misc

Signed-off-by: Mattias Andrée <maandree@member.fsf.org>

5 files changed, 287 insertions, 203 deletions

diff --git a/src/blackbody.c b/src/blackbody.c
index abe03a9..f45ead4 100644
--- a/src/blackbody.c
+++ b/src/blackbody.c
@@ -14,7 +14,7 @@
  * You should have received a copy of the GNU General Public License
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
-#include "blackbody.h"
+#include "libred.h"
 #include "macros.h"
 #include <math.h>
 #include <errno.h>
@@ -22,6 +22,40 @@
 
 
 /**
+ * The file descriptor to the colour lookup table.
+ */
+static int 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)
+{
+  libred_term_colour();
+  fd = open(SYSDEPRESDIR "/" PACKAGE "/10deg", O_RDONLY);
+  return fd < 0 ? -1 : 0;
+}
+
+
+/**
+ * Call this when the process will not
+ * longer make calls to `libred_get_colour`.
+ */
+void libred_term_colour(void)
+{
+  if (fd >= 0)
+    close(fd), fd = -1;
+}
+
+
+/**
  * Convert from CIE xyY to [0, 1] sRGB.
  * 
  * @param  x  The 'x' component.
@@ -32,23 +66,22 @@
  * @param  g  Output parameter for the green value.
  * @param  b  Output parameter for the blue value.
  */
-static void
-ciexyy_to_srgb(double x, double y, double Y, double *r, double *g, double *b)
+static void ciexyy_to_srgb(double x, double y, double Y, double *r, double *g, double *b)
 {
 #define SRGB(C)  (((C) <= 0.0031308) ? (12.92 * (C)) : ((1.0 + 0.055) * pow((C), 1.0 / 2.4) - 0.055))
-	double X, Z;
-
-	/* Convert CIE xyY to CIE XYZ. */
-	X = Y * (y == 0.0 ? 0.0 : (x / y));
-	Z = Y * (y == 0.0 ? 0.0 : ((1.0 - x - y) / y));
-
-	/* Convert CIE XYZ to [0, 1] linear RGB. (ciexyz_to_linear) */
-	*r = ( 3.240450 * X) + (-1.537140 * Y) + (-0.4985320 * Z);
-	*g = (-0.969266 * X) + ( 1.876010 * Y) + ( 0.0415561 * Z);
-	*b = (0.0556434 * X) + (-0.204026 * Y) + ( 1.0572300 * Z);
-
-	/* Convert [0, 1] linear RGB to [0, 1] sRGB. */
-	SRGB(*r), SRGB(*g), SRGB(*b);
+  double X, Z;
+  
+  /* Convert CIE xyY to CIE XYZ. */
+  X = Y * (y == 0.0 ? 0.0 : (x / y));
+  Z = Y * (y == 0.0 ? 0.0 : ((1.0 - x - y) / y));
+  
+  /* Convert CIE XYZ to [0, 1] linear RGB. (ciexyz_to_linear) */
+  *r = ( 3.240450 * X) + (-1.537140 * Y) + (-0.4985320 * Z);
+  *g = (-0.969266 * X) + ( 1.876010 * Y) + ( 0.0415561 * Z);
+  *b = (0.0556434 * X) + (-0.204026 * Y) + ( 1.0572300 * Z);
+  
+  /* Convert [0, 1] linear RGB to [0, 1] sRGB. */
+  SRGB(*r), SRGB(*g), SRGB(*b);
 }
 
 
@@ -68,20 +101,18 @@ ciexyy_to_srgb(double x, double y, double Y, double *r, double *g, double *b)
  * @param  g     Output parameter for the green value.
  * @param  b     Output parameter for the blue value.
  */
-static void
-interpolate(double x1, double y1, double x2, double y2, double temp, double *r, double *g, double *b)
+static void interpolate(double x1, double y1, double x2, double y2, double temp, double *r, double *g, double *b)
 {
-	double weight = fmod(temp, (double)DELTA_TEMPERATURE) / (double)DELTA_TEMPERATURE;
-	double x = x1 * (1 - weight) + x2 * weight;
-	double y = y1 * (1 - weight) + y2 * weight;
-	ciexyy_to_srgb(x, y, 1.0, r, g, b);
+  double weight = fmod(temp, (double)DELTA_TEMPERATURE) / (double)DELTA_TEMPERATURE;
+  double x = x1 * (1 - weight) + x2 * weight;
+  double y = y1 * (1 - weight) + y2 * weight;
+  ciexyy_to_srgb(x, y, 1.0, r, g, b);
 }
 
