/*

-----------------------------------------------------------------------------

This source file is part of OGRE

    (Object-oriented Graphics Rendering Engine)

For the latest info, see http://www.ogre3d.org/

Copyright (c) 2000-2014 Torus Knot Software Ltd

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.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR

IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,

FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE

AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER

LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,

OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN

THE SOFTWARE.

-----------------------------------------------------------------------------

*/

#ifndef _Node_H__

#define _Node_H__

#include "OgrePrerequisites.h"

#include "OgreMatrix4.h"

#include "OgreUserObjectBindings.h"

#include "OgreHeaderPrefix.h"

namespace Ogre {

    template <typename T> class VectorIterator;

    template <typename T> class ConstVectorIterator;

    /** \addtogroup Core

    *  @{

    */

    /** \addtogroup Scene

    *  @{

    */

    /** Class representing a general-purpose node an articulated scene graph.

        A node in the scene graph is a node in a structured tree. A node contains

        information about the transformation which will apply to

        it and all of it's children. Child nodes can have transforms of their own, which

        are combined with their parent's transformations.

    @par

        This is an abstract class - concrete classes are based on this for specific purposes,

        e.g. SceneNode, Bone

    */

    class _OgreExport Node : public NodeAlloc

    {

    public:

        /** Enumeration denoting the spaces which a transform can be relative to.

        */

        enum TransformSpace

        {

            /// Transform is relative to the local space

            TS_LOCAL,

            /// Transform is relative to the space of the parent node

            TS_PARENT,

            /// Transform is relative to world space

            TS_WORLD

        };

        typedef std::vector<Node*> ChildNodeMap;

        typedef VectorIterator<ChildNodeMap> ChildNodeIterator;

        typedef ConstVectorIterator<ChildNodeMap> ConstChildNodeIterator;

        /** Listener which gets called back on Node events.

        */

        class _OgreExport Listener

        {

        public:

            Listener() {}

            virtual ~Listener() {}

            /** Called when a node gets updated.

                Note that this happens when the node's derived update happens,

                not every time a method altering it's state occurs. There may 

                be several state-changing calls but only one of these calls, 

                when the node graph is fully updated.

            */

            virtual void nodeUpdated(const Node*) {}

            /** Node is being destroyed */

            virtual void nodeDestroyed(const Node*) {}

            /** Node has been attached to a parent */

            virtual void nodeAttached(const Node*) {}

            /** Node has been detached from a parent */

            virtual void nodeDetached(const Node*) {}

        };

    protected:

        /// Pointer to parent node

        Node* mParent;

        /// Collection of pointers to direct children

        ChildNodeMap mChildren;

        typedef std::set<Node*> ChildUpdateSet;

        /// List of children which need updating, used if self is not out of date but children are

        ChildUpdateSet mChildrenToUpdate;

        /// Friendly name of this node

        String mName;

        /// Flag to indicate own transform from parent is out of date

        mutable bool mNeedParentUpdate : 1;

        /// Flag indicating that all children need to be updated

        bool mNeedChildUpdate : 1;

        /// Flag indicating that parent has been notified about update request

        bool mParentNotified : 1;

        /// Flag indicating that the node has been queued for update

        bool mQueuedForUpdate : 1;

        /// Stores whether this node inherits orientation from it's parent

        bool mInheritOrientation : 1;

        /// Stores whether this node inherits scale from it's parent

        bool mInheritScale : 1;

        mutable bool mCachedTransformOutOfDate : 1;

        /// Stores the orientation of the node relative to it's parent.

        Quaternion mOrientation;

        /// Stores the position/translation of the node relative to its parent.

        Vector3 mPosition;

        /// Stores the scaling factor applied to this node

        Vector3 mScale;

        /// Cached derived transform as a 4x4 matrix

        mutable Affine3 mCachedTransform;

        /// Only available internally - notification of parent.

        virtual void setParent(Node* parent);

        /** Cached combined orientation.

        @par

            This member is the orientation derived by combining the

            local transformations and those of it's parents.

            This is updated when _updateFromParent is called by the

            SceneManager or the nodes parent.

        */

        mutable Quaternion mDerivedOrientation;

        /** Cached combined position.

        @par

            This member is the position derived by combining the

            local transformations and those of it's parents.

            This is updated when _updateFromParent is called by the

            SceneManager or the nodes parent.

        */

        mutable Vector3 mDerivedPosition;

        /** Cached combined scale.

        @par

            This member is the position derived by combining the

            local transformations and those of it's parents.

            This is updated when _updateFromParent is called by the

            SceneManager or the nodes parent.

