1 /*
2 * Copyright © 2011 Google, Inc.
3 *
4 * This is part of HarfBuzz, a text shaping library.
5 *
6 * Permission is hereby granted, without written agreement and without
7 * license or royalty fees, to use, copy, modify, and distribute this
8 * software and its documentation for any purpose, provided that the
9 * above copyright notice and the following two paragraphs appear in
10 * all copies of this software.
11 *
12 * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
13 * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
14 * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
15 * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
16 * DAMAGE.
17 *
18 * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
19 * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
20 * FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS
21 * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
22 * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
23 *
24 * Google Author(s): Behdad Esfahbod
25 */
26
27 #ifndef SHAPE_OPTIONS_HH
28 #define SHAPE_OPTIONS_HH
29
30 #include "options.hh"
31
32 struct shape_options_t
33 {
~shape_options_tshape_options_t34 ~shape_options_t ()
35 {
36 g_free (direction);
37 g_free (language);
38 g_free (script);
39 free (features);
40 g_strfreev (shapers);
41 }
42
43 void add_options (option_parser_t *parser);
44
setup_buffershape_options_t45 void setup_buffer (hb_buffer_t *buffer)
46 {
47 hb_buffer_set_direction (buffer, hb_direction_from_string (direction, -1));
48 hb_buffer_set_script (buffer, hb_script_from_string (script, -1));
49 hb_buffer_set_language (buffer, hb_language_from_string (language, -1));
50 hb_buffer_set_flags (buffer, (hb_buffer_flags_t)
51 (HB_BUFFER_FLAG_DEFAULT |
52 (bot ? HB_BUFFER_FLAG_BOT : 0) |
53 (eot ? HB_BUFFER_FLAG_EOT : 0) |
54 (verify ? HB_BUFFER_FLAG_VERIFY : 0) |
55 (unsafe_to_concat ? HB_BUFFER_FLAG_PRODUCE_UNSAFE_TO_CONCAT : 0) |
56 (safe_to_insert_tatweel ? HB_BUFFER_FLAG_PRODUCE_SAFE_TO_INSERT_TATWEEL : 0) |
57 (preserve_default_ignorables ? HB_BUFFER_FLAG_PRESERVE_DEFAULT_IGNORABLES : 0) |
58 (remove_default_ignorables ? HB_BUFFER_FLAG_REMOVE_DEFAULT_IGNORABLES : 0) |
59 0));
60 hb_buffer_set_invisible_glyph (buffer, invisible_glyph);
61 hb_buffer_set_not_found_glyph (buffer, not_found_glyph);
62 hb_buffer_set_not_found_variation_selector_glyph (buffer, not_found_variation_selector_glyph);
63 hb_buffer_set_cluster_level (buffer, cluster_level);
64 hb_buffer_guess_segment_properties (buffer);
65 }
66
populate_buffershape_options_t67 void populate_buffer (hb_buffer_t *buffer, const char *text, int text_len,
68 const char *text_before, const char *text_after,
69 hb_font_t *font)
70 {
71 hb_buffer_clear_contents (buffer);
72
73 if (glyphs)
74 {
75 /* Call the setup_buffer first while the buffer is empty,
76 * as guess_segment_properties doesn't like glyphs in the buffer. */
77
78 setup_buffer (buffer);
79 char *glyphs_text = (char *) text;
80 int glyphs_len = text_len;
81 if (glyphs_len < 0)
82 glyphs_len = strlen (glyphs_text);
83
84 if (glyphs_len && glyphs_text[glyphs_len - 1] != ']')
85 {
