src/hb-font.cc

   1 /*
   2  * Copyright © 2009  Red Hat, Inc.
   3  * Copyright © 2012  Google, Inc.
   4  *
   5  *  This is part of HarfBuzz, a text shaping library.
   6  *
   7  * Permission is hereby granted, without written agreement and without
   8  * license or royalty fees, to use, copy, modify, and distribute this
   9  * software and its documentation for any purpose, provided that the
  10  * above copyright notice and the following two paragraphs appear in
  11  * all copies of this software.
  12  *
  13  * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
  14  * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
  15  * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
  16  * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
  17  * DAMAGE.
  18  *
  19  * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
  20  * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
  21  * FITNESS FOR A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS
  22  * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
  23  * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
  24  *
  25  * Red Hat Author(s): Behdad Esfahbod
  26  * Google Author(s): Behdad Esfahbod
  27  */
  28
  29 #include "hb-private.hh"
  30
  31 #include "hb-ot-layout-private.hh"
  32
  33 #include "hb-font-private.hh"
  34 #include "hb-blob.h"
  35 #include "hb-open-file-private.hh"
  36 #include "hb-ot-head-table.hh"
  37
  38 #include "hb-cache-private.hh"
  39
  40 #include <string.h>
  41
  42
  43
  44 /*
  45  * hb_font_funcs_t
  46  */
  47
  48 static hb_bool_t
  49 hb_font_get_glyph_nil (hb_font_t *font,
  50                        void *font_data HB_UNUSED,
  51                        hb_codepoint_t unicode,
  52                        hb_codepoint_t variation_selector,
  53                        hb_codepoint_t *glyph,
  54                        void *user_data HB_UNUSED)
  55 {
  56   if (font->parent)
  57     return font->parent->get_glyph (unicode, variation_selector, glyph);
  58
  59   *glyph = 0;
  60   return false;
  61 }
  62
  63 static hb_position_t
  64 hb_font_get_glyph_h_advance_nil (hb_font_t *font,
  65                                  void *font_data HB_UNUSED,
  66                                  hb_codepoint_t glyph,
  67                                  void *user_data HB_UNUSED)
  68 {
  69   if (font->parent)
  70     return font->parent_scale_x_distance (font->parent->get_glyph_h_advance (glyph));
  71
  72   return font->x_scale;
  73 }
  74
  75 static hb_position_t
  76 hb_font_get_glyph_v_advance_nil (hb_font_t *font,
  77                                  void *font_data HB_UNUSED,
  78                                  hb_codepoint_t glyph,
  79                                  void *user_data HB_UNUSED)
  80 {
  81   if (font->parent)
  82     return font->parent_scale_y_distance (font->parent->get_glyph_v_advance (glyph));
  83
  84   return font->y_scale;
  85 }
  86
  87 static hb_bool_t
  88 hb_font_get_glyph_h_origin_nil (hb_font_t *font,
  89                                 void *font_data HB_UNUSED,
  90                                 hb_codepoint_t glyph,
  91                                 hb_position_t *x,
  92                                 hb_position_t *y,
  93                                 void *user_data HB_UNUSED)
  94 {
  95   if (font->parent) {
  96     hb_bool_t ret = font->parent->get_glyph_h_origin (glyph, x, y);
  97     if (ret)
  98       font->parent_scale_position (x, y);
  99     return ret;
 100   }
 101
 102   *x = *y = 0;
 103   return false;
 104 }
 105
 106 static hb_bool_t
 107 hb_font_get_glyph_v_origin_nil (hb_font_t *font,
 108                                 void *font_data HB_UNUSED,
 109                                 hb_codepoint_t glyph,
