*************************************************************************
* Build and Install HDF4 C and Fortran Libraries and tools with CMake   *
*************************************************************************

                     Table of Contents

Section I:    Preconditions
Section II:   Quick Step Building HDF4 Libraries with CMake Script Mode
Section III:  Quick Step Building HDF4 Libraries with CMake Command Mode
Section IV:   Further Considerations
Section V:    Options for building HDF4 Libraries with CMake Command Line
Section VI:   CMake option defaults for HDF4
Section VII:  User Defined Options for HDF4 Libraries with CMake
Section VIII: Using CMakePresets.json for Compiling
Section IX:   Using the Library
Section X:    Autotools Configuration and Build

************************************************************************


========================================================================
I. Preconditions
========================================================================
Obtaining HDF4 source code
   1. Create a directory for your development; for example, "myhdfstuff".

   2. Obtain HDF4 source from Github
         development branch:  https://github.com/HDFGroup/hdf4
         last release:        https://github.com/HDFGroup/hdf4/releases/latest
             hdf-4_3_"X".tar.gz or hdf-4_3_"X".zip

      and put it in "myhdfstuff".
      Uncompress the file. There should be a hdf-4.3"X" folder.

CMake version
   1. We suggest you obtain the latest CMake from the Kitware web site.
      The HDF 4.3"X" product requires a minimum CMake version 3.18,
      where "X" is the current HDF4 release version. If you are using
      VS2022, the minimum version is 3.21. CMakePresets requires CMake 3.25.

Note:
   To change the install prefix from the platform defaults initialize
   the CMake variable, CMAKE_INSTALL_PREFIX. Users of build scripts
   will use the INSTALLDIR option.


========================================================================
II. Quick Step Building HDF4 Libraries with CMake Script Mode
========================================================================
This short set of instructions is written for users who want to quickly
build the HDF4 C and Fortran shared libraries and tools
from the HDF4 source code package using the CMake tools. This procedure
will use the default settings in the config/cmake/cacheinit.cmake file.
The HDF Group recommends using the presets process to build HDF4.

NOTE: if you are using CMake 3.25 or later, you can use the presets process.
    The CMakePresets.json file in the source directory will configure, build, test,
    and package HDF4 with the same options that are set in the cacheinit.cmake file.
    In addition, it will get the optional files listed below that are needed, from
    the appropriate repositories.
    See Section VIII: Using CMakePresets.json for compiling

-------------------------------------------------------------------------
-------------------------------------------------------------------------
Individual files needed as mentioned in this document
-------------------------------------------------------------------------
CMake build script from https://github.com/HDFGroup/hdf4/tree/master/config/cmake/scripts:
    CTestScript.cmake  -- CMake build script

Configuration files from https://github.com/HDFGroup/hdf4/tree/master/config/cmake/scripts:
    HDF4config.cmake   -- CMake configuration script
    HDF4options.cmake  -- CMake configuration options script

External compression szip, jpeg, and zlib libraries:
    JPEG          "https://www.ijg.org/filesz"/jpegsrc.v9e.tar.gz"
    ZLIB          "https://github.com/madler/zlib/releases/download/v1.3.1/zlib-1.3.1.tar.gz"
    ZLIBNG        "https://github.com/zlib-ng/zlib-ng/archive/refs/tags/2.2.2.tar.gz"
    LIBAEC        "https://github.com/MathisRosenhauer/libaec/releases/download/v1.1.3/libaec-1.1.3.tar.gz"
-------------------------------------------------------------------------
-------------------------------------------------------------------------

Build scripts for windows or linux
-----------------------------------------------

To build HDF4 with the SZIP, ZLIB and JPEG external libraries you will need to:

   1. Change to the development directory "myhdfstuff".

   2. Download/copy the individual files mentioned above to "myhdfstuff".
      Do not uncompress the tar.gz files.

   3. Change to the source directory "hdf-4.3.x".
      CTestScript.cmake file should not be modified.

   4. Edit the platform configuration file, HDF4options.cmake, if you want to change
      the default build environment. The file is a compilation of the most used
      options and by commenting/uncommenting lines the options can easily be changed.

   5. From the "myhdfstuff" directory execute the CTest Script with the
      following options:

      On 32-bit Windows with Visual Studio 2022, execute:
         ctest -S HDF4config.cmake,BUILD_GENERATOR=VS2022 -C Release -VV -O hdf4.log
      On 64-bit Windows with Visual Studio 2022, execute:
         ctest -S HDF4config.cmake,BUILD_GENERATOR=VS202264 -C Release -VV -O hdf4.log
      On 32-bit Windows with Visual Studio 2019, execute:
         ctest -S HDF4config.cmake,BUILD_GENERATOR=VS2019 -C Release -VV -O hdf4.log
      On 64-bit Windows with Visual Studio 2019, execute:
         ctest -S HDF4config.cmake,BUILD_GENERATOR=VS201964 -C Release -VV -O hdf4.log
      On 32-bit Windows with Visual Studio 2017, execute:
         ctest -S HDF4config.cmake,BUILD_GENERATOR=VS2017 -C Release -VV -O hdf4.log
      On 64-bit Windows with Visual Studio 2017, execute:
         ctest -S HDF4config.cmake,BUILD_GENERATOR=VS201764 -C Release -VV -O hdf4.log
      On 32-bit Windows with Visual Studio 2015, execute:
         ctest -S HDF4config.cmake,BUILD_GENERATOR=VS2015 -C Release -VV -O hdf4.log
      On 64-bit Windows with Visual Studio 2015, execute:
         ctest -S HDF4config.cmake,BUILD_GENERATOR=VS201564 -C Release -VV -O hdf4.log
      On Linux and Mac, execute:
         ctest -S HDF4config.cmake,BUILD_GENERATOR=Unix -C Release -VV -O hdf4.log
      The supplied build scripts are versions of the above.

