aboutsummaryrefslogtreecommitdiffstats
path: root/doc/info/chap
diff options
context:
space:
mode:
Diffstat (limited to 'doc/info/chap')
-rw-r--r--doc/info/chap/constants.texinfo47
-rw-r--r--doc/info/chap/functions.texinfo155
-rw-r--r--doc/info/chap/macros.texinfo49
-rw-r--r--doc/info/chap/overview.texinfo13
-rw-r--r--doc/info/chap/variables.texinfo15
5 files changed, 0 insertions, 279 deletions
diff --git a/doc/info/chap/constants.texinfo b/doc/info/chap/constants.texinfo
deleted file mode 100644
index e5e09ac..0000000
--- a/doc/info/chap/constants.texinfo
+++ /dev/null
@@ -1,47 +0,0 @@
-@node Constants
-@chapter Constants
-
-@file{<libred.h>} defines a number of symbolic constants
-suitable for using a @code{#if} preprocessing directives.
-
-@table @code
-@item LIBRED_SOLAR_APPARENT_RADIUS
-The approximate apparent size of the Sun in degrees.
-This value should be about 0.5(3).
-
-@item LIBRED_SOLAR_ELEVATION_SUNSET_SUNRISE
-The Sun's elevation at sunset and sunrise, measured in
-degrees. This value will always be 0.0.
-
-@item LIBRED_SOLAR_ELEVATION_CIVIL_DUSK_DAWN
-The Sun's elevation at civil dusk and civil dawn, measured
-in degrees. This value will always be @math{-6.0}.
-
-@item LIBRED_SOLAR_ELEVATION_NAUTICAL_DUSK_DAWN
-The Sun's elevation at nautical dusk and nautical dawn,
-measured in degrees. This value will always be @math{-12.0}.
-
-@item LIBRED_SOLAR_ELEVATION_ASTRONOMICAL_DUSK_DAWN
-The Sun's elevation at astronomical dusk and astronomical
-dawn, measured in degrees. This value will always be @math{-18.0}.
-
-@item LIBRED_HIGHEST_TEMPERATURE
-The highest temperature, in kelvins, for which there is a
-colour temperature in the table of colour temperature. Any
-temperature above this is automatically truncated by
-@code{libred_get_colour}, as higher values shall be
-unnoticeable. Currently, this value is 40@tie{}000.
-
-@item LIBRED_LOWEST_TEMPERATURE
-The lowest temperature, in kelvins, for which there is a
-colour temperature in the table of colour temperature. Any
-temperature below this results in @code{libred_get_colour}
-failing and setting @code{errno} to @code{EDOM}. Currently
-this value 1000, hypothetical changes will be very small.
-
-@item LIBRED_DELTA_TEMPERATURE
-The temperatures differences between sequential colour
-temperatures in the colour temperatures look up table.
-Currently this value is 100.
-@end table
-
diff --git a/doc/info/chap/functions.texinfo b/doc/info/chap/functions.texinfo
deleted file mode 100644
index d3236ec..0000000
--- a/doc/info/chap/functions.texinfo
+++ /dev/null
@@ -1,155 +0,0 @@
-@node Functions
-@chapter Functions
-
-@file{<libred.h>} defines a small number of functions.
-@example
-int libred_check_timetravel(void);
-double libred_solar_elevation(double latitude, double longitude);
-int libred_init_colour(void);
-void libred_term_colour(void);
-int libred_get_colour(long int temp, double* r, double* g, double* b);
-@end example
-
-@code{libred_check_timetravel} exits the process if @command{libred}
-is not compiled to support the current time, which is the case if it
-was compiled without @option{-DTIMETRAVELLER} and the clock is before
-year 2000.5 in the Julian calendar. Before exiting, the function will
-print an informative error message to standard error. Upon successful
-completion, without time incompatibility, the function returns 0.
-Upon failure, that is,it is unable to read the clock, the function
-returns @math{-1}. The function may fail for any reason specified for
-@code{clock_gettime}, and set the value of errno to the same values.
-It is recommended to call this function at the beginning of the program.
-
-@example
-#include <libred.h>
-#include <stdio.h>
-int main()
-@{
- if (libred_check_timetravel())
- return perror(""), 1;
-
- /* @xrm{}Use @xtt{}libred_solar_elevation@xrm{} to your heart's contempt.@xtt{} */
-
- return 0;
-@}
-@end example
-
-@code{libred_solar_elevation} calculates the Sun's elevation as apparent
-from a select geographical position. Namely from latitude degrees north
-of GPS's equator and longitude degrees east of GPS's prime meridian.