 110                                 hb_position_t *x,
 111                                 hb_position_t *y,
 112                                 void *user_data HB_UNUSED)
 113 {
 114   if (font->parent) {
 115     hb_bool_t ret = font->parent->get_glyph_v_origin (glyph, x, y);
 116     if (ret)
 117       font->parent_scale_position (x, y);
 118     return ret;
 119   }
 120
 121   *x = *y = 0;
 122   return false;
 123 }
 124
 125 static hb_position_t
 126 hb_font_get_glyph_h_kerning_nil (hb_font_t *font,
 127                                  void *font_data HB_UNUSED,
 128                                  hb_codepoint_t left_glyph,
 129                                  hb_codepoint_t right_glyph,
 130                                  void *user_data HB_UNUSED)
 131 {
 132   if (font->parent)
 133     return font->parent_scale_x_distance (font->parent->get_glyph_h_kerning (left_glyph, right_glyph));
 134
 135   return 0;
 136 }
 137
 138 static hb_position_t
 139 hb_font_get_glyph_v_kerning_nil (hb_font_t *font,
 140                                  void *font_data HB_UNUSED,
 141                                  hb_codepoint_t top_glyph,
 142                                  hb_codepoint_t bottom_glyph,
 143                                  void *user_data HB_UNUSED)
 144 {
 145   if (font->parent)
 146     return font->parent_scale_y_distance (font->parent->get_glyph_v_kerning (top_glyph, bottom_glyph));
 147
 148   return 0;
 149 }
 150
 151 static hb_bool_t
 152 hb_font_get_glyph_extents_nil (hb_font_t *font,
 153                                void *font_data HB_UNUSED,
 154                                hb_codepoint_t glyph,
 155                                hb_glyph_extents_t *extents,
 156                                void *user_data HB_UNUSED)
 157 {
 158   if (font->parent) {
 159     hb_bool_t ret = font->parent->get_glyph_extents (glyph, extents);
 160     if (ret) {
 161       font->parent_scale_position (&extents->x_bearing, &extents->y_bearing);
 162       font->parent_scale_distance (&extents->width, &extents->height);
 163     }
 164     return ret;
 165   }
 166
 167   memset (extents, 0, sizeof (*extents));
 168   return false;
 169 }
 170
 171 static hb_bool_t
 172 hb_font_get_glyph_contour_point_nil (hb_font_t *font,
 173                                      void *font_data HB_UNUSED,
 174                                      hb_codepoint_t glyph,
 175                                      unsigned int point_index,
 176                                      hb_position_t *x,
 177                                      hb_position_t *y,
 178                                      void *user_data HB_UNUSED)
 179 {
 180   if (font->parent) {
 181     hb_bool_t ret = font->parent->get_glyph_contour_point (glyph, point_index, x, y);
 182     if (ret)
 183       font->parent_scale_position (x, y);
 184     return ret;
 185   }
 186
 187   *x = *y = 0;
 188   return false;
 189 }
 190
 191 static hb_bool_t
 192 hb_font_get_glyph_name_nil (hb_font_t *font,
 193                             void *font_data HB_UNUSED,
 194                             hb_codepoint_t glyph,
 195                             char *name, unsigned int size,
 196                             void *user_data HB_UNUSED)
 197 {
 198   if (font->parent)
 199     return font->parent->get_glyph_name (glyph, name, size);
 200
 201   if (size) *name = '\0';
 202   return false;
 203 }
 204
 205 static hb_bool_t
 206 hb_font_get_glyph_from_name_nil (hb_font_t *font,
 207                                  void *font_data HB_UNUSED,
 208                                  const char *name, int len, /* -1 means nul-terminated */
 209                                  hb_codepoint_t *glyph,
 210                                  void *user_data HB_UNUSED)
 211 {
 212   if (font->parent)