      The command above will configure, build, test, and create an install
      package in the myhdfstuff folder. It will have the format:
          HDF-4.3.NN-<platform>.<zip or tar.gz>

          On Unix, <platform> will be "Linux". A similar .sh file will also be created.
          On Windows, <platform> will be "win64" or "win32". If you have an
          installer on your system, you will also see a similar file that ends
          in either .exe (NSIS) or .msi (WiX).

      Notes on the command line options.
          The -S option uses the script version of ctest.

          The value for the -C option (as shown above, "-C Release") must
          match the setting for CTEST_CONFIGURATION_TYPE in the platform
          configuration file.

          The -VV option is for most verbose; use -V for less verbose.

          The "-O hdf4.log" option saves the output to a log file hdf4.log.

   6. To install, "X" is the current release version

      On Windows (with WiX installed), execute:
                HDF-4.3."X"-win32.exe or HDF-4.3."X"-win64.exe
      By default this program will install the hdf4 library into the
      "C:\Program Files" directory and will create the following
      directory structure:
         HDF_Group
         --HDF
         ----4.3."X"
         ------bin
         ------include
         ------lib
         ------cmake

      On Linux, change to the install destination directory
      (create it if doesn't exist) and execute:
                <path-to>/myhdfstuff/HDF-4.3."X"-Linux.sh
      After accepting the license, the script will prompt:
        By default the HDF4 will be installed in:
        "<current directory>/HDF-4.3."X"-Linux"
        Do you want to include the subdirectory HDF-4.3."X"-Linux?
        Saying no will install in: "<current directory>" [Yn]:
      Note that the script will create the following directory structure
      relative to the install point:
         HDF_Group
         --HDF
         ----4.3."X"
         ------bin
         ------include
         ------lib
         ------share

      On Mac you will find HDF-4.3"X"-Darwin.dmg in the myhdfstuff folder. Click
      on the dmg file to proceed with installation. After accepting the license,
      there will be a folder with the following structure:
         HDF_Group
         --HDF
         ----4.3."X"
         ------bin
         ------include
         ------lib
         ------share

      By default the installation will create the bin, include, lib and cmake
      folders in the <install destination directory>/HDF_Group/HDF/4.3."X"
      The <install destination directory> depends on the build platform;
        Windows will set the default to:
          C:/Program Files/HDF_Group/HDF/4.3."X"
        Linux will set the default to:
          "myhdfstuff/HDF_Group/HDF/4.3."X"
      The default can be changed by adding ",INSTALLDIR=<my new dir>" to the
          "ctest -S HDF4config.cmake..." command. For example on linux:
         ctest -S HDF4config.cmake,INSTALLDIR=/usr/local/myhdf4,BUILD_GENERATOR=Unix -C Release -VV -O hdf4.log


========================================================================
III. Quick Step Building HDF4 C Static Libraries and Tools with CMake
========================================================================
Notes: This short set of instructions is written for users who want to
       quickly build just the HDF4 C static library and tools from
       the HDF4 source code package using the CMake command line tools.
       Avoid the use of drive letters in paths on Windows.

   Go through these steps:

      1. Change to the development directory "myhdfstuff".

      2. Uncompress the HDF4 source file

      3. Create a folder  "build" in the "myhdfstuff" directory.

      4. Change into the "build" folder.

      5. Configure the C library, tools and tests with one of the following commands:

         On Windows 32 bit
           cmake -G "Visual Studio 16 2019" -A Win32 -DCMAKE_BUILD_TYPE:STRING=Release -DBUILD_TESTING:BOOL=ON -DHDF4_BUILD_TOOLS:BOOL=ON ..\hdf-4.3"X"

         On Windows 64 bit
           cmake -G "Visual Studio 16 2019" -A x64 -DCMAKE_BUILD_TYPE:STRING=Release -DBUILD_TESTING:BOOL=ON -DHDF4_BUILD_TOOLS:BOOL=ON ..\hdf-4.3"X"

         On Linux and Mac
           cmake -G "Unix Makefiles" -DCMAKE_BUILD_TYPE:STRING=Release -DBUILD_TESTING:BOOL=ON -DHDF4_BUILD_TOOLS:BOOL=ON ../hdf-4.3"X"

         where "X" is the current release version.

      6. Build the C library, tools and tests with this command:
           cmake --build . --config Release

      7. Test the C library and tools with this command:
           ctest . -C Release

      8. Create an install image with this command:
           cpack -C Release CPackConfig.cmake

      9. To install
         On Windows (with WiX installed), execute:
                HDF-4.3."X"-win32.msi or HDF-4.3."X"-win64.msi
         By default this program will install the hdf4 library into the
         "C:\Program Files" directory and will create the following
         directory structure:
            HDF_Group
            --HDF
            ----4.3."X"
            ------bin
            ------include
            ------lib
            ------cmake

         On Linux, change to the install destination directory
         (create if doesn't exist) and execute:
                <path-to>/myhdfstuff/build/HDF-4.3."X"-Linux.sh
         After accepting the license, the script will prompt:
           By default the HDF4 will be installed in:
           "<current directory>/HDF-4.3."X"-Linux"
           Do you want to include the subdirectory HDF-4.3."X"-Linux?
           Saying no will install in: "<current directory>" [Yn]:
         Note that the script will create the following directory structure
         relative to the install point:
            HDF_Group
            --HDF
            ----4.3."X"
            ------bin
            ------include
            ------lib
            ------share

         On Mac you will find HDF-4.3."X"-Darwin.dmg in the build folder. Click
         on the dmg file to proceed with installation. After accepting the license,
         there will be a folder with the following structure:
            HDF_Group
            --HDF
            ----4.3."X"
            ------bin
            ------include
            ------lib
            ------share


========================================================================
IV. Further Considerations
========================================================================

   1. We suggest you obtain the latest CMake for windows from the Kitware
      web site. The HDF 4.3"X" product requires a minimum CMake version 3.18.
      If you are using VS2022, the CMake minimum version is 3.21. CMakePresets
      requires CMake 3.25.

