28
29 #include "hb-private.hh"
30
31 #include "hb-shaper-private.hh"
32 #include "hb-shape-plan-private.hh"
33 #include "hb-buffer-private.hh"
34 #include "hb-font-private.hh"
35
36 /**
37 * SECTION:hb-shape
38 * @title: Shaping
39 * @short_description: Conversion of text strings into positioned glyphs
40 * @include: hb.h
41 *
42 * Shaping is the central operation of HarfBuzz. Shaping operates on buffers,
43 * which are sequences of Unicode characters that use the same font and have
44 * the same text direction, script and language. After shaping the buffer
45 * contains the output glyphs and their positions.
46 **/
47
48 static bool
49 parse_space (const char **pp, const char *end)
50 {
51 while (*pp < end && ISSPACE (**pp))
52 (*pp)++;
53 return true;
54 }
55
56 static bool
57 parse_char (const char **pp, const char *end, char c)
58 {
59 parse_space (pp, end);
60
61 if (*pp == end || **pp != c)
62 return false;
63
64 (*pp)++;
65 return true;
66 }
67
68 static bool
69 parse_uint (const char **pp, const char *end, unsigned int *pv)
70 {
71 char buf[32];
72 unsigned int len = MIN (ARRAY_LENGTH (buf) - 1, (unsigned int) (end - *pp));
73 strncpy (buf, *pp, len);
74 buf[len] = '\0';
75
76 char *p = buf;
77 char *pend = p;
78 unsigned int v;
79
80 /* Intentionally use strtol instead of strtoul, such that
81 * -1 turns into "big number"... */
82 errno = 0;
83 v = strtol (p, &pend, 0);
84 if (errno || p == pend)
85 return false;
86
87 *pv = v;
88 *pp += pend - p;
89 return true;
90 }
91
92 static bool
93 parse_bool (const char **pp, const char *end, unsigned int *pv)
94 {
95 parse_space (pp, end);
96
97 const char *p = *pp;
98 while (*pp < end && ISALPHA(**pp))
99 (*pp)++;
100
101 /* CSS allows on/off as aliases 1/0. */
102 if (*pp - p == 2 || 0 == strncmp (p, "on", 2))
103 *pv = 1;
104 else if (*pp - p == 3 || 0 == strncmp (p, "off", 2))
105 *pv = 0;
106 else
107 return false;
108
109 return true;
110 }
111
112 static bool
113 parse_feature_value_prefix (const char **pp, const char *end, hb_feature_t *feature)
114 {
115 if (parse_char (pp, end, '-'))
116 feature->value = 0;
117 else {
118 parse_char (pp, end, '+');
119 feature->value = 1;
120 }
121
122 return true;
123 }
124
125 static bool
126 parse_feature_tag (const char **pp, const char *end, hb_feature_t *feature)
127 {
128 parse_space (pp, end);
129
130 char quote = 0;
131
132 if (*pp < end && (**pp == '\'' || **pp == '"'))
133 {
134 quote = **pp;
135 (*pp)++;
136 }
137
138 const char *p = *pp;
139 while (*pp < end && ISALNUM(**pp))
140 (*pp)++;
141
142 if (p == *pp || *pp - p > 4)
143 return false;
144
145 feature->tag = hb_tag_from_string (p, *pp - p);
146
147 if (quote)
148 {
149 /* CSS expects exactly four bytes. And we only allow quotations for
150 * CSS compatibility. So, enforce the length. */
151 if (*pp - p != 4)
152 return false;
153 if (*pp == end || **pp != quote)
154 return false;
155 (*pp)++;
156 }
157
158 return true;
159 }
160
161 static bool
162 parse_feature_indices (const char **pp, const char *end, hb_feature_t *feature)
163 {
164 parse_space (pp, end);
165
166 bool has_start;
167
168 feature->start = 0;
169 feature->end = (unsigned int) -1;
170
171 if (!parse_char (pp, end, '['))
172 return true;
173
174 has_start = parse_uint (pp, end, &feature->start);
175
176 if (parse_char (pp, end, ':')) {
177 parse_uint (pp, end, &feature->end);
178 } else {
179 if (has_start)
180 feature->end = feature->start + 1;
181 }
182
183 return parse_char (pp, end, ']');
184 }
185
186 static bool
187 parse_feature_value_postfix (const char **pp, const char *end, hb_feature_t *feature)
188 {
189 bool had_equal = parse_char (pp, end, '=');
190 bool had_value = parse_uint (pp, end, &feature->value) ||
191 parse_bool (pp, end, &feature->value);
192 /* CSS doesn't use equal-sign between tag and value.