        */

        mutable Vector3 mDerivedScale;

        /** Triggers the node to update it's combined transforms.

        @par

            This method is called internally by Ogre to ask the node

            to update it's complete transformation based on it's parents

            derived transform.

        */

        void _updateFromParent(void) const;

        /** Class-specific implementation of _updateFromParent.

            Splitting the implementation of the update away from the update call

            itself allows the detail to be overridden without disrupting the 

            general sequence of updateFromParent (e.g. raising events)

        */

        virtual void updateFromParentImpl(void) const;

    private:

        /// The position to use as a base for keyframe animation

        Vector3 mInitialPosition;

        /// The orientation to use as a base for keyframe animation

        Quaternion mInitialOrientation;

        /// The scale to use as a base for keyframe animation

        Vector3 mInitialScale;

        /** Node listener - only one allowed (no list) for size & performance reasons. */

        Listener* mListener;

        /// User objects binding.

        UserObjectBindings mUserObjectBindings;

        typedef std::vector<Node*> QueuedUpdates;

        static QueuedUpdates msQueuedUpdates;

        /** Internal method for creating a new child node - must be overridden per subclass. */

        virtual Node* createChildImpl(void) = 0;

        /** Internal method for creating a new child node - must be overridden per subclass. */

        virtual Node* createChildImpl(const String& name) = 0;

    public:

        /// Constructor, should only be called by parent, not directly.

        Node(const String& name = "");

        virtual ~Node();  

        /** Returns the name of the node. */

        const String& getName(void) const { return mName; }

        /** Gets this node's parent (NULL if this is the root).

        */

        Node* getParent(void) const { return mParent; }

        /** Returns a quaternion representing the nodes orientation.

        */

        const Quaternion & getOrientation() const { return mOrientation; }

        /** Sets the orientation of this node via a quaternion.

            Orientations, unlike other transforms, are not always inherited by child nodes.

            Whether or not orientations affect the orientation of the child nodes depends on

            the setInheritOrientation option of the child. In some cases you want a orientating

            of a parent node to apply to a child node (e.g. where the child node is a part of

            the same object, so you want it to be the same relative orientation based on the

            parent's orientation), but not in other cases (e.g. where the child node is just

            for positioning another object, you want it to maintain it's own orientation).

            The default is to inherit as with other transforms.

        @par

            Note that rotations are oriented around the node's origin.

        */

        void setOrientation( const Quaternion& q );

        /// @overload

        void setOrientation( Real w, Real x, Real y, Real z);

        /** Resets the nodes orientation (local axes as world axes, no rotation).

            Orientations, unlike other transforms, are not always inherited by child nodes.

            Whether or not orientations affect the orientation of the child nodes depends on

            the setInheritOrientation option of the child. In some cases you want a orientating

            of a parent node to apply to a child node (e.g. where the child node is a part of

            the same object, so you want it to be the same relative orientation based on the

            parent's orientation), but not in other cases (e.g. where the child node is just

            for positioning another object, you want it to maintain it's own orientation).

            The default is to inherit as with other transforms.

        @par

            Note that rotations are oriented around the node's origin.

        */

        void resetOrientation(void);

        /** Sets the position of the node relative to it's parent.

        */

        void setPosition(const Vector3& pos);

        /// @overload

        void setPosition(Real x, Real y, Real z) { setPosition(Vector3(x, y, z)); }

        /** Gets the position of the node relative to it's parent.

        */

        const Vector3 & getPosition(void) const { return mPosition; }

        /** Sets the scaling factor applied to this node.

            Scaling factors, unlike other transforms, are not always inherited by child nodes.

            Whether or not scalings affect the size of the child nodes depends on the setInheritScale

            option of the child. In some cases you want a scaling factor of a parent node to apply to

            a child node (e.g. where the child node is a part of the same object, so you want it to be

            the same relative size based on the parent's size), but not in other cases (e.g. where the

            child node is just for positioning another object, you want it to maintain it's own size).

            The default is to inherit as with other transforms.

        @par

            Note that like rotations, scalings are oriented around the node's origin.

        */

        void setScale(const Vector3& scale);

        /// @overload

        void setScale(Real x, Real y, Real z) { setScale(Vector3(x, y, z)); }

        /** Gets the scaling factor of this node.

        */

        const Vector3& getScale(void) const { return mScale; }

        /** Tells the node whether it should inherit orientation from it's parent node.

            Orientations, unlike other transforms, are not always inherited by child nodes.

