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Diffstat (limited to 'extern/draco/draco/src/draco/compression/attributes/prediction_schemes/mesh_prediction_scheme_multi_parallelogram_encoder.h')
-rw-r--r-- | extern/draco/draco/src/draco/compression/attributes/prediction_schemes/mesh_prediction_scheme_multi_parallelogram_encoder.h | 133 |
1 files changed, 133 insertions, 0 deletions
diff --git a/extern/draco/draco/src/draco/compression/attributes/prediction_schemes/mesh_prediction_scheme_multi_parallelogram_encoder.h b/extern/draco/draco/src/draco/compression/attributes/prediction_schemes/mesh_prediction_scheme_multi_parallelogram_encoder.h new file mode 100644 index 00000000000..301b357d411 --- /dev/null +++ b/extern/draco/draco/src/draco/compression/attributes/prediction_schemes/mesh_prediction_scheme_multi_parallelogram_encoder.h @@ -0,0 +1,133 @@ +// 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_MULTI_PARALLELOGRAM_ENCODER_H_ +#define DRACO_COMPRESSION_ATTRIBUTES_PREDICTION_SCHEMES_MESH_PREDICTION_SCHEME_MULTI_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 { + +// Multi parallelogram prediction predicts attribute values using information +// from all opposite faces to the predicted vertex, compared to the standard +// prediction scheme, where only one opposite face is used (see +// prediction_scheme_parallelogram.h). This approach is generally slower than +// the standard parallelogram prediction, but it usually results in better +// prediction (5 - 20% based on the quantization level. Better gains can be +// achieved when more aggressive quantization is used). +template <typename DataTypeT, class TransformT, class MeshDataT> +class MeshPredictionSchemeMultiParallelogramEncoder + : public MeshPredictionSchemeEncoder<DataTypeT, TransformT, MeshDataT> { + public: + using CorrType = + typename PredictionSchemeEncoder<DataTypeT, TransformT>::CorrType; + using CornerTable = typename MeshDataT::CornerTable; + + explicit MeshPredictionSchemeMultiParallelogramEncoder( + const PointAttribute *attribute) + : MeshPredictionSchemeEncoder<DataTypeT, TransformT, MeshDataT>( + attribute) {} + MeshPredictionSchemeMultiParallelogramEncoder(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_MULTI_PARALLELOGRAM; + } + + bool IsInitialized() const override { + return this->mesh_data().IsInitialized(); + } +}; + +template <typename DataTypeT, class TransformT, class MeshDataT> +bool MeshPredictionSchemeMultiParallelogramEncoder<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); + 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 storage of prediction values (already initialized to zero). + std::unique_ptr<DataTypeT[]> pred_vals(new DataTypeT[num_components]()); + std::unique_ptr<DataTypeT[]> parallelogram_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. + for (int p = + static_cast<int>(this->mesh_data().data_to_corner_map()->size() - 1); + p > 0; --p) { + const CornerIndex start_corner_id = + this->mesh_data().data_to_corner_map()->at(p); + + // Go over all corners attached to the vertex and compute the predicted + // value from the parallelograms defined by their opposite faces. + CornerIndex corner_id(start_corner_id); + int num_parallelograms = 0; + for (int i = 0; i < num_components; ++i) { + pred_vals[i] = static_cast<DataTypeT>(0); + } + while (corner_id != kInvalidCornerIndex) { + if (ComputeParallelogramPrediction( + p, corner_id, table, *vertex_to_data_map, in_data, num_components, + parallelogram_pred_vals.get())) { + for (int c = 0; c < num_components; ++c) { + pred_vals[c] += parallelogram_pred_vals[c]; + } + ++num_parallelograms; + } + + // Proceed to the next corner attached to the vertex. + corner_id = table->SwingRight(corner_id); + if (corner_id == start_corner_id) { + corner_id = kInvalidCornerIndex; + } + } + const int dst_offset = p * num_components; + if (num_parallelograms == 0) { + // No parallelogram was valid. + // We use the last encoded point as a reference. + const int src_offset = (p - 1) * num_components; + this->transform().ComputeCorrection( + in_data + dst_offset, in_data + src_offset, out_corr + dst_offset); + } else { + // Compute the correction from the predicted value. + for (int c = 0; c < num_components; ++c) { + pred_vals[c] /= num_parallelograms; + } + 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_MULTI_PARALLELOGRAM_ENCODER_H_ |