add harfbuzz library

libs/harfbuzz/src/hb-subset-repacker.cc

@@ -0,0 +1,58 @@
+/*
+ * Copyright © 2022  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.
+ *
+ */
+#include "hb-repacker.hh"
+
+#ifdef HB_EXPERIMENTAL_API
+
+/**
+ * hb_subset_repack_or_fail:
+ * @table_tag: tag of the table being packed, needed to allow table specific optimizations.
+ * @hb_objects: raw array of struct hb_object_t, which provides
+ * object graph info
+ * @num_hb_objs: number of hb_object_t in the hb_objects array.
+ *
+ * Given the input object graph info, repack a table to eliminate
+ * offset overflows. A nullptr is returned if the repacking attempt fails.
+ * Table specific optimizations (eg. extension promotion in GSUB/GPOS) may be performed.
+ * Passing HB_TAG_NONE will disable table specific optimizations.
+ *
+ * Since: EXPERIMENTAL
+ **/
+hb_blob_t* hb_subset_repack_or_fail (hb_tag_t table_tag,
+                                     hb_object_t* hb_objects,
+                                     unsigned num_hb_objs)
+{
+  hb_vector_t<const hb_object_t *> packed;
+  packed.alloc (num_hb_objs + 1);
+  packed.push (nullptr);
+  for (unsigned i = 0 ; i < num_hb_objs ; i++)
+    packed.push (&(hb_objects[i]));
+
+  return hb_resolve_overflows (packed,
+                               table_tag,
+                               20,
+                               true);
+}
+#endif