Editing Installing STIR with CMake (section)

== Launching CMake==
=== Setting your environment ===
You might need to set your environment correctly first such that CMake finds the correct libraries etc. Examples are
* [https://docs.python.org/3/tutorial/venv.html Python virtual environments] (e.g. via <tt>conda activate</tt> or similar)
* The CERN ROOT library for GATE simulations comes with a [https://github.com/root-project/root/blob/master/config/thisroot.sh thisroot.sh] (or.csh) script that needs to be sourced.

This step is not strictly necessary, as it is also possible to set the location of any libraries/include files in the CMake Configuration step, but this tends to be harder work.

=== Using the CMake GUI ===

If you have Windows or MacOSX, ''CMake'' comes as an application with a nice GUI. For
Unix/linux users, you get that by installing ''cmake-gui''.


Please note that if you launch CMake from your desktop environment, you will have to make sure that any configuration from the previous section is available to such applications (which usually isn't the case). It might be best to launch ''cmake-gui'' from the command line.

After launching it, you
first select the source directory (''STIR'', <b>not</b> ''STIR/src'') and then a build directory. It's recommended to build one level up from STIR. Call it anything you like,  e.g. STIR-bin. 

On Unix/Linux you will probably be using ''make'' to build things. When using ''make'', you want different build directories for every type of build (Debug or Release) you want to make. For systems using an IDE (e.g. Windows with Visual Studio or MacOS with XCode, Linux with eclipse), you can build different versions from one CMake build directory.

=== From a terminal window ===
On Unix/linux, cygwin or MacOSX, you can also launch ''CMake'' from a terminal window. In that case,
you will have to use a slightly more basic user interface. You would launch this as follows.
<pre>
cd /wherever/it/is/STIR
cd ..
mkdir STIR-bin
cd STIR-bin
mkdir Release
cd Release
ccmake ../../STIR
</pre>
If you want to use a non-default compiler,
please check [http://www.cmake.org/Wiki/CMake_FAQ%23How_do_I_use_a_different_compiler.3F the CMake FAQ on how to use a different compiler].

=== Special cases for Windows ===
In some very special cases, you will need to let CMake find non-standard libraries or executables. Most people will not need this, but if you do, please check [[Using CMake on Windows with special requirements]].