colorscheme: Guess wether a color is dark or light - scripts - various script and utils
  HTML git clone git://z3bra.org/scripts
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       ---
   DIR commit 728ebcf1e66d874a29bfb13e438bf70822d646e7
   DIR parent 29f9633eee979478a582cef755f7d8af9bc69155
  HTML Author: Willy Goiffon <dev@z3bra.org>
       Date:   Sat, 29 Aug 2026 08:10:50 +0000
       
       colorscheme: Guess wether a color is dark or light
       
       Diffstat:
         A colorscheme                         |      22 ++++++++++++++++++++++
       
       1 file changed, 22 insertions(+), 0 deletions(-)
       ---
   DIR diff --git a/colorscheme b/colorscheme
       @@ -0,0 +1,22 @@
       +#!/bin/sh
       +#
       +# Compute perceived brightness of an #RGB color
       +# https://en.wikipedia.org/wiki/Rec._709#The_Y'C'BC'R_color_space
       +
       +usage() {
       +        echo "usage: $(basename $0) #RRGGBB" >&2
       +}
       +
       +while getopts "h" OPT; do
       +        case $OPT in
       +        h) usage; exit 0;;
       +        *) usage; exit 1;;
       +        esac
       +done
       +
       +hex=${1#\#}
       +r="0x$(echo $hex|cut -b1-2)"
       +g="0x$(echo $hex|cut -b3-4)"
       +b="0x$(echo $hex|cut -b5-6)"
       +l=$(printf '%d*0.2126 + %d*0.7152 + %d*0.0722\n' $r $g $b|bc|cut -d. -f1)
       +[ $l -gt 128 ] && echo 'light' || echo 'dark'