/* solar.h -- Solar position header
 * This file is part of redshift-ng.
 * 
 * redshift-ng 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.
 * 
 * redshift-ng 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 redshift-ng.  If not, see <http://www.gnu.org/licenses/>.
 * 
 * Copyright (c) 2010  Jon Lund Steffensen <jonlst@gmail.com>
 */
#ifndef REDSHIFT_SOLAR_H
#define REDSHIFT_SOLAR_H

/* Model of atmospheric refraction near horizon (in degrees). */
#define SOLAR_ATM_REFRAC  0.833

#define SOLAR_ASTRO_TWILIGHT_ELEV   -18.0
#define SOLAR_NAUT_TWILIGHT_ELEV    -12.0
#define SOLAR_CIVIL_TWILIGHT_ELEV    -6.0
#define SOLAR_DAYTIME_ELEV           (0.0 - SOLAR_ATM_REFRAC)

enum solar_time {
	SOLAR_TIME_NOON = 0,
	SOLAR_TIME_MIDNIGHT,
	SOLAR_TIME_ASTRO_DAWN,
	SOLAR_TIME_NAUT_DAWN,
	SOLAR_TIME_CIVIL_DAWN,
	SOLAR_TIME_SUNRISE,
	SOLAR_TIME_SUNSET,
	SOLAR_TIME_CIVIL_DUSK,
	SOLAR_TIME_NAUT_DUSK,
	SOLAR_TIME_ASTRO_DUSK,
	SOLAR_TIME_MAX
};


double solar_elevation(double date, double lat, double lon);
void solar_table_fill(double date, double lat, double lon, double *table);

#endif /* ! REDSHIFT_SOLAR_H */