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diff --git a/extern/draco/draco/src/draco/compression/attributes/prediction_schemes/mesh_prediction_scheme_parallelogram_encoder.h b/extern/draco/draco/src/draco/compression/attributes/prediction_schemes/mesh_prediction_scheme_parallelogram_encoder.h
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+++ b/extern/draco/draco/src/draco/compression/attributes/prediction_schemes/mesh_prediction_scheme_parallelogram_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_MESH_PREDICTION_SCHEME_PARALLELOGRAM_ENCODER_H_
+#define DRACO_COMPRESSION_ATTRIBUTES_PREDICTION_SCHEMES_MESH_PREDICTION_SCHEME_PARALLELOGRAM_ENCODER_H_
+
+#include "draco/compression/attributes/prediction_schemes/mesh_prediction_scheme_encoder.h"
+#include "draco/compression/attributes/prediction_schemes/mesh_prediction_scheme_parallelogram_shared.h"
+
+namespace draco {
+
+// Parallelogram prediction predicts an attribute value V from three vertices
+// on the opposite face to the predicted vertex. The values on the three
+// vertices are used to construct a parallelogram V' = O - A - B, where O is the
+// value on the opposite vertex, and A, B are values on the shared vertices:
+//     V
+//    / \
+//   /   \
+//  /     \
+// A-------B
+//  \     /
+//   \   /
+//    \ /
+//     O
+//
+template <typename DataTypeT, class TransformT, class MeshDataT>
+class MeshPredictionSchemeParallelogramEncoder
+    : public MeshPredictionSchemeEncoder<DataTypeT, TransformT, MeshDataT> {
+ public:
+  using CorrType =
+      typename PredictionSchemeEncoder<DataTypeT, TransformT>::CorrType;
+  using CornerTable = typename MeshDataT::CornerTable;
+  explicit MeshPredictionSchemeParallelogramEncoder(
+      const PointAttribute *attribute)
+      : MeshPredictionSchemeEncoder<DataTypeT, TransformT, MeshDataT>(
+            attribute) {}
+  MeshPredictionSchemeParallelogramEncoder(const PointAttribute *attribute,
+                                           const TransformT &transform,
+                                           const MeshDataT &mesh_data)
+      : MeshPredictionSchemeEncoder<DataTypeT, TransformT, MeshDataT>(
+            attribute, transform, mesh_data) {}
+
+  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 MESH_PREDICTION_PARALLELOGRAM;
+  }
+
+  bool IsInitialized() const override {
+    return this->mesh_data().IsInitialized();
+  }
+};
+
+template <typename DataTypeT, class TransformT, class MeshDataT>
+bool MeshPredictionSchemeParallelogramEncoder<DataTypeT, TransformT,
+                                              MeshDataT>::
+    ComputeCorrectionValues(const DataTypeT *in_data, CorrType *out_corr,
+                            int size, int num_components,
+                            const PointIndex * /* entry_to_point_id_map */) {
+  this->transform().Init(in_data, size, num_components);
+  // For storage of prediction values (already initialized to zero).
+  std::unique_ptr<DataTypeT[]> pred_vals(new DataTypeT[num_components]());
+
+  // We start processing from the end because this prediction uses data from
+  // previous entries that could be overwritten when an entry is processed.
+  const CornerTable *const table = this->mesh_data().corner_table();
+  const std::vector<int32_t> *const vertex_to_data_map =
+      this->mesh_data().vertex_to_data_map();
+  for (int p =
+           static_cast<int>(this->mesh_data().data_to_corner_map()->size() - 1);
+       p > 0; --p) {
+    const CornerIndex corner_id = this->mesh_data().data_to_corner_map()->at(p);
+    const int dst_offset = p * num_components;
+    if (!ComputeParallelogramPrediction(p, corner_id, table,
+                                        *vertex_to_data_map, in_data,
+                                        num_components, pred_vals.get())) {
+      // Parallelogram could not be computed, Possible because some of the
+      // vertices are not valid (not encoded yet).
+      // We use the last encoded point as a reference (delta coding).
+      const int src_offset = (p - 1) * num_components;
+      this->transform().ComputeCorrection(
+          in_data + dst_offset, in_data + src_offset, out_corr + dst_offset);
+    } else {
+      // Apply the parallelogram prediction.
+      this->transform().ComputeCorrection(in_data + dst_offset, pred_vals.get(),
+                                          out_corr + dst_offset);
+    }
+  }
+  // First element is always fixed because it cannot be predicted.
+  for (int i = 0; i < num_components; ++i) {
+    pred_vals[i] = static_cast<DataTypeT>(0);
+  }
+  this->transform().ComputeCorrection(in_data, pred_vals.get(), out_corr);
+  return true;
+}
+
+}  // namespace draco
+
+#endif  // DRACO_COMPRESSION_ATTRIBUTES_PREDICTION_SCHEMES_MESH_PREDICTION_SCHEME_PARALLELOGRAM_ENCODER_H_