1 /* 2 * Copyright © 1998-2004 David Turner and Werner Lemberg 3 * Copyright © 2004,2007,2009,2010 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_BUFFER_HH 31 #define HB_BUFFER_HH 32 33 #include "hb.hh" 34 #include "hb-unicode.hh" 35 36 37 #ifndef HB_BUFFER_MAX_LEN_FACTOR 38 #define HB_BUFFER_MAX_LEN_FACTOR 32 39 #endif 40 #ifndef HB_BUFFER_MAX_LEN_MIN 41 #define HB_BUFFER_MAX_LEN_MIN 8192 42 #endif 43 #ifndef HB_BUFFER_MAX_LEN_DEFAULT 44 #define HB_BUFFER_MAX_LEN_DEFAULT 0x3FFFFFFF /* Shaping more than a billion chars? Let us know! */ 45 #endif 46 47 #ifndef HB_BUFFER_MAX_OPS_FACTOR 48 #define HB_BUFFER_MAX_OPS_FACTOR 64 49 #endif 50 #ifndef HB_BUFFER_MAX_OPS_MIN 51 #define HB_BUFFER_MAX_OPS_MIN 1024 52 #endif 53 #ifndef HB_BUFFER_MAX_OPS_DEFAULT 54 #define HB_BUFFER_MAX_OPS_DEFAULT 0x1FFFFFFF /* Shaping more than a billion operations? Let us know! */ 55 #endif 56 57 static_assert ((sizeof (hb_glyph_info_t) == 20), ""); 58 static_assert ((sizeof (hb_glyph_info_t) == sizeof (hb_glyph_position_t)), ""); 59 60 HB_MARK_AS_FLAG_T (hb_buffer_flags_t); 61 HB_MARK_AS_FLAG_T (hb_buffer_serialize_flags_t); 62 HB_MARK_AS_FLAG_T (hb_buffer_diff_flags_t); 63 64 enum hb_buffer_scratch_flags_t { 65 HB_BUFFER_SCRATCH_FLAG_DEFAULT = 0x00000000u, 66 HB_BUFFER_SCRATCH_FLAG_HAS_NON_ASCII = 0x00000001u, 67 HB_BUFFER_SCRATCH_FLAG_HAS_DEFAULT_IGNORABLES = 0x00000002u, 68 HB_BUFFER_SCRATCH_FLAG_HAS_SPACE_FALLBACK = 0x00000004u, 69 HB_BUFFER_SCRATCH_FLAG_HAS_GPOS_ATTACHMENT = 0x00000008u, 70 HB_BUFFER_SCRATCH_FLAG_HAS_UNSAFE_TO_BREAK = 0x00000010u, 71 HB_BUFFER_SCRATCH_FLAG_HAS_CGJ = 0x00000020u, 72 73 /* Reserved for complex shapers' internal use. */ 74 HB_BUFFER_SCRATCH_FLAG_COMPLEX0 = 0x01000000u, 75 HB_BUFFER_SCRATCH_FLAG_COMPLEX1 = 0x02000000u, 76 HB_BUFFER_SCRATCH_FLAG_COMPLEX2 = 0x04000000u, 77 HB_BUFFER_SCRATCH_FLAG_COMPLEX3 = 0x08000000u, 78 }; 79 HB_MARK_AS_FLAG_T (hb_buffer_scratch_flags_t); 80 81 82 /* 83 * hb_buffer_t 84 */ 85 86 struct hb_buffer_t 87 { 88 hb_object_header_t header; 89 90 /* Information about how the text in the buffer should be treated */ 91 hb_unicode_funcs_t *unicode; /* Unicode functions */ 92 hb_buffer_flags_t flags; /* BOT / EOT / etc. */ 93 hb_buffer_cluster_level_t cluster_level; 94 hb_codepoint_t replacement; /* U+FFFD or something else. */ 95 hb_codepoint_t invisible; /* 0 or something else. */ 96 hb_buffer_scratch_flags_t scratch_flags; /* Have space-fallback, etc. */ 97 unsigned int max_len; /* Maximum allowed len. */ 98 int max_ops; /* Maximum allowed operations. */ 99 100 /* Buffer contents */ 101 hb_buffer_content_type_t content_type; 102 hb_segment_properties_t props; /* Script, language, direction */ 103 104 bool successful; /* Allocations successful */ 105 bool have_output; /* Whether we have an output buffer going on */ 106 bool have_positions; /* Whether we have positions */ 107 108 unsigned int idx; /* Cursor into ->info and ->pos arrays */ 109 unsigned int len; /* Length of ->info and ->pos arrays */ 110 unsigned int out_len; /* Length of ->out array if have_output */ 111 112 unsigned int allocated; /* Length of allocated arrays */ 113 hb_glyph_info_t *info; 114 hb_glyph_info_t *out_info; 115 hb_glyph_position_t *pos; 116 117 unsigned int serial; 118 119 /* Text before / after the main buffer contents. 120 * Always in Unicode, and ordered outward. 