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diff --git a/extern/draco/draco/src/draco/compression/bit_coders/folded_integer_bit_encoder.h b/extern/draco/draco/src/draco/compression/bit_coders/folded_integer_bit_encoder.h
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+++ b/extern/draco/draco/src/draco/compression/bit_coders/folded_integer_bit_encoder.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.
+//
+// File provides direct encoding of bits with arithmetic encoder interface.
+#ifndef DRACO_COMPRESSION_BIT_CODERS_FOLDED_INTEGER_BIT_ENCODER_H_
+#define DRACO_COMPRESSION_BIT_CODERS_FOLDED_INTEGER_BIT_ENCODER_H_
+
+#include <vector>
+
+#include "draco/core/encoder_buffer.h"
+
+namespace draco {
+
+// This coding scheme considers every bit of an (up to) 32bit integer as a
+// separate context. This can be a significant advantage when encoding numbers
+// where it is more likely that the front bits are zero.
+// The behavior is essentially the same as other arithmetic encoding schemes,
+// the only difference is that encoding and decoding of bits must be absolutely
+// symmetric, bits handed in by EncodeBit32 must be also decoded in this way.
+// This is the FoldedBit32Encoder, see also FoldedBit32Decoder.
+template <class BitEncoderT>
+class FoldedBit32Encoder {
+ public:
+  FoldedBit32Encoder() {}
+  ~FoldedBit32Encoder() {}
+
+  // Must be called before any Encode* function is called.
+  void StartEncoding() {
+    for (int i = 0; i < 32; i++) {
+      folded_number_encoders_[i].StartEncoding();
+    }
+    bit_encoder_.StartEncoding();
+  }
+
+  // Encode one bit. If |bit| is true encode a 1, otherwise encode a 0.
+  void EncodeBit(bool bit) { bit_encoder_.EncodeBit(bit); }
+
+  // Encode |nbits| of |value|, starting from the least significant bit.
+  // |nbits| must be > 0 and <= 32.
+  void EncodeLeastSignificantBits32(int nbits, uint32_t value) {
+    uint32_t selector = 1 << (nbits - 1);
+    for (int i = 0; i < nbits; i++) {
+      const bool bit = (value & selector);
+      folded_number_encoders_[i].EncodeBit(bit);
+      selector = selector >> 1;
+    }
+  }
+
+  // Ends the bit encoding and stores the result into the target_buffer.
+  void EndEncoding(EncoderBuffer *target_buffer) {
+    for (int i = 0; i < 32; i++) {
+      folded_number_encoders_[i].EndEncoding(target_buffer);
+    }
+    bit_encoder_.EndEncoding(target_buffer);
+  }
+
+ private:
+  void Clear() {
+    for (int i = 0; i < 32; i++) {
+      folded_number_encoders_[i].Clear();
+    }
+    bit_encoder_.Clear();
+  }
+
+  std::array<BitEncoderT, 32> folded_number_encoders_;
+  BitEncoderT bit_encoder_;
+};
+
+}  // namespace draco
+
+#endif  // DRACO_COMPRESSION_BIT_CODERS_FOLDED_INTEGER_BIT_ENCODER_H_