.. Watlab documentation file, created by
   Pierre-Yves Gousenbourger on Wed Aug 2, 2023.

.. _compile:

Compile the code
================

There are two ways to compile the code : directly with the C++ compiler or with `CMake <https://cmake.org/>`_. We highly recommand CMake as it is system independant.
It it recommended to use C++20 (C++17 accepted). There is no backward compatibility for older versions.

Note that the python library for Watlab permits to run the code without hitting the following nauseous lines. Check our :ref:`Tutorials <run-watlab>` for more information.

.. _Cmake-install:

Build the code with CMake
-------------------------

Make sure you installed `CMake <https://cmake.org/>`_ properly.
Open a shell and hit the two following command.

.. code-block::
   
   cmake -S . -B _build/
   cmake --build _build

The code will generate by itself and the executables will be created in `bin/` (for programs) and in `tests/` for test executables.

On **windows**, you may need to specify the C++ Makefiles. If you installed MinGW as recommended in this documentation, you should hit 

.. code-block::
   
   cmake -S . -G "MinGW Makefiles" -B _build/
   cmake --build _build/


To help you, we created scripts in `scripts/`. It is called `scripts/Build-Binaries`.


.. _with-the-compiler:

Compile the code with the C++ compiler
--------------------------------------
   
The command lines to create the cpp code without parallelization is

.. code-block::
   
   g++ -o hydroflow src/cpp/*.cpp src/cpp/writer/*.cpp src/cpp/physicalmodels/*.cpp src/cpp/interfaces/*.cpp src/cpp/helpers/*.cpp -std=c++20


This will create an executable hydroflow.exe.

To compile the code with parallelization, make sure that :ref:`OpenMP <install-openmp>` is installed with your compiler. Now hit the following lines

.. code-block::
   
   g++ -O3 -fopenmp -pthread -o hydroflow src/cpp/*.cpp src/cpp/writer/*.cpp src/cpp/physicalmodels/*.cpp src/cpp/interfaces/*.cpp src/cpp/helpers/*.cpp -std=c++20

This will create an executable hydroflow.exe, but now it is parallelizable.
If no error is thrown, you have successfully compiled the code.



Execute the code
================

When your `data.json` is exported, you can directly execute the C++ code as follows

.. code-block::

   ./hydroflow -f path/to/data.json

If you wish no verbose, you can also add the command ``-nodisplay`` to your line:

.. code-block::

   ./hydroflow -f path/to/data.json -nodisplay