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Diffstat (limited to 'util/hb-fc.cc')
| -rw-r--r-- | util/hb-fc.cc | 149 |
1 files changed, 149 insertions, 0 deletions
diff --git a/util/hb-fc.cc b/util/hb-fc.cc new file mode 100644 index 000000000..e99b1aefc --- /dev/null +++ b/util/hb-fc.cc @@ -0,0 +1,149 @@ +/* + * Copyright © 2014 Google, Inc. + * + * This is part of HarfBuzz, a text shaping library. + * + * Permission is hereby granted, without written agreement and without + * license or royalty fees, to use, copy, modify, and distribute this + * software and its documentation for any purpose, provided that the + * above copyright notice and the following two paragraphs appear in + * all copies of this software. + * + * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR + * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES + * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN + * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH + * DAMAGE. + * + * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING, + * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND + * FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS + * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO + * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS. + * + * Google Author(s): Behdad Esfahbod + */ + +#include <stdlib.h> +#include <stdio.h> + +#include "hb-fc.h" + +static hb_bool_t +hb_fc_get_glyph (hb_font_t *font /*HB_UNUSED*/, + void *font_data, + hb_codepoint_t unicode, + hb_codepoint_t variation_selector, + hb_codepoint_t *glyph, + void *user_data /*HB_UNUSED*/) + +{ + FcCharSet *cs = (FcCharSet *) font_data; + + if (variation_selector) + { + /* Fontconfig doesn't cache cmap-14 info. However: + * 1. If the font maps the variation_selector, assume it's + * supported, + * 2. If the font doesn't map it, still say it's supported, + * but return 0. This way, the caller will see the zero + * and reject. If we return unsupported here, then the + * variation selector will be hidden and ignored. + */ + if (FcCharSetHasChar (cs, unicode) && + FcCharSetHasChar (cs, variation_selector)) + { + unsigned int var_num = 0; + if (variation_selector - 0xFE00u < 16) + var_num = variation_selector - 0xFE00 + 1; + else if (variation_selector - 0xE0100u < (256 - 16)) + var_num = variation_selector - 0xE0100 + 17; + *glyph = (var_num << 21) | unicode; + } + else + { + *glyph = 0; + } + return true; + } + + *glyph = FcCharSetHasChar (cs, unicode) ? unicode : 0; + return *glyph != 0; +} + +static hb_font_funcs_t * +_hb_fc_get_font_funcs (void) +{ + static const hb_font_funcs_t *fc_ffuncs; + + const hb_font_funcs_t *ffuncs; + + if (!(ffuncs = fc_ffuncs)) + { + hb_font_funcs_t *newfuncs = hb_font_funcs_create (); + + hb_font_funcs_set_glyph_func (newfuncs, hb_fc_get_glyph, NULL, NULL); + + /* XXX MT-unsafe */ + if (fc_ffuncs) + hb_font_funcs_destroy (newfuncs); + else + fc_ffuncs = ffuncs = newfuncs; + } + + return const_cast<hb_font_funcs_t *> (fc_ffuncs); +} + + +hb_font_t * +hb_fc_font_create (FcPattern *fcfont) +{ + static hb_face_t *face; + hb_font_t *font; + + FcCharSet *cs; + if (FcResultMatch != FcPatternGetCharSet (fcfont, FC_CHARSET, 0, &cs)) + return hb_font_get_empty (); + + if (!face) /* XXX MT-unsafe */ + face = hb_face_create (hb_blob_get_empty (), 0); + + font = hb_font_create (face); + + hb_font_set_funcs (font, + _hb_fc_get_font_funcs (), + FcCharSetCopy (cs), + (hb_destroy_func_t) FcCharSetDestroy); + + return font; +} + +hb_bool_t +hb_fc_can_render (hb_font_t *font, const char *text) +{ + static const char *ot[] = {"ot", NULL}; + + hb_buffer_t *buffer = hb_buffer_create (); + hb_buffer_add_utf8 (buffer, text, -1, 0, -1); + + /* XXX Do we need this? I think Arabic and Hangul shapers are the + * only one that make any use of this. The Hangul case is not really + * needed, and for Arabic we'll miss a very narrow set of fonts. + * Might be better to force generic shaper perhaps. */ + hb_buffer_guess_segment_properties (buffer); + + if (!hb_shape_full (font, buffer, NULL, 0, ot)) + abort (); /* hb-ot shaper not enabled? */ + + unsigned int len; + hb_glyph_info_t *info = hb_buffer_get_glyph_infos (buffer, &len); + for (unsigned int i = 0; i < len; i++) + { + if (!info[i].codepoint) + { + return false; + } + } + + return true; +} |