This is a port of library PNG 1.6.26 to MSDOS/DJGPP.

1.:     DJGPP specific changes.
        =======================

        This port has been configured using DJGPP 2.05.  It has been configured
        to be build in the /_build directory under the top srcdir.

        The port has been configured and compiled on WinXP SP3 and Win98SE.
        There is no guarantee that this may be possible with any other DOS-
        like OS.  Due to the use of long file names it will not be possible
        to configure and compile without LFN support.

        The port has been compiled using gcc346b and bnu227b.

        As for all binaries and libraries that handle images of any kind, it
        should be noted that files (streams) are *ALWAYS* openend in binary
        mode with all the well known implications on a DOS of WINDOWS OS if the
        stream comes from STDIN and/or STDOUT when these are still connected to
        the console.  The DJGPP specific change is that "SIGINT" and "SIGQUIT"
        signals are reenabled when the stream is connected to a TTY.  Also the
        usual configuration files have been added.  They are located in the
        /djgpp directory.

        To use and compile from sources this library you will have to install
        the zlib library.

        Please *read* the docs to become familiar with the products.


2.:     Installing the binary package.
        ==============================

2.1.:   Copy the binary distribution into the top DJGPP installation directory,
        just unzip it preserving the directory structure running *ONE* of the
        following commands:
          unzip32 png1626b.zip      or
          djtarx png1626b.zip       or
          pkunzip -d png1626b.zip



3.:     Building the binaries from sources.
        ===================================

3.1.:   Create a temporary directory and copy the source package into the
        directory.  If you download the source distribution from one of the
        DJGPP sites, just unzip it preserving the directory structure
        running *ONE* of the following commands:
          unzip32 png1626s.zip      or
          djtarx png1626s.zip       or
          pkunzip -d png1626s.zip

3.2.:   To build the binaries you will need the following binary packages:
          djdev205.zip (or a later but NOT a prior version)
          bsh205bbr4.zip (or a later but NOT a prior version)
          gccNNNb.zip, gppNNN.zip, bnuNNNb.zip, makNNNb.zip, filNNNb.zip,
          shlNNNb.zip, txtNNNb.zip, txiNNNb.zip, grepNNNb.zip, sedNNNb.zip,
          gwkNNNb.zip, mktmpNNb.zip and zlibNNN.zip

        If you want to run the check you will need also:
          difNNNb.zip and gwkNNNb.zip

        All this packages can be found in the v2gnu directory of any
        ftp.delorie.com mirror.  NNN stands for the newest port versions
        available when this port was build but older may do the work as well
        but I have not tested this.

3.3.:   The package has been configured to be build in a separate build directory
        under the top srcdir (aka libpng-1.6.26).  To build the binaries cd
        into /_build directory.  If for some reason you want to reconfigure the
        package cd into the build directory and run the following commands:
          make distclean
          ..\djgpp\config ./..

        Please note that you *MUST* delete the config.cache file in the build
        directory or you will not really reconfigure the sources because the
        configuration informations will be read from the cache file instead
        of being newly computed.

        config.bat, among other things, will start the configure script passing
        to it a couple of arguments.  All other configure specific options are
        not set by config.bat so their values are left as they are.  If no
        arguments are passed to config.bat then the default values are used.

        To build the programs in a directory on a disk or partition other than
        where the sources are, you must add the parameter that specifies the
        source directory, e.g:
          x:\src\contrib\libpng-1.6.26\djgpp\config x:/src/contrib/libpng-1.6.26

        Lets assume you want to build the binaries in a directory placed on a
        different drive (z:\build in this case) from where the sources are,
        then you will run the following commands:
          z:
          md \build
          cd \build
          x:\src\contrib\libpng-1.6.26\djgpp\config x:/src/contrib/libpng-1.6.26

        The order of the options and the srcdir option does not matter.  You
        *MUST* use forward slashes to specify the source directory.

        The batch file will set same environment variables, make MSDOS specific
        modifications to the Makefile.in's and supply all other needed options
        to the configure script.

3.4.:   To compile the package run from the directory where you have configured
        the sources the command:
          make

3.5.:   Now you can run the tests if you like. From the directory where you have
        configured the sources run the command:
          make check

        No test should fail.

3.6.:   To install the binaries, header, library, catalogs, and info docs
        run the following command from the top srcdir:
          make install

        This will install the products into your DJGPP installation tree given
        by the default prefix "/dev/env/DJDIR".  If you prefer to install them
        into some other directory you will have to set prefix to the appropiate
        value:
          make install prefix=z:/some/other/place



        Send library PNG specific bug reports to <glennrp@users.sourceforge.net>.
        Send suggestions and bug reports concerning the DJGPP port to
        comp.os.msdos.djgpp or <djgpp@delorie.com>.


Enjoy.

        Guerrero, Juan Manuel <juan.guerrero@gmx.de>
