# Building the Overviewer from Source

These instructions are for building the C extension for Overviewer. Once you have finished with these instructions, head to Running the Overviewer.

Note

Pre-built Windows and Debian executables are available on the 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: Running the Overviewer.

## 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

- Download most recent zip archive

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

## Build Instructions For Various Operating Systems

- Windows Build Instructions

  - Prerequisites

  - Building with Visual Studio

  - Building with mingw-w64 and msys2

  - Building with mingw

- Linux

- macOS

### Windows Build Instructions

First, you’ll need a compiler. You can either use Visual Studio, or cygwin/mingw. The free Visual Studio 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 3.x

- A copy of the Pillow sources.

- The Pillow Extension for Python.

- The Numpy Extension for Python.

- The extensions can be installed via:

      c:\python37\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:\python37\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:\python37\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.

2. Install the dependencies:

       pacman -S git mingw-w64-x86_64-python3-numpy mingw-w64-x86_64-python3-Pillow mingw-w64-x86_64-python3 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
       python3 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:

       python3 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.

### 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 on Debian-derived distributions (e.g. Ubuntu):

- python3-pil or python3-pillow (the latter is usually aliased to the former)

- python3-dev

- python3-numpy

Note

If you choose to install pillow through pip instead of your distribution’s package manager, you won’t get the pillow headers which Overviewer requires to build its C extension. In that case, you should manually download the header files specific to the version of pillow you installed, and point at them with the `PIL_INCLUDE_DIR` environment variable. A version mismatch between the installed pillow library and the headers can lead to segfaults while running Overviewer due to an ABI mismatch.

Then to build:

    python3 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 `python3 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.

### macOS

1. Install the Xcode Command Line Tools by running the following command in a terminal (located in your /Applications/Utilities folder):

       xcode-select --install

2. Install Python 3 if you don’t already have it, for example from the official Python website.

3. Install PIP, e.g. with:

       sudo easy_install pip

4. Install Pillow (overviewer needs PIL, Pillow is a fork of PIL that provides the same functionality):

       pip install Pillow

5. Install numpy:

       pip install numpy

6. Download the Pillow source files from https://github.com/python-pillow/Pillow/releases/latest and unpack the tar.gz file and move it to a directory you can remember

7. Download the Minercaft Overviewer source-code from https://overviewer.org/builds/overviewer-latest.tar.gz

8. Extract overviewer-[Version].tar.gz and move it to a directory you can remember

9. Go into your Pillow-[Version] folder and navigate to the /src/libImaging directory

10. Drag the following files from the Pillow-[Version]/src/libImaging folder to your overviewer-[Version] folder:

> - `Imaging.h`

> - `ImagingUtils.h`

> - `ImPlatform.h`

1. Make sure your installation of Python 3 is in `$PATH`

2. In a terminal, change your current working directory to your overviewer-[Version] folder (e.g. by using `cd Desktop/overviewer-[Version]`)

3. Build:

       python3 setup.py build

You should now be able to run Overviewer with `./overviewer.py` inside of the Overviewer directory.