Create a wallpaper with GMIC

create_wallpaper.sh

#!/bin/bash

###
# adjust these variables
root="$HOME/pics/wallpaper"
name=$(date +%s)
log="/tmp/$(basename "$0").log"
###

###
# Dependencies
# feh, gmic + gimp-plugin-gmic, imagemagick
command -v feh >/dev/null 2>&1 || { echo >&2 "I require \"feh\" but it's not installed. Aborting."; exit 1; }
command -v gmic >/dev/null 2>&1 || { echo >&2 "I require \"gmic\" but it's not installed. Aborting."; exit 1; }
command -v montage >/dev/null 2>&1 || { echo >&2 "I require \"imagemagick\" but it's not installed. Aborting."; exit 1; }
###

###
# TODO:
# * order of monitors (now: ascending resolution), i.e. via xrandr the
#   position of a monitor
# * montage does not work if the monitors are not in one row
#   (horizontal)
# * other programs to set the background (feh does not work with
#   GNOME, KDE, ...)
#   http://askubuntu.com/questions/72549/how-to-determine-which-window-manager-is-running
# * what if shuf > border values? (0.0 < plasma:alpha < 5.0, with shuf it could be 5.37)
###

###
# Variables
turbulence=1 # standard
plasma=0
gradient=0
rand=0
debug=99 # nothing?
mode="turbulence" # standard
setit=0
###

###
# Functions
function usage() {
cat << !
Usage: $0 [-g|-p|-t] [-r] [-s]
	-g: Use gradient as mode
	-p: Use plasma as mode
	-t: Use turbulence as mode (default)

	-r: generate a random wallpaper for each monitor

	-s: set the wallpaper
!
}


## gradient
# command: gmic $width,$height,$depth,$spectrum -gimp_corner_gradient $ulr,$ulg,$ulb,$ula,$urr,$urg,$urb,$ura,$blr,$blg,$blb,$bla,$brr,$brg,$brb,$bra -o gradient.png
# example: gmic 1920,1080,1,3 -gimp_corner_gradient 255,255,255,128,255,0,0,255,0,255,0,255,0,0,255,255 -o gradient.png

# width: width
# height: height
# depth: normally 1
# spectrum: normally 3
# up left: rgba (0-255 each)
# up right: rgba (0-255 each)
# bottom left: rgba (0-255 each)
# bottom right: rgba (0-255 each)

# beautiful
shuffle_gradient="$(shuf -i 75-255 -n 12 | sed '3~3 a 255' | tr '\n' ',' | sed 's/,$//')"
# normal
# shuffle_gradient="$(shuf -i 0-255 -n 12 | sed '3~3 a 255' | tr '\n' ',' | sed 's/,$//')"
function shuffle_gradient() {
	if [[ "$rand" == 1 ]] ; then
		shuffle_gradient="$(shuf -i 75-255 -n 12 | sed '3~3 a 255' | tr '\n' ',' | sed 's/,$//')"
	fi
}

## turbulence
# command: gmic $width,$height,$depth,$spectrum -gimp_turbulence $radius,$octaves,$damping_per_octave,$difference_mixing,$mode -o turbulence.png
# example: gmic 1920,1080,1,3 -gimp_turbulence 618.54,6,4.43,0,3 -o turbulence.png
# 
# width: width
# height: height
# depth: normally 1
# spectrum: normally 3
# radius: 1 - 1024
# octaves: 1 - 12
# damping per octave: 1.0 - 10.0
# difference mixing: -10.0 - 10.0
# mode: turbulence (0), turbulence 2 (1), fractal noise (2), fractured clouds (3), stardust (4), pea soup (5)

# beautiful
shuffle_turbulence="$(shuf -i 50-1024 -n 1),$(shuf -i 1-12 -n 1),$(shuf -i 5-10 -n 1).$(shuf -i 0-9 -n 2 -z),$(shuf -i 0-10 -n 1).$(shuf -i 0-9 -n 2 -z),$(shuf -i 0-3 -n 1)"
# normal
# shuffle_turbulence="$(shuf -i 1-1024 -n 1),$(shuf -i 1-12 -n 1),$(shuf -i 1-10 -n 1).$(shuf -i 0-9 -n 2 -z),$(echo "$(shuf -i 0-20 -n 1)-10"|bc).$(shuf -i 0-9 -n 2 -z),$(shuf -i 0-5 -n 1)"
function shuffle_turbulence() {
	if [[ "$rand" == 1 ]] ; then
		shuffle_turbulence="$(shuf -i 50-1024 -n 1),$(shuf -i 1-12 -n 1),$(shuf -i 5-10 -n 1).$(shuf -i 0-9 -n 2 -z),$(shuf -i 0-10 -n 1).$(shuf -i 0-9 -n 2 -z),$(shuf -i 0-3 -n 1)"
	fi
}
##

