diff options
Diffstat (limited to 'daylight.txi')
-rw-r--r-- | daylight.txi | 15 |
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 + |