mozjpeg cross compile for windows

mozjpeg.sh

#!/bin/bash -eux

: "install utils" && {
    apt-get update
    apt-get install -y nasm cmake curl git mingw-w64 libz-mingw-w64-dev
}

: "compile libpng" && {
    tmp=$(curl -s "https://sourceforge.net/projects/libpng/rss" | \
        grep "<link>.*.tar.gz" | grep -v "older-releases" | \
        sort -r | head -1 | grep -o "https://.*/download")
    curl -L -o "libpng.tar.gz" "${tmp}"
    mkdir libpng
    tar xvf "libpng.tar.gz" --strip-components 1 -C libpng
    cd libpng
    ./configure --host=x86_64-w64-mingw32 \
        --prefix=/usr/x86_64-w64-mingw32 \
        CPPFLAGS=-I/usr/x86_64-w64-mingw32/include \
        LDFLAGS=-L/usr/x86_64-w64-mingw32/lib
    make
    make install
    cd ../
}

: "compile mozjpeg" && {
    git clone https://github.com/mozilla/mozjpeg.git
    if [ "${MOZJPEG_VERSION:+true}" ];then
        cd mozjpeg
        git checkout "refs/tags/${MOZJPEG_VERSION}"
        cd ../
    fi

    mkdir build
    cd build
    cmake -G"Unix Makefiles" \
        -DCMAKE_SYSTEM_NAME=Windows \
        -DCMAKE_SYSTEM_PROCESSOR=AMD64 \
        -DCMAKE_C_COMPILER=/usr/bin/x86_64-w64-mingw32-gcc \
        -DCMAKE_RC_COMPILER=/usr/bin/x86_64-w64-mingw32-windres \
        -DCMAKE_INCLUDE_PATH=/usr/x86_64-w64-mingw32/include \
        -DCMAKE_LIBRARY_PATH=/usr/x86_64-w64-mingw32/lib \
        "$@" \
        ../mozjpeg
    make
    cd ../
}

: "collect exe" && {
    if [ -d "/exe" ];then
        cp build/*.{exe,dll} libpng/.libs/libpng*.dll "/exe/"
    fi
}