 213     return font->parent->get_glyph_from_name (name, len, glyph);
 214
 215   *glyph = 0;
 216   return false;
 217 }
 218
 219
 220 static const hb_font_funcs_t _hb_font_funcs_nil = {
 221   HB_OBJECT_HEADER_STATIC,
 222
 223   true, /* immutable */
 224
 225   {
 226 #define HB_FONT_FUNC_IMPLEMENT(name) hb_font_get_##name##_nil,
 227     HB_FONT_FUNCS_IMPLEMENT_CALLBACKS
 228 #undef HB_FONT_FUNC_IMPLEMENT
 229   }
 230 };
 231
 232
 233 hb_font_funcs_t *
 234 hb_font_funcs_create (void)
 235 {
 236   hb_font_funcs_t *ffuncs;
 237
 238   if (!(ffuncs = hb_object_create<hb_font_funcs_t> ()))
 239     return hb_font_funcs_get_empty ();
 240
 241   ffuncs->get = _hb_font_funcs_nil.get;
 242
 243   return ffuncs;
 244 }
 245
 246 hb_font_funcs_t *
 247 hb_font_funcs_get_empty (void)
 248 {
 249   return const_cast<hb_font_funcs_t *> (&_hb_font_funcs_nil);
 250 }
 251
 252 hb_font_funcs_t *
 253 hb_font_funcs_reference (hb_font_funcs_t *ffuncs)
 254 {
 255   return hb_object_reference (ffuncs);
 256 }
 257
 258 void
 259 hb_font_funcs_destroy (hb_font_funcs_t *ffuncs)
 260 {
 261   if (!hb_object_destroy (ffuncs)) return;
 262
 263 #define HB_FONT_FUNC_IMPLEMENT(name) if (ffuncs->destroy.name) \
 264   ffuncs->destroy.name (ffuncs->user_data.name);
 265   HB_FONT_FUNCS_IMPLEMENT_CALLBACKS
 266 #undef HB_FONT_FUNC_IMPLEMENT
 267
 268   free (ffuncs);
 269 }
 270
 271 hb_bool_t
 272 hb_font_funcs_set_user_data (hb_font_funcs_t    *ffuncs,
 273                              hb_user_data_key_t *key,
 274                              void *              data,
 275                              hb_destroy_func_t   destroy,
 276                              hb_bool_t           replace)
 277 {
 278   return hb_object_set_user_data (ffuncs, key, data, destroy, replace);
 279 }
 280
 281 void *
 282 hb_font_funcs_get_user_data (hb_font_funcs_t    *ffuncs,
 283                              hb_user_data_key_t *key)
 284 {
 285   return hb_object_get_user_data (ffuncs, key);
 286 }
 287
 288
 289 void
 290 hb_font_funcs_make_immutable (hb_font_funcs_t *ffuncs)
 291 {
 292   if (hb_object_is_inert (ffuncs))
 293     return;
 294
 295   ffuncs->immutable = true;
 296 }
 297
 298 hb_bool_t
 299 hb_font_funcs_is_immutable (hb_font_funcs_t *ffuncs)
 300 {
 301   return ffuncs->immutable;
 302 }
 303
 304
 305 #define HB_FONT_FUNC_IMPLEMENT(name) \
 306                                                                          \
 307 void                                                                     \
 308 hb_font_funcs_set_##name##_func (hb_font_funcs_t             *ffuncs,    \
 309                                  hb_font_get_##name##_func_t  func,      \
 310                                  void                        *user_data, \
 311                                  hb_destroy_func_t            destroy)   \
 312 {                                                                        \
 313   if (ffuncs->immutable) {                                               \
 314     if (destroy)                                                         \
 315       destroy (user_data);                                               \
 316     return;                                                              \
 317   }                                                                      \
 318                                                                          \
 319   if (ffuncs->destroy.name)                                              \
 320     ffuncs->destroy.name (ffuncs->user_data.name);                       \
 321                                                                          \
 322   if (func) {                                                            \
 323     ffuncs->get.name = func;                                             \
