xref: /aosp_15_r20/external/harfbuzz_ng/util/font-options.hh (revision 2d1272b857b1f7575e6e246373e1cb218663db8a)
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 FONT_OPTIONS_HH
28 #define FONT_OPTIONS_HH
29 
30 #include "face-options.hh"
31 
32 #include <hb-ot.h>
33 #ifdef HAVE_FREETYPE
34 #include <hb-ft.h>
35 #endif
36 #ifdef HAVE_CORETEXT
37 #include <hb-coretext.h>
38 #endif
39 
40 #define FONT_SIZE_UPEM 0x7FFFFFFF
41 #define FONT_SIZE_NONE 0
42 
43 extern const unsigned DEFAULT_FONT_SIZE;
44 extern const unsigned SUBPIXEL_BITS;
45 
46 struct font_options_t : face_options_t
47 {
~font_options_tfont_options_t48   ~font_options_t ()
49   {
50 #ifndef HB_NO_VAR
51     free (variations);
52 #endif
53     g_free (font_funcs);
54     hb_font_destroy (font);
55   }
56 
57   void add_options (option_parser_t *parser);
58 
59   void post_parse (GError **error);
60 
61   hb_bool_t sub_font = false;
62 #ifndef HB_NO_VAR
63   hb_variation_t *variations = nullptr;
64   unsigned int num_variations = 0;
65 #endif
66   int x_ppem = 0;
67   int y_ppem = 0;
68   double ptem = 0.;
69   double x_embolden = 0.;
70   double y_embolden = 0.;
71   hb_bool_t embolden_in_place = false;
72   double slant = 0.;
73   unsigned int subpixel_bits = SUBPIXEL_BITS;
74   mutable double font_size_x = DEFAULT_FONT_SIZE;
75   mutable double font_size_y = DEFAULT_FONT_SIZE;
76   char *font_funcs = nullptr;
77   int ft_load_flags = 2;
78   unsigned int named_instance = HB_FONT_NO_VAR_NAMED_INSTANCE;
79 
80   hb_font_t *font = nullptr;
81 };
82 
83 
84 static struct supported_font_funcs_t {
85 	char name[9];
86 	void (*func) (hb_font_t *);
87 } supported_font_funcs[] =
88 {
89   {"ot",	hb_ot_font_set_funcs},
90 #ifdef HAVE_FREETYPE
91   {"ft",	hb_ft_font_set_funcs},
92 #endif
93 #ifdef HAVE_CORETEXT
94   {"coretext",	hb_coretext_font_set_funcs},
95 #endif
96 };
97 
98 
99 void
post_parse(GError ** error)100 font_options_t::post_parse (GError **error)
101 {
102   assert (!font);
103   font = hb_font_create (face);
104 
105   if (font_size_x == FONT_SIZE_UPEM)
106     font_size_x = hb_face_get_upem (face);
107   if (font_size_y == FONT_SIZE_UPEM)
108     font_size_y = hb_face_get_upem (face);
109 
110   hb_font_set_ppem (font, x_ppem, y_ppem);
111   hb_font_set_ptem (font, ptem);
112 
113   hb_font_set_synthetic_bold (font,
114 			      (float) x_embolden, (float) y_embolden,
115 			      embolden_in_place);
116   hb_font_set_synthetic_slant (font, slant);
117 
118   int scale_x = (int) scalbnf (font_size_x, subpixel_bits);
119   int scale_y = (int) scalbnf (font_size_y, subpixel_bits);
120   hb_font_set_scale (font, scale_x, scale_y);
121 
122 #ifndef HB_NO_VAR
123   hb_font_set_var_named_instance (font, named_instance);
124   hb_font_set_variations (font, variations, num_variations);
125 #endif
126 
127   void (*set_font_funcs) (hb_font_t *) = nullptr;
128   if (!font_funcs)
129   {
130     set_font_funcs = supported_font_funcs[0].func;
131   }
132   else
133   {
134     for (unsigned int i = 0; i < ARRAY_LENGTH (supported_font_funcs); i++)
135       if (0 == g_ascii_strcasecmp (font_funcs, supported_font_funcs[i].name))
136       {
137 	set_font_funcs = supported_font_funcs[i].func;
138 	break;
139       }
