src/hb-font-private.hh

   1 /*
   2  * Copyright © 2009  Red Hat, Inc.
   3  * Copyright © 2011  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 #ifndef HB_FONT_PRIVATE_HH
  30 #define HB_FONT_PRIVATE_HH
  31
  32 #include "hb-private.hh"
  33
  34 #include "hb-object-private.hh"
  35 #include "hb-face-private.hh"
  36 #include "hb-shaper-private.hh"
  37
  38
  39
  40 /*
  41  * hb_font_funcs_t
  42  */
  43
  44 #define HB_FONT_FUNCS_IMPLEMENT_CALLBACKS \
  45   HB_FONT_FUNC_IMPLEMENT (font_h_extents) \
  46   HB_FONT_FUNC_IMPLEMENT (font_v_extents) \
  47   HB_FONT_FUNC_IMPLEMENT (nominal_glyph) \
  48   HB_FONT_FUNC_IMPLEMENT (variation_glyph) \
  49   HB_FONT_FUNC_IMPLEMENT (glyph_h_advance) \
  50   HB_FONT_FUNC_IMPLEMENT (glyph_v_advance) \
  51   HB_FONT_FUNC_IMPLEMENT (glyph_h_origin) \
  52   HB_FONT_FUNC_IMPLEMENT (glyph_v_origin) \
  53   HB_FONT_FUNC_IMPLEMENT (glyph_h_kerning) \
  54   HB_FONT_FUNC_IMPLEMENT (glyph_v_kerning) \
  55   HB_FONT_FUNC_IMPLEMENT (glyph_extents) \
  56   HB_FONT_FUNC_IMPLEMENT (glyph_contour_point) \
  57   HB_FONT_FUNC_IMPLEMENT (glyph_name) \
  58   HB_FONT_FUNC_IMPLEMENT (glyph_from_name) \
  59   /* ^--- Add new callbacks here */
  60
  61 struct hb_font_funcs_t {
  62   hb_object_header_t header;
  63   ASSERT_POD ();
  64
  65   hb_bool_t immutable;
  66
  67   struct {
  68 #define HB_FONT_FUNC_IMPLEMENT(name) void *name;
  69     HB_FONT_FUNCS_IMPLEMENT_CALLBACKS
  70 #undef HB_FONT_FUNC_IMPLEMENT
  71   } user_data;
  72
  73   struct {
  74 #define HB_FONT_FUNC_IMPLEMENT(name) hb_destroy_func_t name;
  75     HB_FONT_FUNCS_IMPLEMENT_CALLBACKS
  76 #undef HB_FONT_FUNC_IMPLEMENT
  77   } destroy;
  78
  79   /* Don't access these directly.  Call font->get_*() instead. */
  80   union get_t {
  81     struct get_funcs_t {
  82 #define HB_FONT_FUNC_IMPLEMENT(name) hb_font_get_##name##_func_t name;
  83       HB_FONT_FUNCS_IMPLEMENT_CALLBACKS
  84 #undef HB_FONT_FUNC_IMPLEMENT
  85     } f;
  86     void (*array[VAR]) (void);
  87   } get;
  88 };
  89
  90
  91
  92 /*
  93  * hb_font_t
  94  */
  95
  96 struct hb_font_t {
  97   hb_object_header_t header;
  98   ASSERT_POD ();
  99
 100   hb_bool_t immutable;
 101
 102   hb_font_t *parent;
 103   hb_face_t *face;
 104
 105   int x_scale;
 106   int y_scale;
 107
 108   unsigned int x_ppem;
 109   unsigned int y_ppem;
 110
 111   hb_font_funcs_t   *klass;
 112   void              *user_data;
 113   hb_destroy_func_t  destroy;
 114
 115   struct hb_shaper_data_t shaper_data;
 116
 117
 118   /* Convert from font-space to user-space */
 119   inline hb_position_t em_scale_x (int16_t v) { return em_scale (v, this->x_scale); }
 120   inline hb_position_t em_scale_y (int16_t v) { return em_scale (v, this->y_scale); }
 121
 122   /* Convert from parent-font user-space to our user-space */
 123   inline hb_position_t parent_scale_x_distance (hb_position_t v) {
 124     if (unlikely (parent && parent->x_scale != x_scale))
 125       return (hb_position_t) (v * (int64_t) this->x_scale / this->parent->x_scale);
 126     return v;
 127   }
 128   inline hb_position_t parent_scale_y_distance (hb_position_t v) {
 129     if (unlikely (parent && parent->y_scale != y_scale))
 130       return (hb_position_t) (v * (int64_t) this->y_scale / this->parent->y_scale);
 131     return v;
 132   }
 133   inline hb_position_t parent_scale_x_position (hb_position_t v) {
 134     return parent_scale_x_distance (v);
 135   }
 136   inline hb_position_t parent_scale_y_position (hb_position_t v) {
 137     return parent_scale_y_distance (v);
 138   }
 139