 
 /**
  * Get the [0, 1] sRGB values of a colour temperature.
  * 
- * @param   fd    File descriptor for the colour table.
  * @param   temp  The desired colour temperature.
  * @param   r     Output parameter for the “red” value.
  * @param   g     Output parameter for the green value.
@@ -90,41 +121,41 @@ interpolate(double x1, double y1, double x2, double y2, double temp, double *r,
  * 
  * @throws  0     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
-get_colour(int fd, long int temp, double *r, double *g, double *b)
+int libred_get_colour(long int temp, double *r, double *g, double *b)
 {
-	double values[10]; /* low:x,y,r,g,b + high:x,y,r,g,b */
-	off_t offset;
-	double max;
-
-	/* We do not have any values for above 40 000 K, but
-	 * the differences will be unnoticeable, perhaps even
-	 * unencodeable. */
-	if (temp > HIGHEST_TEMPERATURE)  temp = HIGHEST_TEMPERATURE;
-	/* Things do not glow below 1000 K. Yes, fire is hot! */
-	if (temp < LOWEST_TEMPERATURE)   t ((errno = EDOM));
-
-	/* Read table. */
-	offset = ((off_t)temp - LOWEST_TEMPERATURE) / DELTA_TEMPERATURE;
-	offset *= (off_t)(sizeof(values) / 2);
-	errno = 0; xpread(fd, values, sizeof(values), offset);
-
-	/* Get colour. */
-	if (temp % DELTA_TEMPERATURE)
-		interpolate(values[0], values[1], values[6], values[7], (double)temp, r, g, b);
-	else
-		*r = values[2], *g = values[3], *b = values[4];
-
-	/* Adjust colours for use. */
-	max = fmax(fmax(fabs(*r), fabs(*g)), fabs(*b));
-	if (max != 0)  *r /= max, *g /= max, *b /= max;
-	*r = *r > 0.0 ? *r : 0.0;
-	*g = *g > 0.0 ? *g : 0.0;
-	*b = *b > 0.0 ? *b : 0.0;
-
-	return 0;
-fail:
-	return -1;
+  double values[10]; /* low:x,y,r,g,b + high:x,y,r,g,b */
+  off_t offset;
+  double max;
+  
+  /* We do not have any values for above 40 000 K, but
+   * the differences will be unnoticeable, perhaps even
+   * unencodeable. */
+  if (temp > HIGHEST_TEMPERATURE)  temp = HIGHEST_TEMPERATURE;
+  /* Things do not glow below 1000 K. Yes, fire is hot! */
+  if (temp < LOWEST_TEMPERATURE)   t ((errno = EDOM));
+  
+  /* Read table. */
+  offset = ((off_t)temp - LOWEST_TEMPERATURE) / DELTA_TEMPERATURE;
+  offset *= (off_t)(sizeof(values) / 2);
+  errno = 0; xpread(fd, values, sizeof(values), offset);
+  
+  /* Get colour. */
+  if (temp % DELTA_TEMPERATURE)
+    interpolate(values[0], values[1], values[6], values[7], (double)temp, r, g, b);
+  else
+    *r = values[2], *g = values[3], *b = values[4];
+  
+  /* Adjust colours for use. */
+  max = fmax(fmax(fabs(*r), fabs(*g)), fabs(*b));
+  if (max != 0)  *r /= max, *g /= max, *b /= max;
+  *r = *r > 0.0 ? *r : 0.0;
+  *g = *g > 0.0 ? *g : 0.0;
+  *b = *b > 0.0 ? *b : 0.0;
+  
+  return 0;
+ fail:
+  return -1;
 }
 
diff --git a/src/blackbody.h b/src/blackbody.h
deleted file mode 100644
index 499e9b8..0000000
--- a/src/blackbody.h
+++ /dev/null
@@ -1,51 +0,0 @@
-/**
- * Copyright © 2016  Mattias Andrée <maandree@member.fsf.org>
- * 
- * 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 <http://www.gnu.org/licenses/>.
- */
-
-
-
-/**
- * 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.
- */
-#define LIBRED_DELTA_TEMPERATURE  100
-
-
-
-/**
- * Get the [0, 1] sRGB values of a colour temperature.
- * 
- * @param   fd    File descriptor for the colour table.
- * @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  0     The file did not have the expected size.
- * @throws  EDOM  The selected temperature is below 1000 K.
- */
-int libred_get_colour(int fd, long int temp, double *r, double *g, double *b);
-
diff --git a/src/solar.h b/src/libred.h
index 8e94cf9..615ed04 100644
--- a/src/solar.h
+++ b/src/libred.h
@@ -14,6 +14,9 @@
  * You should have received a copy of the GNU General Public License
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
+#ifndef LIBRED_H
+#define LIBRED_H
+
 
