src/hb-buffer.h

   1 /*
   2  * Copyright © 1998-2004  David Turner and Werner Lemberg
   3  * Copyright © 2004,2007,2009  Red Hat, Inc.
   4  * Copyright © 2011,2012  Google, Inc.
   5  *
   6  *  This is part of HarfBuzz, a text shaping library.
   7  *
   8  * Permission is hereby granted, without written agreement and without
   9  * license or royalty fees, to use, copy, modify, and distribute this
  10  * software and its documentation for any purpose, provided that the
  11  * above copyright notice and the following two paragraphs appear in
  12  * all copies of this software.
  13  *
  14  * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
  15  * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
  16  * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
  17  * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
  18  * DAMAGE.
  19  *
  20  * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
  21  * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
  22  * FITNESS FOR A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS
  23  * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
  24  * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
  25  *
  26  * Red Hat Author(s): Owen Taylor, Behdad Esfahbod
  27  * Google Author(s): Behdad Esfahbod
  28  */
  29
  30 #ifndef HB_H_IN
  31 #error "Include <hb.h> instead."
  32 #endif
  33
  34 #ifndef HB_BUFFER_H
  35 #define HB_BUFFER_H
  36
  37 #include "hb-common.h"
  38 #include "hb-unicode.h"
  39 #include "hb-font.h"
  40
  41 HB_BEGIN_DECLS
  42
  43 /**
  44  * hb_glyph_info_t:
  45  * @codepoint: either a Unicode code point (before shaping) or a glyph index
  46  *             (after shaping).
  47  * @mask:
  48  * @cluster: the index of the character in the original text that corresponds
  49  *           to this #hb_glyph_info_t, or whatever the client passes to
  50  *           hb_buffer_add(). More than one #hb_glyph_info_t can have the same
  51  *           @cluster value, if they resulted from the same character (e.g. one
  52  *           to many glyph substitution), and when more than one character gets
  53  *           merged in the same glyph (e.g. many to one glyph substitution) the
  54  *           #hb_glyph_info_t will have the smallest cluster value of them.
  55  *           By default some characters are merged into the same cluster
  56  *           (e.g. combining marks have the same cluster as their bases)
  57  *           even if they are separate glyphs, hb_buffer_set_cluster_level()
  58  *           allow selecting more fine-grained cluster handling.
  59  *
  60  * The #hb_glyph_info_t is the structure that holds information about the
  61  * glyphs and their relation to input text.
  62  *
  63  */
  64 typedef struct hb_glyph_info_t {
  65   hb_codepoint_t codepoint;
  66   hb_mask_t      mask;
  67   uint32_t       cluster;
  68
  69   /*< private >*/
  70   hb_var_int_t   var1;
  71   hb_var_int_t   var2;
  72 } hb_glyph_info_t;
  73
  74 /**
  75  * hb_glyph_position_t:
  76  * @x_advance: how much the line advances after drawing this glyph when setting
  77  *             text in horizontal direction.
  78  * @y_advance: how much the line advances after drawing this glyph when setting
  79  *             text in vertical direction.
  80  * @x_offset: how much the glyph moves on the X-axis before drawing it, this
  81  *            should not affect how much the line advances.
  82  * @y_offset: how much the glyph moves on the Y-axis before drawing it, this
  83  *            should not affect how much the line advances.
  84  *
  85  * The #hb_glyph_position_t is the structure that holds the positions of the
  86  * glyph in both horizontal and vertical directions. All positions in
  87  * #hb_glyph_position_t are relative to the current point.
  88  *
  89  */
  90 typedef struct hb_glyph_position_t {
  91   hb_position_t  x_advance;
  92   hb_position_t  y_advance;
  93   hb_position_t  x_offset;
  94   hb_position_t  y_offset;
  95
  96   /*< private >*/
  97   hb_var_int_t   var;
  98 } hb_glyph_position_t;
  99
 100 /**
 101  * hb_segment_properties_t:
 102  * @direction: the #hb_direction_t of the buffer, see hb_buffer_set_direction().
 103  * @script: the #hb_script_t of the buffer, see hb_buffer_set_script().
