// Copyright (c) 2022, ETH Zurich and UNC Chapel Hill.
// All rights reserved.
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// Author: Johannes L. Schoenberger (jsch-at-demuc-dot-de)

#ifndef COLMAP_SRC_CONTROLLERS_HIERARCHICAL_MAPPER_H_
#define COLMAP_SRC_CONTROLLERS_HIERARCHICAL_MAPPER_H_

#include "base/reconstruction_manager.h"
#include "base/scene_clustering.h"
#include "controllers/incremental_mapper.h"
#include "util/threading.h"

namespace colmap {

// Hierarchical mapping first hierarchically partitions the scene into multiple
// overlapping clusters, then reconstructs them separately using incremental
// mapping, and finally merges them all into a globally consistent
// reconstruction. This is especially useful for larger-scale scenes, since
// incremental mapping becomes slow with an increasing number of images.
class HierarchicalMapperController : public Thread {
 public:
  struct Options {
    // The path to the image folder which are used as input.
    std::string image_path;

    // The path to the database file which is used as input.
    std::string database_path;

    // The maximum number of trials to initialize a cluster.
    int init_num_trials = 10;

    // The number of workers used to reconstruct clusters in parallel.
    int num_workers = -1;

    bool Check() const;
  };

  HierarchicalMapperController(
      const Options& options,
      const SceneClustering::Options& clustering_options,
      const IncrementalMapperOptions& mapper_options,
      ReconstructionManager* reconstruction_manager);

 private:
  void Run() override;

  const Options options_;
  const SceneClustering::Options clustering_options_;
  const IncrementalMapperOptions mapper_options_;
  ReconstructionManager* reconstruction_manager_;
};

}  // namespace colmap

#endif  // COLMAP_SRC_CONTROLLERS_HIERARCHICAL_MAPPER_H_