   2. HDF4 requires Zlib and JPEG. Szip (aka libaec) is optional:
      A. Download the binary packages and install them in a central location.
         For example on Windows, create a folder extlibs and install the
         packages there. Add the following CMake options:
            -DJPEG_LIBRARY:FILEPATH=some_location/lib/jpeg.lib
            -DJPEG_INCLUDE_DIR:PATH=some_location/include
            -DJPEG_USE_EXTERNAL:BOOL=OFF
            -DZLIB_LIBRARY:FILEPATH=some_location/lib/zlib.lib
            -DZLIB_INCLUDE_DIR:PATH=some_location/include
            -DZLIB_USE_EXTERNAL:BOOL=OFF
            -DSZIP_LIBRARY:FILEPATH=some_location/lib/libszaec.lib
            -DSZIP_INCLUDE_DIR:PATH=some_location/include
            -Dlibaec_LIBRARY:FILEPATH=some_location/lib/libaec.lib
            -Dlibaec_INCLUDE_DIR:PATH=some_location/include
            -DSZIP_USE_EXTERNAL:BOOL=OFF
         where "some_location" is the full path to the extlibs folder.
         Also if the appropriate environment variable is set, the above options are not required;
            set(ENV{JPEG_ROOT} "some_location")
            set(ENV{ZLIB_ROOT} "some_location")
            set(ENV{SZIP_ROOT} "some_location")
            set(ENV{libaec_ROOT} "some_location")

        Note that if there is a problem finding the libraries, try adding the
        CMake variable CMAKE_FIND_DEBUG_MODE:BOOL=ON to the command line.

      B. Use source packages from an GIT server by adding the following CMake
         options:
            HDF4_ALLOW_EXTERNAL_SUPPORT:STRING="GIT"
            JPEG_GIT_URL:STRING="https://some_location/jpeg"
            JPEG_GIT_BRANCH="some_branch"
            ZLIB_GIT_URL:STRING="https://some_location/zlib"
            ZLIB_GIT_BRANCH="some_branch"
            SZIP_GIT_URL:STRING="https://some_location/szip"
            SZIP_GIT_BRANCH="some_branch"
            LIBAEC_GIT_URL:STRING="https://some_location/libaec"
            LIBAEC_GIT_BRANCH="some_branch"
         where "some_location" is the URL to the GIT repository and "some_branch" is
         a branch in the repository, usually the default. Also set
         CMAKE_BUILD_TYPE to the configuration type.

      C. Use source packages from a compressed file by adding the following
         CMake options:
            HDF4_ALLOW_EXTERNAL_SUPPORT:STRING="TGZ"
            JPEG_TGZ_NAME:STRING="jpeg_src.ext"
            ZLIB_TGZ_NAME:STRING="zlib_src.ext"
            LIBAEC_TGZ_NAME:STRING="libaec_src.ext"
            TGZPATH:STRING="some_location"
         where "some_location" is the URL or full path to the compressed
         file and ext is the type of compression file. Also set CMAKE_BUILD_TYPE
         to the configuration type during configuration. See the settings in the
         config/cmake/cacheinit.cmake file HDF uses for testing.

      D. Use original source packages from a compressed file by adding the following
         CMake options:
            JPEG_TGZ_NAME:STRING="jpeg_src.ext"
            JPEG_TGZ_ORIGPATH:STRING="some_location"

            LIBAEC_TGZ_NAME:STRING="szip_src.ext"
            LIBAEC_TGZ_ORIGPATH:STRING="some_location"

            ZLIB_TGZ_NAME:STRING="zlib_src.ext"
            ZLIB_TGZ_ORIGPATH:STRING="some_location"

            HDF4_ALLOW_EXTERNAL_SUPPORT:STRING="TGZ"
         where "some_location" is the URL and by setting
            JPEG_USE_LOCALCONTENT:BOOL=ON
            ZLIB_USE_LOCALCONTENT:BOOL=OFF
            LIBAEC_USE_LOCALCONTENT:BOOL=OFF
         or full path to the compressed file and ext is the type of compression file.
         Also set CMAKE_BUILD_TYPE to the configuration type during configuration.
         See the settings in the config/cmake/cacheinit.cmake file HDF uses for testing.

         The files can also be retrieved from a local path if necessary
            TGZPATH:STRING="some_location"
         by setting
            JPEG_USE_LOCALCONTENT:BOOL=ON
            ZLIB_USE_LOCALCONTENT:BOOL=ON
            LIBAEC_USE_LOCALCONTENT:BOOL=ON

   3. If you are building on Apple Darwin platforms, you should add the
      following options:
          Compiler choice - use xcode by setting the ENV variables of CC
          Shared Fortran is not supported, build static:
            BUILD_SHARED_LIBS:BOOL=OFF
          Additional options:
            BUILD_JPEG_WITH_PIC:BOOL=ON
            CTEST_USE_LAUNCHERS:BOOL=ON
            CMAKE_BUILD_WITH_INSTALL_RPATH:BOOL=OFF

   4. Windows developers should install NSIS or WiX to create an install image with CPack.
      Visual Studio Express users will not be able to package HDF4 into
      an install image executable.

   5. Developers can copy the config/cmake/cacheinit.cmake file and alter the
      the settings for the developers' environment. Then the only options needed
      on the command line are those options that are different. Example using HDF
      default cache file:
           cmake -C ../config/cmake/cacheinit.cmake -G "Visual Studio 16 2019" \
               -DHDF4_ENABLE_SZIP_SUPPORT:BOOL=OFF -DHDF4_ENABLE_EXAMPLES:BOOL=OFF \
               -DCMAKE_BUILD_TYPE:STRING=Release ..

