#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#include <string.h>
#include "mucal.h"
#include "panel.h"

/* **************************************************************************************** */

/* Calculation of Bragg scattering efficiency from mosaic crystals
   of finite thickness. Nomenclature follows "A study of focusing...", nl, 1992
   Niels Lund September 2005

   This routine calculates nominal Bragg energies for each facet and nOption
*/

int reflect2(reflect *REFL, facet *FACET, int nOption)  
{
   static int Z=-2, CM=-1, first = 1;

   int i, j, k, err, len;
   
   float  E, thetaB, PI, TWOPI, GTORAD;
   float  lambda, d;
   float  fwhmt;
   float  arcmin2rad, dE;


   PI = 3.14159;
   TWOPI = 2.0 * PI;
   GTORAD = TWOPI / 360.0;
   arcmin2rad = GTORAD / 60.0;
   CM = REFL->CM;
   /* Calculate Bragg-energy, E, corresponding to Z, Miller-index, Focal length and facet position */

   d = REFL->dist_geo * 1.0e+8;  	/* separation between crystal planes (Angstroem) */
   thetaB = FACET->thetaB;
   lambda = thetaB * 2.0 * d;		/* X-ray wavelength according to Bragg's formula: thetaB = lambda / (2d) */
   E = 12.39 / lambda;			/* lambda in Angstroem, E in KeV */
   dE = E * fwhmt * arcmin2rad / thetaB;

   FACET->E[nOption] = E;
   FACET->dE[nOption] = dE;

   return(1);
}