Clean up

Signed-off-by: Mattias Andrée <maandree@kth.se>

1 files changed, 222 insertions, 0 deletions

diff --git a/libred.h b/libred.h
new file mode 100644
index 0000000..041a49e
--- /dev/null
+++ b/libred.h
@@ -0,0 +1,222 @@
+/* See LICENSE file for copyright and license details. */
+#ifndef LIBRED_H
+#define LIBRED_H
+
+
+
+/**
+ * Approximate apparent size of the Sun in degrees.
+ */
+#define LIBRED_SOLAR_APPARENT_RADIUS  (32.0 / 60.0)
+
+
+/**
+ * The Sun's elevation at sunset and sunrise, measured in degrees.
+ */
+#define LIBRED_SOLAR_ELEVATION_SUNSET_SUNRISE   (-32.0 / 60.0)
+
+/**
+ * The Sun's elevation at civil dusk and civil dawn, measured in degrees.
+ */
+#define LIBRED_SOLAR_ELEVATION_CIVIL_DUSK_DAWN   (-6.0)
+
+/**
+ * The Sun's elevation at nautical dusk and nautical dawn, measured in degrees.
+ */
+#define LIBRED_SOLAR_ELEVATION_NAUTICAL_DUSK_DAWN  (-12.0)
+
+/**
+ * The Sun's elevation at astronomical dusk and astronomical dawn, measured in degrees.
+ */
+#define LIBRED_SOLAR_ELEVATION_ASTRONOMICAL_DUSK_DAWN  (-18.0)
+
+/**
+ * The Sun's elevation at amateur astronomical dusk and amateur astronomical dawn, measured in degrees.
+ */
+#define LIBRED_SOLAR_ELEVATION_AMATEUR_ASTRONOMICAL_DUSK_DAWN  (-15.0)
+
+/**
+ * The Sun's lowest elevation during the golden hour, measured in degrees.
+ */
+#define LIBRED_SOLAR_ELEVATION_GOLDEN_HOUR_LOW  (-4.0)
+
+/**
+ * The Sun's highest elevation during the golden hour, measured in degrees.
+ */
+#define LIBRED_SOLAR_ELEVATION_GOLDEN_HOUR_HIGH  (6.0)
+
+/**
+ * The Sun's lowest elevation during the blue hour, measured in degrees.
+ */
+#define LIBRED_SOLAR_ELEVATION_BLUE_HOUR_LOW  (-6.0)
+
+/**
+ * The Sun's highest elevation during the blue hour, measured in degrees.
+ */
+#define LIBRED_SOLAR_ELEVATION_BLUE_HOUR_HIGH  (-4.0)
+
+
+/**
+ * Test whether it is twilight.
+ * 
+ * @param   ELEV:double  The current elevation.
+ * @return               1 if is twilight, 0 otherwise.
+ */
+#define LIBRED_IS_TWILIGHT(ELEV)  ((-18.0 <= (ELEV)) && ((ELEV) <= -32.0 / 60.0))
+
+/**
+ * Test whether it is civil twilight.
+ * 
+ * @param   ELEV:double  The current elevation.
+ * @return               1 if is civil twilight, 0 otherwise.
+ */
+#define LIBRED_IS_CIVIL_TWILIGHT(ELEV)  ((-6.0 <= (ELEV)) && ((ELEV) <= -32.0 / 60.0))
+
+/**
+ * Test whether it is nautical twilight.
+ * 
+ * @param   ELEV:double  The current elevation.
+ * @return               1 if is nautical twilight, 0 otherwise.
+ */
+#define LIBRED_IS_NAUTICAL_TWILIGHT(ELEV)  ((-12.0 <= (ELEV)) && ((ELEV) <= -32.0 / 60.0))
+
+/**
+ * Test whether it is astronomical twilight.
+ * 
+ * @param   ELEV:double  The current elevation.
+ * @return               1 if is astronomical twilight, 0 otherwise.
+ */
+#define LIBRED_IS_ASTRONOMICAL_TWILIGHT(ELEV)  ((-18.0 <= (ELEV)) && ((ELEV) <= -32.0 / 60.0))
+
+/**
+ * Test whether it is amateur astronomical twilight.
+ * 
+ * @param   ELEV:double  The current elevation.