 324     ffuncs->user_data.name = user_data;                                  \
 325     ffuncs->destroy.name = destroy;                                      \
 326   } else {                                                               \
 327     ffuncs->get.name = hb_font_get_##name##_nil;                         \
 328     ffuncs->user_data.name = NULL;                                       \
 329     ffuncs->destroy.name = NULL;                                         \
 330   }                                                                      \
 331 }
 332
 333 HB_FONT_FUNCS_IMPLEMENT_CALLBACKS
 334 #undef HB_FONT_FUNC_IMPLEMENT
 335
 336
 337 /* Public getters */
 338
 339 hb_bool_t
 340 hb_font_get_glyph (hb_font_t *font,
 341                    hb_codepoint_t unicode, hb_codepoint_t variation_selector,
 342                    hb_codepoint_t *glyph)
 343 {
 344   return font->get_glyph (unicode, variation_selector, glyph);
 345 }
 346
 347 hb_position_t
 348 hb_font_get_glyph_h_advance (hb_font_t *font,
 349                              hb_codepoint_t glyph)
 350 {
 351   return font->get_glyph_h_advance (glyph);
 352 }
 353
 354 hb_position_t
 355 hb_font_get_glyph_v_advance (hb_font_t *font,
 356                              hb_codepoint_t glyph)
 357 {
 358   return font->get_glyph_v_advance (glyph);
 359 }
 360
 361 hb_bool_t
 362 hb_font_get_glyph_h_origin (hb_font_t *font,
 363                             hb_codepoint_t glyph,
 364                             hb_position_t *x, hb_position_t *y)
 365 {
 366   return font->get_glyph_h_origin (glyph, x, y);
 367 }
 368
 369 hb_bool_t
 370 hb_font_get_glyph_v_origin (hb_font_t *font,
 371                             hb_codepoint_t glyph,
 372                             hb_position_t *x, hb_position_t *y)
 373 {
 374   return font->get_glyph_v_origin (glyph, x, y);
 375 }
 376
 377 hb_position_t
 378 hb_font_get_glyph_h_kerning (hb_font_t *font,
 379                              hb_codepoint_t left_glyph, hb_codepoint_t right_glyph)
 380 {
 381   return font->get_glyph_h_kerning (left_glyph, right_glyph);
 382 }
 383
 384 hb_position_t
 385 hb_font_get_glyph_v_kerning (hb_font_t *font,
 386                              hb_codepoint_t left_glyph, hb_codepoint_t right_glyph)
 387 {
 388   return font->get_glyph_v_kerning (left_glyph, right_glyph);
 389 }
 390
 391 hb_bool_t
 392 hb_font_get_glyph_extents (hb_font_t *font,
 393                            hb_codepoint_t glyph,
 394                            hb_glyph_extents_t *extents)
 395 {
 396   return font->get_glyph_extents (glyph, extents);
 397 }
 398
 399 hb_bool_t
 400 hb_font_get_glyph_contour_point (hb_font_t *font,
 401                                  hb_codepoint_t glyph, unsigned int point_index,
 402                                  hb_position_t *x, hb_position_t *y)
 403 {
 404   return font->get_glyph_contour_point (glyph, point_index, x, y);
 405 }
 406
 407 hb_bool_t
 408 hb_font_get_glyph_name (hb_font_t *font,
 409                         hb_codepoint_t glyph,
 410                         char *name, unsigned int size)
 411 {
 412   return font->get_glyph_name (glyph, name, size);
 413 }
 414
 415 hb_bool_t
 416 hb_font_get_glyph_from_name (hb_font_t *font,
 417                              const char *name, int len, /* -1 means nul-terminated */
 418                              hb_codepoint_t *glyph)
 419 {
 420   return font->get_glyph_from_name (name, len, glyph);
 421 }
 422
 423
 424 /* A bit higher-level, and with fallback */
 425
 426 void
 427 hb_font_get_glyph_advance_for_direction (hb_font_t *font,
 428                                          hb_codepoint_t glyph,
 429                                          hb_direction_t direction,
 430                                          hb_position_t *x, hb_position_t *y)
