lib/taglobal.c

   1 /* taglobal.c */
   2
   3 /*
   4  * Copyright (C) 2011-2014 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 #include "taranges.h"
  24 #include "taharfbuzz.h"
  25
  26
  27 #undef SCRIPT
  28 #define SCRIPT(s, S, d, h, sc1, sc2, sc3) \
  29           const TA_ScriptClassRec ta_ ## s ## _script_class = \
  30           { \
  31             TA_SCRIPT_ ## S, \
  32             ta_ ## s ## _uniranges, \
  33             sc1, sc2, sc3 \
  34           };
  35
  36 #include <ttfautohint-scripts.h>
  37
  38
  39 #undef STYLE
  40 #define STYLE(s, S, d, ws, sc, ss, c) \
  41           const TA_StyleClassRec ta_ ## s ## _style_class = \
  42           { \
  43             TA_STYLE_ ## S, \
  44             ws, \
  45             sc, \
  46             ss, \
  47             c \
  48           };
  49
  50 #include "tastyles.h"
  51
  52
  53 /* get writing system specific header files */
  54 #undef WRITING_SYSTEM
  55 #define WRITING_SYSTEM(ws, WS) /* empty */
  56 #include "tawrtsys.h"
  57
  58
  59 #undef WRITING_SYSTEM
  60 #define WRITING_SYSTEM(ws, WS) \
  61           &ta_ ## ws ## _writing_system_class,
  62
  63 TA_WritingSystemClass const ta_writing_system_classes[] =
  64 {
  65
  66 #include "tawrtsys.h"
  67
  68   NULL /* do not remove */
  69 };
  70
  71
  72 #undef SCRIPT
  73 #define SCRIPT(s, S, d, h, sc1, sc2, sc3) \
  74           &ta_ ## s ## _script_class,
  75
  76 TA_ScriptClass const ta_script_classes[] =
  77 {
  78
  79 #include <ttfautohint-scripts.h>
  80
  81   NULL /* do not remove */
  82 };
  83
  84
  85 #undef STYLE
  86 #define STYLE(s, S, d, ws, sc, ss, c) \
  87           &ta_ ## s ## _style_class,
  88
  89 TA_StyleClass const ta_style_classes[] =
  90 {
  91
  92 #include "tastyles.h"
  93
  94   NULL /* do not remove */
  95 };
  96
  97
  98 #ifdef TA_DEBUG
  99
 100 #undef STYLE
 101 #define STYLE(s, S, d, ws, sc, ss, c) #s,
 102
 103 const char* ta_style_names[] =
 104 {
 105
 106 #include <tastyles.h>
 107
 108 };
 109
 110 #endif /* TA_DEBUG */
 111
 112
 113 /* Recursively assign a style to all components of a composite glyph. */
 114
 115 static FT_Error
 116 ta_face_globals_scan_composite(FT_Face face,
 117                                FT_Long gindex,
 118                                FT_Byte gstyle,
 119                                FT_Byte* gstyles,
 120                                FT_Int nesting_level)
 121 {
 122   FT_Error error;
 123   FT_UInt i;
 124
 125   FT_GlyphSlot glyph;
 126
 127   FT_Int* subglyph_indices = NULL;
 128   FT_UInt used_subglyphs;
 129
 130   FT_Int p_index;
 131   FT_UInt p_flags;
 132   FT_Int p_arg1;
 133   FT_Int p_arg2;
 134   FT_Matrix p_transform;
 135
 136
 137   /* limit recursion arbitrarily */
 138   if (nesting_level > 100)
 139     return FT_Err_Invalid_Table;
 140
 141   error = FT_Load_Glyph(face, gindex, FT_LOAD_NO_RECURSE);
 142   if (error)
 143     return error;
 144
 145   glyph = face->glyph;
 146
 147   /* in FreeType < 2.5.4, FT_Get_SubGlyph_Info always returns an error */
 148   /* due to a bug even if the call was successful; */
 149   /* for this reason we do the argument checking by ourselves */
 150   /* and ignore the returned error code of FT_Get_SubGlyph_Info */
 151   if (!glyph->subglyphs
 152       || glyph->format != FT_GLYPH_FORMAT_COMPOSITE)
 153     return FT_Err_Ok;
 154
 155   /* since a call to FT_Load_Glyph changes `glyph', */
 156   /* we have to first store the subglyph indices, then do the recursion */
 157   subglyph_indices = (FT_Int*)malloc(sizeof (FT_Int) * glyph->num_subglyphs);
 158   if (!subglyph_indices)
 159     return FT_Err_Out_Of_Memory;
 160
 161   used_subglyphs = 0;
 162   for (i = 0; i < glyph->num_subglyphs; i++)
 163   {
 164     (void)FT_Get_SubGlyph_Info(glyph,
 165                                i,
 166                                &p_index,