 104  * @language: the #hb_language_t of the buffer, see hb_buffer_set_language().
 105  *
 106  * The structure that holds various text properties of an #hb_buffer_t. Can be
 107  * set and retrieved using hb_buffer_set_segment_properties() and
 108  * hb_buffer_get_segment_properties(), respectively.
 109  */
 110 typedef struct hb_segment_properties_t {
 111   hb_direction_t  direction;
 112   hb_script_t     script;
 113   hb_language_t   language;
 114   /*< private >*/
 115   void           *reserved1;
 116   void           *reserved2;
 117 } hb_segment_properties_t;
 118
 119 #define HB_SEGMENT_PROPERTIES_DEFAULT {HB_DIRECTION_INVALID, \
 120                                        HB_SCRIPT_INVALID, \
 121                                        HB_LANGUAGE_INVALID, \
 122                                        NULL, \
 123                                        NULL}
 124
 125 HB_EXTERN hb_bool_t
 126 hb_segment_properties_equal (const hb_segment_properties_t *a,
 127                              const hb_segment_properties_t *b);
 128
 129 HB_EXTERN unsigned int
 130 hb_segment_properties_hash (const hb_segment_properties_t *p);
 131
 132
 133
 134 /**
 135  * hb_buffer_t:
 136  *
 137  * The main structure holding the input text and its properties before shaping,
 138  * and output glyphs and their information after shaping.
 139  */
 140
 141 typedef struct hb_buffer_t hb_buffer_t;
 142
 143 HB_EXTERN hb_buffer_t *
 144 hb_buffer_create (void);
 145
 146 HB_EXTERN hb_buffer_t *
 147 hb_buffer_get_empty (void);
 148
 149 HB_EXTERN hb_buffer_t *
 150 hb_buffer_reference (hb_buffer_t *buffer);
 151
 152 HB_EXTERN void
 153 hb_buffer_destroy (hb_buffer_t *buffer);
 154
 155 HB_EXTERN hb_bool_t
 156 hb_buffer_set_user_data (hb_buffer_t        *buffer,
 157                          hb_user_data_key_t *key,
 158                          void *              data,
 159                          hb_destroy_func_t   destroy,
 160                          hb_bool_t           replace);
 161
 162 HB_EXTERN void *
 163 hb_buffer_get_user_data (hb_buffer_t        *buffer,
 164                          hb_user_data_key_t *key);
 165
 166 /**
 167  * hb_buffer_content_type_t:
 168  * @HB_BUFFER_CONTENT_TYPE_INVALID: Initial value for new buffer.
 169  * @HB_BUFFER_CONTENT_TYPE_UNICODE: The buffer contains input characters (before shaping).
 170  * @HB_BUFFER_CONTENT_TYPE_GLYPHS: The buffer contains output glyphs (after shaping).
 171  */
 172 typedef enum {
 173   HB_BUFFER_CONTENT_TYPE_INVALID = 0,
 174   HB_BUFFER_CONTENT_TYPE_UNICODE,
 175   HB_BUFFER_CONTENT_TYPE_GLYPHS
 176 } hb_buffer_content_type_t;
 177
 178 HB_EXTERN void
 179 hb_buffer_set_content_type (hb_buffer_t              *buffer,
 180                             hb_buffer_content_type_t  content_type);
 181
 182 HB_EXTERN hb_buffer_content_type_t
 183 hb_buffer_get_content_type (hb_buffer_t *buffer);
 184
 185
 186 HB_EXTERN void
 187 hb_buffer_set_unicode_funcs (hb_buffer_t        *buffer,
 188                              hb_unicode_funcs_t *unicode_funcs);
 189
 190 HB_EXTERN hb_unicode_funcs_t *
 191 hb_buffer_get_unicode_funcs (hb_buffer_t        *buffer);
 192
 193 HB_EXTERN void
 194 hb_buffer_set_direction (hb_buffer_t    *buffer,
 195                          hb_direction_t  direction);
 196
 197 HB_EXTERN hb_direction_t
 198 hb_buffer_get_direction (hb_buffer_t *buffer);
 199
 200 HB_EXTERN void
 201 hb_buffer_set_script (hb_buffer_t *buffer,
 202                       hb_script_t  script);
 203
 204 HB_EXTERN hb_script_t
 205 hb_buffer_get_script (hb_buffer_t *buffer);
 206
 207 HB_EXTERN void
 208 hb_buffer_set_language (hb_buffer_t   *buffer,
 209                         hb_language_t  language);
 210
 211
 212 HB_EXTERN hb_language_t
 213 hb_buffer_get_language (hb_buffer_t *buffer);
 214
 215 HB_EXTERN void
 216 hb_buffer_set_segment_properties (hb_buffer_t *buffer,
 217                                   const hb_segment_properties_t *props);
 218
 219 HB_EXTERN void
 220 hb_buffer_get_segment_properties (hb_buffer_t *buffer,
 221                                   hb_segment_properties_t *props);
 222
 223 HB_EXTERN void
 224 hb_buffer_guess_segment_properties (hb_buffer_t *buffer);
 225
 226
 227 /**
 228  * hb_buffer_flags_t:
 229  * @HB_BUFFER_FLAG_DEFAULT: the default buffer flag.
