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