 167                                &p_flags,
 168                                &p_arg1,
 169                                &p_arg2,
 170                                &p_transform);
 171
 172     if (p_index >= face->num_glyphs
 173         || (gstyles[p_index] & ~TA_DIGIT) != TA_STYLE_UNASSIGNED)
 174       continue;
 175
 176     /* only take subglyphs that are not shifted vertically; */
 177     /* otherwise blue zones don't fit */
 178     if (p_flags & ARGS_ARE_XY_VALUES
 179         && p_arg2 == 0)
 180     {
 181       gstyles[p_index] = gstyle;
 182       subglyph_indices[used_subglyphs++] = p_index;
 183     }
 184   }
 185
 186   /* recurse */
 187   for (i = 0; i < used_subglyphs; i++)
 188   {
 189     error = ta_face_globals_scan_composite(face,
 190                                            subglyph_indices[i],
 191                                            gstyle,
 192                                            gstyles,
 193                                            nesting_level + 1);
 194     if (error)
 195       break;
 196   }
 197
 198   free(subglyph_indices);
 199
 200   return error;
 201 }
 202
 203
 204 /* Compute the style index of each glyph within a given face. */
 205
 206 static FT_Error
 207 ta_face_globals_compute_style_coverage(TA_FaceGlobals globals)
 208 {
 209   FT_Error error;
 210   FT_Face face = globals->face;
 211   FT_CharMap old_charmap = face->charmap;
 212   FT_Byte* gstyles = globals->glyph_styles;
 213   FT_UInt ss;
 214   FT_UInt i;
 215   FT_UInt dflt = -1;
 216
 217
 218   /* the value TA_STYLE_UNASSIGNED means `uncovered glyph' */
 219   memset(globals->glyph_styles, TA_STYLE_UNASSIGNED, globals->glyph_count);
 220
 221   error = FT_Select_Charmap(face, FT_ENCODING_UNICODE);
 222   if (error)
 223   {
 224     /* ignore this error; we simply use the fallback style */
 225     /* XXX: Shouldn't we rather disable hinting? */
 226     error = FT_Err_Ok;
 227     goto Exit;
 228   }
 229
 230   /* scan each style in a Unicode charmap */
 231   for (ss = 0; ta_style_classes[ss]; ss++)
 232   {
 233     TA_StyleClass style_class = ta_style_classes[ss];
 234     TA_ScriptClass script_class = ta_script_classes[style_class->script];
 235     TA_Script_UniRange range;
 236
 237
 238     if (script_class->script_uni_ranges == NULL)
 239       continue;
 240
 241     /* scan all Unicode points in the range and */
 242     /* set the corresponding glyph style index */
 243     if (style_class->coverage == TA_COVERAGE_DEFAULT)
 244     {
 245       if (style_class->script == globals->font->default_script)
 246         dflt = ss;
 247
 248       for (range = script_class->script_uni_ranges; range->first != 0; range++)
 249       {
 250         FT_ULong charcode = range->first;
 251         FT_UInt gindex;
 252
 253
 254         gindex = FT_Get_Char_Index(face, charcode);
 255
 256         if (gindex != 0
 257             && gindex < (FT_ULong)globals->glyph_count
 258             && gstyles[gindex] == TA_STYLE_UNASSIGNED)
 259           gstyles[gindex] = (FT_Byte)ss;
 260
 261         for (;;)
 262         {
 263           charcode = FT_Get_Next_Char(face, charcode, &gindex);
 264
 265           if (gindex == 0 || charcode > range->last)
 266             break;
 267
 268           if (gindex < (FT_ULong)globals->glyph_count
 269               && gstyles[gindex] == TA_STYLE_UNASSIGNED)
 270             gstyles[gindex] = (FT_Byte)ss;
 271         }
 272       }
 273     }
 274     else
 275     {
 276       /* get glyphs not directly addressable by cmap */
 277       ta_get_coverage(globals, style_class, gstyles);
 278     }
 279   }
 280
 281   /* handle the default OpenType features of the default script ... */
 282   ta_get_coverage(globals, ta_style_classes[dflt], gstyles);
 283
 284   /* ... and the remaining default OpenType features */