 140   inline void parent_scale_distance (hb_position_t *x, hb_position_t *y) {
 141     *x = parent_scale_x_distance (*x);
 142     *y = parent_scale_y_distance (*y);
 143   }
 144   inline void parent_scale_position (hb_position_t *x, hb_position_t *y) {
 145     *x = parent_scale_x_position (*x);
 146     *y = parent_scale_y_position (*y);
 147   }
 148
 149
 150   /* Public getters */
 151
 152   HB_INTERNAL bool has_func (unsigned int i);
 153
 154   /* has_* ... */
 155 #define HB_FONT_FUNC_IMPLEMENT(name) \
 156   bool \
 157   has_##name##_func (void) \
 158   { \
 159     hb_font_funcs_t *funcs = this->klass; \
 160     unsigned int i = offsetof (hb_font_funcs_t::get_t::get_funcs_t, name) / sizeof (funcs->get.array[0]); \
 161     return has_func (i); \
 162   }
 163   HB_FONT_FUNCS_IMPLEMENT_CALLBACKS
 164 #undef HB_FONT_FUNC_IMPLEMENT
 165
 166   inline hb_bool_t get_font_h_extents (hb_font_extents_t *extents)
 167   {
 168     memset (extents, 0, sizeof (*extents));
 169     return klass->get.f.font_h_extents (this, user_data,
 170                                         extents,
 171                                         klass->user_data.font_h_extents);
 172   }
 173   inline hb_bool_t get_font_v_extents (hb_font_extents_t *extents)
 174   {
 175     memset (extents, 0, sizeof (*extents));
 176     return klass->get.f.font_v_extents (this, user_data,
 177                                         extents,
 178                                         klass->user_data.font_v_extents);
 179   }
 180
 181   inline bool has_glyph (hb_codepoint_t unicode)
 182   {
 183     hb_codepoint_t glyph;
 184     return get_nominal_glyph (unicode, &glyph);
 185   }
 186
 187   inline hb_bool_t get_nominal_glyph (hb_codepoint_t unicode,
 188                                       hb_codepoint_t *glyph)
 189   {
 190     *glyph = 0;
 191     return klass->get.f.nominal_glyph (this, user_data,
 192                                        unicode, glyph,
 193                                        klass->user_data.nominal_glyph);
 194   }
 195
 196   inline hb_bool_t get_variation_glyph (hb_codepoint_t unicode, hb_codepoint_t variation_selector,
 197                                         hb_codepoint_t *glyph)
 198   {
 199     *glyph = 0;
 200     return klass->get.f.variation_glyph (this, user_data,
 201                                          unicode, variation_selector, glyph,
 202                                          klass->user_data.variation_glyph);
 203   }
 204
 205   inline hb_position_t get_glyph_h_advance (hb_codepoint_t glyph)
 206   {
 207     return klass->get.f.glyph_h_advance (this, user_data,
 208                                          glyph,
 209                                          klass->user_data.glyph_h_advance);
 210   }
 211
 212   inline hb_position_t get_glyph_v_advance (hb_codepoint_t glyph)
 213   {
 214     return klass->get.f.glyph_v_advance (this, user_data,
 215                                          glyph,
 216                                          klass->user_data.glyph_v_advance);
 217   }
 218
 219   inline hb_bool_t get_glyph_h_origin (hb_codepoint_t glyph,
 220                                        hb_position_t *x, hb_position_t *y)
 221   {
 222     *x = *y = 0;
 223     return klass->get.f.glyph_h_origin (this, user_data,
 224                                         glyph, x, y,
 225                                         klass->user_data.glyph_h_origin);
 226   }
 227
 228   inline hb_bool_t get_glyph_v_origin (hb_codepoint_t glyph,
 229                                        hb_position_t *x, hb_position_t *y)