 431 {
 432   return font->get_glyph_advance_for_direction (glyph, direction, x, y);
 433 }
 434
 435 void
 436 hb_font_get_glyph_origin_for_direction (hb_font_t *font,
 437                                         hb_codepoint_t glyph,
 438                                         hb_direction_t direction,
 439                                         hb_position_t *x, hb_position_t *y)
 440 {
 441   return font->get_glyph_origin_for_direction (glyph, direction, x, y);
 442 }
 443
 444 void
 445 hb_font_add_glyph_origin_for_direction (hb_font_t *font,
 446                                         hb_codepoint_t glyph,
 447                                         hb_direction_t direction,
 448                                         hb_position_t *x, hb_position_t *y)
 449 {
 450   return font->add_glyph_origin_for_direction (glyph, direction, x, y);
 451 }
 452
 453 void
 454 hb_font_subtract_glyph_origin_for_direction (hb_font_t *font,
 455                                              hb_codepoint_t glyph,
 456                                              hb_direction_t direction,
 457                                              hb_position_t *x, hb_position_t *y)
 458 {
 459   return font->subtract_glyph_origin_for_direction (glyph, direction, x, y);
 460 }
 461
 462 void
 463 hb_font_get_glyph_kerning_for_direction (hb_font_t *font,
 464                                          hb_codepoint_t first_glyph, hb_codepoint_t second_glyph,
 465                                          hb_direction_t direction,
 466                                          hb_position_t *x, hb_position_t *y)
 467 {
 468   return font->get_glyph_kerning_for_direction (first_glyph, second_glyph, direction, x, y);
 469 }
 470
 471 hb_bool_t
 472 hb_font_get_glyph_extents_for_origin (hb_font_t *font,
 473                                       hb_codepoint_t glyph,
 474                                       hb_direction_t direction,
 475                                       hb_glyph_extents_t *extents)
 476 {
 477   return font->get_glyph_extents_for_origin (glyph, direction, extents);
 478 }
 479
 480 hb_bool_t
 481 hb_font_get_glyph_contour_point_for_origin (hb_font_t *font,
 482                                             hb_codepoint_t glyph, unsigned int point_index,
 483                                             hb_direction_t direction,
 484                                             hb_position_t *x, hb_position_t *y)
 485 {
 486   return font->get_glyph_contour_point_for_origin (glyph, point_index, direction, x, y);
 487 }
 488
 489 /* Generates gidDDD if glyph has no name. */
 490 void
 491 hb_font_glyph_to_string (hb_font_t *font,
 492                          hb_codepoint_t glyph,
 493                          char *s, unsigned int size)
 494 {
 495   font->glyph_to_string (glyph, s, size);
 496 }
 497
 498 /* Parses gidDDD and uniUUUU strings automatically. */
 499 hb_bool_t
 500 hb_font_glyph_from_string (hb_font_t *font,
 501                            const char *s, int len, /* -1 means nul-terminated */
 502                            hb_codepoint_t *glyph)
 503 {
 504   return font->glyph_from_string (s, len, glyph);
 505 }
 506
 507
 508 /*
 509  * hb_face_t
 510  */
 511
 512 static const hb_face_t _hb_face_nil = {
 513   HB_OBJECT_HEADER_STATIC,
 514
 515   true, /* immutable */
 516
 517   NULL, /* reference_table_func */
 518   NULL, /* user_data */
 519   NULL, /* destroy */
 520
 521   0,    /* index */
 522   1000, /* upem */
 523
 524   {
 525 #define HB_SHAPER_IMPLEMENT(shaper) HB_SHAPER_DATA_INVALID,
 526 #include "hb-shaper-list.hh"
 527 #undef HB_SHAPER_IMPLEMENT
 528   },
 529
 530   NULL, /* shape_plans */
 531 };
 532
 533
 534 hb_face_t *
 535 hb_face_create_for_tables (hb_reference_table_func_t  reference_table_func,
