24-bit-color.sh

   1 #!/bin/bash
   2 # This file was originally taken from iterm2 https://github.com/gnachman/iTerm2/blob/master/tests/24-bit-color.sh
   3 #
   4 #   This file echoes a bunch of 24-bit color codes
   5 #   to the terminal to demonstrate its functionality.
   6 #   The foreground escape sequence is ^[38;2;<r>;<g>;<b>m
   7 #   The background escape sequence is ^[48;2;<r>;<g>;<b>m
   8 #   <r> <g> <b> range from 0 to 255 inclusive.
   9 #   The escape sequence ^[0m returns output to default
  10
  11 setBackgroundColor()
  12 {
  13     #printf '\x1bPtmux;\x1b\x1b[48;2;%s;%s;%sm' $1 $2 $3
  14     printf '\x1b[48;2;%s;%s;%sm' $1 $2 $3
  15 }
  16
  17 resetOutput()
  18 {
  19     echo -en "\x1b[0m\n"
  20 }
  21
  22 # Gives a color $1/255 % along HSV
  23 # Who knows what happens when $1 is outside 0-255
  24 # Echoes "$red $green $blue" where
  25 # $red $green and $blue are integers
  26 # ranging between 0 and 255 inclusive
  27 rainbowColor()
  28 {
  29     let h=$1/43
  30     let f=$1-43*$h
  31     let t=$f*255/43
  32     let q=255-t
  33
  34     if [ $h -eq 0 ]
  35     then
  36         echo "255 $t 0"
  37     elif [ $h -eq 1 ]
  38     then
  39         echo "$q 255 0"
  40     elif [ $h -eq 2 ]
  41     then
  42         echo "0 255 $t"
  43     elif [ $h -eq 3 ]
  44     then
  45         echo "0 $q 255"
  46     elif [ $h -eq 4 ]
  47     then
  48         echo "$t 0 255"
  49     elif [ $h -eq 5 ]
  50     then
  51         echo "255 0 $q"
  52     else
  53         # execution should never reach here
  54         echo "0 0 0"
  55     fi
  56 }
  57
  58 for i in `seq 0 127`; do
  59     setBackgroundColor $i 0 0
  60     echo -en " "
  61 done
  62 resetOutput
  63 for i in `seq 255 -1 128`; do
  64     setBackgroundColor $i 0 0
  65     echo -en " "
  66 done
  67 resetOutput
  68
  69 for i in `seq 0 127`; do
  70     setBackgroundColor 0 $i 0
  71     echo -n " "
  72 done
  73 resetOutput
  74 for i in `seq 255 -1 128`; do
  75     setBackgroundColor 0 $i 0
  76     echo -n " "
  77 done
  78 resetOutput
  79
  80 for i in `seq 0 127`; do
  81     setBackgroundColor 0 0 $i
  82     echo -n " "
  83 done
  84 resetOutput
  85 for i in `seq 255 -1 128`; do
  86     setBackgroundColor 0 0 $i
  87     echo -n " "
  88 done
  89 resetOutput
  90
  91 for i in `seq 0 127`; do
  92     setBackgroundColor `rainbowColor $i`
  93     echo -n " "
  94 done
  95 resetOutput
  96 for i in `seq 255 -1 128`; do
  97     setBackgroundColor `rainbowColor $i`
  98     echo -n " "
  99 done
 100 resetOutput