.. _program_listing_file_SPlisHSPlasH_PF_TimeStepPF.h:

Program Listing for File TimeStepPF.h
=====================================

|exhale_lsh| :ref:`Return to documentation for file <file_SPlisHSPlasH_PF_TimeStepPF.h>` (``SPlisHSPlasH/PF/TimeStepPF.h``)

.. |exhale_lsh| unicode:: U+021B0 .. UPWARDS ARROW WITH TIP LEFTWARDS

.. code-block:: cpp

   #ifndef __TimeStepPF_h__
   #define __TimeStepPF_h__
   
   #include "SimulationDataPF.h"
   #include "SPlisHSPlasH/Common.h"
   #include "SPlisHSPlasH/TimeStep.h"
   #include "SPlisHSPlasH/SPHKernels.h"
   #include "SPlisHSPlasH/Utilities/MatrixFreeSolver.h"
   
   // since all diagonal blocks are 3x3 diagonal matrices, a diagonal preconditioner does suffice
   #define PD_USE_DIAGONAL_PRECONDITIONER
   
   namespace SPH
   {
       class TimeStepPF : public TimeStep
       {
       protected:
           using VectorXr = Eigen::Matrix<Real, -1, 1>;
           using VectorXrMap = Eigen::Map<VectorXr>;
   
   #ifdef PD_USE_DIAGONAL_PRECONDITIONER
           using Solver = Eigen::ConjugateGradient<MatrixReplacement, Eigen::Lower | Eigen::Upper, JacobiPreconditioner3D>;
           FORCE_INLINE static void diagonalMatrixElement(const unsigned int row, Vector3r &result, void *userData);
           void preparePreconditioner();
   #else
           using Solver = Eigen::ConjugateGradient<MatrixReplacement, Eigen::Lower | Eigen::Upper, Eigen::IdentityPreconditioner>;
   #endif
   
           SimulationDataPF m_simulationData;
           Solver m_solver;
           Real m_stiffness;
           unsigned int m_numActiveParticlesTotal;
   
           void initialGuessForPositions(const unsigned int fluidModelIndex);
           void solvePDConstraints();
           void updatePositionsAndVelocity(const VectorXr & x);
           void addAccellerationToVelocity();
   
           void matrixFreeRHS(const VectorXr & x, VectorXr & result);
   
           virtual void performNeighborhoodSearchSort();
           virtual void emittedParticles(FluidModel *model, const unsigned int startIndex) override;
   
           virtual void initParameters() override;
   
       public:
           static int STIFFNESS;
   
           TimeStepPF();
           virtual ~TimeStepPF(void);
   
           virtual void step()   override;
           virtual void reset()  override;
           virtual void resize() override;
   
           static void matrixVecProd(const Real* vec, Real *result, void *userData);
       };
   }
   
   #endif