add a lib for rendering text in sdl2 and rules to make in makefile

SDL2_ttf/external/harfbuzz/util/hb-fc.cc

@@ -0,0 +1,147 @@
+/*
+ * 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 ()
+{
+  static const hb_font_funcs_t *fc_ffuncs;
+
+  if (!fc_ffuncs)
+  {
+    hb_font_funcs_t *newfuncs = hb_font_funcs_create ();
+
+    hb_font_funcs_set_glyph_func (newfuncs, hb_fc_get_glyph, nullptr, nullptr);
+
+    /* XXX MT-unsafe */
+    if (fc_ffuncs)
+      hb_font_funcs_destroy (newfuncs);
+    else
+      fc_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", nullptr};
+
+  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, nullptr, 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;
+}