140     if (!set_font_funcs)
141     {
142       GString *s = g_string_new (nullptr);
143       for (unsigned int i = 0; i < ARRAY_LENGTH (supported_font_funcs); i++)
144       {
145 	if (i)
146 	  g_string_append_c (s, '/');
147 	g_string_append (s, supported_font_funcs[i].name);
148       }
149       g_string_append_c (s, '\n');
150       char *p = g_string_free (s, FALSE);
151       g_set_error (error, G_OPTION_ERROR, G_OPTION_ERROR_BAD_VALUE,
152 		   "Unknown font function implementation `%s'; supported values are: %s; default is %s",
153 		   font_funcs,
154 		   p,
155 		   supported_font_funcs[0].name);
156       free (p);
157       return;
158     }
159   }
160   set_font_funcs (font);
161 #ifdef HAVE_FREETYPE
162   hb_ft_font_set_load_flags (font, ft_load_flags);
163 #endif
164 
165   if (sub_font)
166   {
167     hb_font_t *old_font = font;
168     font = hb_font_create_sub_font (old_font);
169     hb_font_set_scale (old_font, scale_x * 2, scale_y * 2);
170     hb_font_destroy (old_font);
171   }
172 }
173 
174 #ifndef HB_NO_VAR
175 static gboolean
parse_variations(const char * name G_GNUC_UNUSED,const char * arg,gpointer data,GError ** error G_GNUC_UNUSED)176 parse_variations (const char *name G_GNUC_UNUSED,
177 		  const char *arg,
178 		  gpointer    data,
179 		  GError    **error G_GNUC_UNUSED)
180 {
181   font_options_t *font_opts = (font_options_t *) data;
182   char *s = (char *) arg;
183   char *p;
184 
185   font_opts->num_variations = 0;
186   g_free (font_opts->variations);
187   font_opts->variations = nullptr;
188 
189   if (!*s)
190     return true;
191 
192   /* count the variations first, so we can allocate memory */
193   p = s;
194   do {
195     font_opts->num_variations++;
196     p = strpbrk (p, ", ");
197     if (p)
198       p++;
199   } while (p);
200 
201   font_opts->variations = (hb_variation_t *) calloc (font_opts->num_variations, sizeof (*font_opts->variations));
202   if (!font_opts->variations)
203     return false;
204 
205   /* now do the actual parsing */
206   p = s;
207   font_opts->num_variations = 0;
208   while (p && *p) {
209     char *end = strpbrk (p, ", ");
210     if (hb_variation_from_string (p, end ? end - p : -1, &font_opts->variations[font_opts->num_variations]))
211       font_opts->num_variations++;
212     p = end ? end + 1 : nullptr;
213   }
214 
215   return true;
216 }
217 #endif
218 
219 static gboolean
parse_font_size(const char * name G_GNUC_UNUSED,const char * arg,gpointer data,GError ** error G_GNUC_UNUSED)220 parse_font_size (const char *name G_GNUC_UNUSED,
221 		 const char *arg,
222 		 gpointer    data,
223 		 GError    **error G_GNUC_UNUSED)
224 {
225   font_options_t *font_opts = (font_options_t *) data;
226   if (0 == strcmp (arg, "upem"))
227   {
228     font_opts->font_size_y = font_opts->font_size_x = FONT_SIZE_UPEM;
229     return true;
230   }
231   switch (sscanf (arg, "%lf%*[ ,]%lf", &font_opts->font_size_x, &font_opts->font_size_y)) {
232     case 1: font_opts->font_size_y = font_opts->font_size_x; HB_FALLTHROUGH;
233     case 2: return true;
234     default:
235       g_set_error (error, G_OPTION_ERROR, G_OPTION_ERROR_BAD_VALUE,
236 		   "%s argument should be one or two space-separated numbers",
