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// Copyright 2017 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_TEX_COORDS_PORTABLE_ENCODER_H_
#define DRACO_COMPRESSION_ATTRIBUTES_PREDICTION_SCHEMES_MESH_PREDICTION_SCHEME_TEX_COORDS_PORTABLE_ENCODER_H_
#include "draco/compression/attributes/prediction_schemes/mesh_prediction_scheme_encoder.h"
#include "draco/compression/attributes/prediction_schemes/mesh_prediction_scheme_tex_coords_portable_predictor.h"
#include "draco/compression/bit_coders/rans_bit_encoder.h"
namespace draco {
// Prediction scheme designed for predicting texture coordinates from known
// spatial position of vertices. For isometric parametrizations, the ratios
// between triangle edge lengths should be about the same in both the spatial
// and UV coordinate spaces, which makes the positions a good predictor for the
// UV coordinates. Note that this may not be the optimal approach for other
// parametrizations such as projective ones.
template <typename DataTypeT, class TransformT, class MeshDataT>
class MeshPredictionSchemeTexCoordsPortableEncoder
: public MeshPredictionSchemeEncoder<DataTypeT, TransformT, MeshDataT> {
public:
using CorrType = typename MeshPredictionSchemeEncoder<DataTypeT, TransformT,
MeshDataT>::CorrType;
MeshPredictionSchemeTexCoordsPortableEncoder(const PointAttribute *attribute,
const TransformT &transform,
const MeshDataT &mesh_data)
: MeshPredictionSchemeEncoder<DataTypeT, TransformT, MeshDataT>(
attribute, transform, mesh_data),
predictor_(mesh_data) {}
bool ComputeCorrectionValues(
const DataTypeT *in_data, CorrType *out_corr, int size,
int num_components, const PointIndex *entry_to_point_id_map) override;
bool EncodePredictionData(EncoderBuffer *buffer) override;
PredictionSchemeMethod GetPredictionMethod() const override {
return MESH_PREDICTION_TEX_COORDS_PORTABLE;
}
bool IsInitialized() const override {
if (!predictor_.IsInitialized())
return false;
if (!this->mesh_data().IsInitialized())
return false;
return true;
}
int GetNumParentAttributes() const override { return 1; }
GeometryAttribute::Type GetParentAttributeType(int i) const override {
DRACO_DCHECK_EQ(i, 0);
(void)i;
return GeometryAttribute::POSITION;
}
bool SetParentAttribute(const PointAttribute *att) override {
if (att->attribute_type() != GeometryAttribute::POSITION)
return false; // Invalid attribute type.
if (att->num_components() != 3)
return false; // Currently works only for 3 component positions.
predictor_.SetPositionAttribute(*att);
return true;
}
private:
MeshPredictionSchemeTexCoordsPortablePredictor<DataTypeT, MeshDataT>
predictor_;
};
template <typename DataTypeT, class TransformT, class MeshDataT>
bool MeshPredictionSchemeTexCoordsPortableEncoder<DataTypeT, TransformT,
MeshDataT>::
ComputeCorrectionValues(const DataTypeT *in_data, CorrType *out_corr,
int size, int num_components,
const PointIndex *entry_to_point_id_map) {
predictor_.SetEntryToPointIdMap(entry_to_point_id_map);
this->transform().Init(in_data, size, 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 corner_id = this->mesh_data().data_to_corner_map()->at(p);
predictor_.template ComputePredictedValue<true>(corner_id, in_data, p);
const int dst_offset = p * num_components;
this->transform().ComputeCorrection(in_data + dst_offset,
predictor_.predicted_value(),
out_corr + dst_offset);
}
return true;
}
template <typename DataTypeT, class TransformT, class MeshDataT>
bool MeshPredictionSchemeTexCoordsPortableEncoder<
DataTypeT, TransformT, MeshDataT>::EncodePredictionData(EncoderBuffer
*buffer) {
// Encode the delta-coded orientations using arithmetic coding.
const int32_t num_orientations = predictor_.num_orientations();
buffer->Encode(num_orientations);
bool last_orientation = true;
RAnsBitEncoder encoder;
encoder.StartEncoding();
for (int i = 0; i < num_orientations; ++i) {
const bool orientation = predictor_.orientation(i);
encoder.EncodeBit(orientation == last_orientation);
last_orientation = orientation;
}
encoder.EndEncoding(buffer);
return MeshPredictionSchemeEncoder<DataTypeT, TransformT,
MeshDataT>::EncodePredictionData(buffer);
}
} // namespace draco
#endif // DRACO_COMPRESSION_ATTRIBUTES_PREDICTION_SCHEMES_MESH_PREDICTION_SCHEME_TEX_COORDS_PORTABLE_ENCODER_H_
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