#! /bin/zsh
#
# this file:
#   https://dataswamp.org/~incal/conf/.zsh/gfx-resize

. ~/.zsh/gfx

upscale () {
    local src=$1
    local src_n=${src:r:l}
    local src_e=${src:e:l}

    local src_w=$(pic-width-1  $src)
    local src_h=$(pic-height-1 $src)
    local src_d=${src_w}x${src_h}

    local dst_a=4k
    local dst=${src_n}-${dst_a}.${src_e}

    local dst_w=2048
    local dst_h=$(( (${dst_w} / (${src_w} + 0.0)) * ${src_h} ))
    local dst_d=${dst_w}x${dst_h}

    # ___----------__    ___---------___
    # \ master incal \  /   in da mix  /
    # /___----------__\/___---------___\
    #                  \
    convert             \
        $src             \
        -background black \
        -gravity center    \
        -extent $src_d      \
        -filter Lanczos      \
        -resize $dst_d        $dst
}

rs () {
    local fs=($@)

    local w=1080
    local h=720
    local gm=${w}x${h}

    for src in $fs; do
        local ext=${src:e}
        local nom=${src:r}
        local dst=${nom}-rs.${ext}

        convert -resize $gm $src $dst
        pad-to-size $dst $w $h
    done
}

pad-to-size () {
    local src=$1
    local nom=${src:r}
    local ext=${src:e}

    local w=$2
    local h=$3

    local col=${4:-#000001}
    local rect=rect.${ext}

    draw-rect $w $h $col $rect

    composite -gravity center $src $rect ${nom}-pad.${ext}

    rm $rect
}

draw-rect () {
    local w=$1
    local h=$2
    local wh=$(( w / 2.0 ))
    local hh=$(( h / 2.0 ))
    local x=$(( w / 4.0 ))
    local y=$(( h / 4.0 ))
    local hh=$(( h / 2.0 ))
    local dim=${w}x${h}

    local col=${3:-red}

    local dst=${4:-${col}-${dim}.png}

    convert \
        -alpha on                               \
        -virtual-pixel transparent              \
        -draw "rectangle ${x},${y},${wh},${hh}" \
        -fill $col                              \
        -size $dim                              \
        xc:blue                                 \
                                                $dst
}