/*******************************************************************************
*
* McStas, neutron ray-tracing package
*         Copyright 1997-2002, All rights reserved
*         Risoe National Laboratory, Roskilde, Denmark
*         Institut Laue Langevin, Grenoble, France
*
* Component: PSD_monitor_psf
*
* %I
* Written by: Kim Lefmann, Linda Udby
* Date: Feb 3, 1998
* Updated: Oct 15, 2007 (with psf)
* Origin: Risoe
*
* Position-sensitive monitor.
*
* %D
* An (n times m) pixel PSD monitor. This component may also be used as a beam
* detector. Models 1/k behaviour and efficiency, based on user defined k0 and eff parameters.
*
* Example: PSD_monitor(xmin=-0.1, xmax=0.1, ymin=-0.1, ymax=0.1, nx=90, ny=90, filename="Output.psd")
*
* %P
* INPUT PARAMETERS:
*
* xmin: [m]             Lower x bound of detector opening
* xmax: [m]             Upper x bound of detector opening
* ymin: [m]             Lower y bound of detector opening
* ymax: [m]             Upper y bound of detector opening
* xwidth: [m]           Width/diameter of detector (x). Overrides xmin, xmax
* yheight: [m]          Height of detector (y). Overrides ymin, ymax
* nx: [1]               Number of pixel columns
* ny: [1]               Number of pixel rows
* filename: [string]    Name of file in which to store the detector image
* restore_neutron: [1]  If set, the monitor does not influence the neutron state
* psf: [m]              Point spread function, ray (x,y) coordinate randomized by gaussion of sigma psf
* k0:  [AA^-1]          Numerator in k0/k weighting 
* eff: [1]              Detector efficiency
* nowritefile: [1]      If set, monitor will skip writing to disk
*
* OUTPUT PARAMETERS:
*
* PSD_N: []             Array of neutron counts
* PSD_p: []             Array of neutron weight counts
* PSD_p2: []            Array of second moments
*
* %E
*******************************************************************************/

DEFINE COMPONENT PSD_monitor_psf_eff

DEFINITION PARAMETERS ()

SETTING PARAMETERS (int nx=90, int ny=90, string filename=0, xmin=0, xmax=0, ymin=0, ymax=0, int nowritefile=0,
  xwidth=0, yheight=0, psf=0, k0=1, eff=1, int restore_neutron=0)

OUTPUT PARAMETERS ()

DECLARE
%{
  DArray2d PSD_N;
  DArray2d PSD_p;
  DArray2d PSD_p2;
  double weight;
%}

INITIALIZE
%{
  if (xwidth  > 0) { xmax = xwidth/2;  xmin = -xmax; }
  if (yheight > 0) { ymax = yheight/2; ymin = -ymax; }

  if ((xmin >= xmax) || (ymin >= ymax)) {
    printf("PSD_monitor: %s: Null detection area !\n"
           "ERROR        (xwidth,yheight,xmin,xmax,ymin,ymax). Exiting",
           NAME_CURRENT_COMP);
    exit(0);
  }

  PSD_N = create_darr2d(nx, ny);
  PSD_p = create_darr2d(nx, ny);
  PSD_p2 = create_darr2d(nx, ny);

  // Use instance name for monitor output if no input was given
  if (!strcmp(filename,"\0")) sprintf(filename,"%s",NAME_CURRENT_COMP);
%}

TRACE
%{
  int i,j;
  double xp,yp;

  PROP_Z0;

  xp = x + psf*randnorm();
  yp = y + psf*randnorm();

  if (xp>xmin && xp<xmax && yp>ymin && yp<ymax)
  {
    weight = eff * k0 / (V2K*sqrt(vx*vx + vy*vy + vz*vz));
    i = floor((xp - xmin)*nx/(xmax - xmin));
    j = floor((yp - ymin)*ny/(ymax - ymin));

    double p2w = p*p*weight*weight;
    double pw = p*weight;
    
    #pragma acc atomic
    PSD_N[i][j] = PSD_N[i][j]+1;

    #pragma acc atomic
    PSD_p[i][j] = PSD_p[i][j]+pw;

    #pragma acc atomic
    PSD_p2[i][j] = PSD_p2[i][j]+p2w;
    
    SCATTER;
  }
  if (restore_neutron) {
    RESTORE_NEUTRON(INDEX_CURRENT_COMP, x, y, z, vx, vy, vz, t, sx, sy, sz, p);
  }
%}

SAVE
%{
if (!nowritefile) {
  DETECTOR_OUT_2D(
      "PSD monitor",
      "X position [cm]",
      "Y position [cm]",
      xmin*100.0, xmax*100.0, ymin*100.0, ymax*100.0,
      nx, ny,
      &PSD_N[0][0],&PSD_p[0][0],&PSD_p2[0][0],
      filename);
}
%}

FINALLY
%{
  destroy_darr2d(PSD_N);
  destroy_darr2d(PSD_p);
  destroy_darr2d(PSD_p2);
%}

MCDISPLAY
%{
  multiline(5, (double)xmin, (double)ymin, 0.0,
               (double)xmax, (double)ymin, 0.0,
               (double)xmax, (double)ymax, 0.0,
               (double)xmin, (double)ymax, 0.0,
               (double)xmin, (double)ymin, 0.0);
%}

END
