Support of @2x and @3x BootLogos

#!/bin/bash
#Script for automatically making use of the right logo version, according to the iDevices screen resolution
#You may use this script in your own package but please don't remove this comment
#this script was written by Niels Muendler (nielstron)

#the screen scale (ie 1 for normal screens, 2 for @2x and 3 for @3x) is read from gsc.main-screen-scale
model=$(dpkg -s gsc.main-screen-scale | grep -i -e "Version" | cut -b 10- )

    #the following is made functions because... well I hope that it's improving readability
    function mvall2x () {
    #rename all @2x versions to normal versions
        for j in $(seq 0 $count)
        do
            #but only if the files really exists (it double checks here, don't want to loose any important files )
            if test -e "$j@2x.png"
            then
                mv -v -f "$j@2x.png" "$j.png"
            fi
        done
    }
    function mvall3x () {
    #rename all @3x versions to normal versions
    for j in $(seq 0 $count)
    do
        #but only if the files really exists (it double checks here, don't want to loose any important files and yes I DID copy pasta here)
        if test -e "$j@3x.png"
            then
                mv -v -f "$j@3x.png" "$j.png"
        #if there's no @3x version just use the @2x version
        elif test -e "$j@2x.png"
            then
                mv -v -f "$j@2x.png" "$j.png"
        fi
    done
    }

#if the end device isn't anything exit with error status
if test -z $model
then
    exit 1
fi

#Go to the Boot Logo home dir
cd /Library/BootLogos/
#read all folders and send them to the while loop
#run the following for each folder in this dir
ls --hide="*.*" ./ | while read dir
do
    #enter the dir
    cd "/Library/BootLogos/$dir"
    #read the amount of logos in this dir and save it to $count
    i="0"
    count="0"
    while test -e "$i.png"
    do
        count="$i"
        i=$(expr $i + 1)
    done

    #if the screen scale is 1
    if test $model = "1"
    then
        #do nothing
        echo ""
    #if the screen scale is 2
    elif test $model = "2"
    then
        #use @2x logos
        mvall2x
    #for future compatibility reasons do this for every other screen scale (>= 3)
    else
        #use @3x logos
        mvall3x
    fi


    #remove all remaining @2x and @3x logos to save disk space (there are no @2x logos left on generation 4 to 6 and no @3x logos left on the 6+)
    # note: this actually removes everything but the logos 0.png-n.png
    #do so by reading all files except 0.png-n.png and send them to the while loop
    ls ./ | grep -v -i "[0-9].png") | while read k
    do
        rm -f "$k"
    done
done