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   inline bool may_have (hb_codepoint_t g) const {
 134     return digest.may_have (g);
 135   }
 136
 137   private:
 138   hb_set_digest_t digest;
 139 };
 140
 141 struct hb_ot_layout_t
 142 {
 143   hb_blob_t *gdef_blob;
 144   hb_blob_t *gsub_blob;
 145   hb_blob_t *gpos_blob;
 146
 147   const struct OT::GDEF *gdef;
 148   const struct OT::GSUB *gsub;
 149   const struct OT::GPOS *gpos;
 150
 151   unsigned int gsub_lookup_count;
 152   unsigned int gpos_lookup_count;
 153
 154   hb_ot_layout_lookup_accelerator_t *gsub_accels;
 155   hb_ot_layout_lookup_accelerator_t *gpos_accels;
 156 };
 157
 158
 159 HB_INTERNAL hb_ot_layout_t *
 160 _hb_ot_layout_create (hb_face_t *face);
 161
 162 HB_INTERNAL void
 163 _hb_ot_layout_destroy (hb_ot_layout_t *layout);
 164
 165
 166 #define hb_ot_layout_from_face(face) ((hb_ot_layout_t *) face->shaper_data.ot)
 167
 168
 169 /*
 170  * Buffer var routines.
 171  */
 172
 173 /* buffer var allocations, used during the entire shaping process */
 174 #define unicode_props0()        var2.u8[0]
 175 #define unicode_props1()        var2.u8[1]
 176
 177 /* buffer var allocations, used during the GSUB/GPOS processing */
 178 #define glyph_props()           var1.u16[0] /* GDEF glyph properties */
 179 #define lig_props()             var1.u8[2] /* GSUB/GPOS ligature tracking */
 180 #define syllable()              var1.u8[3] /* GSUB/GPOS shaping boundaries */
 181
 182 /* unicode_props */
 183
 184 enum {
 185   MASK0_ZWJ       = 0x20u,
 186   MASK0_ZWNJ      = 0x40u,
 187   MASK0_IGNORABLE = 0x80u,
 188   MASK0_GEN_CAT   = 0x1Fu
 189 };
 190
 191 static inline void
 192 _hb_glyph_info_set_unicode_props (hb_glyph_info_t *info, hb_unicode_funcs_t *unicode)
 193 {
 194   /* XXX This shouldn't be inlined, or at least not while is_default_ignorable() is inline. */
 195   info->unicode_props0() = ((unsigned int) unicode->general_category (info->codepoint)) |
 196                            (unicode->is_default_ignorable (info->codepoint) ? MASK0_IGNORABLE : 0) |
 197                            (info->codepoint == 0x200Cu ? MASK0_ZWNJ : 0) |
 198                            (info->codepoint == 0x200Du ? MASK0_ZWJ : 0);
 199   info->unicode_props1() = unicode->modified_combining_class (info->codepoint);
 200 }
 201
 202 static inline void
 203 _hb_glyph_info_set_general_category (hb_glyph_info_t *info,
 204                                      hb_unicode_general_category_t gen_cat)
 205 {
 206   info->unicode_props0() = (unsigned int) gen_cat | ((info->unicode_props0()) & ~MASK0_GEN_CAT);
 207 }
 208
 209 static inline hb_unicode_general_category_t
 210 _hb_glyph_info_get_general_category (const hb_glyph_info_t *info)
 211 {
 212   return (hb_unicode_general_category_t) (info->unicode_props0() & MASK0_GEN_CAT);
 213 }
 214
 215 static inline void
 216 _hb_glyph_info_set_modified_combining_class (hb_glyph_info_t *info,
 217                                              unsigned int modified_class)
 218 {
 219   info->unicode_props1() = modified_class;
 220 }
 221
 222 static inline unsigned int
 223 _hb_glyph_info_get_modified_combining_class (const hb_glyph_info_t *info)
 224 {
 225   return info->unicode_props1();
 226 }
 227
 228 static inline hb_bool_t
 229 _hb_glyph_info_is_default_ignorable (const hb_glyph_info_t *info)
 230 {
 231   return !!(info->unicode_props0() & MASK0_IGNORABLE);
 232 }
 233
 234 static inline hb_bool_t
 235 _hb_glyph_info_is_zwnj (const hb_glyph_info_t *info)
 236 {
 237   return !!(info->unicode_props0() & MASK0_ZWNJ);
 238 }
 239
 240 static inline hb_bool_t
 241 _hb_glyph_info_is_zwj (const hb_glyph_info_t *info)
 242 {
 243   return !!(info->unicode_props0() & MASK0_ZWJ);
 244 }
 245
 246 static inline void
 247 _hb_glyph_info_flip_joiners (hb_glyph_info_t *info)
 248 {
 249   info->unicode_props0() ^= MASK0_ZWNJ | MASK0_ZWJ;
 250 }
 251
 252 /* lig_props: aka lig_id / lig_comp
 253  *
 254  * When a ligature is formed:
 255  *
 256  *   - The ligature glyph and any marks in between all the same newly allocated
 257  *     lig_id,
 258  *   - The ligature glyph will get lig_num_comps set to the number of components
 259  *   - The marks get lig_comp > 0, reflecting which component of the ligature
 260  *     they were applied to.