193 * If there was an equal-sign, then there *must* be a value.
194 * A value without an eqaul-sign is ok, but not required. */
195 return !had_equal || had_value;
196 }
197
198
199 static bool
200 parse_one_feature (const char **pp, const char *end, hb_feature_t *feature)
201 {
202 return parse_feature_value_prefix (pp, end, feature) &&
203 parse_feature_tag (pp, end, feature) &&
204 parse_feature_indices (pp, end, feature) &&
205 parse_feature_value_postfix (pp, end, feature) &&
206 parse_space (pp, end) &&
207 *pp == end;
208 }
209
210 /**
211 * hb_feature_from_string:
212 * @str: (array length=len) (element-type uint8_t): a string to parse
213 * @len: length of @str, or -1 if string is %NULL terminated
214 * @feature: (out): the #hb_feature_t to initialize with the parsed values
215 *
216 * Parses a string into a #hb_feature_t.
217 *
218 * TODO: document the syntax here.
219 *
220 * Return value:
221 * %true if @str is successfully parsed, %false otherwise.
222 *
223 * Since: 0.9.5
224 **/
225 hb_bool_t
226 hb_feature_from_string (const char *str, int len,
227 hb_feature_t *feature)
228 {
229 hb_feature_t feat;
230
231 if (len < 0)
232 len = strlen (str);
233
234 if (likely (parse_one_feature (&str, str + len, &feat)))
235 {
236 if (feature)
237 *feature = feat;
238 return true;
239 }
240
241 if (feature)
242 memset (feature, 0, sizeof (*feature));
243 return false;
244 }
245
246 /**
247 * hb_feature_to_string:
248 * @feature: an #hb_feature_t to convert
249 * @buf: (array length=size) (out): output string
250 * @size: the allocated size of @buf
251 *
252 * Converts a #hb_feature_t into a %NULL-terminated string in the format
253 * understood by hb_feature_from_string(). The client in responsible for
254 * allocating big enough size for @buf, 128 bytes is more than enough.
255 *
256 * Since: 0.9.5
257 **/
258 void
259 hb_feature_to_string (hb_feature_t *feature,
260 char *buf, unsigned int size)
261 {
262 if (unlikely (!size)) return;
263
264 char s[128];
265 unsigned int len = 0;
266 if (feature->value == 0)
267 s[len++] = '-';
268 hb_tag_to_string (feature->tag, s + len);
269 len += 4;
270 while (len && s[len - 1] == ' ')
271 len--;
272 if (feature->start != 0 || feature->end != (unsigned int) -1)
273 {
274 s[len++] = '[';
275 if (feature->start)
276 len += MAX (0, snprintf (s + len, ARRAY_LENGTH (s) - len, "%u", feature->start));
277 if (feature->end != feature->start + 1) {
278 s[len++] = ':';
279 if (feature->end != (unsigned int) -1)
280 len += MAX (0, snprintf (s + len, ARRAY_LENGTH (s) - len, "%u", feature->end));
281 }
282 s[len++] = ']';
283 }
284 if (feature->value > 1)
285 {
286 s[len++] = '=';
287 len += MAX (0, snprintf (s + len, ARRAY_LENGTH (s) - len, "%u", feature->value));
288 }
289 assert (len < ARRAY_LENGTH (s));
290 len = MIN (len, size - 1);
291 memcpy (buf, s, len);
292 buf[len] = '\0';
293 }
294
295
296 static const char **static_shaper_list;
297
298 #ifdef HB_USE_ATEXIT
299 static
300 void free_static_shaper_list (void)
301 {
302 free (static_shaper_list);
303 }
304 #endif
305
306 /**
307 * hb_shape_list_shapers:
308 *
309 * Retrieves the list of shapers supported by HarfBuzz.