   6. CMake uses a toolchain of utilities to compile, link libraries and
      create archives, and other tasks to drive the build. The toolchain
      utilities available are determined by the languages enabled. In normal
      builds, CMake automatically determines the toolchain for host builds
      based on system introspection and defaults. In cross-compiling
      scenarios, a toolchain file may be specified with information about
      compiler and utility paths.
                Variables and Properties
      Several variables relate to the language components of a toolchain which
      are enabled. CMAKE_<LANG>_COMPILER is the full path to the compiler used
      for <LANG>. CMAKE_<LANG>_COMPILER_ID is the identifier used by CMake for
      the compiler and CMAKE_<LANG>_COMPILER_VERSION is the version of the compiler.

      The CMAKE_<LANG>_FLAGS variables and the configuration-specific equivalents
      contain flags that will be added to the compile command when compiling a
      file of a particular language.

      As the linker is invoked by the compiler driver, CMake needs a way to
      determine which compiler to use to invoke the linker. This is calculated
      by the LANGUAGE of source files in the target, and in the case of static
      libraries, the language of the dependent libraries. The choice CMake makes
      may be overridden with the LINKER_LANGUAGE target property.

      See the CMake help for more information on using toolchain files.

      To use a toolchain file with the supplied cmake scripts, see the
      HDF4options.cmake file under the toolchain section.

Notes: CMake and HDF4

   1. CMake support for HDF4 development should be usable on any
      system where CMake is supported. Please send us any comments on
      how CMake support can be improved on any system. Visit the
      Kitware site for more information about CMake.

   2. Build and test results can be submitted to our CDash server:
      The CDash server for community submissions of hdf is at
          https://my.cdash.org.

      We ask that all submissions include the configuration information and
      contact information in the CTest Notes Files upload step. See the
      current reports on CDash for examples.

      Please follow the convention that "NIGHTLY" submissions maintain the same
      configuration every time. "EXPERIMENTAL" submissions can be expected to
      be different for each submission.

   3. See the appendix at the bottom of this file for examples of using
      a ctest script for building and testing. Using a ctest script is
      preferred because of its flexibility.

Notes: CMake in General

   1. More information about using CMake can be found at the Kitware site at
         www.cmake.org.

   2. CMake uses the command line; however, the visual CMake tool is
      available for the configuration step. The steps are similar for
      all the operating systems supported by CMake.

   3. Setting the installation location from the command line at configure time
      a. Using the --install-prefix command line option, which is available since
         CMake version 3.21:
            cmake --install-prefix /my/folder/to/install/to ..
      b. Using -DCMAKE_INSTALL_PREFIX :
            cmake -DCMAKE_INSTALL_PREFIX=/my/folder/to/install/to ..
      c. Using the CMAKE_INSTALL_PREFIX environment variable, which is available
         since CMake version 3.29:
            CMAKE_INSTALL_PREFIX=/my/folder/to/install/to cmake ..

========================================================================
V. Options for Building HDF4 Libraries with the CMake Command Line
========================================================================

To build the HDF4 Libraries with CMake, go through these five steps:

   1. Run CMake
   2. Configure the cache settings
   3. Build HDF4
   4. Test HDF4
   5. Package HDF4 (create install image)

These five steps are described in detail below.

========================================================================

   1. Run CMake

      The visual CMake executable is named "cmake-gui.exe" on Windows and should be
      available in your Start menu. For Linux, UNIX, and Mac users the
      executable is named "cmake-gui" and can be found where CMake was
      installed.
      Another option is to use the presets file, CMakePresets.json, to configure,
      build, test, and package HDF4. See section VIII: Using CMakePresets.json for compiling
      for use of that file. You can create a CMakeUserPresets.json file to create a
      specific configuration for your environment. Note that Visual Studio and XCode can
      use the presets files.

      Specify the source and build directories.

      ***** Make the build and source directories different. ******

      For example on Windows, if the source is at c:\MyHDFstuff\hdf4,
      then use c:\MyHDFstuff\hdf4\build or c:\MyHDFstuff\build\hdf4 as the
      build directory.

      RECOMMENDED:
        Users can perform the configuration step without using the visual
        cmake-gui program. We use the file cacheinit.cmake in the
        config/cmake source folder for our testing. This file enables all of the
        basic options and we turn specific options on or off for testing
        using the following command line within the build directory:

        cmake -C <sourcepath>/config/cmake/cacheinit.cmake -G "<generator>"  [-D<options>]  <sourcepath>

        Where <generator> is
            * MinGW Makefiles
            * NMake Makefiles
            * Unix Makefiles
            * Ninja
            * Visual Studio 15 2017
            * Visual Studio 15 2017 Win64
            * Visual Studio 16 2019
            * Visual Studio 17 2022

        <options> is:
          For installed SZIP/libaec:
              * SZIP_INCLUDE_DIR:PATH=<path to szip includes directory>
              * SZIP_LIBRARY:FILEPATH=<path to szip/library file>
              * libaec_INCLUDE_DIR:PATH=<path to libaec includes directory>
              * libaec_LIBRARY:FILEPATH=<path to libaec/library file>
            or
              * SZIP_ROOT:PATH=<path to szip root directory>
              * libaec_ROOT:PATH=<path to libaec root directory>
          For installed ZLIB/ZLIBNG:
              * ZLIB_INCLUDE_DIR:PATH=<path to zlib includes directory>
              * ZLIB_LIBRARY:FILEPATH=<path to zlib/library file>
            or
              * ZLIB_ROOT:PATH=<path to zlib root directory>
          For installed JPEG:
              * JPEG_INCLUDE_DIR:PATH=<path to jpeg includes directory>
              * JPEG_LIBRARY:FILEPATH=<path to jpeg/library file>
            or
              * JPEG_ROOT:PATH=<path to jpeg root directory>

            * <HDF4OPTION>:BOOL=[ON | OFF]