 
 /**
@@ -105,3 +108,57 @@ int libred_check_timetravel(void);
 # define libred_check_timetravel()  0
 #endif
 
+
+
+/**
+ * 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.
+ */
+#define LIBRED_DELTA_TEMPERATURE  100
+
+
+
+/**
+ * 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  0     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 temp, double *r, double *g, double *b);
+
+
+
+#endif
+
diff --git a/src/macros.h b/src/macros.h
new file mode 100644
index 0000000..c0aeabb
--- /dev/null
+++ b/src/macros.h
@@ -0,0 +1,57 @@
+/**
+ * Copyright © 2016  Mattias Andrée <maandree@member.fsf.org>
+ * 
+ * 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 <http://www.gnu.org/licenses/>.
+ */
+#include <string.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <stdlib.h>
+
+
+
+#define try(...)      do { if (!(__VA_ARGS__)) goto fail; } while (0)
+#define t(...)        do { if   (__VA_ARGS__)  goto fail; } while (0)
+#define CLEANUP(...)  do { int cleanup__ = errno; __VA_ARGS__; errno = cleanup__; } while (0)
+
+#define xstrdup(outp, ...)  \
+do {  \
+  const char *xstrdup__ = (__VA_ARGS__);  \
+  if (xstrdup__)  \
+    try (*(outp) = strdup(xstrdup__));  \
+  else  \
+    *(outp) = NULL;  \
+} while (0)
+
+#define xpread(fd, buf, len, off)   t  (pread(fd, buf, len, off) < (ssize_t)(len))
+#define xpwrite(fd, buf, len, off)  t (pwrite(fd, buf, len, off) < (ssize_t)(len))
+#define xread(fd, buf, len)         t   (read(fd, buf, len)      < (ssize_t)(len))
+#define xwrite(fd, buf, len)        t  (write(fd, buf, len)      < (ssize_t)(len))
+
+#define xcalloc(outp, num)   try (*(outp) = calloc(num, sizeof(**(outp))))
+#define xmalloc(outp, num)   try (*(outp) = malloc((num) * sizeof(**(outp))))
+#define xrealloc(outp, num)  \
+do {  \
+  size_t n__ = (num);  \
+  void *new__ = realloc(*(outp), n__ * sizeof(**(outp)));  \
+  t (n__ && !new__);  \
+  *(outp) = new__;  \
+} while (0)
+
+#define SHRINK(outp, num)  \
+do {  \
+  void *new__ = realloc(*(outp), (num) * sizeof(**(outp)));  \
+  if (new__)  *(outp) = new__;  \
+} while (0)
+
diff --git a/src/solar.c b/src/solar.c
index 8a57507..697ecd6 100644
--- a/src/solar.c
+++ b/src/solar.c
@@ -13,14 +13,21 @@
  * 
  * You should have received a copy of the GNU General Public License
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ * 
+ * This file is a stripped down port of <https://github.com/maandree/solar-python>.
  */
+#include "libred.h"
 #include <math.h>
 #include <time.h>
 #include <errno.h>
 
 
 
-#if !defined(CLOCK_REALTIME_COARSE)
+/* Select clock. */
+#if defined(DO_NOT_USE_COARSEC_CLOCK) || !defined(CLOCK_REALTIME_COARSE)
+# ifdef CLOCK_REALTIME_COARSE
+#  undef CLOCK_REALTIME_COARSE
+# endif
 # define CLOCK_REALTIME_COARSE  CLOCK_REALTIME
 #endif
 
