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| author | David Thompson <dthompson2@worcester.edu> | 2014-06-29 17:50:33 -0400 |
|---|---|---|
| committer | David Thompson <dthompson2@worcester.edu> | 2014-06-29 17:50:33 -0400 |
| commit | a5c0e784b54d4c433209a99789950d6e156548aa (patch) | |
| tree | 2c202402cecce75413478ec95f0a486c077ea52b | |
| parent | a836ff8926768d7ab4393fc4b99344515d681814 (diff) | |
Add color-scale procedure.
* sly/color.scm (color-scale): New procedure.
| -rw-r--r-- | sly/color.scm | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/sly/color.scm b/sly/color.scm index c8ba248..3384510 100644 --- a/sly/color.scm +++ b/sly/color.scm @@ -36,6 +36,7 @@ rgba rgb color* + color-scale color+ color- color-inverse @@ -128,6 +129,13 @@ For example: #xffffff will return a color with RGBA values 1, 1, 1, (* (color-a a) (color-a b)))) +(define (color-scale c k) + "Multiple the RGBA channels of the color C by the scalar K." + (make-color (* (color-r c) k) + (* (color-g c) k) + (* (color-b c) k) + (* (color-a c) k))) + (define (color+ a b) "Add the RGBA channels of colors A and B." (make-color (+ (color-r a) |