third_party/harfbuzz-ng/src/hb-ot-layout-private.hh

   1 /*
   2  * Copyright © 2007,2008,2009  Red Hat, Inc.
   3  * Copyright © 2012,2013  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_OT_LAYOUT_PRIVATE_HH
  30 #define HB_OT_LAYOUT_PRIVATE_HH
  31
  32 #include "hb-private.hh"
  33
  34 #include "hb-font-private.hh"
  35 #include "hb-buffer-private.hh"
  36 #include "hb-set-private.hh"
  37
  38
  39 /*
  40  * GDEF
  41  */
  42
  43 typedef enum
  44 {
  45   /* The following three match LookupFlags::Ignore* numbers. */
  46   HB_OT_LAYOUT_GLYPH_PROPS_BASE_GLYPH   = 0x02u,
  47   HB_OT_LAYOUT_GLYPH_PROPS_LIGATURE     = 0x04u,
  48   HB_OT_LAYOUT_GLYPH_PROPS_MARK         = 0x08u,
  49
  50   /* The following are used internally; not derived from GDEF. */
  51   HB_OT_LAYOUT_GLYPH_PROPS_SUBSTITUTED  = 0x10u,
  52   HB_OT_LAYOUT_GLYPH_PROPS_LIGATED      = 0x20u,
  53   HB_OT_LAYOUT_GLYPH_PROPS_MULTIPLIED   = 0x40u,
  54
  55   HB_OT_LAYOUT_GLYPH_PROPS_PRESERVE     = HB_OT_LAYOUT_GLYPH_PROPS_SUBSTITUTED |
  56                                           HB_OT_LAYOUT_GLYPH_PROPS_LIGATED |
  57                                           HB_OT_LAYOUT_GLYPH_PROPS_MULTIPLIED
  58 } hb_ot_layout_glyph_class_mask_t;
  59
  60
  61 /*
  62  * GSUB/GPOS
  63  */
  64
  65 HB_INTERNAL hb_bool_t
  66 hb_ot_layout_lookup_would_substitute_fast (hb_face_t            *face,
  67                                            unsigned int          lookup_index,
  68                                            const hb_codepoint_t *glyphs,
  69                                            unsigned int          glyphs_length,
  70                                            hb_bool_t             zero_context);
  71
  72
  73 /* Should be called before all the substitute_lookup's are done. */
  74 HB_INTERNAL void
  75 hb_ot_layout_substitute_start (hb_font_t    *font,
  76                                hb_buffer_t  *buffer);
  77
  78
  79 struct hb_ot_layout_lookup_accelerator_t;
  80
  81 namespace OT {
  82   struct hb_apply_context_t;
  83   struct SubstLookup;
  84 }
  85
  86 HB_INTERNAL void
  87 hb_ot_layout_substitute_lookup (OT::hb_apply_context_t *c,
  88                                 const OT::SubstLookup &lookup,
  89                                 const hb_ot_layout_lookup_accelerator_t &accel);
  90
  91
  92 /* Should be called after all the substitute_lookup's are done */
  93 HB_INTERNAL void
  94 hb_ot_layout_substitute_finish (hb_font_t    *font,
  95                                 hb_buffer_t  *buffer);
  96
  97
  98 /* Should be called before all the position_lookup's are done.  Resets positions to zero. */
  99 HB_INTERNAL void
 100 hb_ot_layout_position_start (hb_font_t    *font,
 101                              hb_buffer_t  *buffer);
 102
 103 /* Should be called after all the position_lookup's are done */
 104 HB_INTERNAL void
 105 hb_ot_layout_position_finish (hb_font_t    *font,
 106                               hb_buffer_t  *buffer);
 107
 108
 109
 110 /*
 111  * hb_ot_layout_t
 112  */
 113
 114 namespace OT {
 115   struct GDEF;
 116   struct GSUB;
 117   struct GPOS;
 118 }
 119
 120 struct hb_ot_layout_lookup_accelerator_t
 121 {
 122   template <typename TLookup>
 123   inline void init (const TLookup &lookup)
 124   {
 125     digest.init ();
 126     lookup.add_coverage (&digest);
 127   }
 128
 129   inline void fini (void)
 130   {
 131   }
 132
 133   hb_set_digest_t digest;
 134 };
 135
 136 struct hb_ot_layout_t
 137 {
 138   hb_blob_t *gdef_blob;
 139   hb_blob_t *gsub_blob;
 140   hb_blob_t *gpos_blob;
 141
 142   const struct OT::GDEF *gdef;
 143   const struct OT::GSUB *gsub;
 144   const struct OT::GPOS *gpos;
 145
 146   unsigned int gsub_lookup_count;
 147   unsigned int gpos_lookup_count;
 148
 149   hb_ot_layout_lookup_accelerator_t *gsub_accels;
 150   hb_ot_layout_lookup_accelerator_t *gpos_accels;
 151 };
 152
 153
 154 HB_INTERNAL hb_ot_layout_t *
 155 _hb_ot_layout_create (hb_face_t *face);
 156
 157 HB_INTERNAL void
 158 _hb_ot_layout_destroy (hb_ot_layout_t *layout);
 159
 160
 161 #define hb_ot_layout_from_face(face) ((hb_ot_layout_t *) face->shaper_data.ot)
 162
 163
 164 /*
 165  * Buffer var routines.