            Whether or not orientations affect the orientation of the child nodes depends on

            the setInheritOrientation option of the child. In some cases you want a orientating

            of a parent node to apply to a child node (e.g. where the child node is a part of

            the same object, so you want it to be the same relative orientation based on the

            parent's orientation), but not in other cases (e.g. where the child node is just

            for positioning another object, you want it to maintain it's own orientation).

            The default is to inherit as with other transforms.

        @param inherit If true, this node's orientation will be affected by its parent's orientation.

            If false, it will not be affected.

        */

        void setInheritOrientation(bool inherit);

        /** Returns true if this node is affected by orientation applied to the parent node. 

            Orientations, unlike other transforms, are not always inherited by child nodes.

            Whether or not orientations affect the orientation of the child nodes depends on

            the setInheritOrientation option of the child. In some cases you want a orientating

            of a parent node to apply to a child node (e.g. where the child node is a part of

            the same object, so you want it to be the same relative orientation based on the

            parent's orientation), but not in other cases (e.g. where the child node is just

            for positioning another object, you want it to maintain it's own orientation).

            The default is to inherit as with other transforms.

            See setInheritOrientation for more info.

        */

        bool getInheritOrientation(void) const { return mInheritOrientation; }

        /** Tells the node whether it should inherit scaling factors from it's parent node.

            Scaling factors, unlike other transforms, are not always inherited by child nodes.

            Whether or not scalings affect the size of the child nodes depends on the setInheritScale

            option of the child. In some cases you want a scaling factor of a parent node to apply to

            a child node (e.g. where the child node is a part of the same object, so you want it to be

            the same relative size based on the parent's size), but not in other cases (e.g. where the

            child node is just for positioning another object, you want it to maintain it's own size).

            The default is to inherit as with other transforms.

        @param inherit If true, this node's scale will be affected by its parent's scale. If false,

            it will not be affected.

        */

        void setInheritScale(bool inherit);

        /** Returns true if this node is affected by scaling factors applied to the parent node. 

            See setInheritScale for more info.

        */

        bool getInheritScale(void) const { return mInheritScale; }

        /** Scales the node, combining it's current scale with the passed in scaling factor. 

            This method applies an extra scaling factor to the node's existing scale, (unlike setScale

            which overwrites it) combining it's current scale with the new one. E.g. calling this 

            method twice with Vector3(2,2,2) would have the same effect as setScale(Vector3(4,4,4)) if

            the existing scale was 1.

        @par

            Note that like rotations, scalings are oriented around the node's origin.

        */

        void scale(const Vector3& scale);

        /// @overload

        void scale(Real x, Real y, Real z);

        /** Moves the node along the Cartesian axes.

        @par

            This method moves the node by the supplied vector along the

            world Cartesian axes, i.e. along world x,y,z

        @param d

            Vector with x,y,z values representing the translation.

        @param relativeTo

            The space which this transform is relative to.

        */

        void translate(const Vector3& d, TransformSpace relativeTo = TS_PARENT);

        /// @overload

        void translate(Real x, Real y, Real z, TransformSpace relativeTo = TS_PARENT)

        {

            translate(Vector3(x, y, z), relativeTo);

        }

        /** Moves the node along arbitrary axes.

            This method translates the node by a vector which is relative to

            a custom set of axes.

        @param axes

            A 3x3 Matrix containing 3 column vectors each representing the

            axes X, Y and Z respectively. In this format the standard cartesian

            axes would be expressed as:

            <pre>

            1 0 0

            0 1 0

            0 0 1

            </pre>

            i.e. the identity matrix.

        @param move

            Vector relative to the axes above.

        @param relativeTo

            The space which this transform is relative to.

        */

        void translate(const Matrix3& axes, const Vector3& move, TransformSpace relativeTo = TS_PARENT)

        {

            translate(axes * move, relativeTo);

        }

        /// @overload

        void translate(const Matrix3& axes, Real x, Real y, Real z, TransformSpace relativeTo = TS_PARENT)

        {

            translate(axes, Vector3(x, y, z), relativeTo);

        }

        /** Rotate the node around the Z-axis.

        */

        virtual void roll(const Radian& angle, TransformSpace relativeTo = TS_LOCAL)

        {

            rotate(Quaternion(angle, Vector3::UNIT_Z), relativeTo);

        }

        /** Rotate the node around the X-axis.

        */

        virtual void pitch(const Radian& angle, TransformSpace relativeTo = TS_LOCAL)

        {

            rotate(Quaternion(angle, Vector3::UNIT_X), relativeTo);

        }

        /** Rotate the node around the Y-axis.

