/* Library for computing optical properites of the heavy water, light water,
 * and acrylic in the SNO detector.
 *
 * Copyright (c) 2019, Anthony Latorre <tlatorre at uchicago>
 *
 * This program is free software: you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the Free
 * Software Foundation, either version 3 of the License, or (at your option)
 * any later version.

 * This program is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
 * more details.

 * You should have received a copy of the GNU General Public License along with
 * this program. If not, see <https://www.gnu.org/licenses/>.
 */

#ifndef OPTICS_H
#define OPTICS_H

/* Global error string when optics_init() returns -1. */
extern char optics_err[256];

/* Initialize the optics data by precomputing the average absorption and
 * scattering tables. */
int optics_init(int run);

/* Functions to get the index of refraction in water and heavy water averaged
 * over the Cerenkov spectrum and the PMT quantum efficiency. */
double get_avg_index_d2o(void);
double get_avg_index_h2o(void);

/* Functions for computing the index of refraction. */
double get_index(double p, double wavelength, double T);
double get_index_snoman_h2o(double wavelength);
double get_index_snoman_d2o(double wavelength);
double get_index_snoman_acrylic(double wavelength);

/* Functions for computing the scattering probability as a funcion of
 * wavelength. */
double rayint_prob(double wavelength, double n, double isothermal_comp);
double rayint_prob_d2o(double wavelength);
double rayint_prob_h2o(double wavelength);
double rayint_prob_acrylic(double wavelength);

/* Functions for computing the probability that a photon is not absorbed or
 * scattered after a certain distance. */
double get_fabs_d2o(double x);
double get_fabs_h2o(double x);
double get_fabs_acrylic(double x);
double get_fsct_d2o(double x);
double get_fsct_h2o(double x);
double get_fsct_acrylic(double x);

/* Functions for computing the absorption length as a funcion of wavelength. */
double get_absorption_length_snoman_d2o(double wavelength);
double get_absorption_length_snoman_h2o(double wavelength);
double get_absorption_length_snoman_acrylic(double wavelength);

#endif