121 * Index 0 is for "pre-context", 1 for "post-context". */ 122 static constexpr unsigned CONTEXT_LENGTH = 5u; 123 hb_codepoint_t context[2][CONTEXT_LENGTH]; 124 unsigned int context_len[2]; 125 126 /* Debugging API */ 127 #ifndef HB_NO_BUFFER_MESSAGE 128 hb_buffer_message_func_t message_func; 129 void *message_data; 130 hb_destroy_func_t message_destroy; 131 #endif 132 133 /* Internal debugging. */ 134 /* The bits here reflect current allocations of the bytes in glyph_info_t's var1 and var2. */ 135 #ifndef HB_NDEBUG 136 uint8_t allocated_var_bits; 137 #endif 138 139 140 /* Methods */ 141 in_errorhb_buffer_t142 bool in_error () const { return !successful; } 143 allocate_varhb_buffer_t144 void allocate_var (unsigned int start, unsigned int count) 145 { 146 #ifndef HB_NDEBUG 147 unsigned int end = start + count; 148 assert (end <= 8); 149 unsigned int bits = (1u<<end) - (1u<<start); 150 assert (0 == (allocated_var_bits & bits)); 151 allocated_var_bits |= bits; 152 #endif 153 } deallocate_varhb_buffer_t154 void deallocate_var (unsigned int start, unsigned int count) 155 { 156 #ifndef HB_NDEBUG 157 unsigned int end = start + count; 158 assert (end <= 8); 159 unsigned int bits = (1u<<end) - (1u<<start); 160 assert (bits == (allocated_var_bits & bits)); 161 allocated_var_bits &= ~bits; 162 #endif 163 } assert_varhb_buffer_t164 void assert_var (unsigned int start, unsigned int count) 165 { 166 #ifndef HB_NDEBUG 167 unsigned int end = start + count; 168 assert (end <= 8); 169 unsigned int bits = (1u<<end) - (1u<<start); 170 assert (bits == (allocated_var_bits & bits)); 171 #endif 172 } deallocate_var_allhb_buffer_t173 void deallocate_var_all () 174 { 175 #ifndef HB_NDEBUG 176 allocated_var_bits = 0; 177 #endif 178 } 179 curhb_buffer_t180 hb_glyph_info_t &cur (unsigned int i = 0) { return info[idx + i]; } curhb_buffer_t181 hb_glyph_info_t cur (unsigned int i = 0) const { return info[idx + i]; } 182 cur_poshb_buffer_t183 hb_glyph_position_t &cur_pos (unsigned int i = 0) { return pos[idx + i]; } cur_poshb_buffer_t184 hb_glyph_position_t cur_pos (unsigned int i = 0) const { return pos[idx + i]; } 185 prevhb_buffer_t186 hb_glyph_info_t &prev () { return out_info[out_len ? out_len - 1 : 0]; } prevhb_buffer_t187 hb_glyph_info_t prev () const { return out_info[out_len ? out_len - 1 : 0]; } 188 has_separate_outputhb_buffer_t189 bool has_separate_output () const { return info != out_info; } 190 191 192 HB_INTERNAL void reset (); 193 HB_INTERNAL void clear (); 194 backtrack_lenhb_buffer_t195 unsigned int backtrack_len () const { return have_output? out_len : idx; } lookahead_lenhb_buffer_t196 unsigned int lookahead_len () const { return len - idx; } next_serialhb_buffer_t197 unsigned int next_serial () { return serial++; } 198 199 HB_INTERNAL void add (hb_codepoint_t codepoint, 200 unsigned int cluster); 201 HB_INTERNAL void add_info (const hb_glyph_info_t &glyph_info); 202 203 HB_INTERNAL void reverse_range (unsigned int start, unsigned int end); 204 HB_INTERNAL void reverse (); 205 HB_INTERNAL void reverse_clusters (); 206 HB_INTERNAL void guess_segment_properties (); 207 208 HB_INTERNAL void swap_buffers (); 209 HB_INTERNAL void remove_output (); 210 HB_INTERNAL void clear_output (); 211 HB_INTERNAL void clear_positions (); 212 213 HB_INTERNAL void replace_glyphs (unsigned int num_in, 214 unsigned int num_out, 215 const hb_codepoint_t *glyph_data); 216 replace_glyphhb_buffer_t217 void replace_glyph (hb_codepoint_t glyph_index) 218 { 219 if (unlikely (out_info != info || out_len != idx)) { 220 if (unlikely (!make_room_for (1, 1))) return; 221 out_info[out_len] = info[idx]; 222 } 223 out_info[out_len].codepoint = glyph_index; 224 225 idx++; 226 out_len++; 227 } 228 /* Makes a copy of the glyph at idx