From 5fc891fa4214cdeb7f01be274198711c716b29cd Mon Sep 17 00:00:00 2001 From: Mattias Andrée Date: Tue, 5 Jan 2016 20:29:12 +0100 Subject: m + texinfo manual MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Signed-off-by: Mattias Andrée --- doc/info/chap/macros.texinfo | 49 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 49 insertions(+) create mode 100644 doc/info/chap/macros.texinfo (limited to 'doc/info/chap/macros.texinfo') diff --git a/doc/info/chap/macros.texinfo b/doc/info/chap/macros.texinfo new file mode 100644 index 0000000..2d4a947 --- /dev/null +++ b/doc/info/chap/macros.texinfo @@ -0,0 +1,49 @@ +@node Macros +@chapter Macros + +@file{} 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 + -- cgit v1.2.3-70-g09d2