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 enum { CONTEXT_LENGTH = 5 }; 123 hb_codepoint_t context[2][CONTEXT_LENGTH]; 124 unsigned int context_len[2]; 125 126 /* Debugging API */ 127 hb_buffer_message_func_t message_func; 128 void *message_data; 129 hb_destroy_func_t message_destroy; 130 131 /* Internal debugging. */ 132 /* The bits here reflect current allocations of the bytes in glyph_info_t's var1 and var2. */ 133 #ifndef HB_NDEBUG 134 uint8_t allocated_var_bits; 135 #endif 136 137 138 /* Methods */ 139 140 bool in_error () const { return !successful; } 141 142 void allocate_var (unsigned int start, unsigned int count) 143 { 144 #ifndef HB_NDEBUG 145 unsigned int end = start + count; 146 assert (end <= 8); 147 unsigned int bits = (1u<<end) - (1u<<start); 148 assert (0 == (allocated_var_bits & bits)); 149 allocated_var_bits |= bits; 150 #endif 151 } 152 void deallocate_var (unsigned int start, unsigned int count) 153 { 154 #ifndef HB_NDEBUG 155 unsigned int end = start + count; 156 assert (end <= 8); 157 unsigned int bits = (1u<<end) - (1u<<start); 158 assert (bits == (allocated_var_bits & bits)); 159 allocated_var_bits &= ~bits; 160 #endif 161 } 162 void assert_var (unsigned int start, unsigned int count) 163 { 164 #ifndef HB_NDEBUG 165 unsigned int end = start + count; 166 assert (end <= 8); 167 unsigned int bits = (1u<<end) - (1u<<start); 168 assert (bits == (allocated_var_bits & bits)); 169 #endif 170 } 171 void deallocate_var_all () 172 { 173 #ifndef HB_NDEBUG 174 allocated_var_bits = 0; 175 #endif 176 } 177 178 hb_glyph_info_t &cur (unsigned int i = 0) { return info[idx + i]; } 179 hb_glyph_info_t cur (unsigned int i = 0) const { return info[idx + i]; } 180 181 hb_glyph_position_t &cur_pos (unsigned int i = 0) { return pos[idx + i]; } 182 hb_glyph_position_t cur_pos (unsigned int i = 0) const { return pos[idx + i]; } 183 184 hb_glyph_info_t &prev () { return out_info[out_len ? out_len - 1 : 0]; } 185 hb_glyph_info_t prev () const { return out_info[out_len ? out_len - 1 : 0]; } 186 187 bool has_separate_output () const { return info != out_info; } 188 189 190 HB_INTERNAL void reset (); 191 HB_INTERNAL void clear (); 192 193 unsigned int backtrack_len () const { return have_output? out_len : idx; } 194 unsigned int lookahead_len () const { return len - idx; } 195 unsigned int next_serial () { return serial++; } 196 197 HB_INTERNAL void add (hb_codepoint_t codepoint, 198 unsigned int cluster); 199 HB_INTERNAL void add_info (const hb_glyph_info_t &glyph_info); 200 201 HB_INTERNAL void reverse_range (unsigned int start, unsigned int end); 202 HB_INTERNAL void reverse (); 203 HB_INTERNAL void reverse_clusters (); 204 HB_INTERNAL void guess_segment_properties (); 205 206 HB_INTERNAL void swap_buffers (); 207 HB_INTERNAL void remove_output (); 208 HB_INTERNAL void clear_output (); 209 HB_INTERNAL void clear_positions (); 210 211 HB_INTERNAL void replace_glyphs (unsigned int num_in, 212 unsigned int num_out, 213 const hb_codepoint_t *glyph_data); 214 215 void replace_glyph (hb_codepoint_t glyph_index) 216 { 217 if (unlikely (out_info != info || out_len != idx)) { 218 if (unlikely (!make_room_for (1, 1))) return; 219 out_info[out_len] = info[idx]; 220 } 221 out_info[out_len].codepoint = glyph_index; 222 223 idx++; 224 out_len++; 225 } 226 /* Makes a copy of the glyph at idx to output and replace glyph_index */ 227 hb_glyph_info_t & output_glyph (hb_codepoint_t glyph_index) 228 { 229 if (unlikely (!make_room_for (0, 1))) return Crap(hb_glyph_info_t); 230 231 if (unlikely (idx == len && !out_len)) 232 return Crap(hb_glyph_info_t); 233 234 out_info[out_len] = idx < len ? info[idx] : out_info[out_len - 1]; 235 out_info[out_len].codepoint = glyph_index; 236 237 out_len++; 238 239 return out_info[out_len - 1]; 240 } 241 void output_info (const hb_glyph_info_t &glyph_info) 242 { 243 if (unlikely (!make_room_for (0, 1))) return; 244 245 out_info[out_len] = glyph_info; 246 247 out_len++; 248 } 249 /* Copies glyph at idx to output but doesn't advance idx */ 250 void copy_glyph () 251 { 252 if (unlikely (!make_room_for (0, 1))) return; 253 254 out_info[out_len] = info[idx]; 255 256 out_len++; 257 } 258 /* Copies glyph at idx to output and advance idx. 259 * If there's no output, just advance idx. */ 260 void 261 next_glyph () 262 { 263 if (have_output) 264 { 265 if (out_info != info || out_len != idx) 266 { 267 if (unlikely (!make_room_for (1, 1))) return; 268 out_info[out_len] = info[idx]; 269 } 270 out_len++; 271 } 272 273 idx++; 274 } 275 /* Copies n glyphs at idx to output and advance idx. 276 * If there's no output, just advance idx. */ 277 void 278 next_glyphs (unsigned int n) 279 { 280 if (have_output) 281 { 282 if (out_info != info || out_len != idx) 283 { 284 if (unlikely (!make_room_for (n, n))) return; 285 memmove (out_info + out_len, info + idx, n * sizeof (out_info[0])); 286 } 287 out_len += n; 288 } 289 290 idx += n; 291 } 292 /* Advance idx without copying to output. */ 293 void skip_glyph () { idx++; } 294 void reset_masks (hb_mask_t mask) 295 { 296 for (unsigned int j = 0; j < len; j++) 297 info[j].mask = mask; 298 } 299 void add_masks (hb_mask_t mask) 300 { 301 for (unsigned int j = 0; j < len; j++) 302 info[j].mask |= mask; 303 } 304 HB_INTERNAL void set_masks (hb_mask_t value, hb_mask_t mask, 305 unsigned int cluster_start, unsigned int cluster_end); 306 307 void merge_clusters (unsigned int start, unsigned int end) 308 { 309 if (end - start < 2) 310 return; 311 merge_clusters_impl (start, end); 312 } 313 HB_INTERNAL void merge_clusters_impl (unsigned int start, unsigned int end); 314 HB_INTERNAL void merge_out_clusters (unsigned int start, unsigned int end); 315 /* Merge clusters for deleting current glyph, and skip it. */ 316 HB_INTERNAL void delete_glyph (); 317 318 void unsafe_to_break (unsigned int start, 319 unsigned int end) 320 { 321 if (end - start < 2) 322 return; 323 unsafe_to_break_impl (start, end); 324 } 325 HB_INTERNAL void unsafe_to_break_impl (unsigned int start, unsigned int end); 326 HB_INTERNAL void unsafe_to_break_from_outbuffer (unsigned int start, unsigned int end); 327 328 329 /* Internal methods */ 330 HB_INTERNAL bool move_to (unsigned int i); /* i is output-buffer index. */ 331 332 HB_INTERNAL bool enlarge (unsigned int size); 333 334 bool ensure (unsigned int size) 335 { return likely (!size || size < allocated) ? true : enlarge (size); } 336 337 bool ensure_inplace (unsigned int size) 338 { return likely (!size || size < allocated); } 339 