz->script_metrics_init(metrics, globals->face);
 271       if (error)
 272       {
 273         if (clazz->script_metrics_done)
 274           clazz->script_metrics_done(metrics);
 275
 276         free(metrics);
 277         metrics = NULL;
 278         goto Exit;
 279       }
 280     }
 281
 282     globals->metrics[clazz->script] = metrics;
 283   }
 284
 285 Exit:
 286   *ametrics = metrics;
 287
 288   return error;
 289 }
 290
 291
 292 FT_Bool
 293 ta_face_globals_is_digit(TA_FaceGlobals globals,
 294                          FT_UInt gindex)
 295 {
 296   if (gindex < (FT_ULong)globals->glyph_count)
 297     return (FT_Bool)(globals->glyph_scripts[gindex] & TA_DIGIT);
 298
 299   return (FT_Bool)0;
 300 }
 301
 302 /* end of taglobal.c */