AtomicGameEngine/Source/AtomicSharp/CSComponent.h

//
// Copyright (c) 2008-2014 the Urho3D project.
// Copyright (c) 2014-2015, THUNDERBEAST GAMES LLC All rights reserved
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
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// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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// THE SOFTWARE.
//

#pragma once

#include <Atomic/Scene/Component.h>

namespace Atomic
{

enum CSComponentMethod
{
    CSComponentMethod_Start,
    CSComponentMethod_DelayedStart,
    CSComponentMethod_Update,
    CSComponentMethod_PostUpdate,
    CSComponentMethod_FixedUpdate,
    CSComponentMethod_PostFixedUpdate
};

/// Helper base class for user-defined game logic components that hooks up to update events and forwards them to virtual functions similar to ScriptInstance class.
class ATOMIC_API CSComponent : public Component
{
    friend class CSComponentFactory;

    enum EventFlags
    {
        USE_UPDATE = 0x1,
        USE_POSTUPDATE = 0x2,
        USE_FIXEDUPDATE = 0x4,
        USE_FIXEDPOSTUPDATE = 0x8
    };

public:

    OBJECT(CSComponent);

    /// Construct.
    CSComponent(Context* context);
    /// Destruct.
    virtual ~CSComponent();

    /// Register object factory.
    static void RegisterObject(Context* context);

    bool Load(Deserializer& source, bool setInstanceDefault);
    bool LoadXML(const XMLElement& source, bool setInstanceDefault);
    void ApplyAttributes();

    /// Handle enabled/disabled state change. Changes update event subscription.
    virtual void OnSetEnabled();

    /// Set what update events should be subscribed to. Use this for optimization: by default all are in use. Note that this is not an attribute and is not saved or network-serialized, therefore it should always be called eg. in the subclass constructor.
    void SetUpdateEventMask(unsigned char mask);

    /// Return what update events are subscribed to.
    unsigned char GetUpdateEventMask() const { return updateEventMask_; }
    /// Return whether the DelayedStart() function has been called.
    bool IsDelayedStartCalled() const { return delayedStartCalled_; }

    void SetDestroyed() { destroyed_ = true; }
    void SetManagedID(unsigned id) { managedID_ = id; }

protected:
    /// Handle scene node being assigned at creation.
    virtual void OnNodeSet(Node* node);
    /// Handle scene being assigned.
    virtual void OnSceneSet(Scene* scene);

private:
    /// Subscribe/unsubscribe to update events based on current enabled state and update event mask.
    void UpdateEventSubscription();
    /// Handle scene update event.
    void HandleSceneUpdate(StringHash eventType, VariantMap& eventData);
    /// Handle scene post-update event.
    void HandleScenePostUpdate(StringHash eventType, VariantMap& eventData);
#ifdef ATOMIC_PHYSICS
    /// Handle physics pre-step event.
    void HandlePhysicsPreStep(StringHash eventType, VariantMap& eventData);
    /// Handle physics post-step event.
    void HandlePhysicsPostStep(StringHash eventType, VariantMap& eventData);
#endif

    void CallScriptMethod(CSComponentMethod method, float value = 0.0f);

    /// Called when the component is added to a scene node. Other components may not yet exist.
    virtual void Start();
    /// Called before the first update. At this point all other components of the node should exist. Will also be called if update events are not wanted; in that case the event is immediately unsubscribed afterward.
    virtual void DelayedStart();
    /// Called when the component is detached from a scene node, usually on destruction. Note that you will no longer have access to the node and scene at that point.
    virtual void Stop() {}
    /// Called on scene update, variable timestep.
    virtual void Update(float timeStep);
    /// Called on scene post-update, variable timestep.
    virtual void PostUpdate(float timeStep);
    /// Called on physics update, fixed timestep.
    virtual void FixedUpdate(float timeStep);
    /// Called on physics post-update, fixed timestep.
    virtual void FixedPostUpdate(float timeStep);

    /// Requested event subscription mask.
    unsigned char updateEventMask_;
    /// Current event subscription mask.
    unsigned char currentEventMask_;

    bool instanceInitialized_;
    bool started_;
    bool destroyed_;
    bool scriptClassInstance_;

    /// Flag for delayed start.
    bool delayedStartCalled_;

    bool loading_;

    unsigned managedID_;

};

}