#!/bin/bash

# wallcolGradientAngle

# pick two colors and 
# pick two points for angle and
# set that gradient as wallpaper

# pick colors
one="$(gpick -p -s -o)"
two="$(gpick -p -s -o)"

res="$(xdpyinfo | awk '/dimensions/{print $2}')"

# pick angle
# gpick used as blocker, similar to click-release event
gpick -p -s && read -r X1 Y1 _ < <(xdotool getmouselocation) || exit
gpick -p -s && read -r X2 Y2 _ < <(xdotool getmouselocation) || exit
X1="${X1//[^0-9]/}"; X2="${X2//[^0-9]/}"; Y1="${Y1//[^0-9]/}"; Y2="${Y2//[^0-9]/}"

angleInDegrees() {
    
    #                                                                          ˇ imagemagick friendly 90 degrees
    angle="$(bc -l <<< "(a (($Y2 - $Y1) / ($X2 - $X1))) * 180 / (4 * a (1)) + 90")"

}
if (( X2 != X1 )); then # avoid division by zero
    angleInDegrees
else
    X2="$(( X2 + 1 ))" && angleInDegrees
fi

doit () {
    
    # info
    echo "$one > $two @ $res / $angle"
    
    # make gradient
    convert -size "${res}" -define gradient:angle="${angle}" gradient:"${one}-${two}" -channel RGB -separate -dither FloydSteinberg -colors 256 -combine -depth 8 ~/.gradient.png || exit
    
     # -set colorspace HSB -colorspace RGB
    
    # if there is ~/.noise.png, lets overlay that automagically
    if [[ -f ~/.noise.png ]]; then
        composite -tile -alpha off -compose overlay ~/.noise.png ~/.gradient.png /tmp/tmpout.png
        mv /tmp/tmpout.png ~/.gradient.png
    fi 
    
   
    
    # set wallpaper
    nitrogen --save --set-centered ~/.gradient.png

}

[[ "$one" && "$two" && "$res" ]] && doit