C++

About

Versions
Characteristics

  • Default access control: Private.

Building

Classes

Operator ( :: )

  • Used to access the content of a class , struct , scope , or namespace .

  • The symbol ::  is used like an "address/directory", so using:

    • MyClass::variable_name , refers to a variable of the class MyClass .

    • ::variable_name , refers to a variable in the global scope.

  • Writing using ScopeName  exposes the content of the desired scope in the current scope.

GameDev

Godot

Projekt JENOVA

  • Projekt JENOVA .

  • Is a comprehensive series of extension libraries for the Godot 4 Game Engine that brings fully-featured C++ scripting directly into the Godot Editor. It allows the use of modern C++20 standards within the Godot Engine, similar to GDScript.

  • About .

  • Apparently, it's Windows only.

GDExtension

  • Tutorial .

    • The tutorial was made with Godot 4.3-stable.

    • Demo project used .

    • Template used .

    • The presenter is very nice. He made the Godot Netcode Rollback extension.

    • {18:20 -> 26:55}

      • Creation of a class called Somator, which will be a new class used inside Godot with GDScript.

        • The class is simply created with count = 0 , sums values, and has a function to return the total.

      • In other words, it’s a mix between C++ and GDScript.

      • It's basically a plugin, ~kinda.

    • {26:55 -> 1:14:33}

      • Creation of a Traffic Light.

      • It's a more complex class, with exports, signal emission, and virtual methods.

    • {1:14:33 -> 1:25:30}

      • Creation of a Player.

      • In this case, _physics_process  is used, since the logic will be completely done in C++, not GDScript.

    • Watched the entire video. It’s a very good video.

Important things explained in the video

  • You cannot use C++ new  for Godot classes, but must use memnew .

  • "If you don’t use Ref< >  for all classes that inherit Godot's RefCounted , you will have memory leaks." 

    Ref<Texture2D> my_tex;

  • _bind_methods()  must be used in classes:

    • .

  • He prefers using _notification()  instead of _ready , since setting something in C++ _ready  may conflict with GDScript _ready .

    • Makes sense, since it's an override of a virtual function.

  • "By default, all classes created with GDExtension will work in the editor and the game (like tools). This is the default for all C++ classes."

  • Signals:

    • Creating:

      • ADD_SIGNAL(MethodInfo("light_changed"), PropertyInfo\(Variant:\:INT "new_light"));

    • Emitting:

      • Signals work as in Godot 3, needing to be called via emit_signal("name", parameters)

  • "In C++ there are no real properties; everything is done via setters and getters."

  • "It's verbose enough, it's hard to keep in your memory, that's why I'm always copying code from old projects."

  • Very convenient for creating documentation; it’s highly automated, generating templates.

  • GDExtension files can be placed anywhere in the project and Godot will find them. They don't need to be in the Addon folder.

  • C# code cannot properly access classes made with GDExtension.

C++ Modules

  • We recommend C++ modules  in cases where GDExtension isn't enough:

    • C++ modules provide deeper integration into the engine. GDExtension's access is not as deep as static modules.

    • You can use C++ modules to provide additional features in a project without carrying native library files around. This extends to exported projects.