to output and replace glyph_index */ output_glyphhb_buffer_t229 hb_glyph_info_t & output_glyph (hb_codepoint_t glyph_index) 230 { 231 if (unlikely (!make_room_for (0, 1))) return Crap(hb_glyph_info_t); 232 233 if (unlikely (idx == len && !out_len)) 234 return Crap(hb_glyph_info_t); 235 236 out_info[out_len] = idx < len ? info[idx] : out_info[out_len - 1]; 237 out_info[out_len].codepoint = glyph_index; 238 239 out_len++; 240 241 return out_info[out_len - 1]; 242 } output_infohb_buffer_t243 void output_info (const hb_glyph_info_t &glyph_info) 244 { 245 if (unlikely (!make_room_for (0, 1))) return; 246 247 out_info[out_len] = glyph_info; 248 249 out_len++; 250 } 251 /* Copies glyph at idx to output but doesn't advance idx */ copy_glyphhb_buffer_t252 void copy_glyph () 253 { 254 if (unlikely (!make_room_for (0, 1))) return; 255 256 out_info[out_len] = info[idx]; 257 258 out_len++; 259 } 260 /* Copies glyph at idx to output and advance idx. 261 * If there's no output, just advance idx. */ 262 void next_glyphhb_buffer_t263 next_glyph () 264 { 265 if (have_output) 266 { 267 if (out_info != info || out_len != idx) 268 { 269 if (unlikely (!make_room_for (1, 1))) return; 270 out_info[out_len] = info[idx]; 271 } 272 out_len++; 273 } 274 275 idx++; 276 } 277 /* Copies n glyphs at idx to output and advance idx. 278 * If there's no output, just advance idx. */ 279 void next_glyphshb_buffer_t280 next_glyphs (unsigned int n) 281 { 282 if (have_output) 283 { 284 if (out_info != info || out_len != idx) 285 { 286 if (unlikely (!make_room_for (n, n))) return; 287 memmove (out_info + out_len, info + idx, n * sizeof (out_info[0])); 288 } 289 out_len += n; 290 } 291 292 idx += n; 293 } 294 /* Advance idx without copying to output. */ skip_glyphhb_buffer_t295 void skip_glyph () { idx++; } reset_maskshb_buffer_t296 void reset_masks (hb_mask_t mask) 297 { 298 for (unsigned int j = 0; j < len; j++) 299 info[j].mask = mask; 300 } add_maskshb_buffer_t301 void add_masks (hb_mask_t mask) 302 { 303 for (unsigned int j = 0; j < len; j++) 304 info[j].mask |= mask; 305 } 306 HB_INTERNAL void set_masks (hb_mask_t value, hb_mask_t mask, 307 unsigned int cluster_start, unsigned int cluster_end); 308 merge_clustershb_buffer_t309 void merge_clusters (unsigned int start, unsigned int end) 310 { 311 if (end - start < 2) 312 return; 313 merge_clusters_impl (start, end); 314 } 315 HB_INTERNAL void merge_clusters_impl (unsigned int start, unsigned int end); 316 HB_INTERNAL void merge_out_clusters (unsigned int start, unsigned int end); 317 /* Merge clusters for deleting current glyph, and skip it. */ 318 HB_INTERNAL void delete_glyph (); 319 unsafe_to_breakhb_buffer_t320 void unsafe_to_break (unsigned int start, 321 unsigned int end) 322 { 323 if (end - start < 2) 324 return; 325 unsafe_to_break_impl (start, end); 326 } 327 HB_INTERNAL void unsafe_to_break_impl (unsigned int start, unsigned int end); 328 HB_INTERNAL void unsafe_to_break_from_outbuffer (unsigned int start, unsigned int end); 329 330 331 /* Internal methods */ 332 HB_INTERNAL bool move_to (unsigned int i); /* i is output-buffer index. */ 333 334 HB_INTERNAL bool enlarge (unsigned int size); 335 ensurehb_buffer_t336 bool ensure (unsigned int size) 337 { return likely (!size || size < allocated) ? true : enlarge (size); } 338 ensure_inplacehb_buffer_t339 bool ensure_inplace (unsigned int size) 340 { return likely (!size || size < allocated); } 341 342 HB_INTERNAL bool make_room_for (unsigned int num_in, unsigned int num_out); 343 HB_INTERNAL bool shift_forward (unsigned int count); 344 345 typedef long scratch_buffer_t; 346 HB_INTERNAL scratch_buffer_t *get_scratch_buffer (unsigned int *size); 347 clear_contexthb_buffer_t348 void clear_context (unsigned int side) { context_len[side] = 0; } 349 350 HB_INTERNAL void sort (unsigned int start, unsigned int end, int(*compar)(const hb_glyph_info_t *, const hb_glyph_info_t *)); 351 messaginghb_buffer_t352 bool messaging () 353 { 354 #ifdef HB_NO_BUFFER_MESSAGE 355 return false; 356 #else 357 return unlikely (message_func); 358 #endif 359 } messagehb_buffer_t360 bool message (hb_font_t *font, const char *fmt, ...) HB_PRINTF_FUNC(3, 4) 361 { 362 #ifdef HB_NO_BUFFER_MESSAGE 363 return true; 364 #else 365 if (!messaging ()) 366 return true; 367 va_list ap; 368 va_start (ap, fmt); 369 bool ret = message_impl (font, fmt, ap); 370 va_end (ap); 371 return ret; 372 #endif 373 } 374 HB_INTERNAL bool message_impl (hb_font_t *font, const char *fmt, va_list ap) HB_PRINTF_FUNC(3, 0); 375 376 static void set_clusterhb_buffer_t377 set_cluster (hb_glyph_info_t &inf, unsigned int cluster, unsigned int mask = 0) 378 { 379 if (inf.cluster != cluster) 380 { 381 if (mask & HB_GLYPH_FLAG_UNSAFE_TO_BREAK) 382 inf.mask |= HB_GLYPH_FLAG_UNSAFE_TO_BREAK; 383 else 384 inf.mask &= ~HB_GLYPH_FLAG_UNSAFE_TO_BREAK; 385 } 386 inf.cluster = cluster; 387 } 388 389 int _unsafe_to_break_find_min_clusterhb_buffer_t390 _unsafe_to_break_find_min_cluster (const hb_glyph_info_t *infos, 391 unsigned int start, unsigned int end, 392 unsigned int cluster) const 393 { 394 for (unsigned int i = start; i < end; i++) 395 cluster = hb_min (cluster, infos[i].cluster); 396 return cluster; 397 } 398 void _unsafe_to_break_set_maskhb_buffer_t399 _unsafe_to_break_set_mask (hb_glyph_info_t *infos, 400 unsigned int start, unsigned int end, 401 unsigned int cluster) 402 { 403 for (unsigned int i = start; i < end; i++) 404 if (cluster != infos[i].cluster) 405 { 406 scratch_flags |= HB_BUFFER_SCRATCH_FLAG_HAS_UNSAFE_TO_BREAK; 407 infos[i].mask |= HB_GLYPH_FLAG_UNSAFE_TO_BREAK; 408 } 409 } 410 unsafe_to_break_allhb_buffer_t411 void unsafe_to_break_all () { unsafe_to_break_impl (0, len); } safe_to_break_allhb_buffer_t412 void safe_to_break_all () 413 { 414 for (unsigned int i = 0; i < len; i++) 415 info[i].mask &= ~HB_GLYPH_FLAG_UNSAFE_TO_BREAK; 416 } 417 }; 418 DECLARE_NULL_INSTANCE (hb_buffer_t); 419 420 421 /* Loop over clusters. Duplicated in foreach_syllable(). */ 422 #define foreach_cluster(buffer, start, end) \ 423 for (unsigned int \ 424 _count = buffer->len, \ 425 start = 0, end = _count ? _next_cluster (buffer, 0) : 0; \ 426 start < _count; \ 427 start = end, end = _next_cluster (buffer, start)) 428 429 static inline unsigned int _next_cluster(hb_buffer_t * buffer,unsigned int start)430 _next_cluster (hb_buffer_t *buffer, unsigned int start) 431 { 432 hb_glyph_info_t *info = buffer->info; 433 unsigned int count = buffer->len; 434 435 unsigned int cluster = info[start].cluster; 436 while (++start < count && cluster == info[start].cluster) 437 ; 438 439 return start; 440 } 441 442 443 #define HB_BUFFER_XALLOCATE_VAR(b, func, var) \ 444 b->func (offsetof (hb_glyph_info_t, var) - offsetof(hb_glyph_info_t, var1), \ 445 sizeof (b->info[0].var)) 446 #define HB_BUFFER_ALLOCATE_VAR(b, var) HB_BUFFER_XALLOCATE_VAR (b, allocate_var, var ()) 447 #define HB_BUFFER_DEALLOCATE_VAR(b, var) HB_BUFFER_XALLOCATE_VAR (b, deallocate_var, var ()) 448 #define HB_BUFFER_ASSERT_VAR(b, var) HB_BUFFER_XALLOCATE_VAR (b, assert_var, var ()) 449 450 451 #endif /* HB_BUFFER_HH */ 452