Add hb_tag_from_string()

src/Makefile.am

@@ -14,6 +14,7 @@ HBSOURCES =  \
 	hb-blob-private.h \
 	hb-buffer.cc \
 	hb-buffer-private.hh \
+	hb-common.c \
 	hb-font.cc \
 	hb-font-private.hh \
 	hb-object-private.h \

src/hb-common.c

@@ -0,0 +1,41 @@
+/*
+ * Copyright (C) 2010  Red Hat, 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.
+ *
+ * Red Hat Author(s): Behdad Esfahbod
+ */
+
+#include "hb-private.h"
+
+hb_tag_t
+hb_tag_from_string (const char *s)
+{
+  char tag[4];
+  unsigned int i;
+
+  for (i = 0; i < 4 && s[i]; i++)
+    tag[i] = s[i];
+  for (; i < 4; i++)
+    tag[i] = ' ';
+
+  return HB_TAG_STR (tag);
+}

src/hb-common.h

@@ -65,6 +65,9 @@ typedef uint32_t hb_tag_t;
 				((const char *) s)[3]))
 #define HB_TAG_NONE HB_TAG(0,0,0,0)
 
+hb_tag_t hb_tag_from_string (const char *s);
+
+
 typedef uint32_t hb_codepoint_t;
 typedef int32_t hb_position_t;
 typedef uint32_t hb_mask_t;