 285   for (ss = 0; ta_style_classes[ss]; ss++)
 286   {
 287     TA_StyleClass  style_class = ta_style_classes[ss];
 288
 289
 290     if (ss != dflt && style_class->coverage == TA_COVERAGE_DEFAULT)
 291       ta_get_coverage(globals, style_class, gstyles);
 292   }
 293
 294   /* mark ASCII digits */
 295   for (i = 0x30; i <= 0x39; i++)
 296   {
 297     FT_UInt gindex = FT_Get_Char_Index(face, i);
 298
 299
 300     if (gindex != 0
 301         && gindex < (FT_ULong)globals->glyph_count)
 302       gstyles[gindex] |= TA_DIGIT;
 303   }
 304
 305   /* now walk over all glyphs and check for composites: */
 306   /* since subglyphs are hinted separately if option `hint-composites' */
 307   /* isn't set, we have to tag them with style indices, too */
 308   {
 309     FT_Long nn;
 310
 311
 312     for (nn = 0; nn < globals->glyph_count; nn++)
 313     {
 314       if ((gstyles[nn] & ~TA_DIGIT) == TA_STYLE_UNASSIGNED)
 315         continue;
 316
 317       error = ta_face_globals_scan_composite(globals->face,
 318                                              nn,
 319                                              gstyles[nn],
 320                                              gstyles,
 321                                              0);
 322       if (error)
 323         return error;
 324     }
 325   }
 326
 327 Exit:
 328   /* by default, all uncovered glyphs are set to the fallback style */
 329   /* XXX: Shouldn't we disable hinting or do something similar? */
 330   if (globals->font->fallback_style != TA_STYLE_UNASSIGNED)
 331   {
 332     FT_Long nn;
 333
 334
 335     for (nn = 0; nn < globals->glyph_count; nn++)
 336     {
 337       if ((gstyles[nn] & ~TA_DIGIT) == TA_STYLE_UNASSIGNED)
 338       {
 339         gstyles[nn] &= ~TA_STYLE_UNASSIGNED;
 340         gstyles[nn] |= globals->font->fallback_style;
 341       }
 342     }
 343   }
 344
 345 #ifdef TA_DEBUG
 346
 347   if (face->num_faces > 1)
 348     TA_LOG_GLOBAL(("\n"
 349                    "style coverage (subfont %d, glyf table index %d)\n"
 350                    "================================================\n"
 351                    "\n",
 352                    face->face_index,
 353                    globals->font->sfnts[face->face_index].glyf_idx));
 354   else
 355     TA_LOG_GLOBAL(("\n"
 356                    "style coverage\n"
 357                    "==============\n"
 358                    "\n"));
 359
 360   for (ss = 0; ta_style_classes[ss]; ss++)
 361   {
 362     TA_StyleClass style_class = ta_style_classes[ss];
 363     FT_UInt count = 0;
 364     FT_Long idx;
 365
 366
 367     TA_LOG_GLOBAL(("%s:\n", ta_style_names[style_class->style]));
 368
 369     for (idx = 0; idx < globals->glyph_count; idx++)
 370     {
 371       if ((gstyles[idx] & ~TA_DIGIT) == style_class->style)
 372       {
 373         if (!(count % 10))
 374           TA_LOG_GLOBAL((" "));
 375
 376         TA_LOG_GLOBAL((" %d", idx));
 377         count++;
 378
 379         if (!(count % 10))
 380           TA_LOG_GLOBAL(("\n"));
 381       }
 382     }
 383
 384     if (!count)
 385       TA_LOG_GLOBAL(("  (none)\n"));
 386     if (count % 10)
 387       TA_LOG_GLOBAL(("\n"));
 388   }
 389
 390 #endif /* TA_DEBUG */
 391
 392   FT_Set_Charmap(face, old_charmap);
 393   return error;
 394 }
 395
 396
 397 FT_Error
 398 ta_face_globals_new(FT_Face face,
 399                     TA_FaceGlobals *aglobals,
 400                     FONT* font)
 401 {
 402   FT_Error error;
 403   TA_FaceGlobals globals;
 404
 405
 406   globals = (TA_FaceGlobals)calloc(1, sizeof (TA_FaceGlobalsRec) +
 407                                       face->num_glyphs * sizeof (FT_Byte));
 408   if (!globals)
 409   {
 410     error = FT_Err_Out_Of_Memory;
 411     goto Err;
 412   }
 413
 414   globals->face = face;
 415   globals->glyph_count = face->num_glyphs;
 416   globals->glyph_styles = (FT_Byte*)(globals + 1);
