/*******************************************************************************
*
* McStas, neutron ray-tracing package
*         Copyright 1997-2002, All rights reserved
*         Risoe National Laboratory, Roskilde, Denmark
*         Institut Laue Langevin, Grenoble, France
*
* Component: EPSD_monitor.comp
*
* %I
* Written by: Kim Lefmann
* Date: 16.4.00
* Origin: Risoe
*
* A monitor measuring neutron intensity vs. position, x, and neutron energy, E
*
* %D
*
* A monitor measuring neutron intensity vs. position, x, and neutron energy, E
*
* Example: EPSD_monitor(xmin=-0.1, xmax=0.1, ymin=-0.1, ymax=0.1,
*           Emin=1, Emax=50, nx=20, nE=20, filename="Output.poe")
*
* %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 of detector. Overrides xmin,xmax.
* yheight: [m]          Height of detector. Overrides ymin,ymax.
* Emin: [meV]           Lower bound of energy
* Emax: [meV]           Upper bound of energy
* nx: [1]               Number of pixel columns in scattering plane
* nE: [1]               Number of energy bins
* 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
* nowritefile: [1]      If set, monitor will skip writing to disk
*
* CALCULATED PARAMETERS:
*
* PSD_N: []             Array of neutron counts
* PSD_p: []             Array of neutron weight counts
* PSD_p2: []            Array of second moments
*
* %E
*******************************************************************************/

DEFINE COMPONENT EPSD_monitor

SETTING PARAMETERS (int nx=20, int nE=20, string filename=0, xmin=-0.05, xmax=0.05, ymin=-0.05, ymax=0.05, int nowritefile=0,
  xwidth=0, yheight=0, Emin, Emax, int restore_neutron=0)

/* Neutron parameters: (x,y,z,vx,vy,vz,t,sx,sy,sz,p) */

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

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

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

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

  // 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 E, v;

  PROP_Z0;
  v = vx * vx + vy * vy + vz * vz;
  E = VS2E * (vx * vx + vy * vy + vz * vz);

  if (x > xmin && x < xmax && y > ymin && y < ymax && E > Emin && E < Emax) {
    i = floor ((x - xmin) * nx / (xmax - xmin));
    j = floor ((E - Emin) * nE / (Emax - Emin));

    double p2 = p * p;
    #pragma acc atomic
    PSD_N[i][j] = PSD_N[i][j] + 1;

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

    #pragma acc atomic
    PSD_p2[i][j] = PSD_p2[i][j] + p2;
  }
  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 ("EPSD monitor", "Position [m]", "Energy [meV]", xmin, xmax, Emin, Emax, nx, nE, &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
%{

%}

END