310 *
311 * Return value: (transfer none) (array zero-terminated=1): an array of
312 * constant strings
313 *
314 * Since: 0.9.2
315 **/
316 const char **
317 hb_shape_list_shapers (void)
318 {
319 retry:
320 const char **shaper_list = (const char **) hb_atomic_ptr_get (&static_shaper_list);
321
322 if (unlikely (!shaper_list))
323 {
324 /* Not found; allocate one. */
325 shaper_list = (const char **) calloc (1 + HB_SHAPERS_COUNT, sizeof (const char *));
326 if (unlikely (!shaper_list)) {
327 static const char *nil_shaper_list[] = {NULL};
328 return nil_shaper_list;
329 }
330
331 const hb_shaper_pair_t *shapers = _hb_shapers_get ();
332 unsigned int i;
333 for (i = 0; i < HB_SHAPERS_COUNT; i++)
334 shaper_list[i] = shapers[i].name;
335 shaper_list[i] = NULL;
336
337 if (!hb_atomic_ptr_cmpexch (&static_shaper_list, NULL, shaper_list)) {
338 free (shaper_list);
339 goto retry;
340 }
341
342 #ifdef HB_USE_ATEXIT
343 atexit (free_static_shaper_list); /* First person registers atexit() callback. */
344 #endif
345 }
346
347 return shaper_list;
348 }
349
350
351 /**
352 * hb_shape_full:
353 * @font: an #hb_font_t to use for shaping
354 * @buffer: an #hb_buffer_t to shape
355 * @features: (array length=num_features) (allow-none): an array of user
356 * specified #hb_feature_t or %NULL
357 * @num_features: the length of @features array
358 * @shaper_list: (array zero-terminated=1) (allow-none): a %NULL-terminated
359 * array of shapers to use or %NULL
360 *
361 * See hb_shape() for details. If @shaper_list is not %NULL, the specified
362 * shapers will be used in the given order, otherwise the default shapers list
363 * will be used.
364 *
365 * Return value: %FALSE if all shapers failed, %TRUE otherwise
366 *
367 * Since: 0.9.2
368 **/
369 hb_bool_t
370 hb_shape_full (hb_font_t *font,
371 hb_buffer_t *buffer,
372 const hb_feature_t *features,
373 unsigned int num_features,
374 const char * const *shaper_list)
375 {
376 hb_shape_plan_t *shape_plan = hb_shape_plan_create_cached2 (font->face, &buffer->props,
377 features, num_features,
378 font->coords, font->num_coords,
379 shaper_list);
380 hb_bool_t res = hb_shape_plan_execute (shape_plan, font, buffer, features, num_features);
381 hb_shape_plan_destroy (shape_plan);
382
383 if (res)
384 buffer->content_type = HB_BUFFER_CONTENT_TYPE_GLYPHS;
385 return res;
388 /**
389 * hb_shape:
390 * @font: an #hb_font_t to use for shaping
391 * @buffer: an #hb_buffer_t to shape
392 * @features: (array length=num_features) (allow-none): an array of user
393 * specified #hb_feature_t or %NULL
394 * @num_features: the length of @features array
395 *
396 * Shapes @buffer using @font turning its Unicode characters content to
397 * positioned glyphs. If @features is not %NULL, it will be used to control the
398 * features applied during shaping.
399 *
400 * Since: 0.9.2
401 **/
402 void
403 hb_shape (hb_font_t *font,
404 hb_buffer_t *buffer,
405 const hb_feature_t *features,
406 unsigned int num_features)
407 {
408 hb_shape_full (font, buffer, features, num_features, NULL);
409 }
|
28
29 #include "hb-private.hh"
30
31 #include "hb-shaper-private.hh"
32 #include "hb-shape-plan-private.hh"
33 #include "hb-buffer-private.hh"
34 #include "hb-font-private.hh"
35
36 /**
37 * SECTION:hb-shape
38 * @title: Shaping
39 * @short_description: Conversion of text strings into positioned glyphs
40 * @include: hb.h
41 *
42 * Shaping is the central operation of HarfBuzz. Shaping operates on buffers,
43 * which are sequences of Unicode characters that use the same font and have
44 * the same text direction, script and language. After shaping the buffer
45 * contains the output glyphs and their positions.
