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diff --git a/extern/draco/dracoenc/src/draco/compression/attributes/prediction_schemes/prediction_scheme_delta_decoder.h b/extern/draco/dracoenc/src/draco/compression/attributes/prediction_schemes/prediction_scheme_delta_decoder.h
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+++ b/extern/draco/dracoenc/src/draco/compression/attributes/prediction_schemes/prediction_scheme_delta_decoder.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_DECODER_H_
+#define DRACO_COMPRESSION_ATTRIBUTES_PREDICTION_SCHEMES_PREDICTION_SCHEME_DELTA_DECODER_H_
+
+#include "draco/compression/attributes/prediction_schemes/prediction_scheme_decoder.h"
+
+namespace draco {
+
+// Decoder for values encoded with delta coding. See the corresponding encoder
+// for more details.
+template <typename DataTypeT, class TransformT>
+class PredictionSchemeDeltaDecoder
+    : public PredictionSchemeDecoder<DataTypeT, TransformT> {
+ public:
+  using CorrType =
+      typename PredictionSchemeDecoder<DataTypeT, TransformT>::CorrType;
+  // Initialized the prediction scheme.
+  explicit PredictionSchemeDeltaDecoder(const PointAttribute *attribute)
+      : PredictionSchemeDecoder<DataTypeT, TransformT>(attribute) {}
+  PredictionSchemeDeltaDecoder(const PointAttribute *attribute,
+                               const TransformT &transform)
+      : PredictionSchemeDecoder<DataTypeT, TransformT>(attribute, transform) {}
+
+  bool ComputeOriginalValues(const CorrType *in_corr, DataTypeT *out_data,
+                             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 PredictionSchemeDeltaDecoder<DataTypeT, TransformT>::ComputeOriginalValues(
+    const CorrType *in_corr, DataTypeT *out_data, int size, int num_components,
+    const PointIndex *) {
+  this->transform().Init(num_components);
+  // Decode the original value for the first element.
+  std::unique_ptr<DataTypeT[]> zero_vals(new DataTypeT[num_components]());
+  this->transform().ComputeOriginalValue(zero_vals.get(), in_corr, out_data);
+
+  // Decode data from the front using D(i) = D(i) + D(i - 1).
+  for (int i = num_components; i < size; i += num_components) {
+    this->transform().ComputeOriginalValue(out_data + i - num_components,
+                                           in_corr + i, out_data + i);
+  }
+  return true;
+}
+
+}  // namespace draco
+
+#endif  // DRACO_COMPRESSION_ATTRIBUTES_PREDICTION_SCHEMES_PREDICTION_SCHEME_DELTA_DECODER_H_