 536                            void                      *user_data,
 537                            hb_destroy_func_t          destroy)
 538 {
 539   hb_face_t *face;
 540
 541   if (!reference_table_func || !(face = hb_object_create<hb_face_t> ())) {
 542     if (destroy)
 543       destroy (user_data);
 544     return hb_face_get_empty ();
 545   }
 546
 547   face->reference_table_func = reference_table_func;
 548   face->user_data = user_data;
 549   face->destroy = destroy;
 550
 551   face->upem = 0;
 552
 553   return face;
 554 }
 555
 556
 557 typedef struct hb_face_for_data_closure_t {
 558   hb_blob_t *blob;
 559   unsigned int  index;
 560 } hb_face_for_data_closure_t;
 561
 562 static hb_face_for_data_closure_t *
 563 _hb_face_for_data_closure_create (hb_blob_t *blob, unsigned int index)
 564 {
 565   hb_face_for_data_closure_t *closure;
 566
 567   closure = (hb_face_for_data_closure_t *) malloc (sizeof (hb_face_for_data_closure_t));
 568   if (unlikely (!closure))
 569     return NULL;
 570
 571   closure->blob = blob;
 572   closure->index = index;
 573
 574   return closure;
 575 }
 576
 577 static void
 578 _hb_face_for_data_closure_destroy (hb_face_for_data_closure_t *closure)
 579 {
 580   hb_blob_destroy (closure->blob);
 581   free (closure);
 582 }
 583
 584 static hb_blob_t *
 585 _hb_face_for_data_reference_table (hb_face_t *face HB_UNUSED, hb_tag_t tag, void *user_data)
 586 {
 587   hb_face_for_data_closure_t *data = (hb_face_for_data_closure_t *) user_data;
 588
 589   if (tag == HB_TAG_NONE)
 590     return hb_blob_reference (data->blob);
 591
 592   const OpenTypeFontFile &ot_file = *Sanitizer<OpenTypeFontFile>::lock_instance (data->blob);
 593   const OpenTypeFontFace &ot_face = ot_file.get_face (data->index);
 594
 595   const OpenTypeTable &table = ot_face.get_table_by_tag (tag);
 596
 597   hb_blob_t *blob = hb_blob_create_sub_blob (data->blob, table.offset, table.length);
 598
 599   return blob;
 600 }
 601
 602 hb_face_t *
 603 hb_face_create (hb_blob_t    *blob,
 604                 unsigned int  index)
 605 {
 606   hb_face_t *face;
 607
 608   if (unlikely (!blob || !hb_blob_get_length (blob)))
 609     return hb_face_get_empty ();
 610
 611   hb_face_for_data_closure_t *closure = _hb_face_for_data_closure_create (Sanitizer<OpenTypeFontFile>::sanitize (hb_blob_reference (blob)), index);
 612
 613   if (unlikely (!closure))
 614     return hb_face_get_empty ();
 615
 616   face = hb_face_create_for_tables (_hb_face_for_data_reference_table,
 617                                     closure,
 618                                     (hb_destroy_func_t) _hb_face_for_data_closure_destroy);
 619
 620   hb_face_set_index (face, index);
 621
 622   return face;
 623 }
 624
 625 hb_face_t *
 626 hb_face_get_empty (void)
 627 {
 628   return const_cast<hb_face_t *> (&_hb_face_nil);
 629 }
 630
 631
 632 hb_face_t *
 633 hb_face_reference (hb_face_t *face)
 634 {
 635   return hb_object_reference (face);
 636 }
 637
 638 void
 639 hb_face_destroy (hb_face_t *face)
 640 {
 641   if (!hb_object_destroy (face)) return;
 642
 643   for (hb_face_t::plan_node_t *node = face->shape_plans; node; )
 644   {
 645     hb_face_t::plan_node_t *next = node->next;
 646     hb_shape_plan_destroy (node->shape_plan);
 647     free (node);
 648     node = next;
 649   }
 650
 651 #define HB_SHAPER_IMPLEMENT(shaper) HB_SHAPER_DATA_DESTROY(shaper, face);
 652 #include "hb-shaper-list.hh"
 653 #undef HB_SHAPER_IMPLEMENT
 654
 655   if (face->destroy)
 656     face->destroy (face->user_data);
 657
 658   free (face);
 659 }
 660
 661 hb_bool_t
 662 hb_face_set_user_data (hb_face_t          *face,
 663                        hb_user_data_key_t *key,
 664                        void *              data,