 230  * @HB_BUFFER_FLAG_BOT: flag indicating that special handling of the beginning
 231  *                      of text paragraph can be applied to this buffer. Should usually
 232  *                      be set, unless you are passing to the buffer only part
 233  *                      of the text without the full context.
 234  * @HB_BUFFER_FLAG_EOT: flag indicating that special handling of the end of text
 235  *                      paragraph can be applied to this buffer, similar to
 236  *                      @HB_BUFFER_FLAG_EOT.
 237  * @HB_BUFFER_FLAG_PRESERVE_DEFAULT_IGNORABLES:
 238  *                      flag indication that character with Default_Ignorable
 239  *                      Unicode property should use the corresponding glyph
 240  *                      from the font, instead of hiding them (currently done
 241  *                      by replacing them with the space glyph and zeroing the
 242  *                      advance width.)
 243  *
 244  * Since: 0.9.20
 245  */
 246 typedef enum { /*< flags >*/
 247   HB_BUFFER_FLAG_DEFAULT                        = 0x00000000u,
 248   HB_BUFFER_FLAG_BOT                            = 0x00000001u, /* Beginning-of-text */
 249   HB_BUFFER_FLAG_EOT                            = 0x00000002u, /* End-of-text */
 250   HB_BUFFER_FLAG_PRESERVE_DEFAULT_IGNORABLES    = 0x00000004u
 251 } hb_buffer_flags_t;
 252
 253 HB_EXTERN void
 254 hb_buffer_set_flags (hb_buffer_t       *buffer,
 255                      hb_buffer_flags_t  flags);
 256
 257 HB_EXTERN hb_buffer_flags_t
 258 hb_buffer_get_flags (hb_buffer_t *buffer);
 259
 260 /*
 261  * Since: 0.9.42
 262  */
 263 typedef enum {
 264   HB_BUFFER_CLUSTER_LEVEL_MONOTONE_GRAPHEMES    = 0,
 265   HB_BUFFER_CLUSTER_LEVEL_MONOTONE_CHARACTERS   = 1,
 266   HB_BUFFER_CLUSTER_LEVEL_CHARACTERS            = 2,
 267   HB_BUFFER_CLUSTER_LEVEL_DEFAULT = HB_BUFFER_CLUSTER_LEVEL_MONOTONE_GRAPHEMES
 268 } hb_buffer_cluster_level_t;
 269
 270 HB_EXTERN void
 271 hb_buffer_set_cluster_level (hb_buffer_t               *buffer,
 272                              hb_buffer_cluster_level_t  cluster_level);
 273
 274 HB_EXTERN hb_buffer_cluster_level_t
 275 hb_buffer_get_cluster_level (hb_buffer_t *buffer);
 276
 277 /**
 278  * HB_BUFFER_REPLACEMENT_CODEPOINT_DEFAULT:
 279  *
 280  * The default code point for replacing invalid characters in a given encoding.
 281  * Set to U+FFFD REPLACEMENT CHARACTER.
