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diff --git a/extern/draco/draco/src/draco/compression/attributes/prediction_schemes/prediction_scheme_delta_encoder.h b/extern/draco/draco/src/draco/compression/attributes/prediction_schemes/prediction_scheme_delta_encoder.h
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+++ b/extern/draco/draco/src/draco/compression/attributes/prediction_schemes/prediction_scheme_delta_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.
+//
+#ifndef DRACO_COMPRESSION_ATTRIBUTES_PREDICTION_SCHEMES_PREDICTION_SCHEME_DELTA_ENCODER_H_
+#define DRACO_COMPRESSION_ATTRIBUTES_PREDICTION_SCHEMES_PREDICTION_SCHEME_DELTA_ENCODER_H_
+
+#include "draco/compression/attributes/prediction_schemes/prediction_scheme_encoder.h"
+
+namespace draco {
+
+// Basic prediction scheme based on computing backward differences between
+// stored attribute values (also known as delta-coding). Usually works better
+// than the reference point prediction scheme, because nearby values are often
+// encoded next to each other.
+template <typename DataTypeT, class TransformT>
+class PredictionSchemeDeltaEncoder
+    : public PredictionSchemeEncoder<DataTypeT, TransformT> {
+ public:
+  using CorrType =
+      typename PredictionSchemeEncoder<DataTypeT, TransformT>::CorrType;
+  // Initialized the prediction scheme.
+  explicit PredictionSchemeDeltaEncoder(const PointAttribute *attribute)
+      : PredictionSchemeEncoder<DataTypeT, TransformT>(attribute) {}
+  PredictionSchemeDeltaEncoder(const PointAttribute *attribute,
+                               const TransformT &transform)
+      : PredictionSchemeEncoder<DataTypeT, TransformT>(attribute, transform) {}
+
+  bool ComputeCorrectionValues(
+      const DataTypeT *in_data, CorrType *out_corr, int size,
+      int num_components, const PointIndex *entry_to_point_id_map) override;
+  PredictionSchemeMethod GetPredictionMethod() const override {
+    return PREDICTION_DIFFERENCE;
+  }
+  bool IsInitialized() const override { return true; }
+};
+
+template <typename DataTypeT, class TransformT>
+bool PredictionSchemeDeltaEncoder<
+    DataTypeT, TransformT>::ComputeCorrectionValues(const DataTypeT *in_data,
+                                                    CorrType *out_corr,
+                                                    int size,
+                                                    int num_components,
+                                                    const PointIndex *) {
+  this->transform().Init(in_data, size, num_components);
+  // Encode data from the back using D(i) = D(i) - D(i - 1).
+  for (int i = size - num_components; i > 0; i -= num_components) {
+    this->transform().ComputeCorrection(
+        in_data + i, in_data + i - num_components, out_corr + i);
+  }
+  // Encode correction for the first element.
+  std::unique_ptr<DataTypeT[]> zero_vals(new DataTypeT[num_components]());
+  this->transform().ComputeCorrection(in_data, zero_vals.get(), out_corr);
+  return true;
+}
+
+}  // namespace draco
+
+#endif  // DRACO_COMPRESSION_ATTRIBUTES_PREDICTION_SCHEMES_PREDICTION_SCHEME_DELTA_ENCODER_H_