        <cacheinit.cmake> is:
        # This is the CMakeCache file.
        ########################
        # EXTERNAL cache entries
        ########################
        set (CMAKE_INSTALL_FRAMEWORK_PREFIX "Library/Frameworks" CACHE STRING "Frameworks installation directory" FORCE)
        set (HDF_PACKAGE_EXT "" CACHE STRING "Name of HDF package extension" FORCE)
        set (HDF_PACKAGE_NAMESPACE "hdf4::" CACHE STRING "Name for HDF package namespace" FORCE)
        set (HDF4_BUILD_EXAMPLES ON CACHE BOOL "Build HDF4 Library Examples" FORCE)
        set (HDF4_BUILD_JAVA ON CACHE BOOL "Build HDF4 Java" FORCE)
        set (HDF4_BUILD_UTILS ON CACHE BOOL "Build HDF4 Library Utilities" FORCE)
        set (HDF4_BUILD_GENERATORS OFF CACHE BOOL "Build Test Generators" FORCE)
        set (HDF4_ENABLE_SZIP_SUPPORT ON CACHE BOOL "Use SZip Filter" FORCE)
        set (HDF4_ENABLE_SZIP_ENCODING ON CACHE BOOL "Use SZip Encoding" FORCE)
        set (HDF4_ALLOW_EXTERNAL_SUPPORT "TGZ" CACHE STRING "Allow External Library Building (NO GIT TGZ)" FORCE)
        set_property (CACHE HDF4_ALLOW_EXTERNAL_SUPPORT PROPERTY STRINGS NO GIT TGZ)
        
        ########################
        # compression options
        ########################
        set (ZLIB_PACKAGE_NAME "zlib" CACHE STRING "Name of ZLIB package" FORCE)
        set (ZLIB_TGZ_NAME "zlib-1.3.1.tar.gz" CACHE STRING "Use ZLib from compressed file" FORCE)
        set (ZLIB_TGZ_ORIGPATH "https://github.com/madler/zlib/releases/download/v1.3.1" CACHE STRING "Use ZLIB from original location" FORCE)
        set (ZLIB_USE_LOCALCONTENT ON CACHE BOOL "Use local file for ZLIB FetchContent" FORCE)
        set (ZLIB_GIT_URL "https://github.com/madler/zlib.git" CACHE STRING "Use ZLIB from  GitHub repository" FORCE)
        set (ZLIB_GIT_BRANCH "develop" CACHE STRING "" FORCE)
        set (HDF4_USE_ZLIB_NG OFF CACHE BOOL "Use zlib-ng library as zlib library" FORCE)
        set (ZLIBNG_PACKAGE_NAME "zlib-ng" CACHE STRING "Name of ZLIBNG package" FORCE)
        set (ZLIBNG_TGZ_NAME "2.2.4.tar.gz" CACHE STRING "Use ZLib from compressed file" FORCE)
        set (ZLIBNG_TGZ_ORIGPATH "https://github.com/zlib-ng/zlib-ng/archive/refs/tags" CACHE STRING "Use ZLIBNG from original location" FORCE)
        set (ZLIBNG_GIT_URL "https://github.com/zlib-ng/zlib-ng.git" CACHE STRING "Use ZLIBNG from  GitHub repository" FORCE)
        set (ZLIBNG_GIT_BRANCH "develop" CACHE STRING "" FORCE)
        set (LIBAEC_PACKAGE_NAME "libaec" CACHE STRING "Name of AEC SZIP package" FORCE)
        set (LIBAEC_TGZ_NAME "libaec-1.1.3.tar.gz" CACHE STRING "Use SZip AEC from compressed file" FORCE)
        set (LIBAEC_TGZ_ORIGPATH "https://github.com/MathisRosenhauer/libaec/releases/download/v1.1.3" CACHE STRING "Use LIBAEC from original location" FORCE)
        set (LIBAEC_USE_LOCALCONTENT ON CACHE BOOL "Use local file for LIBAEC FetchContent" FORCE)
        set (LIBAEC_GIT_URL "https://github.com/MathisRosenhauer/libaec.git" CACHE STRING "Use LIBAEC from  GitHub repository" FORCE)
        set (LIBAEC_GIT_BRANCH "v1.1.3" CACHE STRING "" FORCE)

        set (JPEG_PACKAGE_NAME "jpeg" CACHE STRING "Name of JPEG package" FORCE)
        set (JPEG_TGZ_ORIGPATH "https://www.ijg.org/filesz" CACHE STRING "Use JPEG from original location" FORCE)
        set (JPEG_TGZ_NAME "jpegsrc.v9e.tar.gz" CACHE STRING "Use JPEG from original compressed file" FORCE)
        set (JPEG_USE_LOCALCONTENT ON CACHE BOOL "Use local file for JPEG FetchContent" FORCE)
        set (JPEG_GIT_URL "https://github.com/libjpeg-turbo/libjpeg-turbo.git" CACHE STRING "Use JPEG from TurboJPEG" FORCE)
        set (JPEG_GIT_BRANCH "jpeg-9e" CACHE STRING "" FORCE)
        #set (JPEG_GIT_URL "https://github.com/LuaDist/libjpeg.git" CACHE STRING "Use JPEG from ILG" FORCE)
        #set (JPEG_GIT_BRANCH "master" CACHE STRING "" FORCE)

   2. Configure the cache settings

      2.1  Visual CMake users, click the Configure button. If this is the first time you are
           running cmake-gui in this directory, you will be prompted for the
           generator you wish to use (for example on Windows, Visual Studio 14).
           CMake will read in the CMakeLists.txt files from the source directory and
           display options for the HDF4 project. After the first configure you
           can adjust the cache settings and/or specify the locations of other programs.

           Any conflicts or new values will be highlighted by the configure
           process in red. Once you are happy with all the settings and there are no
           more values in red, click the Generate button to produce the appropriate
           build files.

           On Windows, if you are using a Visual Studio generator, the solution and
           project files will be created in the build folder.

           On linux, if you are using the Unix Makefiles generator, the Makefiles will
           be created in the build folder.

      2.2  Preferred command line example on Windows in c:\MyHDFstuff\hdf4\build directory:

               cmake -C ../config/cmake/cacheinit.cmake -G "Visual Studio 16 2019" "-Ax64" \
               -DHDF4_ENABLE_SZIP_SUPPORT:BOOL=OFF -DCMAKE_BUILD_TYPE:STRING=Release ..