 166  */
 167
 168 /* buffer var allocations, used during the entire shaping process */
 169 #define unicode_props0()        var2.u8[0]
 170 #define unicode_props1()        var2.u8[1]
 171
 172 /* buffer var allocations, used during the GSUB/GPOS processing */
 173 #define glyph_props()           var1.u16[0] /* GDEF glyph properties */
 174 #define lig_props()             var1.u8[2] /* GSUB/GPOS ligature tracking */
 175 #define syllable()              var1.u8[3] /* GSUB/GPOS shaping boundaries */
 176
 177 /* unicode_props */
 178
 179 enum {
 180   MASK0_ZWJ       = 0x20u,
 181   MASK0_ZWNJ      = 0x40u,
 182   MASK0_IGNORABLE = 0x80u,
 183   MASK0_GEN_CAT   = 0x1Fu
 184 };
 185
 186 static inline void
 187 _hb_glyph_info_set_unicode_props (hb_glyph_info_t *info, hb_unicode_funcs_t *unicode)
 188 {
 189   /* XXX This shouldn't be inlined, or at least not while is_default_ignorable() is inline. */
 190   info->unicode_props0() = ((unsigned int) unicode->general_category (info->codepoint)) |
 191                            (unicode->is_default_ignorable (info->codepoint) ? MASK0_IGNORABLE : 0) |
 192                            (info->codepoint == 0x200Cu ? MASK0_ZWNJ : 0) |
 193                            (info->codepoint == 0x200Du ? MASK0_ZWJ : 0);
 194   info->unicode_props1() = unicode->modified_combining_class (info->codepoint);
 195 }
 196
 197 static inline void
 198 _hb_glyph_info_set_general_category (hb_glyph_info_t *info,
 199                                      hb_unicode_general_category_t gen_cat)
 200 {
 201   info->unicode_props0() = (unsigned int) gen_cat | ((info->unicode_props0()) & ~MASK0_GEN_CAT);
 202 }
 203
 204 static inline hb_unicode_general_category_t
 205 _hb_glyph_info_get_general_category (const hb_glyph_info_t *info)
 206 {
 207   return (hb_unicode_general_category_t) (info->unicode_props0() & MASK0_GEN_CAT);
 208 }
 209
 210 static inline void
 211 _hb_glyph_info_set_modified_combining_class (hb_glyph_info_t *info,
 212                                              unsigned int modified_class)
 213 {
 214   info->unicode_props1() = modified_class;
 215 }
 216
 217 static inline unsigned int
 218 _hb_glyph_info_get_modified_combining_class (const hb_glyph_info_t *info)
 219 {
 220   return info->unicode_props1();
 221 }
 222
 223 static inline hb_bool_t
 224 _hb_glyph_info_is_default_ignorable (const hb_glyph_info_t *info)
 225 {
 226   return !!(info->unicode_props0() & MASK0_IGNORABLE);
 227 }
 228
 229 static inline hb_bool_t
 230 _hb_glyph_info_is_zwnj (const hb_glyph_info_t *info)
 231 {
 232   return !!(info->unicode_props0() & MASK0_ZWNJ);
 233 }
 234
 235 static inline hb_bool_t
 236 _hb_glyph_info_is_zwj (const hb_glyph_info_t *info)
 237 {
 238   return !!(info->unicode_props0() & MASK0_ZWJ);
 239 }
 240
 241 static inline void
 242 _hb_glyph_info_flip_joiners (hb_glyph_info_t *info)
 243 {
 244   info->unicode_props0() ^= MASK0_ZWNJ | MASK0_ZWJ;
 245 }
 246
 247 /* lig_props: aka lig_id / lig_comp
 248  *
 249  * When a ligature is formed:
 250  *
 251  *   - The ligature glyph and any marks in between all the same newly allocated
 252  *     lig_id,
 253  *   - The ligature glyph will get lig_num_comps set to the number of components
 254  *   - The marks get lig_comp > 0, reflecting which component of the ligature
 255  *     they were applied to.
