1 /*
2 * Copyright © 2014 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 #include <stdlib.h>
28 #include <stdio.h>
29
30 #include "hb-fc.h"
31
32 static hb_bool_t
hb_fc_get_glyph(hb_font_t * font,void * font_data,hb_codepoint_t unicode,hb_codepoint_t variation_selector,hb_codepoint_t * glyph,void * user_data)33 hb_fc_get_glyph (hb_font_t *font /*HB_UNUSED*/,
34 void *font_data,
35 hb_codepoint_t unicode,
36 hb_codepoint_t variation_selector,
37 hb_codepoint_t *glyph,
38 void *user_data /*HB_UNUSED*/)
39
40 {
41 FcCharSet *cs = (FcCharSet *) font_data;
42
43 if (variation_selector)
44 {
45 /* Fontconfig doesn't cache cmap-14 info. However:
46 * 1. If the font maps the variation_selector, assume it's
47 * supported,
48 * 2. If the font doesn't map it, still say it's supported,
49 * but return 0. This way, the caller will see the zero
50 * and reject. If we return unsupported here, then the
51 * variation selector will be hidden and ignored.
52 */
53 if (FcCharSetHasChar (cs, unicode) &&
54 FcCharSetHasChar (cs, variation_selector))
55 {
56 unsigned int var_num = 0;
57 if (variation_selector - 0xFE00u < 16)
58 var_num = variation_selector - 0xFE00 + 1;
59 else if (variation_selector - 0xE0100u < (256 - 16))
60 var_num = variation_selector - 0xE0100 + 17;
61 *glyph = (var_num << 21) | unicode;
62 }
63 else
64 {
65 *glyph = 0;
66 }
67 return true;
68 }
69
70 *glyph = FcCharSetHasChar (cs, unicode) ? unicode : 0;
71 return *glyph != 0;
72 }
73
74 static hb_font_funcs_t *
_hb_fc_get_font_funcs()75 _hb_fc_get_font_funcs ()
76 {
77 static const hb_font_funcs_t *fc_ffuncs;
78
79 if (!fc_ffuncs)
80 {
81 hb_font_funcs_t *newfuncs = hb_font_funcs_create ();
82
83 hb_font_funcs_set_glyph_func (newfuncs, hb_fc_get_glyph, nullptr, nullptr);
84
85 /* XXX MT-unsafe */
86 if (fc_ffuncs)
87 hb_font_funcs_destroy (newfuncs);
88 else
89 fc_ffuncs = newfuncs;
90 }
91
92 return const_cast<hb_font_funcs_t *> (fc_ffuncs);
93 }
94
95
96 hb_font_t *
hb_fc_font_create(FcPattern * fcfont)97 hb_fc_font_create (FcPattern *fcfont)
98 {
99 static hb_face_t *face;
100 hb_font_t *font;
101
102 FcCharSet *cs;
103 if (FcResultMatch != FcPatternGetCharSet (fcfont, FC_CHARSET, 0, &cs))
104 return hb_font_get_empty ();
105
106 if (!face) /* XXX MT-unsafe */
107 face = hb_face_create (hb_blob_get_empty (), 0);
108
109 font = hb_font_create (face);
110
111 hb_font_set_funcs (font,
112 _hb_fc_get_font_funcs (),
113 FcCharSetCopy (cs),
114 (hb_destroy_func_t) FcCharSetDestroy);
115
116 return font;
117 }
118
119 hb_bool_t
hb_fc_can_render(hb_font_t * font,const char * text)120 hb_fc_can_render (hb_font_t *font, const char *text)
121 {
122 static const char *ot[] = {"ot", nullptr};
123
124 hb_buffer_t *buffer = hb_buffer_create ();
125 hb_buffer_add_utf8 (buffer, text, -1, 0, -1);
126
127 /* XXX Do we need this? I think Arabic and Hangul shapers are the
128 * only one that make any use of this. The Hangul case is not really
129 * needed, and for Arabic we'll miss a very narrow set of fonts.
130 * Might be better to force generic shaper perhaps. */
131 hb_buffer_guess_segment_properties (buffer);
132
133 if (!hb_shape_full (font, buffer, nullptr, 0, ot))
134 abort (); /* hb-ot shaper not enabled? */
135
136 unsigned int len;
137 hb_glyph_info_t *info = hb_buffer_get_glyph_infos (buffer, &len);
138 for (unsigned int i = 0; i < len; i++)
139 {
140 if (!info[i].codepoint)
141 {
142 return false;
143 }
144 }
145
146 return true;
147 }
148