 417   globals->font = font;
 418   globals->hb_font = hb_ft_font_create(face, NULL);
 419
 420   error = ta_face_globals_compute_style_coverage(globals);
 421   if (error)
 422   {
 423     ta_face_globals_free(globals);
 424     globals = NULL;
 425   }
 426   else
 427     globals->increase_x_height = TA_PROP_INCREASE_X_HEIGHT_MAX;
 428
 429 Err:
 430   *aglobals = globals;
 431   return error;
 432 }
 433
 434
 435 void
 436 ta_face_globals_free(TA_FaceGlobals globals)
 437 {
 438   if (globals)
 439   {
 440     FT_UInt nn;
 441
 442
 443     for (nn = 0; nn < TA_STYLE_MAX; nn++)
 444     {
 445       if (globals->metrics[nn])
 446       {
 447         TA_StyleClass style_class =
 448           ta_style_classes[nn];
 449         TA_WritingSystemClass writing_system_class =
 450           ta_writing_system_classes[style_class->writing_system];
 451
 452
 453         if (writing_system_class->style_metrics_done)
 454           writing_system_class->style_metrics_done(globals->metrics[nn]);
 455
 456         free(globals->metrics[nn]);
 457         globals->metrics[nn] = NULL;
 458       }
 459     }
 460
 461     hb_font_destroy(globals->hb_font);
 462
 463     globals->hb_font = NULL;
 464     globals->glyph_count = 0;
 465     globals->glyph_styles = NULL; /* no need to free this one! */
 466     globals->face = NULL;
 467
 468     free(globals);
 469     globals = NULL;
 470   }
 471 }
 472
 473
 474 FT_Error
 475 ta_face_globals_get_metrics(TA_FaceGlobals globals,
 476                             FT_UInt gindex,
 477                             FT_UInt options,
 478                             TA_StyleMetrics *ametrics)
 479 {
 480   TA_StyleMetrics metrics = NULL;
 481   TA_Style style = (TA_Style)options;
 482   TA_WritingSystemClass writing_system_class;
 483   TA_StyleClass style_class;
 484   FT_Error error = FT_Err_Ok;
 485
 486
 487   if (gindex >= (FT_ULong)globals->glyph_count)
 488   {
 489     error = FT_Err_Invalid_Argument;
 490     goto Exit;
 491   }
 492
 493   /* if we have a forced style (via `options'), use it, */
 494   /* otherwise look into `glyph_styles' array */
 495   if (style == TA_STYLE_NONE_DFLT || style + 1 >= TA_STYLE_MAX)
 496     style = (TA_Style)(globals->glyph_styles[gindex]
 497                        & TA_STYLE_UNASSIGNED);
 498
 499   style_class =
 500     ta_style_classes[style];
 501   writing_system_class =
 502     ta_writing_system_classes[style_class->writing_system];
 503
 504   metrics = globals->metrics[style];
 505   if (metrics == NULL)
 506   {
 507     /* create the global metrics object if necessary */
 508     metrics = (TA_StyleMetrics)
 509                 calloc(1, writing_system_class->style_metrics_size);
 510     if (!metrics)
 511     {
 512       error = FT_Err_Out_Of_Memory;
 513       goto Exit;
 514     }
 515
 516     metrics->style_class = style_class;
 517     metrics->globals = globals;
 518
 519     if (writing_system_class->style_metrics_init)
 520     {
 521       error = writing_system_class->style_metrics_init(metrics,
 522                                                        globals->face);
 523       if (error)
 524       {
 525         if (writing_system_class->style_metrics_done)
 526           writing_system_class->style_metrics_done(metrics);
 527
 528         free(metrics);
 529         metrics = NULL;
 530         goto Exit;
 531       }
 532     }
 533
 534     globals->metrics[style] = metrics;
 535   }
 536
 537 Exit:
 538   *ametrics = metrics;
 539
 540   return error;
 541 }
 542
 543
 544 FT_Bool
 545 ta_face_globals_is_digit(TA_FaceGlobals globals,
 546                          FT_UInt gindex)
 547 {
 548   if (gindex < (FT_ULong)globals->glyph_count)
 549     return (FT_Bool)(globals->glyph_styles[gindex] & TA_DIGIT);
 550
 551   return (FT_Bool)0;
 552 }
 553
 554 /* end of taglobal.c */