237 		   name);
238       return false;
239   }
240 }
241 
242 static gboolean
parse_font_ppem(const char * name G_GNUC_UNUSED,const char * arg,gpointer data,GError ** error G_GNUC_UNUSED)243 parse_font_ppem (const char *name G_GNUC_UNUSED,
244 		 const char *arg,
245 		 gpointer    data,
246 		 GError    **error G_GNUC_UNUSED)
247 {
248   font_options_t *font_opts = (font_options_t *) data;
249   switch (sscanf (arg, "%d%*[ ,]%d", &font_opts->x_ppem, &font_opts->y_ppem)) {
250     case 1: font_opts->y_ppem = font_opts->x_ppem; HB_FALLTHROUGH;
251     case 2: return true;
252     default:
253       g_set_error (error, G_OPTION_ERROR, G_OPTION_ERROR_BAD_VALUE,
254 		   "%s argument should be one or two space-separated numbers",
255 		   name);
256       return false;
257   }
258 }
259 
260 static gboolean
parse_font_embolden(const char * name G_GNUC_UNUSED,const char * arg,gpointer data,GError ** error G_GNUC_UNUSED)261 parse_font_embolden (const char *name G_GNUC_UNUSED,
262 		     const char *arg,
263 		     gpointer    data,
264 		     GError    **error G_GNUC_UNUSED)
265 {
266   font_options_t *font_opts = (font_options_t *) data;
267   switch (sscanf (arg, "%lf%*[ ,]%lf", &font_opts->x_embolden, &font_opts->y_embolden)) {
268     case 1: font_opts->y_embolden = font_opts->x_embolden; HB_FALLTHROUGH;
269     case 2: return true;
270     default:
271       g_set_error (error, G_OPTION_ERROR, G_OPTION_ERROR_BAD_VALUE,
272 		   "%s argument should be one or two space-separated numbers",
273 		   name);
274       return false;
275   }
276 }
277 
278 static gboolean
parse_font_bold(const char * name G_GNUC_UNUSED,const char * arg,gpointer data,GError ** error G_GNUC_UNUSED)279 parse_font_bold (const char *name G_GNUC_UNUSED,
280 		 const char *arg,
281 		 gpointer    data,
282 		 GError    **error G_GNUC_UNUSED)
283 {
284   font_options_t *font_opts = (font_options_t *) data;
285   font_opts->embolden_in_place = false;
286   return parse_font_embolden ( name, arg, data, error);
287 }
288 
289 static gboolean
parse_font_grade(const char * name G_GNUC_UNUSED,const char * arg,gpointer data,GError ** error G_GNUC_UNUSED)290 parse_font_grade (const char *name G_GNUC_UNUSED,
291 		  const char *arg,
292 		  gpointer    data,
293 		  GError    **error G_GNUC_UNUSED)
294 {
295   font_options_t *font_opts = (font_options_t *) data;
296   font_opts->embolden_in_place = true;
297   return parse_font_embolden ( name, arg, data, error);
298 }
299 
300 void
add_options(option_parser_t * parser)301 font_options_t::add_options (option_parser_t *parser)
302 {
303   face_options_t::add_options (parser);
304 
305   char *font_funcs_text = nullptr;
306   {
307     static_assert ((ARRAY_LENGTH_CONST (supported_font_funcs) > 0),
308 		   "No supported font-funcs found.");
309     GString *s = g_string_new (nullptr);
310     g_string_printf (s, "Set font functions implementation to use (default: %s)\n\n    Supported font function implementations are: %s",
311 		     supported_font_funcs[0].name,
312 		     supported_font_funcs[0].name);
313     for (unsigned int i = 1; i < ARRAY_LENGTH (supported_font_funcs); i++)
314     {
315       g_string_append_c (s, '/');
316       g_string_append (s, supported_font_funcs[i].name);
