Torque Game Engine Understanding Diary, part #3. Console

Decide to continue due to interesting and tricky things understood.

23.

So, after realizing core scheme - TGE, I guess as any game engine, is like ready template game application that you tweak here and there to get FPS, RTS, Racing and other :) - next layer of abstraction came up: scene, objects, light, rendering. I started with RTSUnit, found that I should check ShapeBase, no, I should check GameBase (parent) first, ah, no, I should check SceneObject (GameBase parent)! No, SimObject (SceneObject parent), no...:)

Well, at the end I found ConsoleObject class, the father of all and First Adam of everything here.

24.

Obviously I started to wish to have the Knowledge of Console :). TGE Docs Engine Overview still is great help and first stop. C++ code resides in console/console.* files.

What if I try to make my own script (Console - is Torque Script world from C++ point of view) system? How to simulate a language? :) So when I asked myself this, I quickly started to understand what is for what in Console files.

Everything that concerns Console and Torque Script in C++ engine code is dev's attempts to simulate a nice programming language by the means of another programming language :) trying to create all cool features of that new language (compile and run in real-time, access to inner C++ structure, etc. ) As I saw, successfull attempts.

Now the most scary Namespace, AbstractClassRep, ConsoleConstructor and other Con namespace monsters became quiet and were sitting on their places.

25

Namespace and AbstractClassRep - is like simulation of class system :) inheritance, member methods and vars, overrinding etc. They have also something like a database of classes, and other things not very exciting for me at the moment :)


26

But with ConsoleConstructor class was one interesting trick in understanding. If I want to create new cool function in Torque Script or just make accessible my own C++ class - internally there happen a call to ConsoleConstructor to create function - it somehow make it in Torque Script world.

And there is err... Hard to explain, but instead of one layer, as I thought and expected - you just add and add things through interface - there is layer I totally miss. Coding, compiling & linking of initial C++ code process layer :)

Or from another side - why ConsoleConstructor has 2 initialization functions: one is called Init(), and another Setup() (Without diving in-depth Setup acts like static function called once and prepare all previously prepared in init() phase things) ?! I can understand the scheme, but actually don't see the goal.

Init() is called by constructor of ConsoleConstructor itself - i.e. each time we want to add a function or method to script world. On other hands, Setup() is called from Con:init() method - when we hit Enter over exec-file. Well, actually init() is called also when we hit enter. But, in other words in Init() they prepare to be prepared :). Or "preparing something already prepared" in Setup. :) Why such a things?

Extract from console.h code comments:

"Because it is defined as a global (my note - functions for Console in *.cc files), the constructor for the ConsoleConstructor is called before execution of main()".

I found the goal! Init() - for human, for programmer, for free coding, for not restricting to creation of new functions in one particular big class - for more easy coding process. On the other hand, Setup() - for script world itself, it is assembling-the-script-world phase.

This dividing brings me another small enlightment in the area of C++ coding tactics :)

That is all for now.