 230   {
 231     *x = *y = 0;
 232     return klass->get.f.glyph_v_origin (this, user_data,
 233                                         glyph, x, y,
 234                                         klass->user_data.glyph_v_origin);
 235   }
 236
 237   inline hb_position_t get_glyph_h_kerning (hb_codepoint_t left_glyph, hb_codepoint_t right_glyph)
 238   {
 239     return klass->get.f.glyph_h_kerning (this, user_data,
 240                                          left_glyph, right_glyph,
 241                                          klass->user_data.glyph_h_kerning);
 242   }
 243
 244   inline hb_position_t get_glyph_v_kerning (hb_codepoint_t top_glyph, hb_codepoint_t bottom_glyph)
 245   {
 246     return klass->get.f.glyph_v_kerning (this, user_data,
 247                                          top_glyph, bottom_glyph,
 248                                          klass->user_data.glyph_v_kerning);
 249   }
 250
 251   inline hb_bool_t get_glyph_extents (hb_codepoint_t glyph,
 252                                       hb_glyph_extents_t *extents)
 253   {
 254     memset (extents, 0, sizeof (*extents));
 255     return klass->get.f.glyph_extents (this, user_data,
 256                                        glyph,
 257                                        extents,
 258                                        klass->user_data.glyph_extents);
 259   }
 260
 261   inline hb_bool_t get_glyph_contour_point (hb_codepoint_t glyph, unsigned int point_index,
 262                                             hb_position_t *x, hb_position_t *y)
 263   {
 264     *x = *y = 0;
 265     return klass->get.f.glyph_contour_point (this, user_data,
 266                                              glyph, point_index,
 267                                              x, y,
 268                                              klass->user_data.glyph_contour_point);
 269   }
 270
 271   inline hb_bool_t get_glyph_name (hb_codepoint_t glyph,
 272                                    char *name, unsigned int size)
 273   {
 274     if (size) *name = '\0';
 275     return klass->get.f.glyph_name (this, user_data,
 276                                     glyph,
 277                                     name, size,
 278                                     klass->user_data.glyph_name);
 279   }
 280
 281   inline hb_bool_t get_glyph_from_name (const char *name, int len, /* -1 means nul-terminated */
 282                                         hb_codepoint_t *glyph)
 283   {
 284     *glyph = 0;
 285     if (len == -1) len = strlen (name);
 286     return klass->get.f.glyph_from_name (this, user_data,
 287                                          name, len,
 288                                          glyph,
 289                                          klass->user_data.glyph_from_name);
 290   }
 291
 292
 293   /* A bit higher-level, and with fallback */
 294
 295   inline void get_extents_for_direction (hb_direction_t direction,
 296                                          hb_font_extents_t *extents)
 297   {
 298     if (likely (HB_DIRECTION_IS_HORIZONTAL (direction))) {
 299       if (!get_font_h_extents (extents))
 300       {
 301         extents->ascender = y_scale * .8;
 302         extents->descender = y_scale - extents->ascender;
 303         extents->line_gap = 0;
 304       }
 305     } else {
 306       if (!get_font_v_extents (extents))
 307       {
 308         extents->ascender = x_scale / 2;
 309         extents->descender = x_scale - extents->ascender;
 310         extents->line_gap = 0;
 311       }
 312     }
 313   }
 314