 256  *   - This is used in GPOS to attach marks to the right component of a ligature
 257  *     in MarkLigPos,
 258  *   - Note that when marks are ligated together, much of the above is skipped
 259  *     and the current lig_id reused.
 260  *
 261  * When a multiple-substitution is done:
 262  *
 263  *   - All resulting glyphs will have lig_id = 0,
 264  *   - The resulting glyphs will have lig_comp = 0, 1, 2, ... respectively.
 265  *   - This is used in GPOS to attach marks to the first component of a
 266  *     multiple substitution in MarkBasePos.
 267  *
 268  * The numbers are also used in GPOS to do mark-to-mark positioning only
 269  * to marks that belong to the same component of the same ligature.
 270  */
 271
 272 static inline void
 273 _hb_glyph_info_clear_lig_props (hb_glyph_info_t *info)
 274 {
 275   info->lig_props() = 0;
 276 }
 277
 278 #define IS_LIG_BASE 0x10
 279
 280 static inline void
 281 _hb_glyph_info_set_lig_props_for_ligature (hb_glyph_info_t *info,
 282                                            unsigned int lig_id,
 283                                            unsigned int lig_num_comps)
 284 {
 285   info->lig_props() = (lig_id << 5) | IS_LIG_BASE | (lig_num_comps & 0x0F);
 286 }
 287
 288 static inline void
 289 _hb_glyph_info_set_lig_props_for_mark (hb_glyph_info_t *info,
 290                                        unsigned int lig_id,
 291                                        unsigned int lig_comp)
 292 {
 293   info->lig_props() = (lig_id << 5) | (lig_comp & 0x0F);
 294 }
 295
 296 static inline void
 297 _hb_glyph_info_set_lig_props_for_component (hb_glyph_info_t *info, unsigned int comp)
 298 {
 299   _hb_glyph_info_set_lig_props_for_mark (info, 0, comp);
 300 }
 301
 302 static inline unsigned int
 303 _hb_glyph_info_get_lig_id (const hb_glyph_info_t *info)
 304 {
 305   return info->lig_props() >> 5;
 306 }
 307
 308 static inline bool
 309 _hb_glyph_info_ligated_internal (const hb_glyph_info_t *info)
 310 {
 311   return !!(info->lig_props() & IS_LIG_BASE);
 312 }
 313
 314 static inline unsigned int
 315 _hb_glyph_info_get_lig_comp (const hb_glyph_info_t *info)
 316 {
 317   if (_hb_glyph_info_ligated_internal (info))
 318     return 0;
 319   else
 320     return info->lig_props() & 0x0F;
 321 }
 322
 323 static inline unsigned int
 324 _hb_glyph_info_get_lig_num_comps (const hb_glyph_info_t *info)
 325 {
 326   if ((info->glyph_props() & HB_OT_LAYOUT_GLYPH_PROPS_LIGATURE) &&
 327       _hb_glyph_info_ligated_internal (info))
 328     return info->lig_props() & 0x0F;
 329   else
 330     return 1;
 331 }
 332
 333 static inline uint8_t
 334 _hb_allocate_lig_id (hb_buffer_t *buffer) {
 335   uint8_t lig_id = buffer->next_serial () & 0x07;
 336   if (unlikely (!lig_id))
 337     lig_id = _hb_allocate_lig_id (buffer); /* in case of overflow */
 338   return lig_id;
 339 }
 340
 341 /* glyph_props: */
 342
 343 static inline void
 344 _hb_glyph_info_set_glyph_props (hb_glyph_info_t *info, unsigned int props)
 345 {
 346   info->glyph_props() = props;
 347 }
 348
 349 static inline unsigned int
 350 _hb_glyph_info_get_glyph_props (const hb_glyph_info_t *info)
 351 {
 352   return info->glyph_props();
 353 }