@@ -34,15 +41,14 @@
  * @throws  0  On success.
  * @throws     Any error specified for clock_gettime(3) on error.
  */
-static double
-julian_centuries()
+static double julian_centuries()
 {
-	struct timespec now;
-	double tm;
-	if (clock_gettime(CLOCK_REALTIME_COARSE, &now))  return 0.0;
-	tm = (double)(now.tv_nsec) / 1000000000.0 + (double)(now.tv_sec);
-	tm = (tm / 86400.0 + 2440587.5 - 2451545.0) / 36525.0;
-	return errno = 0, tm;
+  struct timespec now;
+  double tm;
+  if (clock_gettime(CLOCK_REALTIME_COARSE, &now))  return 0.0;
+  tm = (double)(now.tv_nsec) / 1000000000.0 + (double)(now.tv_sec);
+  tm = (tm / 86400.0 + 2440587.5 - 2451545.0) / 36525.0;
+  return errno = 0, tm;
 }
 
 /**
@@ -51,10 +57,9 @@ julian_centuries()
  * @param   tm  The time in Julian Centuries
  * @return      The time in Julian Days
  */
-static inline double
-julian_centuries_to_julian_day(double tm)
+static inline double julian_centuries_to_julian_day(double tm)
 {
-	return tm * 36525.0 + 2451545.0;
+  return tm * 36525.0 + 2451545.0;
 }
 
 
@@ -64,10 +69,9 @@ julian_centuries_to_julian_day(double tm)
  * @param  deg  The angle in degrees.
  * @param       The angle in radians.
  */
-static inline double
-radians(double deg)
+static inline double radians(double deg)
 {
-	return deg * (double)M_PI / 180.0;
+  return deg * (double)M_PI / 180.0;
 }
 
 /**
@@ -76,10 +80,9 @@ radians(double deg)
  * @param  rad  The angle in radians.
  * @param       The angle in degrees.
  */
-static inline double
-degrees(double rad)
+static inline double degrees(double rad)
 {
-	return rad * 180.0 / (double)M_PI;
+  return rad * 180.0 / (double)M_PI;
 }
 
 
@@ -92,13 +95,12 @@ degrees(double rad)
  * @param   hour_angle   The solar hour angle, in radians.
  * @return               The Sun's elevation, in radians.
  */
-static inline double
-elevation_from_hour_angle(double latitude, double declination, double hour_angle)
+static inline double elevation_from_hour_angle(double latitude, double declination, double hour_angle)
 {
-	double rc = cos(radians(latitude));
-	rc *= cos(hour_angle) * cos(declination);
-	rc += sin(radians(latitude)) * sin(declination);
-	return asin(rc);
+  double rc = cos(radians(latitude));
+  rc *= cos(hour_angle) * cos(declination);
+  rc += sin(radians(latitude)) * sin(declination);
+  return asin(rc);
 }
 
 /**
@@ -107,14 +109,13 @@ elevation_from_hour_angle(double latitude, double declination, double hour_angle
  * @param   tm  The time in Julian Centuries.
  * @return      The Sun's geometric mean longitude in radians.
  */
-static inline double
-sun_geometric_mean_longitude(double tm)
+static inline double sun_geometric_mean_longitude(double tm)
 {
-	double rc = fmod(pow(0.0003032 * tm, 2.0) + 36000.76983 * tm + 280.46646, 360.0);
+  double rc = fmod(pow(0.0003032 * tm, 2.0) + 36000.76983 * tm + 280.46646, 360.0);
 #if defined(TIMETRAVELLER)
-	rc = rc < 0.0 ? (rc + 360.0) : rc;
+  rc = rc < 0.0 ? (rc + 360.0) : rc;
 #endif
-	return radians(rc);
+  return radians(rc);
 }
 
 /**
@@ -123,10 +124,9 @@ sun_geometric_mean_longitude(double tm)
  * @param   tm  The time in Julian Centuries.
  * @return      The Sun's geometric mean anomaly in radians.
  */
-static inline double
-sun_geometric_mean_anomaly(double tm)
+static inline double sun_geometric_mean_anomaly(double tm)
 {
-	return radians(pow(-0.0001537 * tm, 2.0) + 35999.05029 * tm + 357.52911);
+  return radians(pow(-0.0001537 * tm, 2.0) + 35999.05029 * tm + 357.52911);
 }
 
 /**
@@ -135,10 +135,9 @@ sun_geometric_mean_anomaly(double tm)
  * @param   tm  The time in Julian Centuries.
  * @return      The Earth's orbit eccentricity.
  */
-static inline double
-earth_orbit_eccentricity(double tm)
+static inline double earth_orbit_eccentricity(double tm)
 {
-	return pow(-0.0000001267 * tm, 2.0) - 0.000042037 * tm + 0.016708634;
+  return pow(-0.0000001267 * tm, 2.0) - 0.000042037 * tm + 0.016708634;
 }
 