-The function is only explicitly defined for values between @math{-90} and
-@math{+90} for latitude and values between @math{-180} and @math{+180} for
-and longitude. Other values may or may not work, no error is thrown if used.
-Upon successful completion, the function sets errno to 0 and returns the
-Sun's current apparent elevation, measured in degrees above the horizon.
-On failure, the function returns an arbitrary value (happens to always be
-0.0) and sets @code{errno} an a non-zero value. The function may fail for
-any reason specified for @code{clock_gettime}, and set the value of
-@code{errno} to the same values. @code{errno} is always set to 0 on success.
-
-@example
-#include <libred.h>
-#include <stdio.h>
-#include <stdlib.h>
-int main(int argc, char* argv[])
-@{
- double elevation, latitude, longitude;
-
- if (libred_check_timetravel())
- return perror(""), 1;
-
- if (argc < 3) return 2;
- latitude = atof(argv[1]);
- longitude = atof(argv[2]);
-
- elevation = libred_solar_elevation(latitude, longitude);
- return errno || printf("Elevation: %lf\n", elevation) < 0;
-@}
-@end example
-
-@code{libred_init_colour} open a file descriptor, without returning it,
-to the colour temperature lookup table, and stores the file descriptor to
-@code{libred_fd}. It is necessary to call this function before the first
-call to @code{libred_get_colour}. Upon successful completion, the
-function returns 0. On failure, the function returns @math{-1} and sets
-@code{errno} appropriately. The function may fail for any reason specified
-for @code{open}, and set the value of @code{errno} to the same values.
-@code{errno} is always set to 0 on success. It is possible that the
-behaviour is changed to loading the colour temperature lookup table rather
-than just open a file descriptor to it.
-
-@code{libred_term_colour} deallocates all resources acquired by
-@code{libred_init_colour}. It is highly recommended to call this function
-before calling an @code{exec}-function. If you want to use
-@code{libred_get_colour} again after a call to this function has been
-made, you must first call @code{libred_init_colour}.
-
-@example
-#include <libred.h>
-#include <stdio.h>
-int main(int argc, char* argv[])
-@{
- if (libred_init_colour())
- return perror(""), 1;
-
- /* @xrm{}Use @xtt{}libred_get_colour@xrm{} to your heart's contempt.@xtt{} */
-
- libred_term_colour();
- return 0;
-@}
-@end example
-
-@code{libred_get_colour} gets or interpolates the colour temperature for
-@code{temp} kelvins, and returns the colour temperature in sRGB. The
-values, between 0.0 and 1.0, for the ``red'', green, and blue channels
-are stored in @code{*r}, @code{*g}, and @code{*b}, respectively.
-Upon successful completion, the function returns 0. On failure, the
-function returns @math{-1} and sets @code{errno} appropriately.
-The function may fail if:
-@table @code
-@item EOVERFLOW
-The colour temperature lookup table is smaller than it should be.
-@item EDOM
-If @code{temp} is less than @code{LIBRED_LOWEST_TEMPERATURE} (which is 1000.)
-@end table
-@noindent
-The function may also fail for any reason specified for @code{pread}, and
-set the value of @code{errno} to the same values.
-
-At least one of the values will be 1.0, none will be greater than 1.0,
-and none will be less than 0.0. It is guaranteed (unless the resources
-file has been modified) that @code{*r}, @code{*g}, and @code{*b} all
-will be 1.0 if @code{temp} is 6500.
-
-You must call @code{libred_init_colour} before the first use of
-@code{libred_get_colour}, and you should call @code{libred_term_colour}
-after the last use of @code{libred_get_colour}.
-
-@example
-#include <libred.h>
-#include <stdio.h>
-#include <stdlib.h>
-int main(int argc, char* argv[])
-@{
- long int temp;
- double r, g, b;
-
- if (argc < 2) return 2;
- temp = atol(argv[1]);
-
- if (libred_init_colour())
- return perror(""), 1;
-
- if (libred_get_colour(temp, &r, &g, &b));
- return perror(""), libred_term_colour(), 1;
-
- libred_term_colour();
-
- return printf("Red: %lf\n"
- "Green: %lf\n"
- "Blue: %lf\n",
- r, g, b) < 0;
-@}
-@end example
-
diff --git a/doc/info/chap/macros.texinfo b/doc/info/chap/macros.texinfo
deleted file mode 100644
index 2d4a947..0000000
--- a/doc/info/chap/macros.texinfo
+++ /dev/null
@@ -1,49 +0,0 @@
-@node Macros
-@chapter Macros
-
-@file{<libred.h>} defines a small set of macros
-suitable for using a @code{#if} preprocessing directives.
