.. _program_listing_file_SPlisHSPlasH_PBF_TimeIntegration.cpp:

Program Listing for File TimeIntegration.cpp
============================================

|exhale_lsh| :ref:`Return to documentation for file <file_SPlisHSPlasH_PBF_TimeIntegration.cpp>` (``SPlisHSPlasH/PBF/TimeIntegration.cpp``)

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

.. code-block:: cpp

   #include "TimeIntegration.h"
   
   using namespace SPH;
   
   
   // ----------------------------------------------------------------------------------------------
   void TimeIntegration::semiImplicitEuler(
       const Real h, 
       const Real mass, 
       Vector3r &position,
       Vector3r &velocity,
       const Vector3r &acceleration)
   {               
       if (mass != 0.0)
       {
           velocity += acceleration * h;
           position += velocity * h;
       }
   }
   
   // ----------------------------------------------------------------------------------------------
   void TimeIntegration::velocityUpdateFirstOrder(
       const Real h,
       const Real mass,
       const Vector3r &position,
       const Vector3r &oldPosition,
       Vector3r &velocity)
   {
       if (mass != 0.0)
           velocity = (1.0 / h) * (position - oldPosition);
   }
   
   // ----------------------------------------------------------------------------------------------
   void TimeIntegration::velocityUpdateSecondOrder(
       const Real h,
       const Real mass,
       const Vector3r &position,
       const Vector3r &oldPosition,
       const Vector3r &positionOfLastStep,
       Vector3r &velocity)
   {
       if (mass != 0.0)
           velocity = (1.0 / h) * (1.5*position - 2.0*oldPosition + 0.5*positionOfLastStep);
   }