86 glyphs_text = g_strdup_printf ("%*s]", glyphs_len, glyphs_text);
87 glyphs_len = -1;
88 }
89
90 hb_buffer_deserialize_glyphs (buffer,
91 glyphs_text, glyphs_len,
92 nullptr,
93 font,
94 HB_BUFFER_SERIALIZE_FORMAT_TEXT);
95
96 if (!strchr (glyphs_text, '+'))
97 {
98 scale_advances = false;
99 unsigned count;
100 hb_direction_t direction = hb_buffer_get_direction (buffer);
101 hb_glyph_info_t *infos = hb_buffer_get_glyph_infos (buffer, &count);
102 hb_glyph_position_t *positions = hb_buffer_get_glyph_positions (buffer, &count);
103 for (unsigned i = 0; i < count; i++)
104 hb_font_get_glyph_advance_for_direction (font,
105 infos[i].codepoint,
106 direction,
107 &positions[i].x_advance,
108 &positions[i].y_advance);
109 }
110
111 if (glyphs_text != text)
112 g_free (glyphs_text);
113
114 return;
115 }
116
117 if (text_before) {
118 unsigned int len = strlen (text_before);
119 hb_buffer_add_utf8 (buffer, text_before, len, len, 0);
120 }
121 hb_buffer_add_utf8 (buffer, text, text_len, 0, text_len);
122 if (text_after) {
123 hb_buffer_add_utf8 (buffer, text_after, -1, 0, 0);
124 }
125
126 if (!utf8_clusters) {
127 /* Reset cluster values to refer to Unicode character index
128 * instead of UTF-8 index. */
129 unsigned int num_glyphs = hb_buffer_get_length (buffer);
130 hb_glyph_info_t *info = hb_buffer_get_glyph_infos (buffer, nullptr);
131 for (unsigned int i = 0; i < num_glyphs; i++)
132 {
133 info->cluster = i;
134 info++;
135 }
136 }
137
138 setup_buffer (buffer);
139 }
140
shapeshape_options_t141 hb_bool_t shape (hb_font_t *font, hb_buffer_t *buffer, const char **error=nullptr)
142 {
143 if (glyphs)
144 {
145 /* Scale positions. */
146 int x_scale, y_scale;
147 hb_font_get_scale (font, &x_scale, &y_scale);
148 unsigned upem = hb_face_get_upem (hb_font_get_face (font));
149 unsigned count;
150 auto *positions = hb_buffer_get_glyph_positions (buffer, &count);
151 for (unsigned i = 0; i < count; i++)
152 {
153 auto &pos = positions[i];
154 pos.x_offset = pos.x_offset * x_scale / upem;
155 pos.y_offset = pos.y_offset * y_scale / upem;
156 if (scale_advances)
157 {
158 pos.x_advance = pos.x_advance * x_scale / upem;
159 pos.y_advance = pos.y_advance * y_scale / upem;
160 }
161 }
162 }
163 else
164 {
165 if (advance <= 0)
166 {
167 if (!hb_shape_full (font, buffer, features, num_features, shapers))
168 {
169 if (error)
170 *error = "Shaping failed.";
171 goto fail;
172 }
173
174 if (advance < 0)
175 {
176 float unit = (1 << SUBPIXEL_BITS);
177
178 /* Calculate buffer advance */
179 float w = 0;
180 unsigned count = 0;
181 hb_glyph_position_t *pos = hb_buffer_get_glyph_positions (buffer, &count);
182 if (HB_DIRECTION_IS_HORIZONTAL (hb_buffer_get_direction (buffer)))
183 for (unsigned i = 0; i < count; i++)
184 w += pos[i].x_advance;
185 else
186 for (unsigned i = 0; i < count; i++)
187 w += pos[i].y_advance;
188
189 printf ("Default size: %u\n", (unsigned) roundf (w / unit));
190 exit (0);
191 }
192 }
193 #ifdef HB_EXPERIMENTAL_API
194 else
195 {
196 float unit = (1 << SUBPIXEL_BITS);
197 float target_advance = advance * unit;
198 float w = 0;
199 hb_tag_t var_tag;
200 float var_value;
201 if (!hb_shape_justify (font, buffer, features, num_features, shapers,
