// 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: sameeragarwal@google.com (Sameer Agarwal)

#ifndef CERES_INTERNAL_BLOCK_RANDOM_ACCESS_DENSE_MATRIX_H_

#define CERES_INTERNAL_BLOCK_RANDOM_ACCESS_DENSE_MATRIX_H_

#include "ceres/block_random_access_matrix.h"

#include <vector>

#include "ceres/internal/macros.h"

#include "ceres/internal/port.h"

#include "ceres/internal/scoped_ptr.h"

namespace ceres {

namespace internal {

// A square block random accessible matrix with the same row and

// column block structure. All cells are stored in the same single

// array, so that its also accessible as a dense matrix of size

// num_rows x num_cols.

//

// This class is NOT thread safe. Since all n^2 cells are stored,

// GetCell never returns NULL for any (row_block_id, col_block_id)

// pair.

//

// ReturnCell is a nop.

class BlockRandomAccessDenseMatrix : public BlockRandomAccessMatrix {

 public:

  // blocks is a vector of block sizes. The resulting matrix has

  // blocks.size() * blocks.size() cells.

  explicit BlockRandomAccessDenseMatrix(const std::vector<int>& blocks);

  // The destructor is not thread safe. It assumes that no one is

  // modifying any cells when the matrix is being destroyed.

  virtual ~BlockRandomAccessDenseMatrix();

  // BlockRandomAccessMatrix interface.

  virtual CellInfo* GetCell(int row_block_id,

                            int col_block_id,

                            int* row,

                            int* col,

                            int* row_stride,

                            int* col_stride);

  // This is not a thread safe method, it assumes that no cell is

  // locked.

  virtual void SetZero();

  // Since the matrix is square with the same row and column block

  // structure, num_rows() = num_cols().

  virtual int num_rows() const { return num_rows_; }

  virtual int num_cols() const { return num_rows_; }

  // The underlying matrix storing the cells.

  const double* values() const { return values_.get(); }

  double* mutable_values() { return values_.get(); }

 private:

  int num_rows_;

  std::vector<int> block_layout_;

  scoped_array<double> values_;

  scoped_array<CellInfo> cell_infos_;

  CERES_DISALLOW_COPY_AND_ASSIGN(BlockRandomAccessDenseMatrix);

};

}  // namespace internal

}  // namespace ceres

#endif  // CERES_INTERNAL_BLOCK_RANDOM_ACCESS_DENSE_MATRIX_H_