## plasma
# command: gmic $width,$height,$depth,$spectrum -gimp_plasma $alpha,$beta,$scale,$randomize,$transparency,$r,$g,$b -o plasma.png
# example: gmic 1920,1080,1,3 -gimp_plasma 3.98058,8.73786,10,0,0,128,128,128 -o plasma.png

# width: width
# height: height
# depth: normally 1
# spectrum: normally 3
# alpha: 0.0 - 5.0
# beta: 0.0 - 100.0
# scale: 2 - 10
# randomize: 0 or 1
# transparency: 0 or 1
# color: rgb (0 - 255 each)

# beautiful
shuffle_plasma="0.00,0.00,$(shuf -i 9-10 -n 1),1,0,$(shuf -i 75-255 -n 3 | tr '\n' ',' | sed 's/,$//')"
# normal
# shuffle_plasma="$(shuf -i 0-5 -n 1).$(shuf -i 0-9 -n 2 -z),$(shuf -i 0-100 -n 1).$(shuf -i 0-9 -n 2 -z),$(shuf -i 2-10 -n 1),$(shuf -i 0-1 -n 1),0,$(shuf -i 0-255 -n 3 | tr '\n' ',' | sed 's/,$//')"
function shuffle_plasma() {
	if [[ "$rand" == 1 ]] ; then
		shuffle_plasma="0.00,0.00,$(shuf -i 9-10 -n 1),1,0,$(shuf -i 75-255 -n 3 | tr '\n' ',' | sed 's/,$//')"
	fi
}

function gradient() {
	shuffle_gradient
	gmic -v -"$debug" "$(sed 's/x/,/' <<<"$res"),1,3" \
		-gimp_corner_gradient "$shuffle_gradient" -o \
		"$root/$res/$mode-$name.png"
}

function plasma() {
	shuffle_plasma
	gmic -v -"$debug" "$(sed 's/x/,/' <<<"$res"),1,3" \
		-gimp_plasma "$shuffle_plasma" -o \
		"$root/$res/$mode-$name.png"
}

function turbulence() {
	shuffle_turbulence
	gmic -v -"$debug" "$(sed 's/x/,/' <<<"$res"),1,3" \
		-gimp_turbulence "$shuffle_turbulence" -o \
		"$root/$res/$mode-$name.png"
}
###

###
# Get and set parameters
while getopts tpgrs OPT ; do
	case "$OPT" in
		t) turbulence=1 ; mode="turbulence" ;;
		p) plasma=1 ; mode="plasma" ;;
		g) gradient=1 ; mode="gradient" ;;
		r) rand=1 ;;
		s) setit=1 ;;
		?) usage ; exit 1 ;;
	esac
done
###

# display size
all=""
while read -r res line ; do
	[ ! -d "$root/$res" ] && mkdir -p "$root/$res"
	if [ "$gradient" -eq 1 ] ; then
		gradient
	elif [ "$plasma" -eq 1 ] ; then
		plasma
	else
		turbulence
	fi
	# swap order here, if you have multiple monitors ordered by
	# descending resolution, i.e. big monitor on the left, little one
	# on the right
	out="shuffle_$mode"
	echo "$name:$mode:${!out}" >> "$log"
	all="$all $root/$res/$mode-$name.png"
done < <(xrandr | grep "\*" | sort -nr)

# montage (only if more than one screen is connected)
cur=$(xrandr | head -1 |  tr -d ' ' | cut -d\, -f 2 | sed 's/current//')
[ ! -d "$root/$cur" ] && mkdir "$root/$cur"
if [[ $(xrandr | grep -c "\ connected") -gt 1 ]] ; then
	montage -background black -mode Concatenate \
		"$all" "$root/$cur/$mode-$name.png"
fi

# set the background with feh, if parameter is given
[ "$setit" -eq 1 ] && feh --bg-tile "$root/$cur/$mode-$name.png"