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_EXPANSION_FACTOR
39 #define HB_BUFFER_MAX_EXPANSION_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 ASSERT_STATIC (sizeof (hb_glyph_info_t) == 20);
49 ASSERT_STATIC (sizeof (hb_glyph_info_t) == sizeof (hb_glyph_position_t));
50
51 HB_MARK_AS_FLAG_T (hb_buffer_flags_t);
52 HB_MARK_AS_FLAG_T (hb_buffer_serialize_flags_t);
53
54 enum hb_buffer_scratch_flags_t {
55 HB_BUFFER_SCRATCH_FLAG_DEFAULT = 0x00000000u,
56 HB_BUFFER_SCRATCH_FLAG_HAS_NON_ASCII = 0x00000001u,
57 HB_BUFFER_SCRATCH_FLAG_HAS_DEFAULT_IGNORABLES = 0x00000002u,
58 HB_BUFFER_SCRATCH_FLAG_HAS_SPACE_FALLBACK = 0x00000004u,
59 HB_BUFFER_SCRATCH_FLAG_HAS_GPOS_ATTACHMENT = 0x00000008u,
60 /* Reserved for complex shapers' internal use. */
61 HB_BUFFER_SCRATCH_FLAG_COMPLEX0 = 0x01000000u,
62 HB_BUFFER_SCRATCH_FLAG_COMPLEX1 = 0x02000000u,
63 HB_BUFFER_SCRATCH_FLAG_COMPLEX2 = 0x04000000u,
64 HB_BUFFER_SCRATCH_FLAG_COMPLEX3 = 0x08000000u,
65 };
66 HB_MARK_AS_FLAG_T (hb_buffer_scratch_flags_t);
67
68
69 /*
70 * hb_buffer_t
71 */
72
73 struct hb_buffer_t {
74 hb_object_header_t header;
75 ASSERT_POD ();
76
77 /* Information about how the text in the buffer should be treated */
78 hb_unicode_funcs_t *unicode; /* Unicode functions */
79 hb_buffer_flags_t flags; /* BOT / EOT / etc. */
80 hb_buffer_cluster_level_t cluster_level;
81 hb_codepoint_t replacement; /* U+FFFD or something else. */
82 hb_buffer_scratch_flags_t scratch_flags; /* Have space-flallback, etc. */
83 unsigned int max_len; /* Maximum allowed len. */
84
85 /* Buffer contents */
86 hb_buffer_content_type_t content_type;
87 hb_segment_properties_t props; /* Script, language, direction */
88
89 bool in_error; /* Allocation failed */
90 bool have_output; /* Whether we have an output buffer going on */
91 bool have_positions; /* Whether we have positions */
92
93 unsigned int idx; /* Cursor into ->info and ->pos arrays */
94 unsigned int len; /* Length of ->info and ->pos arrays */
95 unsigned int out_len; /* Length of ->out array if have_output */
96
97 unsigned int allocated; /* Length of allocated arrays */
98 hb_glyph_info_t *info;
99 hb_glyph_info_t *out_info;
100 hb_glyph_position_t *pos;
101
102 inline hb_glyph_info_t &cur (unsigned int i = 0) { return info[idx + i]; }
103 inline hb_glyph_info_t cur (unsigned int i = 0) const { return info[idx + i]; }
104
105 inline hb_glyph_position_t &cur_pos (unsigned int i = 0) { return pos[idx + i]; }
106 inline hb_glyph_position_t cur_pos (unsigned int i = 0) const { return pos[idx + i]; }
107
108 inline hb_glyph_info_t &prev (void) { return out_info[out_len ? out_len - 1 : 0]; }
109 inline hb_glyph_info_t prev (void) const { return out_info[out_len ? out_len - 1 : 0]; }
110
111 inline bool has_separate_output (void) const { return info != out_info; }
112
113 unsigned int serial;
114
115 /* Text before / after the main buffer contents.
116 * Always in Unicode, and ordered outward.
