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
allocate_varhb_buffer_t139 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 }
deallocate_varhb_buffer_t149 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 }
assert_varhb_buffer_t159 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 }
deallocate_var_allhb_buffer_t168 inline void deallocate_var_all (void)
169 {
170 #ifndef HB_NDEBUG
171 allocated_var_bits = 0;
172 #endif
173 }
174
curhb_buffer_t175 inline hb_glyph_info_t &cur (unsigned int i = 0) { return info[idx + i]; }
curhb_buffer_t176 inline hb_glyph_info_t cur (unsigned int i = 0) const { return info[idx + i]; }
177
cur_poshb_buffer_t178 inline hb_glyph_position_t &cur_pos (unsigned int i = 0) { return pos[idx + i]; }
cur_poshb_buffer_t179 inline hb_glyph_position_t cur_pos (unsigned int i = 0) const { return pos[idx + i]; }
180
prevhb_buffer_t181 inline hb_glyph_info_t &prev (void) { return out_info[out_len ? out_len - 1 : 0]; }
prevhb_buffer_t182 inline hb_glyph_info_t prev (void) const { return out_info[out_len ? out_len - 1 : 0]; }
183
has_separate_outputhb_buffer_t184 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
backtrack_lenhb_buffer_t190 inline unsigned int backtrack_len (void) const
191 { return have_output? out_len : idx; }
lookahead_lenhb_buffer_t192 inline unsigned int lookahead_len (void) const
193 { return len - idx; }
next_serialhb_buffer_t194 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
next_glyphhb_buffer_t224 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. */
skip_glyphhb_buffer_t239 inline void skip_glyph (void) { idx++; }
240
reset_maskshb_buffer_t241 inline void reset_masks (hb_mask_t mask)
242 {
243 for (unsigned int j = 0; j < len; j++)
244 info[j].mask = mask;
245 }
add_maskshb_buffer_t246 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
merge_clustershb_buffer_t254 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
unsafe_to_breakhb_buffer_t265 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
ensurehb_buffer_t279 inline bool ensure (unsigned int size)
280 { return likely (!size || size < allocated) ? true : enlarge (size); }
281
ensure_inplacehb_buffer_t282 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
clear_contexthb_buffer_t291 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
messaginghb_buffer_t295 inline bool messaging (void) { return unlikely (message_func); }
messagehb_buffer_t296 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
set_clusterhb_buffer_t309 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
_unsafe_to_break_find_min_clusterhb_buffer_t322 _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
_unsafe_to_break_set_maskhb_buffer_t331 _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
unsafe_to_break_allhb_buffer_t344 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
safe_to_break_allhb_buffer_t350 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
_next_cluster(hb_buffer_t * buffer,unsigned int start)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