      2.3  On Windows, if you are using a Visual Studio Express version you must
           be sure that the following two options are correctly set/unset:

           HDF4_NO_PACKAGES:BOOL=ON
           HDF4_USE_FOLDERS:BOOL=OFF

   3. Build HDF4

      On Windows, you can build HDF4 using either the Visual Studio Environment
      or the command line. The command line can be used on all platforms;
      Windows, linux, Unix, and Mac.

      To build from the command line, navigate to your build directory and
      execute the following:

              cmake --build . --config {Debug | Release}

      NOTE: "--config {Debug | Release}" may be optional on your platform. We
            recommend choosing either Debug or Release on Windows.

      3.1  If you wish to use the Visual Studio environment, open the solution
           file in your build directory. Be sure to select either Debug or
           Release and build the solution.

      3.2.1  The external libraries (zlib, szip, and jpeg) can be configured
           to allow building the libraries by downloading from a GIT repository.
           The option is 'HDF4_ALLOW_EXTERNAL_SUPPORT'; by adding the following
           configuration option:
               -DHDF4_ALLOW_EXTERNAL_SUPPORT:STRING="GIT"

           The options to control the GIT URL (config/cmake/cacheinit.cmake file) are:
               JPEG_GIT_URL:STRING="https://${git_url}/jpeg9e"
               JPEG_GIT_BRANCH="${git_branch}"
               ZLIB_GIT_URL:STRING="https://${git_url}/zlib"
               ZLIB_GIT_BRANCH="${git_branch}"
               SZIP_GIT_URL:STRING="https://${git_url}/szip"
               SZIP_GIT_BRANCH="${git_branch}"
               LIBAEC_GIT_URL:STRING="https://${git_url}/libaec"
               LIBAEC_GIT_BRANCH="${git_branch}"
           ${git_url} should be changed to your location and ${git_branch} is
           your branch in the repository. Also define CMAKE_BUILD_TYPE
           to be the configuration type.

      3.2.2  Or the external libraries (zlib, szip, and jpeg) can be configured
           to allow building the libraries by using a compressed file.
           The option is 'HDF4_ALLOW_EXTERNAL_SUPPORT' and is enabled by
           adding the following configuration option:
               -DHDF4_ALLOW_EXTERNAL_SUPPORT:STRING="TGZ"

           The options to control the TGZ URL (config/cmake/cacheinit.cmake
           file) are:
               JPEG_TGZ_NAME:STRING="jpeg_src.ext"
               ZLIB_TGZ_NAME:STRING="zlib_src.ext"
               LIBAEC_TGZ_NAME:STRING="libaec_src.ext"
               TGZPATH:STRING="some_location"
            where "some_location/xxxx_src.ext" is the URL or full path to
            the compressed file and where ext is the type of the compression
            file such as .bz2, .tar, .tar.gz, .tgz, or .zip. Also define
            CMAKE_BUILD_TYPE to be the configuration type.

           NOTE: the file named by LIBAEC_TGZ_NAME is used to build SZIP.

   4. Test HDF4

      To test the build, navigate to your build directory and execute:

              ctest . -C {Debug | Release}

      NOTE: "-C {Debug | Release}" may be optional on your platform. We
            recommend choosing either Debug or Release to match the build
            step on Windows.

   5. Packaging HDF4 (create an install image)

      To package the build into a simple installer using WiX toolset or the NullSoft installer NSIS
      on Windows, or into compressed files (.tar.gz, .sh, .zip), use the CPack tool.

      To package the build, navigate to your build directory and execute;

              cpack -C {Debug | Release} CPackConfig.cmake

      NOTE: See note 8 of this document for NSIS information.
            See note 9 of this document for WiX information.
            Also, if you are using a Visual Studio Express version or
            want to disable the packaging components, set HDF4_NO_PACKAGES
            to ON (on the command line add -DHDF4_NO_PACKAGES:BOOL=ON)

   6. The files that support building HDF4 with CMake are all the files in the
      config/cmake folder, the CMakeLists.txt files in each source folder, and
      CTestConfig.cmake. CTestConfig.cmake is specific to the internal testing
      performed by The HDF Group. It should be altered for the user's
      installation and needs. The cacheinit.cmake file settings are used by
      The HDF Group for daily testing. It should be altered/ignored for the user's
      installation and needs.

   7. More information about using CMake can be found at the Kitware site,
         www.cmake.org.

   8. Nullsoft Scriptable Install System
      The Nullsoft Scriptable Install System (NSIS) is an open source installation
      system. It was created by the WinAmp authors to distribute that application,
      but it is now a general-purpose system which anyone might use. NSIS installers
      recognize /S for silent installation and /D=dir to specify the
      "output directory", which is where the program will be installed. These
      options are case-sensitive, so be sure to type them in upper case.

   9. WiX Toolset
      WiX--the Windows Installer XML toolset--lets developers create installers for
      Windows Installer, the Windows installation engine. See http://wixtoolset.org.


========================================================================
VI. CMake Option Defaults for HDF4
========================================================================

In the options listed below, there are three columns of information:
Option Name, Option Description, and Option Default.
The config/cmake/cacheinit.cmake or CMakePresets.json file can override the following values.

