Hacking opentrack

This article describes source code layout and entry points for developers. Grab an IDE with cross-referencing support or at least ctags. I recommend Qt Creator 4.2+ without the Clang module.

I heavily recommend using an IDE or an editor with cross-referencing support (jump to function/class, find all usages). Otherwise navigating through the opentrack code is a real nightmare.

Input, output, and filters

Trackers, filters, and protocols are defined as tracker-*, filter-*, and proto-*. They expose just a few symbols that are in turn used by plugin support code. Interfaces to be implemented by those three are included in api/plugin-api.hpp. The file is heavily commented.

Core code

• To invoke opentrack plugins, include api/plugin-support.hpp. This is header-only, requiring no additional C++ dependencies other than Qt.
• Dependencies other than Qt are included in the opentrack-depends repository. Clone the submodules, there are a few.
• Logic of sending data through tracker -> filter -> protocol pipeline is defined in logic/pipeline.cpp.
• Software logic that isn't purely user interface is defined the logic/ directory.
• Main form of the user interface is defined in variant/default/main-window.cpp. Most user interface forms are in the gui/ subdirectory.
• State of tracking operation while it's running is contained in logic/work.hpp. See also logic/state.hpp for state that persists while the software is running.
• Support for connecting configuration to user interface is contained in options/options.hpp.
• Migrations are for settings getting moved or changing meaning. See migration/.

To be continued.