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-rw-r--r--daylight.txi15
1 files changed, 9 insertions, 6 deletions
diff --git a/daylight.txi b/daylight.txi
index fa24afc..2d921d2 100644
--- a/daylight.txi
+++ b/daylight.txi
@@ -21,16 +21,19 @@ To be meticulous, subtract 4 minutes for each degree of longitude west
of the standard meridian of your time zone.
@end defun
+
@defun solar-declination julian-day
@end defun
+
@defun solar-polar declination latitude solar-hour
Returns a list of @var{theta_s}, the solar angle from the
zenith, and @var{phi_s}, the solar azimuth. 0 <= @var{theta_s}
measured in degrees. @var{phi_s} is measured in degrees from due
south; west of south being positive.
@end defun
+
@noindent
In the following procedures, the number 0 <= @var{theta_s} <= 90 is
the solar angle from the zenith in degrees.
@@ -76,21 +79,19 @@ Returns a vector of 41 values, the spectrum of sunlight from
380.nm to 790.nm for a given @var{turbidity} and @var{theta_s}.
@end defun
-@defun sunlight-xyz turbidity theta_s
-Returns (unnormalized) XYZ values for color of sunlight for a
-given @var{turbidity} and @var{theta_s}.
-@end defun
-@defun sunlight-ciexyz turbidity theta_s
-Given @var{turbidity} and @var{theta_s}, @code{sunlight-ciexyz} returns the CIEXYZ triple for color of
+@defun sunlight-chromaticity turbidity theta_s
+Given @var{turbidity} and @var{theta_s}, @code{sunlight-chromaticity} returns the CIEXYZ triple for color of
sunlight scaled to be just inside the RGB709 gamut.
@end defun
+
@defun zenith-xyy turbidity theta_s
Returns the xyY (chromaticity and luminance) at the zenith. The
Luminance has units kcd/m^2.
@end defun
+
@defun overcast-sky-color-xyy turbidity theta_s
@var{turbidity} is a positive real number expressing the amount of light
scattering. The real number @var{theta_s} is the solar angle from the zenith in
@@ -101,6 +102,7 @@ zenith of the viewing direction (in degrees); and returning the xyY
value for light coming from that elevation of the sky.
@end defun
+
@defun clear-sky-color-xyy turbidity theta_s phi_s
@defunx sky-color-xyy turbidity theta_s phi_s
@var{turbidity} is a positive real number expressing the amount of light
@@ -115,3 +117,4 @@ that direction of the sky.
@code{sky-color-xyY} calls @code{overcast-sky-color-xyY} for
@var{turbidity} <= 20; otherwise the @code{clear-sky-color-xyy} function.
@end defun
+