 /**
@@ -148,14 +147,13 @@ earth_orbit_eccentricity(double tm)
  * @param   tm  The time in Julian Centuries.
  * @return      The Sun's equation of the centre, in radians.
  */
-static inline double
-sun_equation_of_centre(double tm)
+static inline double sun_equation_of_centre(double tm)
 {
-	double a = sun_geometric_mean_anomaly(tm), rc;
-	rc  = sin(1.0 * a) * (pow(-0.000014 * tm, 2.0) - 0.004817 * tm + 1.914602);
-	rc += sin(2.0 * a) * (-0.000101 * tm + 0.019993);
-	rc += sin(3.0 * a) * 0.000289;
-	return radians(rc);
+  double a = sun_geometric_mean_anomaly(tm), rc;
+  rc  = sin(1.0 * a) * (pow(-0.000014 * tm, 2.0) - 0.004817 * tm + 1.914602);
+  rc += sin(2.0 * a) * (-0.000101 * tm + 0.019993);
+  rc += sin(3.0 * a) * 0.000289;
+  return radians(rc);
 }
 
 /**
@@ -164,10 +162,9 @@ sun_equation_of_centre(double tm)
  * @param   tm  The time in Julian Centuries.
  * @return      The longitude, in radians.
  */
-static inline double
-sun_real_longitude(double tm)
+static inline double sun_real_longitude(double tm)
 {
-	return sun_geometric_mean_longitude(tm) + sun_equation_of_centre(tm);
+  return sun_geometric_mean_longitude(tm) + sun_equation_of_centre(tm);
 }
 
 /**
@@ -176,11 +173,10 @@ sun_real_longitude(double tm)
  * @param   tm  The time in Julian Centuries.
  * @return      The longitude, in radians.
  */
-static inline double
-sun_apparent_longitude(double tm)
+static inline double sun_apparent_longitude(double tm)
 {
-    double rc = degrees(sun_real_longitude(tm)) - 0.00569;
-    return radians(rc - 0.00478 * sin(radians(-1934.136 * tm + 125.04)));
+  double rc = degrees(sun_real_longitude(tm)) - 0.00569;
+  return radians(rc - 0.00478 * sin(radians(-1934.136 * tm + 125.04)));
 }
 
 /**
@@ -190,11 +186,10 @@ sun_apparent_longitude(double tm)
  * @param   tm  The time in Julian Centuries.
  * @return      The uncorrected mean obliquity, in radians.
  */
-static double
-mean_ecliptic_obliquity(double tm)
+static double mean_ecliptic_obliquity(double tm)
 {
-	double rc = pow(0.001813 * tm, 3.0) - pow(0.00059 * tm, 2.0) - 46.815 * tm + 21.448;
-	return radians(23.0 + (26.0 + rc / 60.0) / 60.0);
+  double rc = pow(0.001813 * tm, 3.0) - pow(0.00059 * tm, 2.0) - 46.815 * tm + 21.448;
+  return radians(23.0 + (26.0 + rc / 60.0) / 60.0);
 }
 
 /**
@@ -204,11 +199,10 @@ mean_ecliptic_obliquity(double tm)
  * @param   tm  The time in Julian Centuries.
  * @return      The mean obliquity, in radians.
  */
-static double
-corrected_mean_ecliptic_obliquity(double tm)
+static double corrected_mean_ecliptic_obliquity(double tm)
 {
-	double rc = 0.00256 * cos(radians(-1934.136 * tm + 125.04));
-	return radians(rc + degrees(mean_ecliptic_obliquity(tm)));
+  double rc = 0.00256 * cos(radians(-1934.136 * tm + 125.04));
+  return radians(rc + degrees(mean_ecliptic_obliquity(tm)));
 }
 
 /**
@@ -217,11 +211,10 @@ corrected_mean_ecliptic_obliquity(double tm)
  * @param   tm  The time in Julian Centuries.
  * @return      The Sun's declination, in radian.
  */
-static inline double
-solar_declination(double tm)
+static inline double solar_declination(double tm)
 {
-	double rc = sin(corrected_mean_ecliptic_obliquity(tm));
-	return asin(rc * sin(sun_apparent_longitude(tm)));
+  double rc = sin(corrected_mean_ecliptic_obliquity(tm));
+  return asin(rc * sin(sun_apparent_longitude(tm)));
 }
 
