Minecraft-Overviewer/docs/building.rst

===================================
Building the Overviewer from Source
===================================

These instructions are for building the C extension for Overviewer. Once you
have finished with these instructions, head to :doc:`running`.

.. note::

    Pre-built Windows and Debian executables are available on the
    :doc:`installing` page.  These kits already contain the compiled code and
    require no further setup, so you can skip to the next section of the docs:
    :doc:`running`.

Get The Source
==============

First step: download the platform-independent source! Either clone with Git
(recommended if you know Git) or download the most recent snapshot

* Git URL to clone: ``git://github.com/overviewer/Minecraft-Overviewer.git``
* `Download most recent tar archive <https://github.com/overviewer/Minecraft-Overviewer/tarball/master>`_

* `Download most recent zip archive <https://github.com/overviewer/Minecraft-Overviewer/zipball/master>`_

Once you have the source, see below for instructions on building for your
system.

Build Instructions For Various Operating Systems
================================================

.. contents::
    :local:

Windows Build Instructions
--------------------------

First, you'll need a compiler.  You can either use Visual Studio, or
cygwin/mingw. The free `Visual Studio Community
<https://www.visualstudio.com/vs/community/>`_ is okay. You will need to select the "Desktop Development with C++" WORKLOAD. Microsoft has been changing up the names on this with the "Community" edition of Visual Studio. If nothing else works, just install every Individual Visual C++ component you can find :)


Prerequisites
~~~~~~~~~~~~~

You will need the following:

- `Python 2.7 <https://www.python.org/downloads/windows/>`_
- A copy of the `Pillow sources <https://github.com/python-pillow/Pillow>`_.
- The Pillow Extension for Python.
- The Numpy Extension for Python.
- The extensions can be installed via::

    c:\python27\python.exe -m pip -U numpy pillow


Building with Visual Studio
~~~~~~~~~~~~~~~~~~~~~~~~~~~

1. Get the latest Overviewer source code as per above.
2. From the Start menu, navigate to 'Visual Studio 2017' and open the **'Developer Command Prompt for VS 2017'** (*or whatever year*) shortcut. A regular command or powershell prompt will *NOT* work for this.
3. cd to the folder containing the Overviewer source code.
4. Copy Imaging.h and ImPlatform.h from your Pillow sources into the current working directory.
5. First try a build::

    c:\python27\python setup.py build

If you encounter the following errors::

    error: Unable to find vcvarsall.bat

then try the following::

    set DISTUTILS_USE_SDK=1
    set MSSdk=1
    c:\python27\python setup.py build

If the build was successful, there should be a c_overviewer.pyd file in your current working directory.

Building with mingw-w64 and msys2
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

This is the recommended way to build on Windows without MSVC.

1. Install msys2 by following **all** the instructions on 
   `the msys2 installation page <https://msys2.github.io/>`_.

2. Install the dependencies::

    pacman -S git mingw-w64-x86_64-python2-numpy mingw-w64-x86_64-python2-Pillow mingw-w64-x86_64-python2 mingw-w64-x86_64-toolchain

3. Clone the Minecraft-Overviewer git repository::

    git clone https://github.com/overviewer/Minecraft-Overviewer.git

   The source code will be downloaded to your msys2 home directory, e.g.
   ``C:\msys2\home\Potato\Minecraft-Overviewer``

4. Close the msys2 shell. Instead, open the MinGW64 shell.

5. Build the Overviewer by changing your current working directory into the source
   directory and executing the build script::

    cd Minecraft-Overviewer
    python2 setup.py build

After it finishes, you should now be able to execute ``overviewer.py`` from the MINGW64
shell.

Building with mingw
~~~~~~~~~~~~~~~~~~~

1. Open a MinGW shell.
2. cd to the Overviewer directory.
3. Copy Imaging.h and ImPlatform.h from your Pillow sources into the current working directory.
4. Build::

    python setup.py build --compiler=mingw32
    
If the build fails with complaints about ``-mno-cygwin``, open the file ``Lib/distutils/cygwincompiler.py``
in an editor of your choice, and remove all mentions of ``-mno-cygwin``. This is a bug in distutils,
filed as `Issue 12641 <http://bugs.python.org/issue12641>`_. 


Linux
-----

You will need the gcc compiler and a working build environment. On Ubuntu and
Debian, this can be done by installing the ``build-essential`` package.

You will need the following packages (at least):

* python-imaging or python-pillow
* python-imaging-dev or python-pillow-dev
* python-dev
* python-numpy

Then to build::

    python2 setup.py build
    
At this point, you can run ``./overviewer.py`` from the current directory, so to run it you'll have to be in this directory and run ``./overviewer.py`` or provide the the full path to ``overviewer.py``.  Another option would be to add this directory to your ``$PATH``.   Note that there is a ``python2 setup.py install`` step that you can run which will install things into ``/usr/local/bin``, but this is strongly not recommended as it might conflict with other installs of Overviewer.

OSX
---

.. note::

    You will need to have XCode and the XCode Command Line Tools installed (the
    Command Line Tools can be installed by going to the Downloads tab under the
    Xcode Preferences dialog).

1. Download the source code for PIL from http://www.pythonware.com/products/pil/
2. Compile the PIL code (``python2 ./setup.py build``)
3. Install PIL (``sudo python2 ./setup.py install``)
4. Find the path to the ``libImaging`` directory in the PIL source tree.
5. Build Minecraft Overviewer with the path from step 4 as the value for PIL_INCLUDE_DIR::

    PIL_INCLUDE_DIR="path from step 4" python2 ./setup.py build

The following script (copied into your MCO source directory) should handle everything for you:

.. code-block:: bash

    #!/bin/bash

    # start with a clean place to work
    python2 ./setup.py clean

    # get PIL
    if [ ! -d "`pwd`/Imaging-1.1.7/libImaging" ]; then
        /usr/bin/curl -o imaging.tgz http://effbot.org/media/downloads/Imaging-1.1.7.tar.gz
        tar xzf imaging.tgz
        rm imaging.tgz
    fi

    # build MCO
    PIL_INCLUDE_DIR="`pwd`/Imaging-1.1.7/libImaging" python2 ./setup.py build

FreeBSD
-------
FreeBSD is similar to OSX and Linux, but ensure you're using Python 2.7. The port of Python 2.6 has bugs with threading under FreeBSD.
Everything else you should need is ported, in particular math/py-numpy and graphics/py-imaging.

You may need or want to add the line::

    PYTHON_VERSION=2.7

to the file /etc/make.conf, but read the ports documentation to be sure of what this might do to other Python applications on your system.