HairSample2Overlay.sh

#!/bin/bash

# Check number of inputs
if [ $# -lt 2 -o $# -gt 3 ]; then
    echo "Needs two or three input arguments"
    exit 0;
fi

# Split hair image
convert "$1" -crop 40x40 +repage zzztmp.png

# Get row to use
n=`ls -1 zzztmp*.png | wc -l`
nrows=`echo "$n/3" | bc`
if [ $# -eq 3 ]; then
    if [ $3 -gt $nrows ]; then
        echo "Chosen row does not exist, selecting row 1"
        row="1"
    else
        row="$3"
    fi
else
    row="-1"
fi


# this function takes:
# (1) the image number of the front-facing hair in the row you want to use
# (2) the output image name
disthair () {

    # Distribute hair from the chosen row
    front=`echo "("$1"-1)*3" | bc`
    back=`echo "$front+1" | bc`
    right=`echo "$back+1" | bc`
    left="r$right"

    # Make a left-facing hair image
    convert zzztmp-$right.png -flop zzztmp-$left.png

    # Create blank convas
    convert -size 576x256 canvas:none "$2"

    # Now place the hair on the blank canvas where needed.
    # Rear-facing
    composite -geometry +12+8 zzztmp-$back.png "$2" "$2"
    composite -geometry +76+8 zzztmp-$back.png "$2" "$2"
    composite -geometry +140+8 zzztmp-$back.png "$2" "$2"
    composite -geometry +204+9 zzztmp-$back.png "$2" "$2"
    composite -geometry +268+8 zzztmp-$back.png "$2" "$2"
    composite -geometry +332+8 zzztmp-$back.png "$2" "$2"
    composite -geometry +396+8 zzztmp-$back.png "$2" "$2"
    composite -geometry +460+9 zzztmp-$back.png "$2" "$2"
    composite -geometry +524+8 zzztmp-$back.png "$2" "$2"

    # Left-facing
    composite -geometry +14+72 zzztmp-$left.png "$2" "$2"
    composite -geometry +78+73 zzztmp-$left.png "$2" "$2"
    composite -geometry +142+73 zzztmp-$left.png "$2" "$2"
    composite -geometry +206+72 zzztmp-$left.png "$2" "$2"
    composite -geometry +270+72 zzztmp-$left.png "$2" "$2"
    composite -geometry +334+73 zzztmp-$left.png "$2" "$2"
    composite -geometry +398+73 zzztmp-$left.png "$2" "$2"
    composite -geometry +462+72 zzztmp-$left.png "$2" "$2"
    composite -geometry +526+72 zzztmp-$left.png "$2" "$2"

    # Front-facing
    composite -geometry +12+135 zzztmp-$front.png "$2" "$2"
    composite -geometry +76+135 zzztmp-$front.png "$2" "$2"
    composite -geometry +140+135 zzztmp-$front.png "$2" "$2"
    composite -geometry +204+136 zzztmp-$front.png "$2" "$2"
    composite -geometry +268+135 zzztmp-$front.png "$2" "$2"
    composite -geometry +332+135 zzztmp-$front.png "$2" "$2"
    composite -geometry +396+135 zzztmp-$front.png "$2" "$2"
    composite -geometry +460+136 zzztmp-$front.png "$2" "$2"
    composite -geometry +524+135 zzztmp-$front.png "$2" "$2"

    # Right-facing
    composite -geometry +10+200 zzztmp-$right.png "$2" "$2"
    composite -geometry +74+201 zzztmp-$right.png "$2" "$2"
    composite -geometry +138+201 zzztmp-$right.png "$2" "$2"
    composite -geometry +202+200 zzztmp-$right.png "$2" "$2"
    composite -geometry +266+200 zzztmp-$right.png "$2" "$2"
    composite -geometry +330+201 zzztmp-$right.png "$2" "$2"
    composite -geometry +394+201 zzztmp-$right.png "$2" "$2"
    composite -geometry +458+200 zzztmp-$right.png "$2" "$2"
    composite -geometry +522+200 zzztmp-$right.png "$2" "$2"

}


# Finally, run disthair on the selected row (or all rows)
if [ "$row" -ne "-1" ]; then
    disthair "$row" "$2"
    echo "Converted row $row into $2"
else
    for (( k=1; k<=$nrows; k++ ))
    do
        fn=${2%.*}
        ex=${2##*.}
        outname="$fn-$k.$ex"
        disthair "$k" "$outname"
        echo "Converted row $k into $outname"
    done
fi

rm zzztmp-*.png