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diff --git a/extern/draco/dracoenc/src/draco/mesh/mesh_misc_functions.h b/extern/draco/dracoenc/src/draco/mesh/mesh_misc_functions.h
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+// Copyright 2016 The Draco Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+// This file contains misc functions that are needed by several mesh related
+// algorithms.
+
+#ifndef DRACO_MESH_MESH_MISC_FUNCTIONS_H_
+#define DRACO_MESH_MESH_MISC_FUNCTIONS_H_
+
+#include "draco/mesh/corner_table.h"
+#include "draco/mesh/mesh.h"
+
+// The file contains functions that use both Mesh and CornerTable as inputs.
+namespace draco {
+
+// Creates a CornerTable from the position attribute of |mesh|. Returns nullptr
+// on error.
+std::unique_ptr<CornerTable> CreateCornerTableFromPositionAttribute(
+    const Mesh *mesh);
+
+// Creates a CornerTable from all attributes of |mesh|. Boundaries are
+// automatically introduced on all attribute seams. Returns nullptr on error.
+std::unique_ptr<CornerTable> CreateCornerTableFromAllAttributes(
+    const Mesh *mesh);
+
+// Returns true when the given corner lies opposite to an attribute seam.
+inline bool IsCornerOppositeToAttributeSeam(CornerIndex ci,
+                                            const PointAttribute &att,
+                                            const Mesh &mesh,
+                                            const CornerTable &ct) {
+  const CornerIndex opp_ci = ct.Opposite(ci);
+  if (opp_ci == kInvalidCornerIndex)
+    return false;  // No opposite corner == no attribute seam.
+  // Compare attribute value indices on both ends of the opposite edge.
+  CornerIndex c0 = ct.Next(ci);
+  CornerIndex c1 = ct.Previous(opp_ci);
+  if (att.mapped_index(mesh.CornerToPointId(c0)) !=
+      att.mapped_index(mesh.CornerToPointId(c1)))
+    return true;
+  c0 = ct.Previous(ci);
+  c1 = ct.Next(opp_ci);
+  if (att.mapped_index(mesh.CornerToPointId(c0)) !=
+      att.mapped_index(mesh.CornerToPointId(c1)))
+    return true;
+  return false;
+}
+
+}  // namespace draco
+
+#endif  // DRACO_MESH_MESH_MISC_FUNCTIONS_H_