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_PRIVATE_HH 31 #define HB_BUFFER_PRIVATE_HH 32 33 #include "hb-private.hh" 34 #include "hb-object-private.hh" 35 #include "hb-unicode-private.hh" 36 37 38 #ifndef HB_BUFFER_MAX_LEN_FACTOR 39 #define HB_BUFFER_MAX_LEN_FACTOR 32 40 #endif 41 #ifndef HB_BUFFER_MAX_LEN_MIN 42 #define HB_BUFFER_MAX_LEN_MIN 8192 43 #endif 44 #ifndef HB_BUFFER_MAX_LEN_DEFAULT 45 #define HB_BUFFER_MAX_LEN_DEFAULT 0x3FFFFFFF /* Shaping more than a billion chars? Let us know! */ 46 #endif 47 48 #ifndef HB_BUFFER_MAX_OPS_FACTOR 49 #define HB_BUFFER_MAX_OPS_FACTOR 64 50 #endif 51 #ifndef HB_BUFFER_MAX_OPS_MIN 52 #define HB_BUFFER_MAX_OPS_MIN 1024 53 #endif 54 #ifndef HB_BUFFER_MAX_OPS_DEFAULT 55 #define HB_BUFFER_MAX_OPS_DEFAULT 0x1FFFFFFF /* Shaping more than a billion operations? Let us know! */ 56 #endif 57 58 static_assert ((sizeof (hb_glyph_info_t) == 20), ""); 59 static_assert ((sizeof (hb_glyph_info_t) == sizeof (hb_glyph_position_t)), ""); 60 61 HB_MARK_AS_FLAG_T (hb_buffer_flags_t); 62 HB_MARK_AS_FLAG_T (hb_buffer_serialize_flags_t); 63 HB_MARK_AS_FLAG_T (hb_buffer_diff_flags_t); 64 65 enum hb_buffer_scratch_flags_t { 66 HB_BUFFER_SCRATCH_FLAG_DEFAULT = 0x00000000u, 67 HB_BUFFER_SCRATCH_FLAG_HAS_NON_ASCII = 0x00000001u, 68 HB_BUFFER_SCRATCH_FLAG_HAS_DEFAULT_IGNORABLES = 0x00000002u, 69 HB_BUFFER_SCRATCH_FLAG_HAS_SPACE_FALLBACK = 0x00000004u, 70 HB_BUFFER_SCRATCH_FLAG_HAS_GPOS_ATTACHMENT = 0x00000008u, 71 HB_BUFFER_SCRATCH_FLAG_HAS_UNSAFE_TO_BREAK = 0x00000010u, 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 hb_object_header_t header; 88 ASSERT_POD (); 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_buffer_scratch_flags_t scratch_flags; /* Have space-flallback, etc. */ 96 unsigned int max_len; /* Maximum allowed len. */ 97 int max_ops; /* Maximum allowed operations. */ 98 99 /* Buffer contents */ 100 hb_buffer_content_type_t content_type; 101 hb_segment_properties_t props; /* Script, language, direction */ 102 103 bool in_error; /* Allocation failed */ 104 bool have_output; /* Whether we have an output buffer going on */ 105 bool have_positions; /* Whether we have positions */ 106 107 unsigned int idx; /* Cursor into ->info and ->pos arrays */ 108 unsigned int len; /* Length of ->info and ->pos arrays */ 109 unsigned int out_len; /* Length of ->out array if have_output */ 110 111 unsigned int allocated; /* Length of allocated arrays */ 112 hb_glyph_info_t *info; 113 hb_glyph_info_t *out_info; 114 hb_glyph_position_t *pos; 115 116 unsigned int serial; 117 118 /* Text before / after the main buffer contents. 119 * Always in Unicode, and ordered outward. 120 * Index 0 is for "pre-context", 1 for "post-context". */ 121 static const unsigned int CONTEXT_LENGTH = 5; 122 hb_codepoint_t context[2][CONTEXT_LENGTH]; 123 unsigned int context_len[2]; 124 125 /* Debugging API */ 126 hb_buffer_message_func_t message_func; 127 void *message_data; 128 hb_destroy_func_t message_destroy; 129 130 /* Internal debugging. */ 131 /* The bits here reflect current allocations of the bytes in glyph_info_t's var1 and var2. */ 132 #ifndef HB_NDEBUG 133 uint8_t allocated_var_bits; 134 #endif 135 136 137 /* Methods */ 138 139 inline void allocate_var (unsigned int start, unsigned int count) 140 { 141 #ifndef HB_NDEBUG 142 unsigned int end = start + count; 143 assert (end <= 8); 144 unsigned int bits = (1u<<end) - (1u<<start); 145 assert (0 == (allocated_var_bits & bits)); 146 allocated_var_bits |= bits; 147 #endif 148 } 149 inline void deallocate_var (unsigned int start, unsigned int count) 150 { 151 #ifndef HB_NDEBUG 152 unsigned int end = start + count; 153 assert (end <= 8); 154 unsigned int bits = (1u<<end) - (1u<<start); 155 assert (bits == (allocated_var_bits & bits)); 156 allocated_var_bits &= ~bits; 157 #endif 158 } 159 inline void assert_var (unsigned int