[utils] Add hb-fc-list
This is a tool that lists all fonts that can render a given string.
It uses hb_shape() to do so, and as such is aware of HarfBuzz's
normalizer.
diff --git a/util/hb-fc.cc b/util/hb-fc.cc
new file mode 100644
index 0000000..e99b1ae
--- /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;
+}
