diff options
-rw-r--r-- | guile/starlet/colours.scm | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/guile/starlet/colours.scm b/guile/starlet/colours.scm index c7d1de0..f18b986 100644 --- a/guile/starlet/colours.scm +++ b/guile/starlet/colours.scm @@ -27,6 +27,7 @@ make-colour-rgb colour-as-cmy colour-as-rgb + colour-as-rgbw cyan magenta @@ -117,6 +118,15 @@ (make-exception-with-irritants (colour-type col)))))))) +(define (colour-as-rgbw col) + (let ((rgb (colour-as-rgb col))) + (let ((w (apply min rgb))) + (list (- (red rgb) w) + (- (green rgb) w) + (- (blue rgb) w) + w)))) + + (define (colour-as-cmy col) (let ((val (colour-value col))) (case (colour-type col) |