 665                        hb_destroy_func_t   destroy,
 666                        hb_bool_t           replace)
 667 {
 668   return hb_object_set_user_data (face, key, data, destroy, replace);
 669 }
 670
 671 void *
 672 hb_face_get_user_data (hb_face_t          *face,
 673                        hb_user_data_key_t *key)
 674 {
 675   return hb_object_get_user_data (face, key);
 676 }
 677
 678 void
 679 hb_face_make_immutable (hb_face_t *face)
 680 {
 681   if (hb_object_is_inert (face))
 682     return;
 683
 684   face->immutable = true;
 685 }
 686
 687 hb_bool_t
 688 hb_face_is_immutable (hb_face_t *face)
 689 {
 690   return face->immutable;
 691 }
 692
 693
 694 hb_blob_t *
 695 hb_face_reference_table (hb_face_t *face,
 696                          hb_tag_t   tag)
 697 {
 698   return face->reference_table (tag);
 699 }
 700
 701 hb_blob_t *
 702 hb_face_reference_blob (hb_face_t *face)
 703 {
 704   return face->reference_table (HB_TAG_NONE);
 705 }
 706
 707 void
 708 hb_face_set_index (hb_face_t    *face,
 709                    unsigned int  index)
 710 {
 711   if (hb_object_is_inert (face))
 712     return;
 713
 714   face->index = index;
 715 }
 716
 717 unsigned int
 718 hb_face_get_index (hb_face_t    *face)
 719 {
 720   return face->index;
 721 }
 722
 723 void
 724 hb_face_set_upem (hb_face_t    *face,
 725                   unsigned int  upem)
 726 {
 727   if (hb_object_is_inert (face))
 728     return;
 729
 730   face->upem = upem;
 731 }
 732
 733 unsigned int
 734 hb_face_get_upem (hb_face_t *face)
 735 {
 736   return face->get_upem ();
 737 }
 738
 739
 740 void
 741 hb_face_t::load_upem (void) const
 742 {
 743   hb_blob_t *head_blob = Sanitizer<head>::sanitize (reference_table (HB_OT_TAG_head));
 744   const head *head_table = Sanitizer<head>::lock_instance (head_blob);
 745   upem = head_table->get_upem ();
 746   hb_blob_destroy (head_blob);
 747 }
 748
 749
 750 /*
 751  * hb_font_t
 752  */
 753
 754 hb_font_t *
 755 hb_font_create (hb_face_t *face)
 756 {
 757   hb_font_t *font;
 758
 759   if (unlikely (!face))
 760     face = hb_face_get_empty ();
 761   if (unlikely (hb_object_is_inert (face)))
 762     return hb_font_get_empty ();
 763   if (!(font = hb_object_create<hb_font_t> ()))
 764     return hb_font_get_empty ();
 765
 766   hb_face_make_immutable (face);
 767   font->face = hb_face_reference (face);
 768   font->klass = hb_font_funcs_get_empty ();
 769
 770   return font;
 771 }
 772
 773 hb_font_t *
 774 hb_font_create_sub_font (hb_font_t *parent)
 775 {
 776   if (unlikely (!parent))
 777     return hb_font_get_empty ();
 778
 779   hb_font_t *font = hb_font_create (parent->face);
 780
 781   if (unlikely (hb_object_is_inert (font)))
 782     return font;
 783
 784   hb_font_make_immutable (parent);
 785   font->parent = hb_font_reference (parent);
 786
 787   font->x_scale = parent->x_scale;
 788   font->y_scale = parent->y_scale;
 789   font->x_ppem = parent->x_ppem;
 790   font->y_ppem = parent->y_ppem;
 791
 792   return font;
 793 }
 794
 795 hb_font_t *
 796 hb_font_get_empty (void)
 797 {
 798   static const hb_font_t _hb_font_nil = {
 799     HB_OBJECT_HEADER_STATIC,
 800
 801     true, /* immutable */
 802
 803     NULL, /* parent */
 804     const_cast<hb_face_t *> (&_hb_face_nil),
 805
 806     0, /* x_scale */
 807     0, /* y_scale */
 808
 809     0, /* x_ppem */
 810     0, /* y_ppem */
 811
 812     const_cast<hb_font_funcs_t *> (&_hb_font_funcs_nil), /* klass */
 813     NULL, /* user_data */
 814     NULL, /* destroy */
 815
 816     {
 817 #define HB_SHAPER_IMPLEMENT(shaper) HB_SHAPER_DATA_INVALID,
 818 #include "hb-shaper-list.hh"
 819 #undef HB_SHAPER_IMPLEMENT
 820     }
 821   };
 822
 823   return const_cast<hb_font_t *> (&_hb_font_nil);
 824 }
 825
 826 hb_font_t *
