jacobianComputationLogic.hpp

/*
 * CoDiPack, a Code Differentiation Package
 *
 * Copyright (C) 2015-2025 Chair for Scientific Computing (SciComp), University of Kaiserslautern-Landau
 * Homepage: http://scicomp.rptu.de
 * Contact:  Prof. Nicolas R. Gauger (codi@scicomp.uni-kl.de)
 *
 * Lead developers: Max Sagebaum, Johannes Blühdorn (SciComp, University of Kaiserslautern-Landau)
 *
 * This file is part of CoDiPack (http://scicomp.rptu.de/software/codi).
 *
 * CoDiPack is free software: you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation, either version 3 of the
 * License, or (at your option) any later version.
 *
 * CoDiPack is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty
 * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 *
 * See the GNU General Public License for more details.
 * You should have received a copy of the GNU
 * General Public License along with CoDiPack.
 * If not, see <http://www.gnu.org/licenses/>.
 *
 * For other licensing options please contact us.
 *
 * Authors:
 *  - SciComp, University of Kaiserslautern-Landau:
 *    - Max Sagebaum
 *    - Johannes Blühdorn
 *    - Former members:
 *      - Tim Albring
 */
#pragma once
 
#include <type_traits>
#include <utility>
 
#include "../../../config.h"
#include "../../../misc/macros.hpp"
#include "../../../traits/expressionTraits.hpp"
#include "../../constantExpression.hpp"
#include "../traversalLogic.hpp"

namespace codi {

  template<typename T_Impl>
  struct JacobianComputationLogic : public TraversalLogic<T_Impl> {
    public:
 
      using Impl = CODI_DD(T_Impl, CODI_T(TraversalLogic<CODI_ANY>));  
 
      /*******************************************************************************/

      template<typename Node, typename Jacobian, typename... Args>
      void handleJacobianOnActive(Node const& node, Jacobian jacobian, Args&&... args);

      /*******************************************************************************/

      template<typename Node, typename Jacobian, typename... Args>
      CODI_INLINE ExpressionTraits::EnableIfLhsExpression<Node> leaf(Node const& node, Jacobian jacobian,
                                                                     Args&&... args) {
        cast().handleJacobianOnActive(node, jacobian, std::forward<Args>(args)...);
      }
 
      using TraversalLogic<Impl>::leaf;

      template<size_t ChildNumber, typename Child, typename Root, typename Jacobian, typename... Args>
      CODI_INLINE void link(Child const& child, Root const& root, Jacobian const& jacobian, Args&&... args) {
        auto curJacobian = root.template applyAdjoint<ChildNumber>(jacobian);
        cast().toNode(child, curJacobian, std::forward<Args>(args)...);
      }

      template<size_t ChildNumber, typename Real, template<typename> class ConvOp, typename Root, typename Jacobian,
               typename... Args>
      CODI_INLINE void link(ConstantExpression<Real, ConvOp> const& child, Root const& root, Jacobian const& jacobian,
                            Args&&... args) {
        CODI_UNUSED(child, root, jacobian, args...);
 
        // Do not compute Jacobian for constant arguments.
      }

 
    private:
 
      CODI_INLINE Impl& cast() {
        return static_cast<Impl&>(*this);
      }
  };
}