317     }
318     font_funcs_text = g_string_free (s, FALSE);
319     parser->free_later (font_funcs_text);
320   }
321 
322   char *font_size_text;
323   if (DEFAULT_FONT_SIZE == FONT_SIZE_UPEM)
324     font_size_text = (char *) "Font size (default: upem)";
325   else
326   {
327     font_size_text = g_strdup_printf ("Font size (default: %u)", DEFAULT_FONT_SIZE);
328     parser->free_later (font_size_text);
329   }
330 
331   int font_size_flags = DEFAULT_FONT_SIZE == FONT_SIZE_NONE ? G_OPTION_FLAG_HIDDEN : 0;
332   GOptionEntry entries[] =
333   {
334     {"font-size",	0, font_size_flags,
335 			      G_OPTION_ARG_CALLBACK,	(gpointer) &parse_font_size,	font_size_text,					"1/2 integers or 'upem'"},
336     {"font-ppem",	0, font_size_flags,
337 			      G_OPTION_ARG_CALLBACK,	(gpointer) &parse_font_ppem,	"Set x,y pixels per EM (default: 0; disabled)",	"1/2 integers"},
338     {"font-ptem",	0, font_size_flags,
339 			      G_OPTION_ARG_DOUBLE,	&this->ptem,			"Set font point-size (default: 0; disabled)",	"point-size"},
340     {"font-bold",	0, font_size_flags,
341 			      G_OPTION_ARG_CALLBACK,	(gpointer) &parse_font_bold,	"Set synthetic bold (default: 0)",		"1/2 numbers; eg. 0.05"},
342     {"font-grade",	0, font_size_flags,
343 			      G_OPTION_ARG_CALLBACK,	(gpointer) &parse_font_grade,	"Set synthetic grade (default: 0)",		"1/2 numbers; eg. 0.05"},
344     {"font-slant",	0, font_size_flags,
345 			      G_OPTION_ARG_DOUBLE,	&this->slant,			"Set synthetic slant (default: 0)",		 "slant ratio; eg. 0.2"},
346     {"font-funcs",	0, 0, G_OPTION_ARG_STRING,	&this->font_funcs,		font_funcs_text,				"impl"},
347     {"sub-font",	0, G_OPTION_FLAG_HIDDEN,
348 			      G_OPTION_ARG_NONE,	&this->sub_font,		"Create a sub-font (default: false)",		"boolean"},
349     {"ft-load-flags",	0, 0, G_OPTION_ARG_INT,		&this->ft_load_flags,		"Set FreeType load-flags (default: 2)",		"integer"},
350     {nullptr}
351   };
352   parser->add_group (entries,
353 		     "font",
354 		     "Font-instance options:",
355 		     "Options for the font instance",
356 		     this,
357 		     false /* We add below. */);
358 
359 #ifndef HB_NO_VAR
360   const gchar *variations_help = "Comma-separated list of font variations\n"
361     "\n"
362     "    Variations are set globally. The format for specifying variation settings\n"
363     "    follows.  All valid CSS font-variation-settings values other than 'normal'\n"
364     "    and 'inherited' are also accepted, though, not documented below.\n"
365     "\n"
366     "    The format is a tag, optionally followed by an equals sign, followed by a\n"
367     "    number. For example:\n"
368     "\n"
369     "      \"wght=500\"\n"
370     "      \"slnt=-7.5\"";
371 
372   GOptionEntry entries2[] =
373   {
374     {"named-instance",	0, 0, G_OPTION_ARG_INT,         &this->named_instance,		"Set named-instance index (default: none)",	"index"},
375     {"variations",	0, 0, G_OPTION_ARG_CALLBACK,	(gpointer) &parse_variations,	variations_help,	"list"},
376     {nullptr}
377   };
378   parser->add_group (entries2,
379 		     "variations",
380 		     "Variations options:",
381 		     "Options for font variations used",
382 		     this);
383 #endif
384 }
385 
386 #endif
387