C/C++ bindings to the Real Virtuality engine
Intercept is a C/C++ binding interface to the Arma 3 engine (internally refered to as the Real Virtuality or RV engine). It's goal is to provide easy to use library for addon makers to develop addons in a native language, or to develope language extensions for the Arma 3 engine.
In a nutshell, Intercept provides a full C/C++ binding system for calling the base C++ functions which are declared in RVEngine for SQF functions. All SQF functions within the RVEngine are actually native code, which is called by SQF via the function names. Intercept bypasses SQF entirely, allowing native C++ plugins to seamlessly interact with the game engine. In essense, Intercept allows for expansions of the game engine, calling internal functionality of the engine which is exposed to SQF via functions.
So how does it work?
Intercept works on a host/client based system, in which the host, Intercept itself, hosts client DLLs that implement the Intercept library.
The Intercept host handles access to the RV engine by clients through a layer that provides thread concurrency, memory handling, and event dispatching.
Client DLLs are then able to be written in a way that can safely ignore most internal nuances of handling data in the RV engine and work with standard C++ STD/STL data types,
and only a few specialized objects (all of which are wrapped in
std::shared_ptr to properly handle memory releasing).
The intercept library also provides raw C bindings to the C++ versions of SQF functions, so it is entirely possible to use Intercept as the basis for writing in additional scripting languages to the RV engine, such as Python or Lua.
You can find a basic tutorial on how to build and install Intercept on our wiki.
The underlying game engine of ArmA 3. This is the core of the game, which performs simulations and manages all objects and data within the game.
SQF Functions, in the specific case of Intercept, are C++ functions which are exposed within RVEngine via SQF functions. The SQF language itself is just a collection of 'functions' which map to C++ code, which then interact with the game engine itself. An SQF script is a collection of these function calls, which are parsed (lexed) to a series of C++ function calls.
The SQF engine can be considered the underlying parser and manager of SQF function calls. The way the engine works is actually directly parsing strings (an SQF script) and then mapping these to control flows of C++ function calls.
Functions within intercept directly call SQF functions 100% in native machine code. We have identified the functions which the engine exposes, and are directly calling these via a complex method of hooking and object manipulation. For the less technically inclined, we completely bypass the SQF engine entirely - this allows for the functions to basically exist as any other C++ library.