start, unsigned int count) 160 { 161 #ifndef HB_NDEBUG 162 unsigned int end = start + count; 163 assert (end <= 8); 164 unsigned int bits = (1u<<end) - (1u<<start); 165 assert (bits == (allocated_var_bits & bits)); 166 #endif 167 } 168 inline void deallocate_var_all (void) 169 { 170 #ifndef HB_NDEBUG 171 allocated_var_bits = 0; 172 #endif 173 } 174 175 inline hb_glyph_info_t &cur (unsigned int i = 0) { return info[idx + i]; } 176 inline hb_glyph_info_t cur (unsigned int i = 0) const { return info[idx + i]; } 177 178 inline hb_glyph_position_t &cur_pos (unsigned int i = 0) { return pos[idx + i]; } 179 inline hb_glyph_position_t cur_pos (unsigned int i = 0) const { return pos[idx + i]; } 180 181 inline hb_glyph_info_t &prev (void) { return out_info[out_len ? out_len - 1 : 0]; } 182 inline hb_glyph_info_t prev (void) const { return out_info[out_len ? out_len - 1 : 0]; } 183 184 inline bool has_separate_output (void) const { return info != out_info; } 185 186 187 HB_INTERNAL void reset (void); 188 HB_INTERNAL void clear (void); 189 190 inline unsigned int backtrack_len (void) const 191 { return have_output? out_len : idx; } 192 inline unsigned int lookahead_len (void) const 193 { return len - idx; } 194 inline unsigned int next_serial (void) { return serial++; } 195 196 HB_INTERNAL void add (hb_codepoint_t codepoint, 197 unsigned int cluster); 198 HB_INTERNAL void add_info (const hb_glyph_info_t &glyph_info); 199 200 HB_INTERNAL void reverse_range (unsigned int start, unsigned int end); 201 HB_INTERNAL void reverse (void); 202 HB_INTERNAL void reverse_clusters (void); 203 HB_INTERNAL void guess_segment_properties (void); 204 205 HB_INTERNAL void swap_buffers (void); 206 HB_INTERNAL void remove_output (void); 207 HB_INTERNAL void clear_output (void); 208 HB_INTERNAL void clear_positions (void); 209 210 HB_INTERNAL void replace_glyphs (unsigned int num_in, 211 unsigned int num_out, 212 const hb_codepoint_t *glyph_data); 213 214 HB_INTERNAL void replace_glyph (hb_codepoint_t glyph_index); 215 /* Makes a copy of the glyph at idx to output and replace glyph_index */ 216 HB_INTERNAL void output_glyph (hb_codepoint_t glyph_index); 217 HB_INTERNAL void output_info (const hb_glyph_info_t &glyph_info); 218 /* Copies glyph at idx to output but doesn't advance idx */ 219 HB_INTERNAL void copy_glyph (void); 220 HB_INTERNAL bool move_to (unsigned int i); /* i is output-buffer index. */ 221 /* Copies glyph at idx to output and advance idx. 222 * If there's no output, just advance idx. */ 223 inline void 224 next_glyph (void) 225 { 226 if (have_output) 227 { 228 if (unlikely (out_info != info || out_len != idx)) { 229 if (unlikely (!make_room_for (1, 1))) return; 230 out_info[out_len] = info[idx]; 231 } 232 out_len++; 233 } 234 235 idx++; 236 } 237 238 /* Advance idx without copying to output. */ 239 inline void skip_glyph (void) { idx++; } 240 241 inline void reset_masks (hb_mask_t mask) 242 { 243 for (unsigned int j = 0; j < len; j++) 244 info[j].mask = mask; 245 } 246 inline void add_masks (hb_mask_t mask) 247 { 248 for (unsigned int j = 0; j < len; j++) 249 info[j].mask |= mask; 250 } 251 HB_INTERNAL void set_masks (hb_mask_t value, hb_mask_t mask, 252 unsigned int cluster_start, unsigned int cluster_end); 253 254 inline void merge_clusters (unsigned int start, unsigned int end) 255 { 256 if (end - start < 2) 257 return; 258 merge_clusters_impl (start, end); 259 } 260 HB_INTERNAL void merge_clusters_impl (unsigned int start, unsigned int end); 261 HB_INTERNAL void merge_out_clusters (unsigned int start, unsigned int end); 262 /* Merge clusters for deleting current glyph, and skip it. */ 263 HB_INTERNAL void delete_glyph (void); 264 265 inline void unsafe_to_break (unsigned int start, 266 unsigned int end) 267 { 268 if (end - start < 2) 269 return; 270 unsafe_to_break_impl (start, end); 271 } 272 