 282  *
 283  * Since: 0.9.31
 284  */
 285 #define HB_BUFFER_REPLACEMENT_CODEPOINT_DEFAULT 0xFFFDu
 286
 287 HB_EXTERN void
 288 hb_buffer_set_replacement_codepoint (hb_buffer_t    *buffer,
 289                                      hb_codepoint_t  replacement);
 290
 291 HB_EXTERN hb_codepoint_t
 292 hb_buffer_get_replacement_codepoint (hb_buffer_t    *buffer);
 293
 294
 295 HB_EXTERN void
 296 hb_buffer_reset (hb_buffer_t *buffer);
 297
 298 HB_EXTERN void
 299 hb_buffer_clear_contents (hb_buffer_t *buffer);
 300
 301 HB_EXTERN hb_bool_t
 302 hb_buffer_pre_allocate (hb_buffer_t  *buffer,
 303                         unsigned int  size);
 304
 305
 306 HB_EXTERN hb_bool_t
 307 hb_buffer_allocation_successful (hb_buffer_t  *buffer);
 308
 309 HB_EXTERN void
 310 hb_buffer_reverse (hb_buffer_t *buffer);
 311
 312 HB_EXTERN void
 313 hb_buffer_reverse_range (hb_buffer_t *buffer,
 314                          unsigned int start, unsigned int end);
 315
 316 HB_EXTERN void
 317 hb_buffer_reverse_clusters (hb_buffer_t *buffer);
 318
 319
 320 /* Filling the buffer in */
 321
 322 HB_EXTERN void
 323 hb_buffer_add (hb_buffer_t    *buffer,
 324                hb_codepoint_t  codepoint,
 325                unsigned int    cluster);
 326
 327 HB_EXTERN void
 328 hb_buffer_add_utf8 (hb_buffer_t  *buffer,
 329                     const char   *text,
 330                     int           text_length,
 331                     unsigned int  item_offset,
 332                     int           item_length);
 333
 334 HB_EXTERN void
 335 hb_buffer_add_utf16 (hb_buffer_t    *buffer,
 336                      const uint16_t *text,
 337                      int             text_length,
 338                      unsigned int    item_offset,
 339                      int             item_length);
 340
 341 HB_EXTERN void
 342 hb_buffer_add_utf32 (hb_buffer_t    *buffer,
 343                      const uint32_t *text,
 344                      int             text_length,
 345                      unsigned int    item_offset,
 346                      int             item_length);
 347
 348 HB_EXTERN void
 349 hb_buffer_add_latin1 (hb_buffer_t   *buffer,
 350                       const uint8_t *text,
 351                       int            text_length,
 352                       unsigned int   item_offset,
 353                       int            item_length);
 354
 355 HB_EXTERN void
 356 hb_buffer_add_codepoints (hb_buffer_t          *buffer,
 357                           const hb_codepoint_t *text,
 358                           int                   text_length,
 359                           unsigned int          item_offset,
 360                           int                   item_length);
 361
 362
 363 HB_EXTERN hb_bool_t
 364 hb_buffer_set_length (hb_buffer_t  *buffer,
 365                       unsigned int  length);
 366
 367 HB_EXTERN unsigned int
 368 hb_buffer_get_length (hb_buffer_t *buffer);
 369
 370 /* Getting glyphs out of the buffer */
 371
 372 HB_EXTERN hb_glyph_info_t *
 373 hb_buffer_get_glyph_infos (hb_buffer_t  *buffer,
 374                            unsigned int *length);
 375
 376 HB_EXTERN hb_glyph_position_t *
 377 hb_buffer_get_glyph_positions (hb_buffer_t  *buffer,
 378                                unsigned int *length);
 379
 380
 381 HB_EXTERN void
 382 hb_buffer_normalize_glyphs (hb_buffer_t *buffer);
 383
 384
 385 /*
 386  * Serialize
 387  */
 388
 389 /**
 390  * hb_buffer_serialize_flags_t:
 391  * @HB_BUFFER_SERIALIZE_FLAG_DEFAULT: serialize glyph names, clusters and positions.
