// Ceres Solver - A fast non-linear least squares minimizer

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// Author: keir@google.com (Keir Mierle)

//

// A evaluate preparer which puts jacobian the evaluated jacobian blocks

// directly into their final resting place in an overall block sparse matrix.

// The evaluator takes care to avoid evaluating the jacobian for fixed

// parameters.

#ifndef CERES_INTERNAL_BLOCK_EVALUATE_PREPARER_H_

#define CERES_INTERNAL_BLOCK_EVALUATE_PREPARER_H_

#include "ceres/scratch_evaluate_preparer.h"

namespace ceres {

namespace internal {

class ResidualBlock;

class SparseMatrix;

class BlockEvaluatePreparer {

 public:

  // Using Init() instead of a constructor allows for allocating this structure

  // with new[]. This is because C++ doesn't allow passing arguments to objects

  // constructed with new[] (as opposed to plain 'new').

  void Init(int const* const* jacobian_layout,

            int max_derivatives_per_residual_block);

  // EvaluatePreparer interface

  // Point the jacobian blocks directly into the block sparse matrix, if

  // jacobian is non-null. Otherwise, uses an internal per-thread buffer to

  // store the jacobians temporarily.

  void Prepare(const ResidualBlock* residual_block,

               int residual_block_index,

               SparseMatrix* jacobian,

               double** jacobians);

 private:

  int const* const* jacobian_layout_;

  // For the case that the overall jacobian is not available, but the

  // individual jacobians are requested, use a pass-through scratch evaluate

  // preparer.

  ScratchEvaluatePreparer scratch_evaluate_preparer_;

};

}  // namespace internal

}  // namespace ceres

#endif  // CERES_INTERNAL_BLOCK_EVALUATE_PREPARER_H_