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 ASSERT_STATIC (sizeof (hb_glyph_info_t) == 20);
39 ASSERT_STATIC (sizeof (hb_glyph_info_t) == sizeof (hb_glyph_position_t));
40
41
42 /*
43 * hb_buffer_t
44 */
45
46 struct hb_buffer_t {
47 hb_object_header_t header;
48 ASSERT_POD ();
49
50 /* Information about how the text in the buffer should be treated */
51 hb_unicode_funcs_t *unicode; /* Unicode functions */
52 hb_buffer_flags_t flags; /* BOT / EOT / etc. */
53 hb_buffer_cluster_level_t cluster_level;
54 hb_codepoint_t replacement; /* U+FFFD or something else. */
55
56 /* Buffer contents */
57 hb_buffer_content_type_t content_type;
58 hb_segment_properties_t props; /* Script, language, direction */
59
60 bool in_error; /* Allocation failed */
61 bool have_output; /* Whether we have an output buffer going on */
62 bool have_positions; /* Whether we have positions */
63
64 unsigned int idx; /* Cursor into ->info and ->pos arrays */
65 unsigned int len; /* Length of ->info and ->pos arrays */
66 unsigned int out_len; /* Length of ->out array if have_output */
67
68 unsigned int allocated; /* Length of allocated arrays */
69 hb_glyph_info_t *info;
70 hb_glyph_info_t *out_info;
71 hb_glyph_position_t *pos;
72
73 inline hb_glyph_info_t &cur (unsigned int i = 0) { return info[idx + i]; }
74 inline hb_glyph_info_t cur (unsigned int i = 0) const { return info[idx + i]; }
75
76 inline hb_glyph_position_t &cur_pos (unsigned int i = 0) { return pos[idx + i]; }
77 inline hb_glyph_position_t cur_pos (unsigned int i = 0) const { return pos[idx + i]; }
78
79 inline hb_glyph_info_t &prev (void) { return out_info[out_len - 1]; }
80 inline hb_glyph_info_t prev (void) const { return info[out_len - 1]; }
81
82 inline bool has_separate_output (void) const { return info != out_info; }
83
84 unsigned int serial;
85
86 /* These reflect current allocations of the bytes in glyph_info_t's var1 and var2. */
87 uint8_t allocated_var_bytes[8];
88 const char *allocated_var_owner[8];
89
90 /* Text before / after the main buffer contents.
91 * Always in Unicode, and ordered outward.
92 * Index 0 is for "pre-context", 1 for "post-context". */
93 static const unsigned int CONTEXT_LENGTH = 5;
94 hb_codepoint_t context[2][CONTEXT_LENGTH];
95 unsigned int context_len[2];
96
97
98 /* Methods */
99
100 HB_INTERNAL void reset (void);
101 HB_INTERNAL void clear (void);
102
103 inline unsigned int backtrack_len (void) const
104 { return have_output? out_len : idx; }
105 inline unsigned int lookahead_len (void) const
106 { return len - idx; }
107 inline unsigned int next_serial (void) { return serial++; }
108
109 HB_INTERNAL void allocate_var (unsigned int byte_i, unsigned int count, const char *owner);
110 HB_INTERNAL void deallocate_var (unsigned int byte_i, unsigned int count, const char *owner);
111 HB_INTERNAL void assert_var (unsigned int byte_i, unsigned int count, const char *owner);
112 HB_INTERNAL void deallocate_var_all (void);
113
114 HB_INTERNAL void add (hb_codepoint_t codepoint,
115 unsigned int cluster);
116 HB_INTERNAL void add_info (const hb_glyph_info_t &glyph_info);
117
118 HB_INTERNAL void reverse_range (unsigned int start, unsigned int end);
119 HB_INTERNAL void reverse (void);
120 HB_INTERNAL void reverse_clusters (void);
121 HB_INTERNAL void guess_segment_properties (void);
122
123 HB_INTERNAL void swap_buffers (void);
124 HB_INTERNAL void remove_output (void);
125 HB_INTERNAL void clear_output (void);
126 HB_INTERNAL void clear_positions (void);
127
128 HB_INTERNAL void replace_glyphs (unsigned int num_in,
129 unsigned int num_out,
130 const hb_codepoint_t *glyph_data);
131
132 HB_INTERNAL void replace_glyph (hb_codepoint_t glyph_index);
133 /* Makes a copy of the glyph at idx to output and replace glyph_index */
134 HB_INTERNAL void output_glyph (hb_codepoint_t glyph_index);
135 HB_INTERNAL void output_info (const hb_glyph_info_t &glyph_info);
136 /* Copies glyph at idx to output but doesn't advance idx */
137 HB_INTERNAL void copy_glyph (void);
138 HB_INTERNAL bool move_to (unsigned int i); /* i is output-buffer index. */
139 /* Copies glyph at idx to output and advance idx.
