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 HB_BUFFER_SCRATCH_FLAG_HAS_CGJ = 0x00000020u,
73
74 /* Reserved for complex shapers' internal use. */
75 HB_BUFFER_SCRATCH_FLAG_COMPLEX0 = 0x01000000u,
76 HB_BUFFER_SCRATCH_FLAG_COMPLEX1 = 0x02000000u,
77 HB_BUFFER_SCRATCH_FLAG_COMPLEX2 = 0x04000000u,
78 HB_BUFFER_SCRATCH_FLAG_COMPLEX3 = 0x08000000u,
79 };
80 HB_MARK_AS_FLAG_T (hb_buffer_scratch_flags_t);
81
82
83 /*
84 * hb_buffer_t
85 */
86
87 struct hb_buffer_t {
88 hb_object_header_t header;
89 ASSERT_POD ();
90
91 /* Information about how the text in the buffer should be treated */
92 hb_unicode_funcs_t *unicode; /* Unicode functions */
93 hb_buffer_flags_t flags; /* BOT / EOT / etc. */
94 hb_buffer_cluster_level_t cluster_level;
95 hb_codepoint_t replacement; /* U+FFFD 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 const unsigned int 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 inline void allocate_var (unsigned int start, unsigned int count)
141 {
142 #ifndef HB_NDEBUG
143 unsigned int end = start + count;
144 assert (end <= 8);
145 unsigned int bits = (1u<<end) - (1u<<start);
146 assert (0 == (allocated_var_bits & bits));
147 allocated_var_bits |= bits;
148 #endif
149 }
150 inline void deallocate_var (unsigned int start, unsigned int count)
151 {
152 #ifndef HB_NDEBUG
153 unsigned int end = start + count;
154 assert (end <= 8);
155 unsigned int bits = (1u<<end) - (1u<<start);
156 assert (bits == (allocated_var_bits & bits));
157 allocated_var_bits &= ~bits;
158 #endif
159 }
160 inline void assert_var (unsigned int start, unsigned int count)
161 {
162 #ifndef HB_NDEBUG
163 unsigned int end = start + count;
164 assert (end <= 8);
165 unsigned int bits = (1u<<end) - (1u<<start);
166 assert (bits == (allocated_var_bits & bits));
167 #endif
168 }
169 inline void deallocate_var_all (void)
170 {
171 #ifndef HB_NDEBUG
172 allocated_var_bits = 0;
173 #endif
174 }
175
176 inline hb_glyph_info_t &cur (unsigned int i = 0) { return info[idx + i]; }
177 inline hb_glyph_info_t cur (unsigned int i = 0) const { return info[idx + i]; }
178
179 inline hb_glyph_position_t &cur_pos (unsigned int i = 0) { return pos[idx + i]; }
180 inline hb_glyph_position_t cur_pos (unsigned int i = 0) const { return pos[idx + i]; }
181
182 inline hb_glyph_info_t &prev (void) { return out_info[out_len ? out_len - 1 : 0]; }
183 inline hb_glyph_info_t prev (void) const { return out_info[out_len ? out_len - 1 : 0]; }
184
185 inline bool has_separate_output (void) const { return info != out_info; }
186
187
188 HB_INTERNAL void reset (void);
189 HB_INTERNAL void clear (void);
190
191 inline unsigned int backtrack_len (void) const
192 { return have_output? out_len : idx; }
193 inline unsigned int lookahead_len (void) const
194 { return len - idx; }
195 inline unsigned int next_serial (void) { 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 (void);
203 HB_INTERNAL void reverse_clusters (void);
204 HB_INTERNAL void guess_segment_properties (void);
205
206 HB_INTERNAL void swap_buffers (void);
207 HB_INTERNAL void remove_output (void);
208 HB_INTERNAL void clear_output (void);
209 HB_INTERNAL void clear_positions (void);
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 HB_INTERNAL void replace_glyph (hb_codepoint_t glyph_index);
216 /* Makes a copy of the glyph at idx to output and replace glyph_index */
217 HB_INTERNAL void output_glyph (hb_codepoint_t glyph_index);
218 HB_INTERNAL void output_info (const hb_glyph_info_t &glyph_info);
219 /* Copies glyph at idx to output but doesn't advance idx */
220 HB_INTERNAL void copy_glyph (void);
221 HB_INTERNAL bool move_to (unsigned int i); /* i is output-buffer index. */
222 /* Copies glyph at idx to output and advance idx.
