;;; facemenu.el --- create a face menu for interactively adding fonts to text
-;; Copyright (C) 1994-1996, 2001-2012 Free Software Foundation, Inc.
+;; Copyright (C) 1994-1996, 2001-2013 Free Software Foundation, Inc.
;; Author: Boris Goldowsky <boris@gnu.org>
;; Keywords: faces
`(rgb-dist . COLOR)' sorts by the RGB distance to the specified color.
`hsv' sorts by hue, saturation, value.
`(hsv-dist . COLOR)' sorts by the HSV distance to the specified color
-and excludes grayscale colors."
+and excludes grayscale colors.
+`luminance' sorts by relative luminance in the CIE XYZ color space."
:type '(choice (const :tag "Unsorted" nil)
(const :tag "Color Name" name)
(const :tag "Red-Green-Blue" rgb)
(const :tag "Hue-Saturation-Value" hsv)
(cons :tag "Distance on HSV cylinder"
(const :tag "Distance from Color" hsv-dist)
- (color :tag "Source Color Name")))
+ (color :tag "Source Color Name"))
+ (const :tag "Luminance" luminance))
:group 'facemenu
:version "24.1")
(+ (expt (- 180 (abs (- 180 (abs (- (nth 0 c-hsv) ; wrap hue
(nth 0 o-hsv)))))) 2)
(expt (- (nth 1 c-hsv) (nth 1 o-hsv)) 2)
- (expt (- (nth 2 c-hsv) (nth 2 o-hsv)) 2)))))))
+ (expt (- (nth 2 c-hsv) (nth 2 o-hsv)) 2)))))
+ ((eq list-colors-sort 'luminance)
+ (let ((c-rgb (color-name-to-rgb color)))
+ (+ (* (nth 0 c-rgb) 0.21266729)
+ (* (nth 1 c-rgb) 0.7151522)
+ (* (nth 2 c-rgb) 0.0721750))))))
(defun list-colors-display (&optional list buffer-name callback)
"Display names of defined colors, and show what they look like.