 392  * @HB_BUFFER_SERIALIZE_FLAG_NO_CLUSTERS: do not serialize glyph cluster.
 393  * @HB_BUFFER_SERIALIZE_FLAG_NO_POSITIONS: do not serialize glyph position information.
 394  * @HB_BUFFER_SERIALIZE_FLAG_NO_GLYPH_NAMES: do no serialize glyph name.
 395  * @HB_BUFFER_SERIALIZE_FLAG_GLYPH_EXTENTS: serialize glyph extents.
 396  *
 397  * Flags that control what glyph information are serialized in hb_buffer_serialize_glyphs().
 398  *
 399  * Since: 0.9.20
 400  */
 401 typedef enum { /*< flags >*/
 402   HB_BUFFER_SERIALIZE_FLAG_DEFAULT              = 0x00000000u,
 403   HB_BUFFER_SERIALIZE_FLAG_NO_CLUSTERS          = 0x00000001u,
 404   HB_BUFFER_SERIALIZE_FLAG_NO_POSITIONS         = 0x00000002u,
 405   HB_BUFFER_SERIALIZE_FLAG_NO_GLYPH_NAMES       = 0x00000004u,
 406   HB_BUFFER_SERIALIZE_FLAG_GLYPH_EXTENTS        = 0x00000008u
 407 } hb_buffer_serialize_flags_t;
 408
 409 /**
 410  * hb_buffer_serialize_format_t:
 411  * @HB_BUFFER_SERIALIZE_FORMAT_TEXT: a human-readable, plain text format.
 412  * @HB_BUFFER_SERIALIZE_FORMAT_JSON: a machine-readable JSON format.
 413  * @HB_BUFFER_SERIALIZE_FORMAT_INVALID: invalid format.
 414  *
 415  * The buffer serialization and de-serialization format used in
 416  * hb_buffer_serialize_glyphs() and hb_buffer_deserialize_glyphs().
 417  *
 418  * Since: 0.9.2
 419  */
 420 typedef enum {
 421   HB_BUFFER_SERIALIZE_FORMAT_TEXT       = HB_TAG('T','E','X','T'),
 422   HB_BUFFER_SERIALIZE_FORMAT_JSON       = HB_TAG('J','S','O','N'),
 423   HB_BUFFER_SERIALIZE_FORMAT_INVALID    = HB_TAG_NONE
 424 } hb_buffer_serialize_format_t;
 425
 426 HB_EXTERN hb_buffer_serialize_format_t
 427 hb_buffer_serialize_format_from_string (const char *str, int len);
 428
 429 HB_EXTERN const char *
 430 hb_buffer_serialize_format_to_string (hb_buffer_serialize_format_t format);
 431
 432 HB_EXTERN const char **
 433 hb_buffer_serialize_list_formats (void);
 434
 435 HB_EXTERN unsigned int
 436 hb_buffer_serialize_glyphs (hb_buffer_t *buffer,
 437                             unsigned int start,
 438                             unsigned int end,
 439                             char *buf,
 440                             unsigned int buf_size,
 441                             unsigned int *buf_consumed,
 442                             hb_font_t *font,
 443                             hb_buffer_serialize_format_t format,
 444                             hb_buffer_serialize_flags_t flags);
 445
 446 HB_EXTERN hb_bool_t
 447 hb_buffer_deserialize_glyphs (hb_buffer_t *buffer,
 448                               const char *buf,
 449                               int buf_len,
 450                               const char **end_ptr,
 451                               hb_font_t *font,
 452                               hb_buffer_serialize_format_t format);
 453
 454
 455 /*
 456  * Debugging.
 457  */
 458
 459 typedef hb_bool_t       (*hb_buffer_message_func_t)     (hb_buffer_t *buffer,
 460                                                          hb_font_t   *font,
 461                                                          const char  *message,
 462                                                          void        *user_data);
 463
 464 HB_EXTERN void
 465 hb_buffer_set_message_func (hb_buffer_t *buffer,
 466                             hb_buffer_message_func_t func,
 467                             void *user_data, hb_destroy_func_t destroy);
 468
 469
 470 HB_END_DECLS
 471
 472 #endif /* HB_BUFFER_H */