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