        */

        virtual void yaw(const Radian& angle, TransformSpace relativeTo = TS_LOCAL)

        {

            rotate(Quaternion(angle, Vector3::UNIT_Y), relativeTo);

        }

        /** Rotate the node around an arbitrary axis.

        */

        void rotate(const Vector3& axis, const Radian& angle, TransformSpace relativeTo = TS_LOCAL)

        {

            rotate(Quaternion(angle, axis), relativeTo);

        }

        /** Rotate the node around an arbitrary axis using a Quarternion.

        */

        void rotate(const Quaternion& q, TransformSpace relativeTo = TS_LOCAL);

        /** Gets a matrix whose columns are the local axes based on

            the nodes orientation relative to it's parent. */

        Matrix3 getLocalAxes(void) const;

        /** Creates an unnamed new Node as a child of this node.

        @param translate

            Initial translation offset of child relative to parent

        @param rotate

            Initial rotation relative to parent

        */

        virtual Node* createChild(

            const Vector3& translate = Vector3::ZERO, 

            const Quaternion& rotate = Quaternion::IDENTITY );

        /** Creates a new named Node as a child of this node.

            This creates a child node with a given name, which allows you to look the node up from 

            the parent which holds this collection of nodes.

        @param name Name of the Node to create

        @param translate

            Initial translation offset of child relative to parent

        @param rotate

            Initial rotation relative to parent

        */

        virtual Node* createChild(const String& name, const Vector3& translate = Vector3::ZERO, const Quaternion& rotate = Quaternion::IDENTITY);

        /** Adds a (precreated) child scene node to this node. If it is attached to another node,

            it must be detached first.

        @param child The Node which is to become a child node of this one

        */

        void addChild(Node* child);

        /** Reports the number of child nodes under this one.

        @deprecated use getChildren()

        */

        uint16 numChildren(void) const { return static_cast< uint16 >( mChildren.size() ); }

        /** Gets a pointer to a child node.

            There is an alternate getChild method which returns a named child.

        @deprecated use getChildren()

        */

        Node* getChild(unsigned short index) const;

        /** Gets a pointer to a named child node.

        */

        Node* getChild(const String& name) const;

        /// @deprecated use getChildren()

        OGRE_DEPRECATED ChildNodeIterator getChildIterator(void);

        /// @deprecated use getChildren()

        OGRE_DEPRECATED ConstChildNodeIterator getChildIterator(void) const;

        /// List of sub-nodes of this Node

        const ChildNodeMap& getChildren() const { return mChildren; }

        /** Drops the specified child from this node. 

            Does not delete the node, just detaches it from

            this parent, potentially to be reattached elsewhere. 

            There is also an alternate version which drops a named

            child from this node.

        */

        virtual Node* removeChild(unsigned short index);

        /// @overload

        virtual Node* removeChild(Node* child);

        /** Drops the named child from this node. 

            Does not delete the node, just detaches it from

            this parent, potentially to be reattached elsewhere.

        */

        virtual Node* removeChild(const String& name);

        /** Removes all child Nodes attached to this node. Does not delete the nodes, just detaches them from

            this parent, potentially to be reattached elsewhere.

        */

        virtual void removeAllChildren(void);

        /** Sets the final world position of the node directly.

            It's advisable to use the local setPosition if possible

        */

        void _setDerivedPosition(const Vector3& pos);

        /** Sets the final world orientation of the node directly.

            It's advisable to use the local setOrientation if possible, this simply does

            the conversion for you.

        */

        void _setDerivedOrientation(const Quaternion& q);

        /** Gets the orientation of the node as derived from all parents.

        */

        const Quaternion & _getDerivedOrientation(void) const;

        /** Gets the position of the node as derived from all parents.

        */

        const Vector3 & _getDerivedPosition(void) const;

        /** Gets the scaling factor of the node as derived from all parents.

        */

        const Vector3 & _getDerivedScale(void) const;

        /** Gets the full transformation matrix for this node.

            This method returns the full transformation matrix

            for this node, including the effect of any parent node

            transformations, provided they have been updated using the Node::_update method.

            This should only be called by a SceneManager which knows the

            derived transforms have been updated before calling this method.

            Applications using Ogre should just use the relative transforms.

        */

        const Affine3& _getFullTransform(void) const;

        /** Internal method to update the Node.

        @note

            Updates this node and any relevant children to incorporate transforms etc.

            Don't call this yourself unless you are writing a SceneManager implementation.

        @param updateChildren

            If @c true, the update cascades down to all children. Specify false if you wish to

            update children separately, e.g. because of a more selective SceneManager implementation.