223 * If there's no output, just advance idx. */
224 inline void
225 next_glyph (void)
226 {
227 if (have_output)
228 {
229 if (unlikely (out_info != info || out_len != idx)) {
230 if (unlikely (!make_room_for (1, 1))) return;
231 out_info[out_len] = info[idx];
232 }
233 out_len++;
234 }
235
236 idx++;
237 }
238
239 /* Advance idx without copying to output. */
240 inline void skip_glyph (void) { idx++; }
241
242 inline void reset_masks (hb_mask_t mask)
243 {
244 for (unsigned int j = 0; j < len; j++)
245 info[j].mask = mask;
246 }
247 inline void add_masks (hb_mask_t mask)
248 {
249 for (unsigned int j = 0; j < len; j++)
250 info[j].mask |= mask;
251 }
252 HB_INTERNAL void set_masks (hb_mask_t value, hb_mask_t mask,
253 unsigned int cluster_start, unsigned int cluster_end);
254
255 inline void merge_clusters (unsigned int start, unsigned int end)
256 {
257 if (end - start < 2)
258 return;
259 merge_clusters_impl (start, end);
260 }
261 HB_INTERNAL void merge_clusters_impl (unsigned int start, unsigned int end);
262 HB_INTERNAL void merge_out_clusters (unsigned int start, unsigned int end);
263 /* Merge clusters for deleting current glyph, and skip it. */
264 HB_INTERNAL void delete_glyph (void);
265
266 inline void unsafe_to_break (unsigned int start,
267 unsigned int end)
268 {
269 if (end - start < 2)
270 return;
271 unsafe_to_break_impl (start, end);
272 }
273 HB_INTERNAL void unsafe_to_break_impl (unsigned int start, unsigned int end);
274 HB_INTERNAL void unsafe_to_break_from_outbuffer (unsigned int start, unsigned int end);
275
276
277 /* Internal methods */
278 HB_INTERNAL bool enlarge (unsigned int size);
279
280 inline bool ensure (unsigned int size)
281 { return likely (!size || size < allocated) ? true : enlarge (size); }
282
283 inline bool ensure_inplace (unsigned int size)
284 { return likely (!size || size < allocated); }
285
286 HB_INTERNAL bool make_room_for (unsigned int num_in, unsigned int num_out);
287 HB_INTERNAL bool shift_forward (unsigned int count);
288
289 typedef long scratch_buffer_t;
290 HB_INTERNAL scratch_buffer_t *get_scratch_buffer (unsigned int *size);
291
292 inline void clear_context (unsigned int side) { context_len[side] = 0; }
293
294 HB_INTERNAL void sort (unsigned int start, unsigned int end, int(*compar)(const hb_glyph_info_t *, const hb_glyph_info_t *));
295
296 inline bool messaging (void) { return unlikely (message_func); }
297 inline bool message (hb_font_t *font, const char *fmt, ...) HB_PRINTF_FUNC(3, 4)
298 {
299 if (!messaging ())
300 return true;
301 va_list ap;
302 va_start (ap, fmt);
303 bool ret = message_impl (font, fmt, ap);
304 va_end (ap);
305 return ret;
306 }
307 HB_INTERNAL bool message_impl (hb_font_t *font, const char *fmt, va_list ap) HB_PRINTF_FUNC(3, 0);
308
309 static inline void
310 set_cluster (hb_glyph_info_t &inf, unsigned int cluster, unsigned int mask = 0)
311 {
312 if (inf.cluster != cluster)
313 {
314 if (mask & HB_GLYPH_FLAG_UNSAFE_TO_BREAK)
315 inf.mask |= HB_GLYPH_FLAG_UNSAFE_TO_BREAK;
316 else
317 inf.mask &= ~HB_GLYPH_FLAG_UNSAFE_TO_BREAK;
318 }
319 inf.cluster = cluster;
320 }
321
322 inline int
323 _unsafe_to_break_find_min_cluster (const hb_glyph_info_t *infos,
324 unsigned int start, unsigned int end,
325 unsigned int cluster) const
326 {
327 for (unsigned int i = start; i < end; i++)
328 cluster = MIN<unsigned int> (cluster, infos[i].cluster);
329 return cluster;
330 }
331 inline void
332 _unsafe_to_break_set_mask (hb_glyph_info_t *infos,
333 unsigned int start, unsigned int end,
334 unsigned int cluster)
335 {
336 for (unsigned int i = start; i < end; i++)
337 if (cluster != infos[i].cluster)
338 {
339 scratch_flags |= HB_BUFFER_SCRATCH_FLAG_HAS_UNSAFE_TO_BREAK;
340 infos[i].mask |= HB_GLYPH_FLAG_UNSAFE_TO_BREAK;
341 }
342 }
343
344 inline void
345 unsafe_to_break_all (void)
346 {
347 unsafe_to_break_impl (0, len);
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 */