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diff --git a/extern/draco/dracoenc/src/draco/compression/mesh/mesh_decoder_helpers.h b/extern/draco/dracoenc/src/draco/compression/mesh/mesh_decoder_helpers.h
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+++ b/extern/draco/dracoenc/src/draco/compression/mesh/mesh_decoder_helpers.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.
+//
+#ifndef DRACO_COMPRESSION_MESH_MESH_DECODER_HELPERS_H_
+#define DRACO_COMPRESSION_MESH_MESH_DECODER_HELPERS_H_
+
+#include "draco/compression/mesh/mesh_decoder.h"
+
+namespace draco {
+
+// Function for decoding a stream previously encoded by a MeshEncoder. The
+// result is stored into a stream of single precision floating point numbers
+// in a XYZ|UV format, where one value is stored for every corner of each
+// triangle.
+// On error, the function sets the input stream "is" to an invalid state.
+template <typename InStreamT>
+InStreamT &DecodePos3Tex2DataFromStream(InStreamT &&is,
+                                        std::vector<float> *out_data) {
+  // Determine the size of the encoded data and write it into a vector.
+  const auto start_pos = is.tellg();
+  is.seekg(0, std::ios::end);
+  const std::streampos is_size = is.tellg() - start_pos;
+  is.seekg(start_pos);
+  std::vector<char> data(is_size);
+  is.read(&data[0], is_size);
+
+  // Create a mesh from the data.
+  std::unique_ptr<Mesh> mesh = draco::DecodeMesh(&data[0], data.size());
+
+  if (mesh == nullptr) {
+    is.setstate(ios_base::badbit);
+    return is;
+  }
+
+  const PointAttribute *pos_att =
+      mesh->GetNamedAttribute(GeometryAttribute::POSITION);
+  const PointAttribute *tex_att =
+      mesh->GetNamedAttribute(GeometryAttribute::TEX_COORD_0);
+
+  // Both position and texture attributes must be present.
+  if (pos_att == nullptr || tex_att == nullptr) {
+    is.setstate(ios_base::badbit);
+    return is;
+  }
+
+  // Copy the mesh data into the provided output.
+  constexpr int data_stride = 5;
+  // Prepare the output storage for 3 output values per face.
+  out_data->resize(mesh->num_faces() * 3 * data_stride);
+
+  std::array<float, 3> pos_val;
+  std::array<float, 2> tex_val;
+  int out_it = 0;
+  for (int f = 0; f < mesh->num_faces(); ++f) {
+    const Mesh::Face &face = mesh->face(f);
+    for (int p = 0; p < 3; ++p) {
+      pos_att->ConvertValue<float, 3>(pos_att->mapped_index(face[p]),
+                                      &pos_val[0]);
+      memcpy(&out_data->at(0) + out_it, &pos_val[0], sizeof(pos_val));
+      out_it += 3;
+      tex_att->ConvertValue<float, 2>(tex_att->mapped_index(face[p]),
+                                      &tex_val[0]);
+      memcpy(&out_data->at(0) + out_it, &tex_val[0], sizeof(tex_val));
+      out_it += 2;
+    }
+  }
+
+  return is;
+}
+
+}  // namespace draco
+
+#endif  // DRACO_COMPRESSION_MESH_MESH_DECODER_HELPERS_H_