340 HB_INTERNAL bool make_room_for (unsigned int num_in, unsigned int num_out); 341 HB_INTERNAL bool shift_forward (unsigned int count); 342 343 typedef long scratch_buffer_t; 344 HB_INTERNAL scratch_buffer_t *get_scratch_buffer (unsigned int *size); 345 346 void clear_context (unsigned int side) { context_len[side] = 0; } 347 348 HB_INTERNAL void sort (unsigned int start, unsigned int end, int(*compar)(const hb_glyph_info_t *, const hb_glyph_info_t *)); 349 350 bool messaging () { return unlikely (message_func); } 351 bool message (hb_font_t *font, const char *fmt, ...) HB_PRINTF_FUNC(3, 4) 352 { 353 if (!messaging ()) 354 return true; 355 va_list ap; 356 va_start (ap, fmt); 357 bool ret = message_impl (font, fmt, ap); 358 va_end (ap); 359 return ret; 360 } 361 HB_INTERNAL bool message_impl (hb_font_t *font, const char *fmt, va_list ap) HB_PRINTF_FUNC(3, 0); 362 363 static void 364 set_cluster (hb_glyph_info_t &inf, unsigned int cluster, unsigned int mask = 0) 365 { 366 if (inf.cluster != cluster) 367 { 368 if (mask & HB_GLYPH_FLAG_UNSAFE_TO_BREAK) 369 inf.mask |= HB_GLYPH_FLAG_UNSAFE_TO_BREAK; 370 else 371 inf.mask &= ~HB_GLYPH_FLAG_UNSAFE_TO_BREAK; 372 } 373 inf.cluster = cluster; 374 } 375 376 int 377 _unsafe_to_break_find_min_cluster (const hb_glyph_info_t *infos, 378 unsigned int start, unsigned int end, 379 unsigned int cluster) const 380 { 381 for (unsigned int i = start; i < end; i++) 382 cluster = MIN<unsigned int> (cluster, infos[i].cluster); 383 return cluster; 384 } 385 void 386 _unsafe_to_break_set_mask (hb_glyph_info_t *infos, 387 unsigned int start, unsigned int end, 388 unsigned int cluster) 389 { 390 for (unsigned int i = start; i < end; i++) 391 if (cluster != infos[i].cluster) 392 { 393 scratch_flags |= HB_BUFFER_SCRATCH_FLAG_HAS_UNSAFE_TO_BREAK; 394 infos[i].mask |= HB_GLYPH_FLAG_UNSAFE_TO_BREAK; 395 } 396 } 397 398 void unsafe_to_break_all () 399 { unsafe_to_break_impl (0, len); } 400 void safe_to_break_all () 401 { 402 for (unsigned int i = 0; i < len; i++) 403 info[i].mask &= ~HB_GLYPH_FLAG_UNSAFE_TO_BREAK; 404 } 405 }; 406 DECLARE_NULL_INSTANCE (hb_buffer_t); 407 408 409 /* Loop over clusters. Duplicated in foreach_syllable(). */ 410 #define foreach_cluster(buffer, start, end) \ 411 for (unsigned int \ 412 _count = buffer->len, \ 413 start = 0, end = _count ? _next_cluster (buffer, 0) : 0; \ 414 start < _count; \ 415 start = end, end = _next_cluster (buffer, start)) 416 417 static inline unsigned int 418 _next_cluster (hb_buffer_t *buffer, unsigned int start) 419 { 420 hb_glyph_info_t *info = buffer->info; 421 unsigned int count = buffer->len; 422 423 unsigned int cluster = info[start].cluster; 424 while (++start < count && cluster == info[start].cluster) 425 ; 426 427 return start; 428 } 429 430 431 #define HB_BUFFER_XALLOCATE_VAR(b, func, var) \ 432 b->func (offsetof (hb_glyph_info_t, var) - offsetof(hb_glyph_info_t, var1), \ 433 sizeof (b->info[0].var)) 434 #define HB_BUFFER_ALLOCATE_VAR(b, var) HB_BUFFER_XALLOCATE_VAR (b, allocate_var, var ()) 435 #define HB_BUFFER_DEALLOCATE_VAR(b, var) HB_BUFFER_XALLOCATE_VAR (b, deallocate_var, var ()) 436 #define HB_BUFFER_ASSERT_VAR(b, var) HB_BUFFER_XALLOCATE_VAR (b, assert_var, var ()) 437 438 439 #endif /* HB_BUFFER_HH */ 440
