The FreeCAD source code is commented to allow automatic programming documentation generation using Doxygen, a popular source code documentation system. Doxygen can document both the C++ and Python parts of FreeCAD, resulting in HTML pages with hyperlinks to each documented function and class.
Compiling the API documentation follows the same general steps as compiling the FreeCAD executable, as indicated in the Compile on Linux page.
General workflow to compile FreeCAD's programming documentation. The Doxygen and Graphviz packages must be in the system, as well as the FreeCAD source code itself. CMake configures the system so that with a single make instruction the documentation for the the entire project is compiled into many HTML files with diagrams.
Build source documentation
If you have Doxygen installed, it is very easy to build the documentation. Also install Graphviz to be able to produce diagrams showing the relationships between different classes and libraries in the FreeCAD code. Graphviz is also used by FreeCAD's dependency graph to show the relationships between different objects.
sudo apt install doxygen graphviz
Then follow the same steps you would do to compile FreeCAD, as described on the compile on Linux page, and summarized here for convenience.
- Get the source code of FreeCAD and place it in its own directory
- Create another directory
freecad-buildin which you will compile FreeCAD and its documentation.
- Configure the sources with
cmake, making sure you indicate the source directory, and specify the required options for your build.
- Trigger the creation of the documentation using
git clone https://github.com/FreeCAD/FreeCAD.git freecad-source mkdir freecad-build cd freecad-build cmake -DBUILD_QT5=ON -DPYTHON_EXECUTABLE=/usr/bin/python3 ../freecad-source
While you are inside the build directory issue the following instruction to create only the documentation.
make -j$(nproc --ignore=2) DevDoc
As mentioned in compiling (speeding up), the
-j option sets the number of CPU cores used for compilation. The resulting documentation files will appear in the directory
The point of entrance to the documentation is the
index.html file, which you can open with a web browser:
DevDoc target will generate a significant amount of data, around 5 GB of new files, particularly due to the diagrams created by Graphviz.
The complete documentation uses around 3Gb of disk space. An alternative, smaller version of the documentation which takes only around 600 MB can be generated with a different target. This is the version displayed on the FreeCAD API website.
make -j$(nproc --ignore=2) WebDoc
- Fork the repo at https://github.com/FreeCAD/SourceDoc
- on your machine: clone the FreeCAD code (if you haven't yet), create a build dir for the doc, and clone the above SourceDoc repo inside. That SourceDoc will be updated when you rebuild the doc, and you'll be able to commit & push the results afterwards:
git clone https://github.com/FreeCAD/FreeCAD cd FreeCAD mkdir build cd build mkdir -p doc/SourceDocu/html cd doc/SourceDocu/html git clone your-fork-url cd ../../.. cmake -DBUILD_QT5=ON -DPYTHON_EXECUTABLE=/usr/bin/python3 .. make WebDoc cd doc/SourceDocu/html git commit git push
- Go to your fork online, and create a pull request.
Integrate Coin3D documentation
On Unix systems it is possible to link Coin3D source documentation with FreeCAD's. This allows for easier navigation and complete inheritance diagrams for Coin derived classes.
- Install the
libcoin80-doc, or similarly named package.
- Unpack the archive
/usr/share/doc/libcoin-doc/html; the files may be already unpacked in your system.
- Generate again the source documentation.
If you don't install the documentation package for Coin, the links will be generated to access the online documentation at BitBucket. This will happen if a Doxygen tag file can be downloaded at configure time with
See the Doxygen page for an extensive explanation on how to comment C++ and Python source code so that it can be processed by Doxygen to automatically create the documentation.
Essentially, a comment block, starting with
/// for C++, or
## for Python, needs to appear before every class or function definition, so that it is picked up by Doxygen. Many special commands, which start with
@, can be used to define parts of the code and format the output. Markdown syntax is also understood within the comment block, which makes it convenient to emphasize certain parts of the documentation.
/** * Returns the name of the workbench object. */ std::string name() const; /** * Set the name to the workbench object. */ void setName(const std::string&); /// remove the added TaskWatcher void removeTaskWatcher(void);