 315   inline void get_glyph_advance_for_direction (hb_codepoint_t glyph,
 316                                                hb_direction_t direction,
 317                                                hb_position_t *x, hb_position_t *y)
 318   {
 319     if (likely (HB_DIRECTION_IS_HORIZONTAL (direction))) {
 320       *x = get_glyph_h_advance (glyph);
 321       *y = 0;
 322     } else {
 323       *x = 0;
 324       *y = get_glyph_v_advance (glyph);
 325     }
 326   }
 327
 328   /* Internal only */
 329   inline void guess_v_origin_minus_h_origin (hb_codepoint_t glyph,
 330                                              hb_position_t *x, hb_position_t *y)
 331   {
 332     *x = get_glyph_h_advance (glyph) / 2;
 333
 334     /* TODO use font_extents.ascender */
 335     *y = y_scale;
 336   }
 337
 338   inline void get_glyph_origin_for_direction (hb_codepoint_t glyph,
 339                                               hb_direction_t direction,
 340                                               hb_position_t *x, hb_position_t *y)
 341   {
 342     if (likely (HB_DIRECTION_IS_HORIZONTAL (direction)))
 343     {
 344       if (!get_glyph_h_origin (glyph, x, y) &&
 345            get_glyph_v_origin (glyph, x, y))
 346       {
 347         hb_position_t dx, dy;
 348         guess_v_origin_minus_h_origin (glyph, &dx, &dy);
 349         *x -= dx; *y -= dy;
 350       }
 351     }
 352     else
 353     {
 354       if (!get_glyph_v_origin (glyph, x, y) &&
 355            get_glyph_h_origin (glyph, x, y))
 356       {
 357         hb_position_t dx, dy;
 358         guess_v_origin_minus_h_origin (glyph, &dx, &dy);
 359         *x += dx; *y += dy;
 360       }
 361     }
 362   }
 363
 364   inline void add_glyph_h_origin (hb_codepoint_t glyph,
 365                                   hb_position_t *x, hb_position_t *y)
 366   {
 367     hb_position_t origin_x, origin_y;
 368
 369     get_glyph_h_origin (glyph, &origin_x, &origin_y);
 370
 371     *x += origin_x;
 372     *y += origin_y;
 373   }
 374   inline void add_glyph_v_origin (hb_codepoint_t glyph,
 375                                   hb_position_t *x, hb_position_t *y)
 376   {
 377     hb_position_t origin_x, origin_y;
 378
 379     get_glyph_v_origin (glyph, &origin_x, &origin_y);
 380
 381     *x += origin_x;
 382     *y += origin_y;
 383   }
 384   inline void add_glyph_origin_for_direction (hb_codepoint_t glyph,
 385                                               hb_direction_t direction,
 386                                               hb_position_t *x, hb_position_t *y)
 387   {
 388     hb_position_t origin_x, origin_y;
 389
 390     get_glyph_origin_for_direction (glyph, direction, &origin_x, &origin_y);
 391
 392     *x += origin_x;
 393     *y += origin_y;
 394   }
 395
 396   inline void subtract_glyph_h_origin (hb_codepoint_t glyph,
 397                                        hb_position_t *x, hb_position_t *y)
 398   {
 399     hb_position_t origin_x, origin_y;
 400
 401     get_glyph_h_origin (glyph, &origin_x, &origin_y);
 402
 403     *x -= origin_x;
 404     *y -= origin_y;
 405   }
 406   inline void subtract_glyph_v_origin (hb_codepoint_t glyph,
 407                                        hb_position_t *x, hb_position_t *y)
 408   {
 409     hb_position_t origin_x, origin_y;
 410
 411     get_glyph_v_origin (glyph, &origin_x, &origin_y);
 412
 413     *x -= origin_x;
 414     *y -= origin_y;
 415   }
 416   inline void subtract_glyph_origin_for_direction (hb_codepoint_t glyph,
 417                                                    hb_direction_t direction,