202 target_advance - unit * 0.5f, target_advance + unit * 0.5f,
203 &w, &var_tag, &var_value))
204 {
205 if (error)
206 *error = "Shaping failed.";
207 goto fail;
208 }
209 }
210 #endif
211 }
212
213 if (normalize_glyphs)
214 hb_buffer_normalize_glyphs (buffer);
215
216 return true;
217
218 fail:
219 return false;
220 }
221
shape_closureshape_options_t222 void shape_closure (const char *text, int text_len,
223 hb_font_t *font, hb_buffer_t *buffer,
224 hb_set_t *glyphs)
225 {
226 hb_buffer_reset (buffer);
227 hb_buffer_add_utf8 (buffer, text, text_len, 0, text_len);
228 setup_buffer (buffer);
229 hb_ot_shape_glyphs_closure (font, buffer, features, num_features, glyphs);
230 }
231
232 /* Buffer properties */
233 char *direction = nullptr;
234 char *language = nullptr;
235 char *script = nullptr;
236
237 /* Buffer flags */
238 hb_bool_t bot = false;
239 hb_bool_t eot = false;
240 hb_bool_t preserve_default_ignorables = false;
241 hb_bool_t remove_default_ignorables = false;
242
243 hb_feature_t *features = nullptr;
244 unsigned int num_features = 0;
245 char **shapers = nullptr;
246 signed advance = 0;
247 hb_bool_t utf8_clusters = false;
248 hb_codepoint_t invisible_glyph = 0;
249 hb_codepoint_t not_found_glyph = 0;
250 hb_codepoint_t not_found_variation_selector_glyph = HB_CODEPOINT_INVALID;
251 hb_buffer_cluster_level_t cluster_level = HB_BUFFER_CLUSTER_LEVEL_DEFAULT;
252 hb_bool_t normalize_glyphs = false;
253 hb_bool_t glyphs = false;
254 bool scale_advances = true;
255 hb_bool_t verify = false;
256 hb_bool_t unsafe_to_concat = false;
257 hb_bool_t safe_to_insert_tatweel = false;
258 unsigned int num_iterations = 1;
259 };
260
261
262 static gboolean
parse_shapers(const char * name G_GNUC_UNUSED,const char * arg,gpointer data,GError ** error)263 parse_shapers (const char *name G_GNUC_UNUSED,
264 const char *arg,
265 gpointer data,
266 GError **error)
267 {
268 shape_options_t *shape_opts = (shape_options_t *) data;
269 char **shapers = g_strsplit (arg, ",", 0);
270
271 for (char **shaper = shapers; *shaper; shaper++)
272 {
273 bool found = false;
274 for (const char **hb_shaper = hb_shape_list_shapers (); *hb_shaper; hb_shaper++) {
275 if (strcmp (*shaper, *hb_shaper) == 0)
276 {
277 found = true;
278 break;
279 }
280 }
281 if (!found)
282 {
283 g_set_error (error, G_OPTION_ERROR, G_OPTION_ERROR_BAD_VALUE,
284 "Unknown or unsupported shaper: %s", *shaper);
285 g_strfreev (shapers);
286 return false;
287 }
288 }
289
290 g_strfreev (shape_opts->shapers);
291 shape_opts->shapers = shapers;
292 return true;
293 }
294
295 static G_GNUC_NORETURN gboolean
list_shapers(const char * name G_GNUC_UNUSED,const char * arg G_GNUC_UNUSED,gpointer data G_GNUC_UNUSED,GError ** error G_GNUC_UNUSED)296 list_shapers (const char *name G_GNUC_UNUSED,
297 const char *arg G_GNUC_UNUSED,
298 gpointer data G_GNUC_UNUSED,
299 GError **error G_GNUC_UNUSED)
300 {
301 for (const char **shaper = hb_shape_list_shapers (); *shaper; shaper++)
302 g_printf ("%s\n", *shaper);
303
304 exit(0);
305 }
306
307
308 static gboolean