117 * Index 0 is for "pre-context", 1 for "post-context". */
118 static const unsigned int CONTEXT_LENGTH = 5;
119 hb_codepoint_t context[2][CONTEXT_LENGTH];
120 unsigned int context_len[2];
121
122 /* Debugging API */
123 hb_buffer_message_func_t message_func;
124 void *message_data;
125 hb_destroy_func_t message_destroy;
126
127 /* Internal debugging. */
128 /* The bits here reflect current allocations of the bytes in glyph_info_t's var1 and var2. */
129 #ifndef HB_NDEBUG
130 uint8_t allocated_var_bits;
131 #endif
132 inline void allocate_var (unsigned int start, unsigned int count)
133 {
134 #ifndef HB_NDEBUG
135 unsigned int end = start + count;
136 assert (end <= 8);
137 unsigned int bits = (1u<<end) - (1u<<start);
138 assert (0 == (allocated_var_bits & bits));
139 allocated_var_bits |= bits;
140 #endif
141 }
142 inline void deallocate_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 (bits == (allocated_var_bits & bits));
149 allocated_var_bits &= ~bits;
150 #endif
151 }
152 inline void assert_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 #endif
160 }
161 inline void deallocate_var_all (void)
162 {
163 #ifndef HB_NDEBUG
164 allocated_var_bits = 0;
165 #endif
166 }
167
168
169 /* Methods */
170
171 HB_INTERNAL void reset (void);
172 HB_INTERNAL void clear (void);
173
174 inline unsigned int backtrack_len (void) const
175 { return have_output? out_len : idx; }
176 inline unsigned int lookahead_len (void) const
177 { return len - idx; }
178 inline unsigned int next_serial (void) { return serial++; }
179
180 HB_INTERNAL void add (hb_codepoint_t codepoint,
181 unsigned int cluster);
182 HB_INTERNAL void add_info (const hb_glyph_info_t &glyph_info);
183
184 HB_INTERNAL void reverse_range (unsigned int start, unsigned int end);
185 HB_INTERNAL void reverse (void);
186 HB_INTERNAL void reverse_clusters (void);
187 HB_INTERNAL void guess_segment_properties (void);
188
189 HB_INTERNAL void swap_buffers (void);
190 HB_INTERNAL void remove_output (void);
191 HB_INTERNAL void clear_output (void);
192 HB_INTERNAL void clear_positions (void);
193
194 HB_INTERNAL void replace_glyphs (unsigned int num_in,
195 unsigned int num_out,
196 const hb_codepoint_t *glyph_data);
197
198 HB_INTERNAL void replace_glyph (hb_codepoint_t glyph_index);
199 /* Makes a copy of the glyph at idx to output and replace glyph_index */
200 HB_INTERNAL void output_glyph (hb_codepoint_t glyph_index);
201 HB_INTERNAL void output_info (const hb_glyph_info_t &glyph_info);
202 /* Copies glyph at idx to output but doesn't advance idx */
203 HB_INTERNAL void copy_glyph (void);
204 HB_INTERNAL bool move_to (unsigned int i); /* i is output-buffer index. */
205 /* Copies glyph at idx to output and advance idx.
206 * If there's no output, just advance idx. */
207 inline void
208 next_glyph (void)
209 {
210 if (have_output)
211 {
212 if (unlikely (out_info != info || out_len != idx)) {
213 if (unlikely (!make_room_for (1, 1))) return;
214 out_info[out_len] = info[idx];
215 }
216 out_len++;
217 }
218
219 idx++;
220 }
221
222 /* Advance idx without copying to output. */
223 inline void skip_glyph (void) { idx++; }
224
225 inline void reset_masks (hb_mask_t mask)
226 {
227 for (unsigned int j = 0; j < len; j++)
228 info[j].mask = mask;
229 }
230 inline void add_masks (hb_mask_t mask)
231 {
232 for (unsigned int j = 0; j < len; j++)
233 info[j].mask |= mask;
234 }
235 HB_INTERNAL void set_masks (hb_mask_t value,
236 hb_mask_t mask,
237 unsigned int cluster_start,
238 unsigned int cluster_end);
239
240 HB_INTERNAL void merge_clusters (unsigned int start,
241 unsigned int end)
242 {
243 if (end - start < 2)
244 return;
245 merge_clusters_impl (start, end);
246 }
247 HB_INTERNAL void merge_clusters_impl (unsigned int start,
248 unsigned int end);
249 HB_INTERNAL void merge_out_clusters (unsigned int start,
250 unsigned int end);
251 /* Merge clusters for deleting current glyph, and skip it. */
252 HB_INTERNAL void delete_glyph (void);
253
254 /* Internal methods */
255 HB_INTERNAL bool enlarge (unsigned int size);
256
257 inline bool ensure (unsigned int size)
258 { return likely (!size || size < allocated) ? true : enlarge (size); }
259
260 inline bool ensure_inplace (unsigned int size)
261 { return likely (!size || size < allocated); }
262
263 HB_INTERNAL bool make_room_for (unsigned int num_in, unsigned int num_out);
264 HB_INTERNAL bool shift_forward (unsigned int count);
265
266 typedef long scratch_buffer_t;
267 HB_INTERNAL scratch_buffer_t *get_scratch_buffer (unsigned int *size);
268
269 inline void clear_context (unsigned int side) { context_len[side] = 0; }
270
271 HB_INTERNAL void sort (unsigned int start, unsigned int end, int(*compar)(const hb_glyph_info_t *, const hb_glyph_info_t *));
272
273 inline bool messaging (void) { return unlikely (message_func); }
274 inline bool message (hb_font_t *font, const char *fmt, ...) HB_PRINTF_FUNC(3, 4)
275 {
276 if (!messaging ())
277 return true;
278 va_list ap;
279 va_start (ap, fmt);
280 bool ret = message_impl (font, fmt, ap);
281 va_end (ap);
282 return ret;
283 }
284 HB_INTERNAL bool message_impl (hb_font_t *font, const char *fmt, va_list ap) HB_PRINTF_FUNC(3, 0);
285 };
286
287
288 #define HB_BUFFER_XALLOCATE_VAR(b, func, var) \
289 b->func (offsetof (hb_glyph_info_t, var) - offsetof(hb_glyph_info_t, var1), \
290 sizeof (b->info[0].var))
291 #define HB_BUFFER_ALLOCATE_VAR(b, var) HB_BUFFER_XALLOCATE_VAR (b, allocate_var, var ())
292 #define HB_BUFFER_DEALLOCATE_VAR(b, var) HB_BUFFER_XALLOCATE_VAR (b, deallocate_var, var ())
293 #define HB_BUFFER_ASSERT_VAR(b, var) HB_BUFFER_XALLOCATE_VAR (b, assert_var, var ())
294
295
296 #endif /* HB_BUFFER_PRIVATE_HH */