+ * @return               1 if is amatuer astronomical twilight, 0 otherwise.
+ */
+#define LIBRED_IS_AMATEUR_ASTRONOMICAL_TWILIGHT(ELEV)  ((-18.0 <= (ELEV)) && ((ELEV) <= -15.0))
+
+/**
+ * Test whether it is nighttime.
+ * 
+ * @param   ELEV:double  The current elevation.
+ * @return               1 if is nighttime, 0 otherwise.
+ */
+#define LIBRED_IS_NIGHTTIME(ELEV)  ((ELEV) < -18.0)
+
+/**
+ * Test whether it is daytime.
+ * 
+ * @param   ELEV:double  The current elevation.
+ * @return               1 if is daytime, 0 otherwise.
+ */
+#define LIBRED_IS_DAYTIME(ELEV)  ((ELEV) > -32.0 / 60.0)
+
+/**
+ * Test whether it is the golden hour.
+ * 
+ * @param   ELEV:double  The current elevation.
+ * @return               1 if is golden hour, 0 otherwise.
+ */
+#define LIBRED_IS_GOLDEN_HOUR(ELEV)  ((-4.0 <= (ELEV)) && ((ELEV) <= 6.0))
+
+/**
+ * Test whether it is the blue hour.
+ * 
+ * @param   ELEV:double  The current elevation.
+ * @return               1 if is blue hour, 0 otherwise.
+ */
+#define LIBRED_IS_BLUE_HOUR(ELEV)  ((-6.0 <= (ELEV)) && ((ELEV) <= -4.0))
+
+
+/**
+ * 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 libred_solar_elevation(double, double);
+
+
+/**
+ * Exit if time the is before year 0 in J2000.
+ * 
+ * @return  0 on success, -1 on error.
+ */
+int libred_check_timetravel(void);
+
+
+
+/**
+ * The highest colour temperature in the table.
+ */
+#define LIBRED_HIGHEST_TEMPERATURE  40000
+
+/**
+ * The lowest colour temperature in the table.
+ */
+#define LIBRED_LOWEST_TEMPERATURE  1000
+
+/**
+ * The temperature difference between the colours in the table.
+ * Note, `libred_get_colour` will make interpolation for colours
+ * that are not in the table.
+ */
+#define LIBRED_DELTA_TEMPERATURE  100
+
+
+/**
+ * The file descriptor to the colour lookup table.
+ * -1 if none is open.
+ */
+extern int libred_fd;
+
+/**
+ * Iff this macro is define `libred_fd` is available.
+ */
+#define LIBRED_HAVE_FD  1
+
+
+/**
+ * This function must be called, once,
+ * before calling `libred_get_colour`.
+ * 
+ * @return  0 on success, -1 on error.
+ * 
+ * @throws  Any error specified for `open(3)`.
+ */
+int libred_init_colour(void);
+
+/**
+ * Call this when the process will not
+ * longer make calls to `libred_get_colour`.
+ */
+void libred_term_colour(void);
+
+/**
+ * Get the [0, 1] sRGB values of a colour temperature.
+ * 
+ * @param   temp  The desired colour temperature.
+ * @param   r     Output parameter for the “red” value.
+ * @param   g     Output parameter for the green value.
+ * @param   b     Output parameter for the blue value.
+ * @return        0 on succeess, -1 on error.
+ * 
+ * @throws  EOVERFLOW  The file did not have the expected size.
+ * @throws  EDOM       The selected temperature is below 1000 K.
+ * @throws             Any error specified for pread(3).
+ */
+int libred_get_colour(long int, double*, double*, double*);
+
+
+
+#endif
+