parse_features(const char * name G_GNUC_UNUSED,const char * arg,gpointer data,GError ** error G_GNUC_UNUSED)309 parse_features (const char *name G_GNUC_UNUSED,
310 const char *arg,
311 gpointer data,
312 GError **error G_GNUC_UNUSED)
313 {
314 shape_options_t *shape_opts = (shape_options_t *) data;
315 char *s = (char *) arg;
316 size_t l = strlen (s);
317 char *p;
318
319 shape_opts->num_features = 0;
320 g_free (shape_opts->features);
321 shape_opts->features = nullptr;
322
323 /* if the string is quoted, strip the quotes */
324 if (s[0] == s[l - 1] && (s[0] == '\"' || s[0] == '\''))
325 {
326 s[l - 1] = '\0';
327 s++;
328 }
329
330 if (!*s)
331 return true;
332
333 /* count the features first, so we can allocate memory */
334 p = s;
335 do {
336 shape_opts->num_features++;
337 p = strpbrk (p, ", ");
338 if (p)
339 p++;
340 } while (p);
341
342 shape_opts->features = (hb_feature_t *) calloc (shape_opts->num_features, sizeof (*shape_opts->features));
343 if (!shape_opts->features)
344 return false;
345
346 /* now do the actual parsing */
347 p = s;
348 shape_opts->num_features = 0;
349 while (p && *p) {
350 char *end = strpbrk (p, ", ");
351 if (hb_feature_from_string (p, end ? end - p : -1, &shape_opts->features[shape_opts->num_features]))
352 shape_opts->num_features++;
353 p = end ? end + 1 : nullptr;
354 }
355
356 return true;
357 }
358
359 void
add_options(option_parser_t * parser)360 shape_options_t::add_options (option_parser_t *parser)
361 {
362 GOptionEntry entries[] =
363 {
364 {"list-shapers", 0, G_OPTION_FLAG_NO_ARG,
365 G_OPTION_ARG_CALLBACK, (gpointer) &list_shapers, "List available shapers and quit", nullptr},
366 {"shaper", 0, G_OPTION_FLAG_HIDDEN,
367 G_OPTION_ARG_CALLBACK, (gpointer) &parse_shapers, "Hidden duplicate of --shapers", nullptr},
368 {"shapers", 0, 0, G_OPTION_ARG_CALLBACK, (gpointer) &parse_shapers, "Set comma-separated list of shapers to try","list"},
369 {"direction", 0, 0, G_OPTION_ARG_STRING, &this->direction, "Set text direction (default: auto)", "ltr/rtl/ttb/btt"},
370 {"language", 0, 0, G_OPTION_ARG_STRING, &this->language, "Set text language (default: $LANG)", "BCP 47 tag"},
371 {"script", 0, 0, G_OPTION_ARG_STRING, &this->script, "Set text script (default: auto)", "ISO-15924 tag"},
372 {"bot", 0, 0, G_OPTION_ARG_NONE, &this->bot, "Treat text as beginning-of-paragraph", nullptr},
373 {"eot", 0, 0, G_OPTION_ARG_NONE, &this->eot, "Treat text as end-of-paragraph", nullptr},
374 #ifdef HB_EXPERIMENTAL_API
375 {"justify-to", 0, 0,
376 G_OPTION_ARG_INT, &this->advance, "Target size to justify to", "SIZE, or -1"},
377 #endif
378 {"preserve-default-ignorables",0, 0, G_OPTION_ARG_NONE, &this->preserve_default_ignorables, "Preserve Default-Ignorable characters", nullptr},
379 {"remove-default-ignorables",0, 0, G_OPTION_ARG_NONE, &this->remove_default_ignorables, "Remove Default-Ignorable characters", nullptr},
380 {"invisible-glyph", 0, 0, G_OPTION_ARG_INT, &this->invisible_glyph, "Glyph value to replace Default-Ignorables with", nullptr},
381 {"not-found-glyph", 0, 0, G_OPTION_ARG_INT, &this->not_found_glyph, "Glyph value to replace not-found characters with", nullptr},
382 {"not-found-variation-selector-glyph",