        @param parentHasChanged

            This flag indicates that the parent transform has changed,

            so the child should retrieve the parent's transform and combine

            it with its own even if it hasn't changed itself.

        */

        virtual void _update(bool updateChildren, bool parentHasChanged);

        /** Sets a listener for this Node.

            Note for size and performance reasons only one listener per node is

            allowed.

        */

        void setListener(Listener* listener) { mListener = listener; }

        /** Gets the current listener for this Node.

        */

        Listener* getListener(void) const { return mListener; }

        /** Sets the current transform of this node to be the 'initial state' ie that

            position / orientation / scale to be used as a basis for delta values used

            in keyframe animation.

            You never need to call this method unless you plan to animate this node. If you do

            plan to animate it, call this method once you've loaded the node with it's base state,

            ie the state on which all keyframes are based.

        @par

            If you never call this method, the initial state is the identity transform, ie do nothing.

        */

        void setInitialState(void);

        /** Resets the position / orientation / scale of this node to it's initial state, see setInitialState for more info. */

        void resetToInitialState(void);

        /** Gets the initial position of this node, see setInitialState for more info. 

            Also resets the cumulative animation weight used for blending.

        */

        const Vector3& getInitialPosition(void) const { return mInitialPosition; }

        /** Gets the local position, relative to this node, of the given world-space position */

        Vector3 convertWorldToLocalPosition( const Vector3 &worldPos );

        /** Gets the world position of a point in the node local space

            useful for simple transforms that don't require a child node.*/

        Vector3 convertLocalToWorldPosition( const Vector3 &localPos );

        /** Gets the local direction, relative to this node, of the given world-space direction */

        Vector3 convertWorldToLocalDirection( const Vector3 &worldDir, bool useScale );

        /** Gets the world direction of a point in the node local space

            useful for simple transforms that don't require a child node.*/

        Vector3 convertLocalToWorldDirection( const Vector3 &localDir, bool useScale );

        /** Gets the local orientation, relative to this node, of the given world-space orientation */

        Quaternion convertWorldToLocalOrientation( const Quaternion &worldOrientation );

        /** Gets the world orientation of an orientation in the node local space

            useful for simple transforms that don't require a child node.*/

        Quaternion convertLocalToWorldOrientation( const Quaternion &localOrientation );

        /** Gets the initial orientation of this node, see setInitialState for more info. */

        const Quaternion& getInitialOrientation(void) const { return mInitialOrientation; }

        /** Gets the initial position of this node, see setInitialState for more info. */

        const Vector3& getInitialScale(void) const { return mInitialScale; }

        /** Helper function, get the squared view depth.  */

        Real getSquaredViewDepth(const Camera* cam) const;

        /** To be called in the event of transform changes to this node that require it's recalculation.

            This not only tags the node state as being 'dirty', it also requests it's parent to 

            know about it's dirtiness so it will get an update next time.

        @param forceParentUpdate Even if the node thinks it has already told it's

            parent, tell it anyway

        */

        virtual void needUpdate(bool forceParentUpdate = false);

        /** Called by children to notify their parent that they need an update.

        @param child The child Node to be updated

        @param forceParentUpdate Even if the node thinks it has already told it's

            parent, tell it anyway

        */

        void requestUpdate(Node* child, bool forceParentUpdate = false);

        /** Called by children to notify their parent that they no longer need an update. */

        void cancelUpdate(Node* child);

        /** Queue a 'needUpdate' call to a node safely.

            You can't call needUpdate() during the scene graph update, e.g. in

            response to a Node::Listener hook, because the graph is already being 

            updated, and update flag changes cannot be made reliably in that context. 

            Call this method if you need to queue a needUpdate call in this case.

        */

        static void queueNeedUpdate(Node* n);

        /** Process queued 'needUpdate' calls. */

        static void processQueuedUpdates(void);

        /** @deprecated use UserObjectBindings::setUserAny via getUserObjectBindings() instead.

        */

        OGRE_DEPRECATED void setUserAny(const Any& anything) { getUserObjectBindings().setUserAny(anything); }

        /** @deprecated use UserObjectBindings::getUserAny via getUserObjectBindings() instead.

        */

        OGRE_DEPRECATED const Any& getUserAny(void) const { return getUserObjectBindings().getUserAny(); }

        /// @copydoc UserObjectBindings

        UserObjectBindings& getUserObjectBindings() { return mUserObjectBindings; }

        /// @overload

        const UserObjectBindings& getUserObjectBindings() const { return mUserObjectBindings; }

    };

    /** @} */

    /** @} */

} // namespace Ogre

#include "OgreHeaderSuffix.h"

#endif // _Node_H__