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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_POINT_CLOUD_ALGORITHMS_FLOAT_POINTS_TREE_ENCODER_H_
#define DRACO_COMPRESSION_POINT_CLOUD_ALGORITHMS_FLOAT_POINTS_TREE_ENCODER_H_
#include <memory>
#include <vector>
#include "draco/compression/point_cloud/algorithms/point_cloud_compression_method.h"
#include "draco/compression/point_cloud/algorithms/point_cloud_types.h"
#include "draco/compression/point_cloud/algorithms/quantize_points_3.h"
#include "draco/core/encoder_buffer.h"
namespace draco {
// This class encodes a given point cloud based on the point cloud compression
// algorithm in:
// Olivier Devillers and Pierre-Marie Gandoin
// "Geometric compression for interactive transmission"
//
// In principle the algorithm keeps on splitting the point cloud in the middle
// while alternating the axes. For 3D this results in an Octree like structure.
// In each step we encode the number of points in the first half.
// The algorithm uses quantization and does not preserve the order of points.
//
// However, the algorithm here differs from the original as follows:
// The algorithm keeps on splitting the point cloud in the middle of the axis
// that keeps the point cloud as clustered as possible, which gives a better
// compression rate.
// The number of points is encode by the deviation from the half of the points
// in the smaller half of the two. This results in a better compression rate as
// there are more leading zeros, which is then compressed better by the
// arithmetic encoding.
// TODO(b/199760123): Remove class because it duplicates quantization code.
class FloatPointsTreeEncoder {
public:
explicit FloatPointsTreeEncoder(PointCloudCompressionMethod method);
explicit FloatPointsTreeEncoder(PointCloudCompressionMethod method,
uint32_t quantization_bits,
uint32_t compression_level);
template <class InputIteratorT>
bool EncodePointCloud(InputIteratorT points_begin, InputIteratorT points_end);
EncoderBuffer *buffer() { return &buffer_; }
uint32_t version() const { return version_; }
uint32_t quantization_bits() const { return qinfo_.quantization_bits; }
uint32_t &quantization_bits() { return qinfo_.quantization_bits; }
uint32_t compression_level() const { return compression_level_; }
uint32_t &compression_level() { return compression_level_; }
float range() const { return qinfo_.range; }
uint32_t num_points() const { return num_points_; }
std::string identification_string() const {
if (method_ == KDTREE) {
return "FloatPointsTreeEncoder: IntegerPointsKDTreeEncoder";
} else {
return "FloatPointsTreeEncoder: Unsupported Method";
}
}
private:
void Clear() { buffer_.Clear(); }
bool EncodePointCloudKdTreeInternal(std::vector<Point3ui> *qpoints);
static const uint32_t version_;
QuantizationInfo qinfo_;
PointCloudCompressionMethod method_;
uint32_t num_points_;
EncoderBuffer buffer_;
uint32_t compression_level_;
};
template <class InputIteratorT>
bool FloatPointsTreeEncoder::EncodePointCloud(InputIteratorT points_begin,
InputIteratorT points_end) {
Clear();
// Collect necessary data for encoding.
num_points_ = std::distance(points_begin, points_end);
// TODO(b/199760123): Extend quantization tools to make this more automatic.
// Compute range of points for quantization
std::vector<Point3ui> qpoints;
qpoints.reserve(num_points_);
QuantizePoints3(points_begin, points_end, &qinfo_,
std::back_inserter(qpoints));
// Encode header.
buffer()->Encode(version_);
buffer()->Encode(static_cast<int8_t>(method_));
buffer()->Encode(qinfo_.quantization_bits);
buffer()->Encode(qinfo_.range);
buffer()->Encode(num_points_);
if (method_ == KDTREE) {
buffer()->Encode(compression_level_);
}
if (num_points_ == 0) {
return true;
}
if (method_ == KDTREE) {
return EncodePointCloudKdTreeInternal(&qpoints);
} else { // Unsupported method.
fprintf(stderr, "Method not supported. \n");
return false;
}
}
} // namespace draco
#endif // DRACO_COMPRESSION_POINT_CLOUD_ALGORITHMS_FLOAT_POINTS_TREE_ENCODER_H_
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