// Ceres Solver - A fast non-linear least squares minimizer
// Copyright 2010, 2011, 2012 Google Inc. All rights reserved.
// http://code.google.com/p/ceres-solver/
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are met:
//
// * Redistributions of source code must retain the above copyright notice,
//   this list of conditions and the following disclaimer.
// * Redistributions in binary form must reproduce the above copyright notice,
//   this list of conditions and the following disclaimer in the documentation
//   and/or other materials provided with the distribution.
// * Neither the name of Google Inc. nor the names of its contributors may be
//   used to endorse or promote products derived from this software without
//   specific prior written permission.
//
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// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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//
// Author: sameeragarwal@google.com (Sameer Agarwal)

#include "ceres/linear_solver.h"

#include "ceres/cgnr_solver.h"
#include "ceres/dense_normal_cholesky_solver.h"
#include "ceres/dense_qr_solver.h"
#include "ceres/iterative_schur_complement_solver.h"
#include "ceres/schur_complement_solver.h"
#include "ceres/sparse_normal_cholesky_solver.h"
#include "ceres/types.h"
#include "glog/logging.h"

namespace ceres {
namespace internal {

LinearSolver::~LinearSolver() {
}

LinearSolver* LinearSolver::Create(const LinearSolver::Options& options) {
  switch (options.type) {
    case CGNR:
      return new CgnrSolver(options);

    case SPARSE_NORMAL_CHOLESKY:
#if defined(CERES_NO_SUITESPARSE) && defined(CERES_NO_CXSPARSE)
      LOG(WARNING) << "SPARSE_NORMAL_CHOLESKY is not available. Please "
                   << "build Ceres with SuiteSparse or CXSparse. "
                   << "Returning NULL.";
      return NULL;
#else
      return new SparseNormalCholeskySolver(options);
#endif

    case SPARSE_SCHUR:
#if defined(CERES_NO_SUITESPARSE) && defined(CERES_NO_CXSPARSE)
      LOG(WARNING) << "SPARSE_SCHUR is not available. Please "
                   << "build Ceres with SuiteSparse or CXSparse. "
                   << "Returning NULL.";
      return NULL;
#else
      return new SparseSchurComplementSolver(options);
#endif

    case DENSE_SCHUR:
      return new DenseSchurComplementSolver(options);

    case ITERATIVE_SCHUR:
      return new IterativeSchurComplementSolver(options);

    case DENSE_QR:
      return new DenseQRSolver(options);

    case DENSE_NORMAL_CHOLESKY:
      return new DenseNormalCholeskySolver(options);

    default:
      LOG(FATAL) << "Unknown linear solver type :"
                 << options.type;
      return NULL;  // MSVC doesn't understand that LOG(FATAL) never returns.
  }
}

}  // namespace internal
}  // namespace ceres