---------------- General Build Options -------------------------------------
BUILD_SHARED_LIBS  "Build Shared Libraries"    ON
BUILD_STATIC_LIBS  "Build Static Libraries"    ON
BUILD_TESTING      "Build HDF4 Unit Testing"   ON

---------------- HDF4 Build Options ----------------------------------------
HDF4_BUILD_EXAMPLES        "Build HDF4 Library Examples"              OFF
HDF4_BUILD_FORTRAN         "Build FORTRAN support"                    OFF
HDF4_BUILD_TOOLS           "Build HDF4 Tools"                         ON
HDF4_BUILD_UTILS           "Build HDF4 Utilities"                     OFF
HDF4_ENABLE_NETCDF         "Build HDF4 versions of NetCDF-3 APIS"     ON
HDF4_BUILD_JAVA            "Build Java HDF Library"                   OFF
HDF4_BUILD_NETCDF_TOOLS    "Build HDF4 versions of ncdump and ncgen"  ON
HDF4_BUILD_STATIC_TOOLS    "Build Static Tools Not Shared Tools"      OFF

---------------- HDF4 Folder Build Options ---------------------------------
Defaults relative to $<INSTALL_PREFIX>
HDF4_INSTALL_BIN_DIR      "bin"
HDF4_INSTALL_LIB_DIR      "lib"
HDF4_INSTALL_INCLUDE_DIR  "include"
HDF4_INSTALL_MODULE_DIR   "mod"
HDF4_INSTALL_CMAKE_DIR    "cmake"
if (MSVC)
  HDF4_INSTALL_DATA_DIR   "."
else ()
  HDF4_INSTALL_DATA_DIR   "share"
HDF4_INSTALL_DOC_DIR      "HDF4_INSTALL_DATA_DIR"

HDF4_USE_GNU_DIRS              "ON to use GNU Coding Standard install directory variables,
                                OFF to use historical settings"                             OFF
Defaults as defined by the `GNU Coding Standards`
HDF4_INSTALL_BIN_DIR      "bin"
HDF4_INSTALL_LIB_DIR      "lib"
HDF4_INSTALL_INCLUDE_DIR  "include"
HDF4_INSTALL_MODULE_DIR   "HDF4_INSTALL_INCLUDE_DIR/mod"
HDF4_INSTALL_CMAKE_DIR    "HDF4_INSTALL_LIB_DIR/cmake"
HDF4_INSTALL_DATA_DIR     "share"
HDF4_INSTALL_DOC_DIR      "HDF4_INSTALL_DATA_DIR/doc/hdf"

---------------- HDF4 Advanced Options ---------------------
HDF4_ONLY_SHARED_LIBS               "Only Build Shared Libraries"                                     OFF
HDF4_DISABLE_COMPILER_WARNINGS "Disable compiler warnings"                                       OFF
HDF4_ENABLE_COVERAGE           "Enable code coverage for Libraries and Programs"                 OFF
HDF4_ENABLE_DEPRECATED_SYMBOLS "Enable deprecated public API symbols"                            ON
HDF4_ENABLE_LARGE_FILE         "Enable support for large (64-bit) files on Linux."               ON
HDF4_NO_PACKAGES               "Do not include CPack Packaging"                                  OFF
HDF4_PACKAGE_EXTLIBS           "CPACK - include external libraries"                              OFF
HDF4_USE_FOLDERS               "Enable folder grouping of projects in IDEs."                     OFF
HDF4_MSVC_NAMING_CONVENTION    "Use MSVC Naming conventions for Shared Libraries"                OFF
HDF4_MINGW_STATIC_GCC_LIBS     "Statically link libgcc/libstdc++"                                OFF
if (APPLE)
    HDF4_BUILD_WITH_INSTALL_NAME "Build with library install_name set to the installation path"  OFF
if (WIN32)
    HDF_LEGACY_NAMING          "Use Legacy Names for Libraries and Programs"   OFF
HDF4_ENABLE_NETCDF             "Build HDF4 versions of NetCDF-3 APIS"          ON
HDF4_BUILD_DOC                 "Build documentation"                           OFF
HDF4_ENABLE_DOXY_WARNINGS      "Enable fail if doxygen parsing has warnings."  OFF
HDF4_USING_ANALYSIS_TOOL       "Indicate that an analysis checker is used"     ON

---------------- External Library Options ---------------------
HDF4_ALLOW_EXTERNAL_SUPPORT    "Allow External Library Building"         "NO"
HDF4_ENABLE_SZIP_SUPPORT       "Use SZip Filter"                         OFF

JPEG_USE_EXTERNAL              "Use External Library Building for JPEG"  OFF
JPEG_TGZ_ORIGPATH              "Use JPEG from original location"         "https://www.ijg.org/filesz"
JPEG_TGZ_NAME                  "Use JPEG from original compressed file"  "jpegsrc.v9e.tar.gz"
JPEG_USE_LOCALCONTENT          "Use local file for JPEG FetchContent"    OFF

if (HDF4_USE_ZLIB_NG)
    ZLIBNG_USE_EXTERNAL     "Use External Library Building for ZLIBNG"      OFF
    ZLIBNG_TGZ_ORIGPATH     "Use ZLIBNG from original location"             "https://github.com/zlib-ng/zlib-ng/releases/tag/2.2.2"
    ZLIBNG_TGZ_NAME         "Use ZLIBNG from original compressed file"      "2.2.2.tar.gz"
else
    ZLIB_USE_EXTERNAL       "Use External Library Building for ZLIB"        OFF
    ZLIB_TGZ_ORIGPATH       "Use ZLIB from original location"               "https://github.com/madler/zlib/releases/download/v1.3.1"
    ZLIB_TGZ_NAME           "Use ZLIB from original compressed file"        "zlib-1.3.1.tar.gz"
ZLIB_USE_LOCALCONTENT       "Use local file for ZLIB FetchContent"          ON
HDF4_USE_ZLIB_STATIC        "Find static zlib library"                      OFF

SZIP_USE_EXTERNAL           "Use External Library Building for SZIP"        OFF
if (HDF4_ENABLE_SZIP_SUPPORT)
    HDF4_ENABLE_SZIP_ENCODING "Use SZip Encoding"                           OFF
LIBAEC_TGZ_ORIGPATH         "Use LIBAEC from original location"             "https://github.com/MathisRosenhauer/libaec/releases/download/v1.1.3"
LIBAEC_TGZ_NAME             "Use LIBAEC from original compressed file"      "libaec-1.1.3.tar.gz"
LIBAEC_USE_LOCALCONTENT     "Use local file for LIBAEC FetchContent"        ON
HDF4_USE_LIBAEC_STATIC      "Find static AEC library"                       OFF

NOTE:
  The HDF4_USE_GNU_DIRS option is usually recommended for linux platforms, but may
  be useful on other platforms. See the CMake documentation for more details.

