From 3812e8caed82fb2a8301e78cdfc05b7f954b06fb Mon Sep 17 00:00:00 2001 From: Mattias Andrée Date: Sat, 2 Jan 2016 08:31:37 +0100 Subject: solar MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Signed-off-by: Mattias Andrée --- src/solar.h | 100 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 100 insertions(+) create mode 100644 src/solar.h (limited to 'src/solar.h') diff --git a/src/solar.h b/src/solar.h new file mode 100644 index 0000000..7eec736 --- /dev/null +++ b/src/solar.h @@ -0,0 +1,100 @@ +/** + * Copyright © 2016 Mattias Andrée + * + * Permission is hereby granted, free of charge, to any person obtaining a + * copy of this software and associated documentation files (the "Software"), + * to deal in the Software without restriction, including without limitation + * the rights to use, copy, modify, merge, publish, distribute, sublicense, + * and/or sell copies of the Software, and to permit persons to whom the + * Software is furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL + * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING + * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER + * DEALINGS IN THE SOFTWARE. + */ + + +/** + * Approximate apparent size of the Sun in degrees. + */ +#define SOLAR_APPARENT_RADIUS (32.0 / 60.0) + + +/** + * The Sun's elevation at sunset and sunrise, measured in degrees. + */ +#define SOLAR_ELEVATION_SUNSET_SUNRISE (0.0) + +/** + * The Sun's elevation at civil dusk and civil dawn, measured in degrees. + */ +#define SOLAR_ELEVATION_CIVIL_DUSK_DAWN (-6.0) + +/** + * The Sun's elevation at nautical dusk and nautical dawn, measured in degrees. + */ +#define SOLAR_ELEVATION_NAUTICAL_DUSK_DAWN (-12.0) + +/** + * The Sun's elevation at astronomical dusk and astronomical dawn, measured in degrees. + */ +#define SOLAR_ELEVATION_ASTRONOMICAL_DUSK_DAWN (-18.0) + + +/** + * Test whether it is twilight. + * + * @param ELEV:double The current elevation. + * @return 1 if is twilight, 0 otherwise. + */ +#define SOLAR_IS_TWILIGHT(ELEV) ((-18.0 <= (ELEV)) && ((ELEV) <= 0.0)) + +/** + * Test whether it is civil twilight. + * + * @param ELEV:double The current elevation. + * @return 1 if is civil twilight, 0 otherwise. + */ +#define SOLAR_IS_CIVIL_TWILIGHT(ELEV) ((-6.0 <= (ELEV)) && ((ELEV) <= 0.0)) + +/** + * Test whether it is nautical twilight. + * + * @param ELEV:double The current elevation. + * @return 1 if is nautical twilight, 0 otherwise. + */ +#define SOLAR_IS_NAUTICAL_TWILIGHT(ELEV) ((-12.0 <= (ELEV)) && ((ELEV) <= -6.0)) + +/** + * Test whether it is astronomical twilight. + * + * @param ELEV:double The current elevation. + * @return 1 if is astronomical twilight, 0 otherwise. + */ +#define SOLAR_IS_ASTRONOMICAL_TWILIGHT(ELEV) ((-18.0 <= (ELEV)) && ((ELEV) <= -12.0)) + + + +/** + * Calculates the Sun's elevation as apparent. + * from a geographical position. + * + * @param latitude The latitude in degrees northwards from + * the equator, negative for southwards. + * @param longitude The longitude in degrees eastwards from + * Greenwich, negative for westwards. + * @return The Sun's apparent elevation as seen, right now, + * from the specified position, measured in degrees. + * + * @throws 0 On success. + * @throws Any error specified for clock_gettime(3) on error. + */ +double solar_elevation(double latitude, double longitude); + -- cgit v1.2.3-70-g09d2