383 0, 0, G_OPTION_ARG_INT, &this->not_found_variation_selector_glyph,
384 "Glyph value to replace not-found variation-selector characters with", nullptr},
385 {"utf8-clusters", 0, 0, G_OPTION_ARG_NONE, &this->utf8_clusters, "Use UTF8 byte indices, not char indices", nullptr},
386 {"cluster-level", 0, 0, G_OPTION_ARG_INT, &this->cluster_level, "Cluster merging level (default: 0)", "0/1/2"},
387 {"normalize-glyphs",0, 0, G_OPTION_ARG_NONE, &this->normalize_glyphs, "Rearrange glyph clusters in nominal order", nullptr},
388 {"unsafe-to-concat",0, 0, G_OPTION_ARG_NONE, &this->unsafe_to_concat, "Produce unsafe-to-concat glyph flag", nullptr},
389 {"safe-to-insert-tatweel",0, 0, G_OPTION_ARG_NONE, &this->safe_to_insert_tatweel, "Produce safe-to-insert-tatweel glyph flag", nullptr},
390 {"glyphs", 0, 0, G_OPTION_ARG_NONE, &this->glyphs, "Interpret input as glyph string", nullptr},
391 {"verify", 0, 0, G_OPTION_ARG_NONE, &this->verify, "Perform sanity checks on shaping results", nullptr},
392 {"num-iterations", 'n',G_OPTION_FLAG_IN_MAIN,
393 G_OPTION_ARG_INT, &this->num_iterations, "Run shaper N times (default: 1)", "N"},
394 {nullptr}
395 };
396 parser->add_group (entries,
397 "shape",
398 "Shape options:",
399 "Options for the shaping process",
400 this);
401
402 const gchar *features_help = "Comma-separated list of font features\n"
403 "\n"
404 " Features can be enabled or disabled, either globally or limited to\n"
405 " specific character ranges. The format for specifying feature settings\n"
406 " follows. All valid CSS font-feature-settings values other than 'normal'\n"
407 " and the global values are also accepted, though not documented below.\n"
408 " CSS string escapes are not supported."
409 "\n"
410 " The range indices refer to the positions between Unicode characters,\n"
411 " unless the --utf8-clusters is provided, in which case range indices\n"
412 " refer to UTF-8 byte indices. The position before the first character\n"
413 " is always 0.\n"
414 "\n"
415 " The format is Python-esque. Here is how it all works:\n"
416 "\n"
417 " Syntax: Value: Start: End:\n"
418 "\n"
419 " Setting value:\n"
420 " \"kern\" 1 0 ∞ # Turn feature on\n"
421 " \"+kern\" 1 0 ∞ # Turn feature on\n"
422 " \"-kern\" 0 0 ∞ # Turn feature off\n"
423 " \"kern=0\" 0 0 ∞ # Turn feature off\n"
424 " \"kern=1\" 1 0 ∞ # Turn feature on\n"
425 " \"aalt=2\" 2 0 ∞ # Choose 2nd alternate\n"
426 "\n"
427 " Setting index:\n"
428 " \"kern[]\" 1 0 ∞ # Turn feature on\n"
429 " \"kern[:]\" 1 0 ∞ # Turn feature on\n"
430 " \"kern[5:]\" 1 5 ∞ # Turn feature on, partial\n"
431 " \"kern[:5]\" 1 0 5 # Turn feature on, partial\n"
432 " \"kern[3:5]\" 1 3 5 # Turn feature on, range\n"
433 " \"kern[3]\" 1 3 3+1 # Turn feature on, single char\n"
434 "\n"
435 " Mixing it all:\n"
436 "\n"
437 " \"aalt[3:5]=2\" 2 3 5 # Turn 2nd alternate on for range";
438
439 GOptionEntry entries2[] =
440 {
441 {"features", 0, 0, G_OPTION_ARG_CALLBACK, (gpointer) &parse_features, features_help, "list"},
442 {nullptr}
443 };
444 parser->add_group (entries2,
445 "features",
446 "Features options:",
447 "Options for font features used",
448 this);
449 }
450
451 #endif
452