text: /*
   * Copyright (c) 2011-2021, The DART development contributors
   * All rights reserved.
   *
   * The list of contributors can be found at:
   *   https://github.com/dartsim/dart/blob/main/LICENSE
   *
   * This file is provided under the following "BSD-style" License:
   *   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.
   *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
   *   CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
   *   INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
   *   MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
   *   DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR
   *   CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
   *   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
   *   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
   *   USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
   *   AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   *   LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
   *   ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
   *   POSSIBILITY OF SUCH DAMAGE.
   */
  
  #ifndef DART_CONSTRAINT_BOXEDLCPCONSTRAINTSOLVER_HPP_
  #define DART_CONSTRAINT_BOXEDLCPCONSTRAINTSOLVER_HPP_
  
  #include "dart/dynamics/ConstraintSolver.hpp"
  #include "dart/dynamics/SmartPointer.hpp"
  
  namespace dart {
  namespace dynamics {
  
  class BoxedLcpConstraintSolver : public ConstraintSolver
  {
  public:
    /// Constructor
    ///
    /// \param[in] timeStep Simulation time step
    /// \param[in] boxedLcpSolver The primary boxed LCP solver. When nullptr is
    /// passed, Dantzig solver will be used.
    /// \param[in] secondaryBoxedLcpSolver The secondary boxed-LCP solver. When
    /// nullptr is passed, PGS solver will be used. This is to make the default
    /// solver setting to be Dantzig + PGS. In order to disable use of secondary
    /// solver, call setSecondaryBoxedLcpSolver(nullptr) explicitly.
    ///
    /// \deprecated Deprecated in DART 6.8. Please use other constructors that
    /// doesn't take timespte. Timestep should be set by the owner of this solver
    /// such as dart::simulation::World when the solver added.
    DART_DEPRECATED(6.8)
    BoxedLcpConstraintSolver(
        double timeStep,
        BoxedLcpSolverPtr boxedLcpSolver = nullptr,
        BoxedLcpSolverPtr secondaryBoxedLcpSolver = nullptr);
  
    /// Constructos with default primary and secondary LCP solvers, which are
    /// Dantzig and PGS, respectively.
    BoxedLcpConstraintSolver();
  
    /// Constructors with specific primary LCP solver.
    ///
    /// \param[in] boxedLcpSolver The primary boxed LCP solver. When nullptr is
    /// passed, which is discouraged, Dantzig solver will be used.
    BoxedLcpConstraintSolver(BoxedLcpSolverPtr boxedLcpSolver);
  
    /// Constructs with specific primary and secondary LCP solvers.
    ///
    /// \param[in] boxedLcpSolver The primary boxed LCP solver. When nullptr is
    /// passed, which is discouraged, Dantzig solver will be used.
    /// \param[in] secondaryBoxedLcpSolver The secondary boxed-LCP solver. Pass
    /// nullptr to disable using secondary LCP solver.
    BoxedLcpConstraintSolver(
        BoxedLcpSolverPtr boxedLcpSolver,
        BoxedLcpSolverPtr secondaryBoxedLcpSolver);
  
    /// Sets boxed LCP (BLCP) solver
    ///
    /// \param[in] lcpSolver The primary boxed LCP solver. When nullptr is
    /// passed, Dantzig solver will be used.
    void setBoxedLcpSolver(BoxedLcpSolverPtr lcpSolver);
  
    /// Returns boxed LCP (BLCP) solver
    ConstBoxedLcpSolverPtr getBoxedLcpSolver() const;
  
    /// Sets boxed LCP (BLCP) solver that is used when the primary solver failed
    void setSecondaryBoxedLcpSolver(BoxedLcpSolverPtr lcpSolver);
  
    /// Returns boxed LCP (BLCP) solver that is used when the primary solver
    /// failed
    ConstBoxedLcpSolverPtr getSecondaryBoxedLcpSolver() const;
  
  protected:
    // Documentation inherited.
    void solveConstrainedGroup(ConstrainedGroup& group) override;
  
    /// Boxed LCP solver
    BoxedLcpSolverPtr mBoxedLcpSolver;
    // TODO(JS): Hold as unique_ptr because there is no reason to share. Make this
    // change in DART 7 because it's API breaking change.
  
    /// Boxed LCP solver to be used when the primary solver failed
    BoxedLcpSolverPtr mSecondaryBoxedLcpSolver;
    // TODO(JS): Hold as unique_ptr because there is no reason to share. Make this
    // change in DART 7 because it's API breaking change.
  
    /// Cache data for boxed LCP formulation
    Eigen::Matrix<double, Eigen::Dynamic, Eigen::Dynamic, Eigen::RowMajor> mA;
  
    /// Cache data for boxed LCP formulation
    Eigen::Matrix<double, Eigen::Dynamic, Eigen::Dynamic, Eigen::RowMajor>
        mABackup;
  
    /// Cache data for boxed LCP formulation
    Eigen::VectorXd mX;
  
    /// Cache data for boxed LCP formulation
    Eigen::VectorXd mXBackup;
  
    /// Cache data for boxed LCP formulation
    Eigen::VectorXd mB;
  
    /// Cache data for boxed LCP formulation
    Eigen::VectorXd mBBackup;
  
    /// Cache data for boxed LCP formulation
    Eigen::VectorXd mW;
  
    /// Cache data for boxed LCP formulation
    Eigen::VectorXd mLo;
  
    /// Cache data for boxed LCP formulation
    Eigen::VectorXd mLoBackup;
  
    /// Cache data for boxed LCP formulation
    Eigen::VectorXd mHi;
  
    /// Cache data for boxed LCP formulation
    Eigen::VectorXd mHiBackup;
  
    /// Cache data for boxed LCP formulation
    Eigen::VectorXi mFIndex;
  
    /// Cache data for boxed LCP formulation
    Eigen::VectorXi mFIndexBackup;
  
    /// Cache data for boxed LCP formulation
    Eigen::VectorXi mOffset;
  
  #ifndef NDEBUG
  private:
    /// Return true if the matrix is symmetric
    bool isSymmetric(std::size_t n, double* A);
  
    /// Return true if the diagonla block of matrix is symmetric
    bool isSymmetric(
        std::size_t n, double* A, std::size_t begin, std::size_t end);
  
    /// Print debug information
    void print(
        std::size_t n,
        double* A,
        double* x,
        double* lo,
        double* hi,
        double* b,
        double* w,
        int* findex);
  #endif
  };
  
  } // namespace dynamics
  } // namespace dart
  
  #endif // DART_CONSTRAINT_BOXEDLCPCONSTRAINTSOLVER_HPP_
  