========================================================================
VII. User Defined Options for HDF4 Libraries with CMake
========================================================================

Support for User Defined macros and options has been added. The file
UserMacros.cmake has an example of the technique.

Replace the template code with your macro in the UserMacros.cmake file.
Then enable the option to the CMake configuration, build and test process.


========================================================================
VIII:    Using CMakePresets.json for Compiling
========================================================================

One problem that CMake users often face is sharing settings with other people for common
ways to configure a project. This may be done to support CI builds, or for users who
frequently use the same build. CMake supports two main files, CMakePresets.json and CMakeUserPresets.json,
that allow users to specify common configure options and share them with others. CMake also supports
files included with the include field.

CMakePresets.json and CMakeUserPresets.json live in the project's root directory. They
both have exactly the same format, and both are optional (though at least one must be
present if --preset is specified). CMakePresets.json is meant to specify project-wide build
details, while CMakeUserPresets.json is meant for developers to specify their own local build details.

See CMake documentation for details: https://cmake.org/cmake/help/latest/manual/cmake-presets.7.html

HDF-provided CMakePresets.json
-------------------------------
The CMakePresets.json provided by HDF requires CMake version 3.25, which supports package
and workflow presets, and ninja build system. The top-level configuration group is intended to be
a standard set of options to produce a package of shared and staic libraries and tools. Other configurations
used for inheriting settings are in the included json file in "config/cmake-presets/hidden-presets.json".

Available configurations presets can be displayed by executing:
    cmake -S <path-to-source> --list-presets

Using individual command presets (where <compiler-type> is  GNUC or MSVC or Clang):
    change directory to the hdf4 source folder
    cmake --preset ci-StdShar-<compiler-type>
    cmake --build --preset ci-StdShar-<compiler-type>
    ctest --preset ci-StdShar-<compiler-type>
    cpack --preset ci-StdShar-<compiler-type>

Using the workflow preset to configure, build, test and package the standard configuration:
    change directory to the hdf4 source folder
    execute "cmake --workflow --preset ci-StdShar-<compiler-type> --fresh"
          where <compiler-type> is  GNUC or MSVC or Clang

Creating your own configurations
--------------------------------
The quickest way is to copy CMakePresets.json to CMakeUserPresets.json and
edit CMakeUserPresets.json configuration names from ci-* to my-*. Change the
"configurePresets" section "inherits" field only for those that you have alternate
options. Then change the "configurePreset" field entries in the "buildPresets",
"testPresets", "packagePresets" sections to match your my-StdShar-<compiler-type>.
And finally the names settings in the "workflowPresets" steps will also need the ci-* to my-* change.

For instance, to change the support files to use a local directory, edit CMakeUserPresets.json:
......
    {
      "name": "my-base-tgz",
      "hidden": true,
      "inherits": "ci-base",
      "cacheVariables": {
        "HDF4_ALLOW_EXTERNAL_SUPPORT": {"type": "STRING", "value": "TGZ"},
        "TGZPATH": {"type": "PATH", "value": "${sourceParentDir}/temp"}
      }
    },
    {
      "name": "my-StdCompression",
      "hidden": true,
      "inherits": "my-base-tgz",
      "cacheVariables": {
......
   {
      "name": "my-StdShar",
      "hidden": true,
      "inherits": "my-StdCompression",
      "cacheVariables": {
......
    {
      "name": "my-StdShar-GNUC",
      "description": "GNUC Standard Config for x64 (Release)",
      "inherits": [
        "ci-x64-Release-GNUC",
        "ci-Java",
        "my-StdShar",
        "my-StdExamples"
      ]
    }
......


Then you can change or add options for your specific case.

========================================================================
IX. Using the Library
========================================================================
    For information on using HDF4 see the documentation, tutorials and examples
    found here:

       https://support.hdfgroup.org/documentation/index.html

    A summary of the features included in the built HDF4 installation can be found
    in the libhdf4.settings file in the same directory as the static and/or
    shared HDF5 libraries. However CMake provides a programmable method to
    determine the features of the library. The CMake installation will
    provide a CMake package configuration file, located in the installation folder,
    cmake/hdf4-config.cmake, and can be used to determine the features of the library.
    The file is accessed by using the find_package command in your CMakeLists.txt file.

   1. Set the HDF5_ROOT CMake variable, -DHDF4_ROOT=<install_path>
      or environment variable, set(ENV{HDF4_ROOT} "<install_path>")
      to the installed location of HDF4.
         On Windows:
            HDF4_ROOT=C:/Program Files/HDF_Group/HDF4/z.y.x/
         On unix:
            HDF4_ROOT=<install root folder>/HDF_Group/HDF4/z.y.x/

      If you are using shared libraries, you may need to add to the path
      environment variable. Set the path environment variable to the
      installed location of the library files for HDF4.
         On Windows (*.dll):
            PATH=%PATH%;C:/Program Files/HDF_Group/HDF4/z.y.x/bin
         On unix (*.so):
            LD_LIBRARY_PATH=$LD_LIBRARY_PATH:<install root folder>/HDF_Group/HDF4/z.y.x/lib

      (Note there are no quote characters used on Windows and all platforms
      use forward slashes)

   2. Add the following to your CMakeLists.txt file:
        find_package (HDF4 NAMES hdf4 COMPONENTS  C shared)

      The components are optional and can be omitted if not needed. The
      components are: shared, static, C, Fortran, Java and Tools.


========================================================================
X. Autotools Configuration and Build
========================================================================
See RELEASE.txt in the release_notes/ directory for the list of platforms 
tested for this release.

Instructions for building and testing HDF4 using autotools can be found in the
INSTALL_Auto.txt file found in this folder.


========================================================================
For further assistance, send email to help@hdfgroup.org
========================================================================