How to use key bindings in Godot from C++ extension code?

Question

I have created a simple C++ "game" in godot. Lacking any good documentation, I based my work off examples on the internet, and for input I have this:

    const Input* i = Input::get_singleton();

    double delta_v = 0;
    if (i->is_action_pressed("ui_up"))
        delta_v += acceleration * delta;
    if (i->is_action_pressed("ui_down"))
        delta_v -= acceleration * delta;
    if (i->is_action_pressed("ui_left"))
        angular_velocity -= angular_acceleration * delta;
    if (i->is_action_pressed("ui_right"))
        angular_velocity += angular_acceleration * delta;

Based on that, I wanted to add a new action triggered by space. So I tried this:

    const Input* i = Input::get_singleton();
    if (i->is_action_pressed("game_shoot"))
    {
        
    }

I then added this action in the project key mapping:

But I am getting an error:

The InputMap action "game_shoot" doesn't exist.

Curiously, it works from a script like this:

func _input(event):
    if event.is_action_pressed("game_shoot"):
        print("game_shoot occurred!")

Answer 1

I finally figured this out. There is a method on the InputMap singleton. You probably should call this only once.

    InputMap* map = InputMap::get_singleton();
    map->load_from_project_settings();