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

white-bg () {
    local src=$1

    local name=${src:r}
    local ext=${2:-png}

    local dst=${name}-white.${ext}

    convert $src -background white -alpha remove -alpha off $dst
}

pdf2img () {
    local src=$1

    local name=${src:r}
    local ext=${2:-png}

    local dst=${name}.${ext}

    local dep=32
    local den=300

    convert -density $den -depth $dep $src $dst
    white-bg $dst
}
alias pdf2png=pdf2img

pdf2imgs () {
    local src=$1
    pdf2img $src png
    pdf2img $src jpg
}

png2pdf () {
    local png=$1
    local name=${png:r}

    local pnm=${name}.pnm
    pngtopnm $png > $pnm

    local ps=${name}.ps
    pnmtops $pnm > $ps

    ps2pdf-crop $ps
}

ps2pdf-crop () {
    local ps=$1
    local name=${ps:r}

    local final_pdf=${name}.pdf
    local large_pdf=${name}-large.pdf

    ps2pdf $ps $large_pdf
    pdfcrop --margins 12 $large_pdf $final_pdf
}

# N.B. not any picture but pic(1) source
pic2pdf () {
    # pic(1) image
    local img=$1
    local name=${img:r}

    # PS
    local ps=${name}.ps
    groff -p $img -T ps > $ps

    # PDF
    ps2pdf-crop $ps
}