46 **/
47
48 static const char **static_shaper_list;
49
50 #ifdef HB_USE_ATEXIT
51 static
52 void free_static_shaper_list (void)
53 {
54 free (static_shaper_list);
55 }
56 #endif
57
58 /**
59 * hb_shape_list_shapers:
60 *
61 * Retrieves the list of shapers supported by HarfBuzz.
62 *
63 * Return value: (transfer none) (array zero-terminated=1): an array of
64 * constant strings
65 *
66 * Since: 0.9.2
67 **/
68 const char **
69 hb_shape_list_shapers (void)
70 {
71 retry:
72 const char **shaper_list = (const char **) hb_atomic_ptr_get (&static_shaper_list);
73
74 if (unlikely (!shaper_list))
75 {
76 /* Not found; allocate one. */
77 shaper_list = (const char **) calloc (1 + HB_SHAPERS_COUNT, sizeof (const char *));
78 if (unlikely (!shaper_list)) {
79 static const char *nil_shaper_list[] = {nullptr};
80 return nil_shaper_list;
81 }
82
83 const hb_shaper_pair_t *shapers = _hb_shapers_get ();
84 unsigned int i;
85 for (i = 0; i < HB_SHAPERS_COUNT; i++)
86 shaper_list[i] = shapers[i].name;
87 shaper_list[i] = nullptr;
88
89 if (!hb_atomic_ptr_cmpexch (&static_shaper_list, nullptr, shaper_list)) {
90 free (shaper_list);
91 goto retry;
92 }
93
94 #ifdef HB_USE_ATEXIT
95 atexit (free_static_shaper_list); /* First person registers atexit() callback. */
96 #endif
97 }
98
99 return shaper_list;
100 }
101
102
103 /**
104 * hb_shape_full:
105 * @font: an #hb_font_t to use for shaping
106 * @buffer: an #hb_buffer_t to shape
107 * @features: (array length=num_features) (allow-none): an array of user
108 * specified #hb_feature_t or %NULL
109 * @num_features: the length of @features array
110 * @shaper_list: (array zero-terminated=1) (allow-none): a %NULL-terminated
111 * array of shapers to use or %NULL
112 *
113 * See hb_shape() for details. If @shaper_list is not %NULL, the specified
114 * shapers will be used in the given order, otherwise the default shapers list
115 * will be used.
116 *
117 * Return value: false if all shapers failed, true otherwise
118 *
119 * Since: 0.9.2
120 **/
121 hb_bool_t
122 hb_shape_full (hb_font_t *font,
123 hb_buffer_t *buffer,
124 const hb_feature_t *features,
125 unsigned int num_features,
126 const char * const *shaper_list)
127 {
128 hb_shape_plan_t *shape_plan = hb_shape_plan_create_cached2 (font->face, &buffer->props,
129 features, num_features,
130 font->coords, font->num_coords,
131 shaper_list);
132 hb_bool_t res = hb_shape_plan_execute (shape_plan, font, buffer, features, num_features);
133 hb_shape_plan_destroy (shape_plan);
134
135 if (res)
136 buffer->content_type = HB_BUFFER_CONTENT_TYPE_GLYPHS;
137 return res;
140 /**
141 * hb_shape:
142 * @font: an #hb_font_t to use for shaping
143 * @buffer: an #hb_buffer_t to shape
144 * @features: (array length=num_features) (allow-none): an array of user
145 * specified #hb_feature_t or %NULL
146 * @num_features: the length of @features array
147 *
148 * Shapes @buffer using @font turning its Unicode characters content to
149 * positioned glyphs. If @features is not %NULL, it will be used to control the
150 * features applied during shaping.
151 *
152 * Since: 0.9.2
153 **/
154 void
155 hb_shape (hb_font_t *font,
156 hb_buffer_t *buffer,
157 const hb_feature_t *features,
158 unsigned int num_features)
159 {
160 hb_shape_full (font, buffer, features, num_features, nullptr);
161 }
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