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| author | Hugo Hörnquist <hugo@lysator.liu.se> | 2022-02-02 02:36:43 +0100 |
|---|---|---|
| committer | Hugo Hörnquist <hugo@lysator.liu.se> | 2022-02-02 02:36:43 +0100 |
| commit | cf692903b848d7b02a1966da671f5c653212a25c (patch) | |
| tree | c2eadcfc96a0f533c09bf2fea30aebb900045104 /module/hnh | |
| parent | Documentation of (hnh util ...) (diff) | |
| download | calp-cf692903b848d7b02a1966da671f5c653212a25c.tar.gz calp-cf692903b848d7b02a1966da671f5c653212a25c.tar.xz | |
Move calculate-fg-color into calp subtree.
While the algorithm was general, the packing of colors, along with the
error handling made it to non-portable.
Diffstat (limited to 'module/hnh')
| -rw-r--r-- | module/hnh/util/color.scm | 22 |
1 files changed, 0 insertions, 22 deletions
diff --git a/module/hnh/util/color.scm b/module/hnh/util/color.scm deleted file mode 100644 index b626316d..00000000 --- a/module/hnh/util/color.scm +++ /dev/null @@ -1,22 +0,0 @@ -(define-module (hnh util color) - ) - -;; Returns a color with good contrast to the given background color. -;; https://stackoverflow.com/questions/1855884/determine-font-color-based-on-background-color/1855903#1855903 -(define-public (calculate-fg-color c) - (catch #t - (lambda () - (define (str->num c n) (string->number (substring/shared c n (+ n 2)) 16)) - ;; (format (current-error-port) "COLOR = ~s~%" c) - (let ((r (str->num c 1)) - (g (str->num c 3)) - (b (str->num c 5))) - (if (< 1/2 (/ (+ (* 0.299 r) - (* 0.587 g) - (* 0.114 b)) - #xFF)) - "#000000" "#FFFFFF"))) - (lambda args - (format (current-error-port) "Error calculating foreground color?~%~s~%" args) - "#FF0000" - ))) |