140 * If there's no output, just advance idx. */
141 inline void
142 next_glyph (void)
143 {
144 if (have_output)
145 {
146 if (unlikely (out_info != info || out_len != idx)) {
147 if (unlikely (!make_room_for (1, 1))) return;
148 out_info[out_len] = info[idx];
149 }
150 out_len++;
151 }
152
153 idx++;
154 }
155
156 /* Advance idx without copying to output. */
157 inline void skip_glyph (void) { idx++; }
158
159 inline void reset_masks (hb_mask_t mask)
160 {
161 for (unsigned int j = 0; j < len; j++)
162 info[j].mask = mask;
163 }
164 inline void add_masks (hb_mask_t mask)
165 {
166 for (unsigned int j = 0; j < len; j++)
167 info[j].mask |= mask;
168 }
169 HB_INTERNAL void set_masks (hb_mask_t value,
170 hb_mask_t mask,
171 unsigned int cluster_start,
172 unsigned int cluster_end);
173
174 HB_INTERNAL void merge_clusters (unsigned int start,
175 unsigned int end)
176 {
177 if (end - start < 2)
178 return;
179 merge_clusters_impl (start, end);
180 }
181 HB_INTERNAL void merge_clusters_impl (unsigned int start,
182 unsigned int end);
183 HB_INTERNAL void merge_out_clusters (unsigned int start,
184 unsigned int end);
185 /* Merge clusters for deleting current glyph, and skip it. */
186 HB_INTERNAL void delete_glyph (void);
187
188 /* Internal methods */
189 HB_INTERNAL bool enlarge (unsigned int size);
190
191 inline bool ensure (unsigned int size)
192 { return likely (!size || size < allocated) ? true : enlarge (size); }
193
194 inline bool ensure_inplace (unsigned int size)
195 { return likely (!size || size < allocated); }
196
197 HB_INTERNAL bool make_room_for (unsigned int num_in, unsigned int num_out);
198 HB_INTERNAL bool shift_forward (unsigned int count);
199
200 typedef long scratch_buffer_t;
201 HB_INTERNAL scratch_buffer_t *get_scratch_buffer (unsigned int *size);
202
203 inline void clear_context (unsigned int side) { context_len[side] = 0; }
204
205 HB_INTERNAL void sort (unsigned int start, unsigned int end, int(*compar)(const hb_glyph_info_t *, const hb_glyph_info_t *));
206 };
207
208
209 #define HB_BUFFER_XALLOCATE_VAR(b, func, var, owner) \
210 b->func (offsetof (hb_glyph_info_t, var) - offsetof(hb_glyph_info_t, var1), \
211 sizeof (b->info[0].var), owner)
212 #define HB_BUFFER_ALLOCATE_VAR(b, var) \
213 HB_BUFFER_XALLOCATE_VAR (b, allocate_var, var (), #var)
214 #define HB_BUFFER_DEALLOCATE_VAR(b, var) \
215 HB_BUFFER_XALLOCATE_VAR (b, deallocate_var, var (), #var)
216 #define HB_BUFFER_ASSERT_VAR(b, var) \
217 HB_BUFFER_XALLOCATE_VAR (b, assert_var, var (), #var)
218
219
220 #endif /* HB_BUFFER_PRIVATE_HH */