/*nphot one of Kevin Kolk's quantum heating routines for grains */
#include "cddefines.h"
#include "rfield.h"
#include "grainvar.h"
#include "nphotl.h"
#include "lget.h"
#include "nphot.h"

void nphot(float umin, 
	  float umax, 
	  float *xphot, 
	  long int ndust1)
{
	long int j, 
	  ipj1, 
	  ipj2;

	double val1, 
	  val2;

#	ifdef DEBUG_FUN
	fputs( "<+>nphot()\n", debug_fp );
#	endif

	/* one of Kevin Kolk's quantum heating routines for grains
	 * This routine calculates the photon flux able to produce a 
	 * transition.  umin and umax give the energy range in rydberg 
	 * for which the total flux of photons weighted by the absorption
	 * cross-section of the grain is to be calculated. */

	/* The following assumes that nflux is always larger than 1 */
	if( nphotl.iflnph < rfield.nflux )
	{

		for( j=nphotl.iflnph-1; j < rfield.nflux; j++ )
		{
			nphotl.vmin[j] = (float)((rfield.anu[j] - rfield.widflx[j]/2.));
			nphotl.vmax[j] = (float)(rfield.anu[j] + rfield.widflx[j]/ 2.);
		}

		nphotl.iflnph = rfield.nflux;
	}

	*xphot = 0.;
	ipj1 = lget(rfield.anu,rfield.nflux,umin) - 1;
	ipj2 = lget(rfield.anu,rfield.nflux,umax) + 1;

	/* >>chng 97 june get rid of go to
	 * do j=ipj1,ipj2 */
	j = ipj1-1;
	while( j < ipj2-1 && nphotl.vmin[j] <= umax )
	{
		if( nphotl.vmax[j] >= umin )
		{
			/* if(vmin(j).gt.umax) goto 515 */
			val1 = MAX2(umin,nphotl.vmin[j]);
			val2 = MIN2(umax,nphotl.vmax[j]);
			/* xphot =xphot+(flux(j)+otslin(j)+outcon(j)+otscon(j))*
			 * >>chng 97 july 17, summedcon */
			*xphot += (float)(rfield.SummedCon[j]*GrainVar.dstab1[ndust1][j]*
			  (val2 - val1)/rfield.widflx[j]);
		}
		j += 1;
	}
	*xphot *= GrainVar.dstAbund[ndust1];

	/* this assumes that the flux arrays are in photons/s/rydb/cm^2 units,
	 * rather than cgs flux density units
	 *515  xphot = xphot*qhnrat(ndust1)/qdep(ndust1) */
	*xphot = *xphot*GrainVar.qhnrat[ndust1]/GrainVar.qdep[ndust1];

#	ifdef DEBUG_FUN
	fputs( " <->nphot()\n", debug_fp );
#	endif
	return;
}