 827 hb_font_reference (hb_font_t *font)
 828 {
 829   return hb_object_reference (font);
 830 }
 831
 832 void
 833 hb_font_destroy (hb_font_t *font)
 834 {
 835   if (!hb_object_destroy (font)) return;
 836
 837 #define HB_SHAPER_IMPLEMENT(shaper) HB_SHAPER_DATA_DESTROY(shaper, font);
 838 #include "hb-shaper-list.hh"
 839 #undef HB_SHAPER_IMPLEMENT
 840
 841   if (font->destroy)
 842     font->destroy (font->user_data);
 843
 844   hb_font_destroy (font->parent);
 845   hb_face_destroy (font->face);
 846   hb_font_funcs_destroy (font->klass);
 847
 848   free (font);
 849 }
 850
 851 hb_bool_t
 852 hb_font_set_user_data (hb_font_t          *font,
 853                        hb_user_data_key_t *key,
 854                        void *              data,
 855                        hb_destroy_func_t   destroy,
 856                        hb_bool_t           replace)
 857 {
 858   return hb_object_set_user_data (font, key, data, destroy, replace);
 859 }
 860
 861 void *
 862 hb_font_get_user_data (hb_font_t          *font,
 863                        hb_user_data_key_t *key)
 864 {
 865   return hb_object_get_user_data (font, key);
 866 }
 867
 868 void
 869 hb_font_make_immutable (hb_font_t *font)
 870 {
 871   if (hb_object_is_inert (font))
 872     return;
 873
 874   font->immutable = true;
 875 }
 876
 877 hb_bool_t
 878 hb_font_is_immutable (hb_font_t *font)
 879 {
 880   return font->immutable;
 881 }
 882
 883 hb_font_t *
 884 hb_font_get_parent (hb_font_t *font)
 885 {
 886   return font->parent;
 887 }
 888
 889 hb_face_t *
 890 hb_font_get_face (hb_font_t *font)
 891 {
 892   return font->face;
 893 }
 894
 895
 896 void
 897 hb_font_set_funcs (hb_font_t         *font,
 898                    hb_font_funcs_t   *klass,
 899                    void              *user_data,
 900                    hb_destroy_func_t  destroy)
 901 {
 902   if (font->immutable) {
 903     if (destroy)
 904       destroy (user_data);
 905     return;
 906   }
 907
 908   if (font->destroy)
 909     font->destroy (font->user_data);
 910
 911   if (!klass)
 912     klass = hb_font_funcs_get_empty ();
 913
 914   hb_font_funcs_reference (klass);
 915   hb_font_funcs_destroy (font->klass);
 916   font->klass = klass;
 917   font->user_data = user_data;
 918   font->destroy = destroy;
 919 }
 920
 921 void
 922 hb_font_set_funcs_data (hb_font_t         *font,
 923                         void              *user_data,
 924                         hb_destroy_func_t  destroy)
 925 {
 926   /* Destroy user_data? */
 927   if (font->immutable) {
 928     if (destroy)
 929       destroy (user_data);
 930     return;
 931   }
 932
 933   if (font->destroy)
 934     font->destroy (font->user_data);
 935
 936   font->user_data = user_data;
 937   font->destroy = destroy;
 938 }
 939
 940
 941 void
 942 hb_font_set_scale (hb_font_t *font,
 943                    int x_scale,
 944                    int y_scale)
 945 {
 946   if (font->immutable)
 947     return;
 948
 949   font->x_scale = x_scale;
 950   font->y_scale = y_scale;
 951 }
 952
 953 void
 954 hb_font_get_scale (hb_font_t *font,
 955                    int *x_scale,
 956                    int *y_scale)
 957 {
 958   if (x_scale) *x_scale = font->x_scale;
 959   if (y_scale) *y_scale = font->y_scale;
 960 }
 961
 962 void
 963 hb_font_set_ppem (hb_font_t *font,
 964                   unsigned int x_ppem,
 965                   unsigned int y_ppem)
 966 {
 967   if (font->immutable)
 968     return;
 969
 970   font->x_ppem = x_ppem;
 971   font->y_ppem = y_ppem;
 972 }
 973
 974 void
 975 hb_font_get_ppem (hb_font_t *font,
 976                   unsigned int *x_ppem,
 977                   unsigned int *y_ppem)
 978 {
 979   if (x_ppem) *x_ppem = font->x_ppem;
 980   if (y_ppem) *y_ppem = font->y_ppem;
 981 }