Requirements
============
You should be able to build OpenClonk with any C++ compiler that supports
ISO C++14. That said, on Windows, we recommend using Microsoft Visual C++
2015 or higher; the Express edition will be sufficient. On Linux, you will
be fine with GNU g++ 4.9 or later. Apple users should use a clang-based
XCode version.

To generate project files for your chosen build system, you will also have to
install CMake from http://www.cmake.org/.

Additionally, OpenClonk depends on a number of third-party libraries:
  - zlib (http://zlib.net/)
  - libpng (http://www.libpng.org/pub/png/libpng.html)
  - libjpeg-turbo (http://sourceforge.net/projects/libjpeg-turbo/files/)
  - FreeType (http://www.freetype.org/)
  - The OpenGL Extension Wrangler Library (http://glew.sourceforge.net/)
  - FreeALUT (https://github.com/vancegroup/freealut)
  - libogg and libvorbis (https://www.xiph.org/downloads/)
  - Qt >= 5.7 (https://www.qt.io/download-open-source/)

OS X Specific
=============
OpenClonk supports OS X versions 10.8 "Mountain Lion" and later.
If you are using brew (https://github.com/mxcl/homebrew) or MacPorts
(http://www.macports.org/), the packages you'll have to install are:
    libjpeg, libpng, freetype, glew, libogg, libvorbis

Linux Specific
==============
For building OpenClonk on Linux, you need the following libraries in addition
to the ones listed above:
  - SDL 2.0 (https://www.libsdl.org/download-2.0.php)
  - libGL (http://www.mesa3d.org/)
  - OpenAL Soft >= 1.13 (https://github.com/kcat/openal-soft)
  - miniupnpc (http://miniupnp.free.fr/)
  - libxrandr
Most distributions should provide these dependencies via their packaging
system. At least gcc-4.9 is required.

Windows Specific
================
In addition to the libraries above, you will need one more if you want to
target Windows:
  - OpenAL Soft (http://kcat.strangesoft.net/openal.html)
To create an installer, you will also need the Nullsoft Install System
(http://nsis.sourceforge.net/). To create the installer, build the "setup" target.
