// 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)

#include "ceres/block_random_access_dense_matrix.h"

#include <vector>

#include "ceres/internal/eigen.h"

#include "ceres/internal/scoped_ptr.h"

#include "glog/logging.h"

namespace ceres {

namespace internal {

BlockRandomAccessDenseMatrix::BlockRandomAccessDenseMatrix(

    const std::vector<int>& blocks) {

  const int num_blocks = blocks.size();

  block_layout_.resize(num_blocks, 0);

  num_rows_ = 0;

  for (int i = 0; i < num_blocks; ++i) {

    block_layout_[i] = num_rows_;

    num_rows_ += blocks[i];

  }

  values_.reset(new double[num_rows_ * num_rows_]);

  cell_infos_.reset(new CellInfo[num_blocks * num_blocks]);

  for (int i = 0; i < num_blocks * num_blocks; ++i) {

    cell_infos_[i].values = values_.get();

  }

  SetZero();

}

// Assume that the user does not hold any locks on any cell blocks

// when they are calling SetZero.

BlockRandomAccessDenseMatrix::~BlockRandomAccessDenseMatrix() {

}

CellInfo* BlockRandomAccessDenseMatrix::GetCell(const int row_block_id,

                                                const int col_block_id,

                                                int* row,

                                                int* col,

                                                int* row_stride,

                                                int* col_stride) {

  *row = block_layout_[row_block_id];

  *col = block_layout_[col_block_id];

  *row_stride = num_rows_;

  *col_stride = num_rows_;

  return &cell_infos_[row_block_id * block_layout_.size() + col_block_id];

}

// Assume that the user does not hold any locks on any cell blocks

// when they are calling SetZero.

void BlockRandomAccessDenseMatrix::SetZero() {

  if (num_rows_) {

    VectorRef(values_.get(), num_rows_ * num_rows_).setZero();

  }

}

}  // namespace internal

}  // namespace ceres