dotfiles/shell/common/colours

# vim: ft=sh
# A script to make using 256 colours less painful.
#
# Adapted from http://github.com/sykora/etc/blob/master/zsh/functions/spectrum/
# P.C. Shyamshankar <sykora@lucentbeing.com>

# Create foreground and background colour arrays for 256 colours.
declare -a FG BG

# Determine prompt colour escape strings.
if [[ -n ${BASH_VERSION-} ]]; then
  cStart='\[\e['
  cEnd='m\]'
elif [[ -n ${ZSH_VERSION-} ]]; then
  # ZSH specifics: A = associative array, H = hide value when echoed, g = global
  declare -AHg FG BG
  cStart='%{['
  cEnd='m%}'
fi

# The arrays will be 1-based because this is ZSH default behaviour.
# This can be changed with the `KSH_ARRAYS` option, but we do not.
# First 16 are the ANSI Terminal colours and bright variants:
# Black, Red, Green, Yellow, Blue, Magenta, Cyan, White
for colour in {0..255}; do
    FG[$colour]=$cStart"38;5;"$colour$cEnd
    BG[$colour]=$cStart"48;5;"$colour$cEnd
done

# Create text effects.
cReset=$cStart"0"$cEnd
cBol=$cStart"1"$cEnd # bold
cIta=$cStart"3"$cEnd # italic
cUnd=$cStart"4"$cEnd # underline
cBli=$cStart"5"$cEnd # blink
cRev=$cStart"7"$cEnd # reverse
cnBol=$cStart"22"$cEnd # no-bold
cnIta=$cStart"23"$cEnd # no-italic
cnUnd=$cStart"24"$cEnd # no-underline
cnBli=$cStart"25"$cEnd # no-blink
cnRev=$cStart"27"$cEnd # no-reverse

SPECTRUM_TEXT=${SPECTRUM_TEXT:-Arma virumque cano Troiae qui primus ab oris}

# Show all 256 colours with colour number
function spectrum_ls() {
  local line
  for code in {0..255}; do
    line="$code: ${FG[$code]}$SPECTRUM_TEXT$cReset"
    [[ -n $(command -v print) ]] && print -P -- $line || printf "$line\n"
  done
}

# Show all 256 colours where the background is set to specific colour
function spectrum_bls() {
  local line
  for code in {0..255}; do
    line="$code: ${BG[$code]}$SPECTRUM_TEXT$cReset"
    [[ -n $(command -v print) ]] && print -P -- $line || printf "$line\n"
  done
}