-
-@table @code
-@item LIBRED_IS_TWILIGHT(const double)
-Evaluates to 1 if the given expression is between @math{-18.0}
-and 0.0 (this is, between
-@code{LIBRED_SOLAR_ELEVATION_ASTRONOMICAL_DUSK_DAWN} and
-@code{LIBRED_SOLAR_ELEVATION_SUNSET_SUNRISE}), inclusively,
-otherwise, this macro evaluates to 0. The input should be
-the Sun's apparent elevation, and the macro evaluates to 1
-if it is currently twilight. The given expression is evaluted
-either once or twice, therefore, it must not have side-effects.
-
-@item LIBRED_IS_CIVIL_TWILIGHT(const double)
-Evaluates to 1 if the given expression is between @math{-6.0}
-and 0.0 (this is, between
-@code{LIBRED_SOLAR_ELEVATION_CIVIL_DUSK_DAWN} and
-@code{LIBRED_SOLAR_ELEVATION_SUNSET_SUNRISE}), inclusively,
-otherwise, this macro evaluates to 0. The input should be
-the Sun's apparent elevation, and the macro evaluates to 1
-if it is currently civil twilight. The given expression is
-evaluted either once or twice, therefore, it must not have
-side-effects.
-
-@item LIBRED_IS_NAUTICAL_TWILIGHT(const double)
-Evaluates to 1 if the given expression is between @math{-12.0}
-and @math{-6.0} (this is, between
-@code{LIBRED_SOLAR_ELEVATION_NAUTICAL_DUSK_DAWN} and
-@code{LIBRED_SOLAR_ELEVATION_CIVIL_DUSK_DAWN}), inclusively,
-otherwise, this macro evaluates to 0. The input should be the
-Sun's apparent elevation, and the macro evaluates to 1 if it
-is currently nautical twilight. The given expression is evaluted
-either once or twice, therefore, it must not have side-effects.
-
-@item LIBRED_IS_ASTRONOMICAL_TWILIGHT(const double)
-Evaluates to 1 if the given expression is between @math{-18.0}
-and @math{-12.0} (this is, between
-@code{LIBRED_SOLAR_ELEVATION_ASTRONOMICAL_DUSK_DAWN} and
-@code{LIBRED_SOLAR_ELEVATION_NAUTICAL_DUSK_DAWN}), inclusively,
-otherwise, this macro evaluates to 0. The input should be the
-Sun's apparent elevation, and the macro evaluates to 1 if it is
-currently astronomical twilight. The given expression is evaluted
-either once or twice, therefore, it must not have side-effects.
-@end table
-
diff --git a/doc/info/chap/overview.texinfo b/doc/info/chap/overview.texinfo
deleted file mode 100644
index 34f0f71..0000000
--- a/doc/info/chap/overview.texinfo
+++ /dev/null
@@ -1,13 +0,0 @@
-@node Overview
-@chapter Overview
-
-@command{libred} is a C library that can be used to calculate
-the Sun's apparent elevation, and colour temperatures, the
-colour of blackbodies.
-
-To use @command{libred}, include the header file
-@file{<libred.h>}, and link with @option{-lred}. The
-@command{libred} package includes a @command{librarian}
-file and a @command{pkgconfig} file, both named
-@command{libred}.
-
diff --git a/doc/info/chap/variables.texinfo b/doc/info/chap/variables.texinfo
deleted file mode 100644
index aa44f19..0000000
--- a/doc/info/chap/variables.texinfo
+++ /dev/null
@@ -1,15 +0,0 @@
-@node Variables
-@chapter Variables
-
-@file{<libred.h>} defines the variable
-@example
-extern int libred_fd
-@end example
-@indent
-which is either @code{-1} or the file descriptor the
-library uses to access the colour temperature lookup
-table. The header also defines @code{LIBRED_HAVE_FD}.
-It is possible that @code{libred_fd} is removed in a
-future version. If it is, @code{LIBRED_HAVE_FD} will
-be removed too.
-