Component.h File Reference

Abstract base for all GameObject components and the COMPONENT macro. More...

#include "Types.h"
#include "nlohmann/json.hpp"

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Classes
class	mnd::Component
class	mnd::ComponentCreatorBase
class	mnd::ComponentCreator< T >
class	mnd::ComponentFactory

Namespaces
namespace	mnd

Macros
#define	COMPONENT(ComponentClass)

Detailed Description

Abstract base for all GameObject components and the COMPONENT macro.

Entity-Component pattern

A GameObject is a named scene node with a transform. Behaviour and rendering are added by attaching Component subclasses. Each component type gets a unique numeric ID at runtime so that typed lookup via GameObject::GetComponent<T>() works in O(n) without RTTI.

Adding a new component type

1. Subclass Component.
2. Place the COMPONENT(MyComponent) macro at the top of the public section.
3. Implement Update(f32 deltaTime).
4. Attach via GameObject::AddComponent(new MyComponent(...)).

class SpinComponent : public mnd::Component {
    COMPONENT(SpinComponent)
public:
    void Update(mnd::f32 dt) override { m_owner->SetRotation(...); }
};

See also

GameObject::AddComponent, GameObject::GetComponent, COMPONENT

Definition in file Component.h.

Macro Definition Documentation

COMPONENT

#define COMPONENT

(

ComponentClass

)

Value:

public: \
    static size_t TypeId() \
    { \
        return mnd::Component::StaticTypeId<ComponentClass>(); \
    } \
    size_t GetTypeId() const override \
    { \
        return TypeId(); \
    } \
    static void Register() \
    { \
        mnd::ComponentFactory::GetInstance().RegisterComponent<ComponentClass>(std::string(#ComponentClass)); \
    }

Definition at line 105 of file Component.h.