 261  *   - This is used in GPOS to attach marks to the right component of a ligature
 262  *     in MarkLigPos,
 263  *   - Note that when marks are ligated together, much of the above is skipped
 264  *     and the current lig_id reused.
 265  *
 266  * When a multiple-substitution is done:
 267  *
 268  *   - All resulting glyphs will have lig_id = 0,
 269  *   - The resulting glyphs will have lig_comp = 0, 1, 2, ... respectively.
 270  *   - This is used in GPOS to attach marks to the first component of a
 271  *     multiple substitution in MarkBasePos.
 272  *
 273  * The numbers are also used in GPOS to do mark-to-mark positioning only
 274  * to marks that belong to the same component of the same ligature.
 275  */
 276
 277 static inline void
 278 _hb_glyph_info_clear_lig_props (hb_glyph_info_t *info)
 279 {
 280   info->lig_props() = 0;
 281 }
 282
 283 #define IS_LIG_BASE 0x10
 284
 285 static inline void
 286 _hb_glyph_info_set_lig_props_for_ligature (hb_glyph_info_t *info,
 287                                            unsigned int lig_id,
 288                                            unsigned int lig_num_comps)
 289 {
 290   info->lig_props() = (lig_id << 5) | IS_LIG_BASE | (lig_num_comps & 0x0F);
 291 }
 292
 293 static inline void
 294 _hb_glyph_info_set_lig_props_for_mark (hb_glyph_info_t *info,
 295                                        unsigned int lig_id,
 296                                        unsigned int lig_comp)
 297 {
 298   info->lig_props() = (lig_id << 5) | (lig_comp & 0x0F);
 299 }
 300
 301 static inline void
 302 _hb_glyph_info_set_lig_props_for_component (hb_glyph_info_t *info, unsigned int comp)
 303 {
 304   _hb_glyph_info_set_lig_props_for_mark (info, 0, comp);
 305 }
 306
 307 static inline unsigned int
 308 _hb_glyph_info_get_lig_id (const hb_glyph_info_t *info)
 309 {
 310   return info->lig_props() >> 5;
 311 }
 312
 313 static inline bool
 314 _hb_glyph_info_ligated_internal (const hb_glyph_info_t *info)
 315 {
 316   return !!(info->lig_props() & IS_LIG_BASE);
 317 }
 318
 319 static inline unsigned int
 320 _hb_glyph_info_get_lig_comp (const hb_glyph_info_t *info)
 321 {
 322   if (_hb_glyph_info_ligated_internal (info))
 323     return 0;
 324   else
 325     return info->lig_props() & 0x0F;
 326 }
 327
 328 static inline unsigned int
 329 _hb_glyph_info_get_lig_num_comps (const hb_glyph_info_t *info)
 330 {
 331   if ((info->glyph_props() & HB_OT_LAYOUT_GLYPH_PROPS_LIGATURE) &&
 332       _hb_glyph_info_ligated_internal (info))
 333     return info->lig_props() & 0x0F;
 334   else
 335     return 1;
 336 }
 337
 338 static inline uint8_t
 339 _hb_allocate_lig_id (hb_buffer_t *buffer) {
 340   uint8_t lig_id = buffer->next_serial () & 0x07;
 341   if (unlikely (!lig_id))
 342     lig_id = _hb_allocate_lig_id (buffer); /* in case of overflow */
 343   return lig_id;
 344 }
 345
 346 /* glyph_props: */
 347
 348 static inline void
 349 _hb_glyph_info_set_glyph_props (hb_glyph_info_t *info, unsigned int props)
 350 {
 351   info->glyph_props() = props;
 352 }
 353
 354 static inline unsigned int
 355 _hb_glyph_info_get_glyph_props (const hb_glyph_info_t *info)
 356 {
 357   return info->glyph_props();
 358 }
