// Ceres Solver - A fast non-linear least squares minimizer
// Copyright 2015 Google Inc. All rights reserved.
// http://ceres-solver.org/
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// Author: keir@google.com (Keir Mierle)
//
// A dense matrix implemented under the SparseMatrix interface.

#ifndef CERES_INTERNAL_DENSE_SPARSE_MATRIX_H_
#define CERES_INTERNAL_DENSE_SPARSE_MATRIX_H_

#include "ceres/internal/eigen.h"
#include "ceres/internal/port.h"
#include "ceres/sparse_matrix.h"
#include "ceres/types.h"

namespace ceres {
namespace internal {

class TripletSparseMatrix;

class CERES_EXPORT_INTERNAL DenseSparseMatrix : public SparseMatrix {
 public:
  // Build a matrix with the same content as the TripletSparseMatrix
  // m. This assumes that m does not have any repeated entries.
  explicit DenseSparseMatrix(const TripletSparseMatrix& m);
  explicit DenseSparseMatrix(const Matrix& m);
  DenseSparseMatrix(int num_rows, int num_cols);

  virtual ~DenseSparseMatrix() = default;

  // SparseMatrix interface.
  void SetZero() final;
  void RightMultiply(const double* x, double* y) const final;
  void LeftMultiply(const double* x, double* y) const final;
  void SquaredColumnNorm(double* x) const final;
  void ScaleColumns(const double* scale) final;
  void ToDenseMatrix(Matrix* dense_matrix) const final;
  void ToTextFile(FILE* file) const final;
  int num_rows() const final;
  int num_cols() const final;
  int num_nonzeros() const final;
  const double* values() const final { return m_.data(); }
  double* mutable_values() final { return m_.data(); }

  const Matrix& matrix() const;
  Matrix* mutable_matrix();

 private:
  Matrix m_;
};

}  // namespace internal
}  // namespace ceres

#endif  // CERES_INTERNAL_DENSE_SPARSE_MATRIX_H_