Creating a Basic Actor

To demonstrate the registration process, we will create a simple actor that will display a rotating model, and register it to the game.

First, define the class for the actor, inheriting from Actor

#include <actor/Actor.h>
#include <graphics/AnimModel.h>
 
class DemoActor : public Actor {
public:
    // Holds registry information
    static Profile* sProfile;
 
    DemoActor(const ActorCreateParam& param); // The constructor is only used for setting initial values
    ~DemoActor() override = default; // The heap is managed, unnecessary to implement beyond default
    
    // Basic lifecycle functions
    Result create() override;
    bool execute() override;
    bool draw() override;
 
private:
    // Add custom data
    AnimModel* mModel;
};

To learn more about the actor lifecycle, see Actor.

Next, register the actor to the game using the getRegistrar() function we created earlier:

Profile* DemoActor::sProfile = getRegistrar()->newProfile<DemoActor>("demo_actor")
    .resources<"star_coin">(ProfileInfo::cResType_Course)
    .build();

The builder has additional methods for setting different properties of the profile, see red::ProfileBuilder for more information.

Finally, create the actor's constructor and implement the lifecycle functions:

DemoActor::DemoActor(const ActorCreateParam& param)
    : Actor(param)
    , mModel(nullptr)
{ }
 
ActorBase::Result DemoActor::create() {
    // Load a model from content/Common/actor/
    // SZS/BFRES name, then the model name inside
    mModel = AnimModel::create("star_coin", "star_coinA");
    
    return cResult_Success;
}
 
bool DemoActor::execute() {
    mAngle.z() += sead::Mathf::deg2idx(2.0f); // Spin 2 degrees per frame
    
    // Update the model's transformation/animation
    mModel->update(mPos, mAngle, mScale);
    
    return true;
}
 
bool DemoActor::draw() {
    mModel->draw();
    return true;
}

Finally, to test the actor, you must inform the level editor that it exists so that it can be placed in a level. See here for an example.