HB_INTERNAL void unsafe_to_break_impl (unsigned int start, unsigned int end); 273 HB_INTERNAL void unsafe_to_break_from_outbuffer (unsigned int start, unsigned int end); 274 275 276 /* Internal methods */ 277 HB_INTERNAL bool enlarge (unsigned int size); 278 279 inline bool ensure (unsigned int size) 280 { return likely (!size || size < allocated) ? true : enlarge (size); } 281 282 inline bool ensure_inplace (unsigned int size) 283 { return likely (!size || size < allocated); } 284 285 HB_INTERNAL bool make_room_for (unsigned int num_in, unsigned int num_out); 286 HB_INTERNAL bool shift_forward (unsigned int count); 287 288 typedef long scratch_buffer_t; 289 HB_INTERNAL scratch_buffer_t *get_scratch_buffer (unsigned int *size); 290 291 inline void clear_context (unsigned int side) { context_len[side] = 0; } 292 293 HB_INTERNAL void sort (unsigned int start, unsigned int end, int(*compar)(const hb_glyph_info_t *, const hb_glyph_info_t *)); 294 295 inline bool messaging (void) { return unlikely (message_func); } 296 inline bool message (hb_font_t *font, const char *fmt, ...) HB_PRINTF_FUNC(3, 4) 297 { 298 if (!messaging ()) 299 return true; 300 va_list ap; 301 va_start (ap, fmt); 302 bool ret = message_impl (font, fmt, ap); 303 va_end (ap); 304 return ret; 305 } 306 HB_INTERNAL bool message_impl (hb_font_t *font, const char *fmt, va_list ap) HB_PRINTF_FUNC(3, 0); 307 308 static inline void 309 set_cluster (hb_glyph_info_t &info, unsigned int cluster, unsigned int mask = 0) 310 { 311 if (info.cluster != cluster) 312 { 313 if (mask & HB_GLYPH_FLAG_UNSAFE_TO_BREAK) 314 info.mask |= HB_GLYPH_FLAG_UNSAFE_TO_BREAK; 315 else 316 info.mask &= ~HB_GLYPH_FLAG_UNSAFE_TO_BREAK; 317 } 318 info.cluster = cluster; 319 } 320 321 inline int 322 _unsafe_to_break_find_min_cluster (const hb_glyph_info_t *info, 323 unsigned int start, unsigned int end, 324 unsigned int cluster) const 325 { 326 for (unsigned int i = start; i < end; i++) 327 cluster = MIN<unsigned int> (cluster, info[i].cluster); 328 return cluster; 329 } 330 inline void 331 _unsafe_to_break_set_mask (hb_glyph_info_t *info, 332 unsigned int start, unsigned int end, 333 unsigned int cluster) 334 { 335 for (unsigned int i = start; i < end; i++) 336 if (cluster != info[i].cluster) 337 { 338 scratch_flags |= HB_BUFFER_SCRATCH_FLAG_HAS_UNSAFE_TO_BREAK; 339 info[i].mask |= HB_GLYPH_FLAG_UNSAFE_TO_BREAK; 340 } 341 } 342 343 inline void 344 unsafe_to_break_all (void) 345 { 346 for (unsigned int i = 0; i < len; i++) 347 info[i].mask |= HB_GLYPH_FLAG_UNSAFE_TO_BREAK; 348 } 349 inline void 350 safe_to_break_all (void) 351 { 352 for (unsigned int i = 0; i < len; i++) 353 info[i].mask &= ~HB_GLYPH_FLAG_UNSAFE_TO_BREAK; 354 } 355 }; 356 357 358 /* Loop over clusters. Duplicated in foreach_syllable(). */ 359 #define foreach_cluster(buffer, start, end) \ 360 for (unsigned int \ 361 _count = buffer->len, \ 362 start = 0, end = _count ? _next_cluster (buffer, 0) : 0; \ 363 start < _count; \ 364 start = end, end = _next_cluster (buffer, start)) 365 366 static inline unsigned int 367 _next_cluster (hb_buffer_t *buffer, unsigned int start) 368 { 369 hb_glyph_info_t *info = buffer->info; 370 unsigned int count = buffer->len; 371 372 unsigned int cluster = info[start].cluster; 373 while (++start < count && cluster == info[start].cluster) 374 ; 375 376 return start; 377 } 378 379 380 #define HB_BUFFER_XALLOCATE_VAR(b, func, var) \ 381 b->func (offsetof (hb_glyph_info_t, var) - offsetof(hb_glyph_info_t, var1), \ 382 sizeof (b->info[0].var)) 383 #define HB_BUFFER_ALLOCATE_VAR(b, var) HB_BUFFER_XALLOCATE_VAR (b, allocate_var, var ()) 384 #define HB_BUFFER_DEALLOCATE_VAR(b, var) HB_BUFFER_XALLOCATE_VAR (b, deallocate_var, var ()) 385 #define HB_BUFFER_ASSERT_VAR(b, var) HB_BUFFER_XALLOCATE_VAR (b, assert_var, var ()) 386 387 388 #endif /* HB_BUFFER_PRIVATE_HH */ 389
