1 files changed, 54 insertions, 0 deletions
diff --git a/libred_get_colour.3 b/libred_get_colour.3
new file mode 100644
index 0000000..d169a60
--- /dev/null
+++ b/libred_get_colour.3
@@ -0,0 +1,54 @@
+.TH LIBRED_GET_COLOUR 3 LIBRED
+.SH NAME
+libred_get_colour \- Calculate a colour temperature
+.SH SYNOPSIS
+.nf
+#include <libred.h>
+
+int \fBlibred_get_colour\fP(long int \fItemp\fP, double *\fIr\fP, double *\fIg\fP, double *\fIb\fP);
+.fi
+.PP
+Link with
+.IR -lred .
+.SH DESCRIPTION
+.BR libred_get_colour ()
+gets or interpolates the colour temperature for
+.I temp
+kelvins, and returns the colour temperature in sRGB. The values,
+between 0.0 and 1.0, for the \(dqred\(dq, green, and blue channels
+are stored in
+.IR *r ,
+.IR *g ,
+and
+.IR *b ,
+respectively.
+.PP
+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
+.IR *r ,
+.IR *g ,
+and
+.I *b
+all will be 1.0 if
+.I temp
+is 6500.
+.SH RETURN VALUE
+Upon successful completion, the
+.BR libred_get_colour ()
+function returns 0. On failure, the function returns -1 and sets
+.I errno
+to indicate the error.
+.SH ERRORS
+The function may fail if:
+.TP
+.B EDOM
+If
+.I temp
+is less than
+.B LIBRED_LOWEST_TEMPERATURE
+(which is 1000).
+.SH SEE ALSO
+.BR libred.h (0),
+.BR libred (7),
+.BR libred_get_solar_elevation (3)