 359
 360 static inline bool
 361 _hb_glyph_info_is_base_glyph (const hb_glyph_info_t *info)
 362 {
 363   return !!(info->glyph_props() & HB_OT_LAYOUT_GLYPH_PROPS_BASE_GLYPH);
 364 }
 365
 366 static inline bool
 367 _hb_glyph_info_is_ligature (const hb_glyph_info_t *info)
 368 {
 369   return !!(info->glyph_props() & HB_OT_LAYOUT_GLYPH_PROPS_LIGATURE);
 370 }
 371
 372 static inline bool
 373 _hb_glyph_info_is_mark (const hb_glyph_info_t *info)
 374 {
 375   return !!(info->glyph_props() & HB_OT_LAYOUT_GLYPH_PROPS_MARK);
 376 }
 377
 378 static inline bool
 379 _hb_glyph_info_substituted (const hb_glyph_info_t *info)
 380 {
 381   return !!(info->glyph_props() & HB_OT_LAYOUT_GLYPH_PROPS_SUBSTITUTED);
 382 }
 383
 384 static inline bool
 385 _hb_glyph_info_ligated (const hb_glyph_info_t *info)
 386 {
 387   return !!(info->glyph_props() & HB_OT_LAYOUT_GLYPH_PROPS_LIGATED);
 388 }
 389
 390 static inline bool
 391 _hb_glyph_info_multiplied (const hb_glyph_info_t *info)
 392 {
 393   return !!(info->glyph_props() & HB_OT_LAYOUT_GLYPH_PROPS_MULTIPLIED);
 394 }
 395
 396 static inline bool
 397 _hb_glyph_info_ligated_and_didnt_multiply (const hb_glyph_info_t *info)
 398 {
 399   return _hb_glyph_info_ligated (info) && !_hb_glyph_info_multiplied (info);
 400 }
 401
 402 static inline void
 403 _hb_glyph_info_clear_ligated_and_multiplied (hb_glyph_info_t *info)
 404 {
 405   info->glyph_props() &= ~(HB_OT_LAYOUT_GLYPH_PROPS_LIGATED |
 406                            HB_OT_LAYOUT_GLYPH_PROPS_MULTIPLIED);
 407 }
 408
 409
 410 /* Allocation / deallocation. */
 411
 412 static inline void
 413 _hb_buffer_allocate_unicode_vars (hb_buffer_t *buffer)
 414 {
 415   HB_BUFFER_ALLOCATE_VAR (buffer, unicode_props0);
 416   HB_BUFFER_ALLOCATE_VAR (buffer, unicode_props1);
 417 }
 418
 419 static inline void
 420 _hb_buffer_deallocate_unicode_vars (hb_buffer_t *buffer)
 421 {
 422   HB_BUFFER_DEALLOCATE_VAR (buffer, unicode_props0);
 423   HB_BUFFER_DEALLOCATE_VAR (buffer, unicode_props1);
 424 }
 425
 426 static inline void
 427 _hb_buffer_assert_unicode_vars (hb_buffer_t *buffer)
 428 {
 429   HB_BUFFER_ASSERT_VAR (buffer, unicode_props0);
 430   HB_BUFFER_ASSERT_VAR (buffer, unicode_props1);
 431 }
 432
 433 static inline void
 434 _hb_buffer_allocate_gsubgpos_vars (hb_buffer_t *buffer)
 435 {
 436   HB_BUFFER_ALLOCATE_VAR (buffer, glyph_props);
 437   HB_BUFFER_ALLOCATE_VAR (buffer, lig_props);
 438   HB_BUFFER_ALLOCATE_VAR (buffer, syllable);
 439 }
 440
 441 static inline void
 442 _hb_buffer_deallocate_gsubgpos_vars (hb_buffer_t *buffer)
 443 {
 444   HB_BUFFER_DEALLOCATE_VAR (buffer, syllable);
 445   HB_BUFFER_DEALLOCATE_VAR (buffer, lig_props);
 446   HB_BUFFER_DEALLOCATE_VAR (buffer, glyph_props);
 447 }
 448
 449 static inline void
 450 _hb_buffer_assert_gsubgpos_vars (hb_buffer_t *buffer)
 451 {
 452   HB_BUFFER_ASSERT_VAR (buffer, glyph_props);
 453   HB_BUFFER_ASSERT_VAR (buffer, lig_props);
 454   HB_BUFFER_ASSERT_VAR (buffer, syllable);
 455 }
 456
 457 /* Make sure no one directly touches our props... */
 458 #undef unicode_props0
 459 #undef unicode_props1
 460 #undef lig_props
 461 #undef glyph_props
 462
 463
 464 #endif /* HB_OT_LAYOUT_PRIVATE_HH */