1 files changed, 34 insertions, 0 deletions
diff --git a/gfx/ots/src/gsub.h b/gfx/ots/src/gsub.h
new file mode 100644
index 0000000000..9ceb5c7170
--- /dev/null
+++ b/gfx/ots/src/gsub.h
@@ -0,0 +1,34 @@
+// Copyright (c) 2011-2017 The OTS Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef OTS_GSUB_H_
+#define OTS_GSUB_H_
+
+#include "ots.h"
+#include "layout.h"
+
+namespace ots {
+
+class OpenTypeGSUB : public OpenTypeLayoutTable {
+ public:
+  explicit OpenTypeGSUB(Font *font, uint32_t tag)
+      : OpenTypeLayoutTable(font, tag, tag) { }
+
+ private:
+  bool ValidLookupSubtableType(uint16_t lookup_type,
+                               bool extension = false) const;
+  bool ParseLookupSubtable(const uint8_t *data, const size_t length,
+                           const uint16_t lookup_type);
+
+  bool ParseSingleSubstitution(const uint8_t *data, const size_t length);
+  bool ParseMutipleSubstitution(const uint8_t *data, const size_t length);
+  bool ParseAlternateSubstitution(const uint8_t *data, const size_t length);
+  bool ParseLigatureSubstitution(const uint8_t *data, const size_t length);
+  bool ParseReverseChainingContextSingleSubstitution(const uint8_t *data, const size_t length);
+};
+
+}  // namespace ots
+
+#endif  // OTS_GSUB_H_
+