/*******************************************************************************
*
* McStas, neutron ray-tracing package
*         Copyright 1997-2002, All rights reserved
*         Risoe National Laboratory, Roskilde, Denmark
*         Institut Laue Langevin, Grenoble, France
*
* Component: Scatter_log_iterator_stop.comp
*
* %I
*
* Written by: Erik B Knudsen 
* Date: November 2012
* Version: $Revision: 1.21 $
* Release: McStas 2.1
* Origin: DTU Physics
*
* Iteration stop element for a Scatter_log
*
* %D
*
* This component marks the end of the trace-region in which pseudo-neutrons are handled. Please see the Scatter_log_iterator-component for more details.
* N.B. This component should be immediately followed by a construction like:
* COMPONENT a1 = Arm()
* AT (0,0,0) ABSOLUTE
* JUMP a0 WHEN(MC_GETPAR(iterator_stop_comp_name,loop))
*
* This is to extract the value of the loop variable from the innards of this component
*
* %P
* Input parameters:
*
* iterator [ ] Instance name of the Scatter_log_iterator log component preceeding this one.
*
* %E
*******************************************************************************/

DEFINE COMPONENT Shielding_log_iterator_stop
DEFINITION PARAMETERS (iterator)
SETTING PARAMETERS (int last=0)
OUTPUT PARAMETERS (loop)
/* Neutron parameters: (x,y,z,vx,vy,vz,t,sx,sy,sz,p) */ 

SHARE 
%{
%}

DECLARE
%{
  int loop;
%}

INITIALIZE 
%{
  loop=1;
%}


TRACE
%{
#ifdef scatter_iterator_stop
#undef scatter_iterator_stop
#endif
#define scatter_iterator_stop iterator
scatter_iterator_stop:
  loop=1;
  struct Generalized_State_t *s1=MC_GETPAR(iterator,s1);

  if (s1->_p==-1){
    /*we have reached the end - unset loop and reset neutron state to whatever it was before we entered the pseudo neutron iterator*/
    loop=0;
    double *ns=MC_GETPAR(iterator,nstate_initial);
    x=ns[0];y=ns[1];z=ns[2];
    vx=ns[3];vy=ns[4];vz=ns[5];
    t=ns[6];
    sx=ns[7];sy=ns[8];sz=ns[9];
    p=ns[10];

    free(ns);
    MC_GETPAR(iterator,nstate_initial)=NULL;
    /* Restore std ABSORB */
#undef mcabsorb
#define mcabsorb mcabsorbAll
  // printf("No ABSORB after the iterator\n");
  } else if (s1->_p==-2) { 
  /*if the weight equals -2 it means that the neutron was absorbed in components within the scatter_logger (see scatter logger definition) 
    and should not be propagated further after this iterator*/
  // printf("Performing ABSORB after the iterator\n");
   /*we have reached the end - unset loop and reset neutron state to whatever it was before we entered the pseudo neutron iterator*/
    loop=0;
    double *ns=MC_GETPAR(iterator,nstate_initial);
    x=ns[0];y=ns[1];z=ns[2];
    vx=ns[3];vy=ns[4];vz=ns[5];
    t=ns[6];
    sx=ns[7];sy=ns[8];sz=ns[9];
    p=ns[10];

    free(ns);
    MC_GETPAR(iterator,nstate_initial)=NULL;
    /* Restore std ABSORB */
#undef mcabsorb
#define mcabsorb mcabsorbAll
   if (last>0) ABSORB; //Will sample new neutron. 
  }
%}

MCDISPLAY
%{
  /* A bit ugly; hard-coded dimensions. */
  magnify("");
  line(0,0,0,0.2,0,0);
  line(0,0,0,0,0.2,0);
  line(0,0,0,0,0,0.2);
%}

END