 354
 355 static inline bool
 356 _hb_glyph_info_is_base_glyph (const hb_glyph_info_t *info)
 357 {
 358   return !!(info->glyph_props() & HB_OT_LAYOUT_GLYPH_PROPS_BASE_GLYPH);
 359 }
 360
 361 static inline bool
 362 _hb_glyph_info_is_ligature (const hb_glyph_info_t *info)
 363 {
 364   return !!(info->glyph_props() & HB_OT_LAYOUT_GLYPH_PROPS_LIGATURE);
 365 }
 366
 367 static inline bool
 368 _hb_glyph_info_is_mark (const hb_glyph_info_t *info)
 369 {
 370   return !!(info->glyph_props() & HB_OT_LAYOUT_GLYPH_PROPS_MARK);
 371 }
 372
 373 static inline bool
 374 _hb_glyph_info_substituted (const hb_glyph_info_t *info)
 375 {
 376   return !!(info->glyph_props() & HB_OT_LAYOUT_GLYPH_PROPS_SUBSTITUTED);
 377 }
 378
 379 static inline bool
 380 _hb_glyph_info_ligated (const hb_glyph_info_t *info)
 381 {
 382   return !!(info->glyph_props() & HB_OT_LAYOUT_GLYPH_PROPS_LIGATED);
 383 }
 384
 385 static inline bool
 386 _hb_glyph_info_multiplied (const hb_glyph_info_t *info)
 387 {
 388   return !!(info->glyph_props() & HB_OT_LAYOUT_GLYPH_PROPS_MULTIPLIED);
 389 }
 390
 391 static inline bool
 392 _hb_glyph_info_ligated_and_didnt_multiply (const hb_glyph_info_t *info)
 393 {
 394   return _hb_glyph_info_ligated (info) && !_hb_glyph_info_multiplied (info);
 395 }
 396
 397 static inline void
 398 _hb_glyph_info_clear_ligated_and_multiplied (hb_glyph_info_t *info)
 399 {
 400   info->glyph_props() &= ~(HB_OT_LAYOUT_GLYPH_PROPS_LIGATED |
 401                            HB_OT_LAYOUT_GLYPH_PROPS_MULTIPLIED);
 402 }
 403
 404
 405 /* Allocation / deallocation. */
 406
 407 static inline void
 408 _hb_buffer_allocate_unicode_vars (hb_buffer_t *buffer)
 409 {
 410   HB_BUFFER_ALLOCATE_VAR (buffer, unicode_props0);
 411   HB_BUFFER_ALLOCATE_VAR (buffer, unicode_props1);
 412 }
 413
 414 static inline void
 415 _hb_buffer_deallocate_unicode_vars (hb_buffer_t *buffer)
 416 {
 417   HB_BUFFER_DEALLOCATE_VAR (buffer, unicode_props0);
 418   HB_BUFFER_DEALLOCATE_VAR (buffer, unicode_props1);
 419 }
 420
 421 static inline void
 422 _hb_buffer_assert_unicode_vars (hb_buffer_t *buffer)
 423 {
 424   HB_BUFFER_ASSERT_VAR (buffer, unicode_props0);
 425   HB_BUFFER_ASSERT_VAR (buffer, unicode_props1);
 426 }
 427
 428 static inline void
 429 _hb_buffer_allocate_gsubgpos_vars (hb_buffer_t *buffer)
 430 {
 431   HB_BUFFER_ALLOCATE_VAR (buffer, glyph_props);
 432   HB_BUFFER_ALLOCATE_VAR (buffer, lig_props);
 433   HB_BUFFER_ALLOCATE_VAR (buffer, syllable);
 434 }
 435
 436 static inline void
 437 _hb_buffer_deallocate_gsubgpos_vars (hb_buffer_t *buffer)
 438 {
 439   HB_BUFFER_DEALLOCATE_VAR (buffer, syllable);
 440   HB_BUFFER_DEALLOCATE_VAR (buffer, lig_props);
 441   HB_BUFFER_DEALLOCATE_VAR (buffer, glyph_props);
 442 }
 443
 444 static inline void
 445 _hb_buffer_assert_gsubgpos_vars (hb_buffer_t *buffer)
 446 {
 447   HB_BUFFER_ASSERT_VAR (buffer, glyph_props);
 448   HB_BUFFER_ASSERT_VAR (buffer, lig_props);
 449   HB_BUFFER_ASSERT_VAR (buffer, syllable);
 450 }
 451
 452 /* Make sure no one directly touches our props... */
 453 #undef unicode_props0
 454 #undef unicode_props1
 455 #undef lig_props
 456 #undef glyph_props
 457
 458
 459 #endif /* HB_OT_LAYOUT_PRIVATE_HH */