 418                                                    hb_position_t *x, hb_position_t *y)
 419   {
 420     hb_position_t origin_x, origin_y;
 421
 422     get_glyph_origin_for_direction (glyph, direction, &origin_x, &origin_y);
 423
 424     *x -= origin_x;
 425     *y -= origin_y;
 426   }
 427
 428   inline void get_glyph_kerning_for_direction (hb_codepoint_t first_glyph, hb_codepoint_t second_glyph,
 429                                                hb_direction_t direction,
 430                                                hb_position_t *x, hb_position_t *y)
 431   {
 432     if (likely (HB_DIRECTION_IS_HORIZONTAL (direction))) {
 433       *x = get_glyph_h_kerning (first_glyph, second_glyph);
 434       *y = 0;
 435     } else {
 436       *x = 0;
 437       *y = get_glyph_v_kerning (first_glyph, second_glyph);
 438     }
 439   }
 440
 441   inline hb_bool_t get_glyph_extents_for_origin (hb_codepoint_t glyph,
 442                                                  hb_direction_t direction,
 443                                                  hb_glyph_extents_t *extents)
 444   {
 445     hb_bool_t ret = get_glyph_extents (glyph, extents);
 446
 447     if (ret)
 448       subtract_glyph_origin_for_direction (glyph, direction, &extents->x_bearing, &extents->y_bearing);
 449
 450     return ret;
 451   }
 452
 453   inline hb_bool_t get_glyph_contour_point_for_origin (hb_codepoint_t glyph, unsigned int point_index,
 454                                                        hb_direction_t direction,
 455                                                        hb_position_t *x, hb_position_t *y)
 456   {
 457     hb_bool_t ret = get_glyph_contour_point (glyph, point_index, x, y);
 458
 459     if (ret)
 460       subtract_glyph_origin_for_direction (glyph, direction, x, y);
 461
 462     return ret;
 463   }
 464
 465   /* Generates gidDDD if glyph has no name. */
 466   inline void
 467   glyph_to_string (hb_codepoint_t glyph,
 468                    char *s, unsigned int size)
 469   {
 470     if (get_glyph_name (glyph, s, size)) return;
 471
 472     if (size && snprintf (s, size, "gid%u", glyph) < 0)
 473       *s = '\0';
 474   }
 475
 476   /* Parses gidDDD and uniUUUU strings automatically. */
 477   inline hb_bool_t
 478   glyph_from_string (const char *s, int len, /* -1 means nul-terminated */
 479                      hb_codepoint_t *glyph)
 480   {
 481     if (get_glyph_from_name (s, len, glyph)) return true;
 482
 483     if (len == -1) len = strlen (s);
 484
 485     /* Straight glyph index. */
 486     if (hb_codepoint_parse (s, len, 10, glyph))
 487       return true;
 488
 489     if (len > 3)
 490     {
 491       /* gidDDD syntax for glyph indices. */
 492       if (0 == strncmp (s, "gid", 3) &&
 493           hb_codepoint_parse (s + 3, len - 3, 10, glyph))
 494         return true;
 495
 496       /* uniUUUU and other Unicode character indices. */
 497       hb_codepoint_t unichar;
 498       if (0 == strncmp (s, "uni", 3) &&
 499           hb_codepoint_parse (s + 3, len - 3, 16, &unichar) &&
 500           get_nominal_glyph (unichar, glyph))
 501         return true;
 502     }
 503
 504     return false;
 505   }
 506
 507   private:
 508   inline hb_position_t em_scale (int16_t v, int scale) { return (hb_position_t) (v * (int64_t) scale / face->get_upem ()); }
 509 };
 510
 511 #define HB_SHAPER_DATA_CREATE_FUNC_EXTRA_ARGS
 512 #define HB_SHAPER_IMPLEMENT(shaper) HB_SHAPER_DATA_PROTOTYPE(shaper, font);
 513 #include "hb-shaper-list.hh"
 514 #undef HB_SHAPER_IMPLEMENT
 515 #undef HB_SHAPER_DATA_CREATE_FUNC_EXTRA_ARGS
 516
 517
 518 #endif /* HB_FONT_PRIVATE_HH */