 /**
@@ -231,18 +224,17 @@ solar_declination(double tm)
  * @param   tm  The time in Julian Centuries.
  * @return      The equation of time, in degrees.
  */
-static inline double
-equation_of_time(double tm)
+static inline double equation_of_time(double tm)
 {
-	double l = sun_geometric_mean_longitude(tm);
-	double e = earth_orbit_eccentricity(tm);
-	double m = sun_geometric_mean_anomaly(tm);
-	double y = pow(tan(corrected_mean_ecliptic_obliquity(tm) / 2.0), 2.0);
-	double rc = y * sin(2.0 * l);
-	rc += (4.0 * y * cos(2.0 * l) - 2.0) * e * sin(m);
-	rc -= pow(0.5 * y, 2.0) * sin(4.0 * l);
-	rc -= pow(1.25 * e, 2.0) * sin(2.0 * m);
-	return 4.0 * degrees(rc);
+  double l = sun_geometric_mean_longitude(tm);
+  double e = earth_orbit_eccentricity(tm);
+  double m = sun_geometric_mean_anomaly(tm);
+  double y = pow(tan(corrected_mean_ecliptic_obliquity(tm) / 2.0), 2.0);
+  double rc = y * sin(2.0 * l);
+  rc += (4.0 * y * cos(2.0 * l) - 2.0) * e * sin(m);
+  rc -= pow(0.5 * y, 2.0) * sin(4.0 * l);
+  rc -= pow(1.25 * e, 2.0) * sin(2.0 * m);
+  return 4.0 * degrees(rc);
 }
 
 /**
@@ -257,14 +249,13 @@ equation_of_time(double tm)
  * @return             The Sun's apparent elevation at the specified time as seen
  *                     from the specified position, measured in radians.
  */
-static inline double
-solar_elevation_from_time(double tm, double latitude, double longitude)
+static inline double solar_elevation_from_time(double tm, double latitude, double longitude)
 {
-	double rc = julian_centuries_to_julian_day(tm);
-	rc = (rc - round(rc) - 0.5) * 1440;
-	rc = 720.0 - rc - equation_of_time(tm);
-	rc = radians(rc / 4.0 - longitude);
-	return elevation_from_hour_angle(latitude, solar_declination(tm), rc);
+  double rc = julian_centuries_to_julian_day(tm);
+  rc = (rc - round(rc) - 0.5) * 1440;
+  rc = 720.0 - rc - equation_of_time(tm);
+  rc = radians(rc / 4.0 - longitude);
+  return elevation_from_hour_angle(latitude, solar_declination(tm), rc);
 }
 
 
@@ -282,11 +273,10 @@ solar_elevation_from_time(double tm, double latitude, double longitude)
  * @throws  0  On success.
  * @throws     Any error specified for clock_gettime(3) on error.
  */
-double
-solar_elevation(double latitude, double longitude)
+double libred_solar_elevation(double latitude, double longitude)
 {
-	double tm = julian_centuries();
-	return errno ? -1 : degrees(solar_elevation_from_time(tm, latitude, longitude));
+  double tm = julian_centuries();
+  return errno ? -1 : degrees(solar_elevation_from_time(tm, latitude, longitude));
 }
 
 
@@ -295,18 +285,18 @@ solar_elevation(double latitude, double longitude)
  * 
  * @return  0 on success, -1 on error.
  */
-#if defined(TIMETRAVELLER)
-int
-check_timetravel(void)
+int libred_check_timetravel(void)
 {
-	struct timespec now;
-	if (clock_gettime(CLOCK_REALTIME, &now))  return -1;
-	if (now.tv_nsec < (time_t)946728000L)
-		fprintf(stderr, "We have detected that you are a time-traveller"
-		                "(or your clock is not configured correctly.)"
-		                "Please recompile with -DTIMETRAVELLER"
-	                        "(or correct your clock.)"), exit(1);
-	return 0;
-}
+#if !defined(TIMETRAVELLER)
+  struct timespec now;
+  if (clock_gettime(CLOCK_REALTIME, &now))  return -1;
+  if (now.tv_nsec < (time_t)946728000L)
+    fprintf(stderr,
+	    "We have detected that you are a time-traveller"
+	    "(or your clock is not configured correctly.)"
+	    "Please recompile libred with -DTIMETRAVELLER"
+	    "(or correct your clock.)"), exit(1);
 #endif
+  return 0;
+}