====== Compiling and running Doomsday 2.0–2.3 with CMake ======

Doomsday 2 is built with [[https://cmake.org|CMake]] 3.1 (or later).

===== Get the source =====

There are a couple of ways to get the source code:

  * Download a [[http://dengine.net/source|source package]]. 
  * Check out the [[https://github.com/skyjake/Doomsday-Engine|Doomsday-Engine]] repository from GitHub: <code bash>git clone --recursive https://github.com/skyjake/Doomsday-Engine</code> You can then switch to any release or a specific build via tags. Stable releases are tagged "release-x.y.z".

===== Install dependencies =====

The following libraries are required for compilation:

  * Qt 5 (modules: Core, Network, Gui, OpenGLExtensions, Widgets)
  * Qt 5 X11Extras module (on Unix/X11)
  * DirectX (on Windows)

The following are optional:

  * SDL 2 (joystick support)
  * SDL_mixer 2 (audio plugin)
  * FMOD Studio Low-Level Programmer API for Doomsday 2.1+, or FMOD Ex for  Doomsday 2.0 or earlier (audio plugin)
  * OpenAL (audio plugin)
  * libXrandr and libXxf86vm (X11 display mode support)

===== Create build directory =====

You must create a separate directory that is used for the build files. In-tree builds are not supported.
===== Build and deploy =====

After the dependencies are available, run CMake and configure the appropriate build variables. The following variables are noteworthy:

  * Normally you will want to set the ''CMAKE_BUILD_TYPE'' to "Release". Note that with gcc/clang, omitting this variable will result in an unoptimized build.
  * Set the ''DE_PREFIX'' variable to define the installation root path.
  * Set the ''QMAKE'' variable to the path of the qmake tool to use (unless autodetected). This determines which version of Qt will be used in the build.
  * ''DENG_ENABLE_*'' are used for enabling and disabling Doomsday features.
  * ''*_DIR'' (e.g., ''FMOD_DIR'') are used for configuring locations of third-party libraries.

When CMake has configured the build successfully, run your chosen build tool.

After building, you must still deploy the binaries (e.g., using ''make install'') because Doomsday expects a particular runtime directory layout.