/*
-----------------------------------------------------------------------------
This source file is part of OGRE
(Object-oriented Graphics Rendering Engine)
For the latest info, see http://www.ogre3d.org/

Copyright (c) 2000-2006 Torus Knot Software Ltd
Also see acknowledgements in Readme.html

This program is free software; you can redistribute it and/or modify it under
the terms of the GNU Lesser General Public License as published by the Free Software
Foundation; either version 2 of the License, or (at your option) any later
version.

This program is distributed in the hope that it will be useful, but WITHOUT
ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public License along with
this program; if not, write to the Free Software Foundation, Inc., 59 Temple
Place - Suite 330, Boston, MA 02111-1307, USA, or go to
http://www.gnu.org/copyleft/lesser.txt.

You may alternatively use this source under the terms of a specific version of
the OGRE Unrestricted License provided you have obtained such a license from
Torus Knot Software Ltd.
-----------------------------------------------------------------------------
*/

#ifndef __SkeletonInstance_H__
#define __SkeletonInstance_H__

#include "OgrePrerequisites.h"
#include "OgreSkeleton.h"

namespace Ogre {

    /** A SkeletonInstance is a single instance of a Skeleton used by a world object.
    @remarks
        The difference between a Skeleton and a SkeletonInstance is that the
        Skeleton is the 'master' version much like Mesh is a 'master' version of
        Entity. Many SkeletonInstance objects can be based on a single Skeleton, 
        and are copies of it when created. Any changes made to this are not
        reflected in the master copy. The exception is animations; these are
        shared on the Skeleton itself and may not be modified here.
    */
    class _OgreExport SkeletonInstance : public Skeleton
    {
    public:
        /** Constructor, don't call directly, this will be created automatically
        when you create an Entity based on a skeletally animated Mesh.
        */
        SkeletonInstance(const SkeletonPtr& masterCopy);
        ~SkeletonInstance();

        /** Gets the number of animations on this skeleton. */
        unsigned short getNumAnimations(void) const;

        /** Gets a single animation by index. */
        Animation* getAnimation(unsigned short index) const;
		/// Internal accessor for animations (returns null if animation does not exist)
		Animation* _getAnimationImpl(const String& name, 
			const LinkedSkeletonAnimationSource** linker = 0) const;

        /** Creates a new Animation object for animating this skeleton. 
        @remarks
            This method updates the reference skeleton, not just this instance!
        @param name The name of this animation
        @param length The length of the animation in seconds
        */
        Animation* createAnimation(const String& name, Real length);

        /** Returns the named Animation object. */
        Animation* getAnimation(const String& name, 
			const LinkedSkeletonAnimationSource** linker = 0) const;

        /** Removes an Animation from this skeleton. 
        @remarks
            This method updates the reference skeleton, not just this instance!
        */
        void removeAnimation(const String& name);


        /** Creates a TagPoint ready to be attached to a bone */
        TagPoint* createTagPointOnBone(Bone* bone, 
            const Quaternion &offsetOrientation = Quaternion::IDENTITY, 
            const Vector3 &offsetPosition = Vector3::ZERO);

        /** Frees a TagPoint that already attached to a bone */
        void freeTagPoint(TagPoint* tagPoint);

		/// @copydoc Skeleton::addLinkedSkeletonAnimationSource
		void addLinkedSkeletonAnimationSource(const String& skelName, 
			Real scale = 1.0f);
		/// @copydoc Skeleton::removeAllLinkedSkeletonAnimationSources
		void removeAllLinkedSkeletonAnimationSources(void);
		/// @copydoc Skeleton::getLinkedSkeletonAnimationSourceIterator
		LinkedSkeletonAnimSourceIterator 
			getLinkedSkeletonAnimationSourceIterator(void) const;

		/// @copydoc Skeleton::_initAnimationState
		void _initAnimationState(AnimationStateSet* animSet);

		/// @copydoc Skeleton::_refreshAnimationState
		void _refreshAnimationState(AnimationStateSet* animSet);

		/// @copydoc Resource::getName
		const String& getName(void) const;
		/// @copydoc Resource::getHandle
		ResourceHandle getHandle(void) const;
		/// @copydoc Resource::getGroup
		const String& getGroup(void);

    protected:
        /// Pointer back to master Skeleton
        SkeletonPtr mSkeleton;

        typedef std::list<TagPoint*> TagPointList;

        /** Active tag point list.
        @remarks
            This is a linked list of pointers to actived tag point
        @par
            This allows very fast instertions and deletions from anywhere in the list to activate / deactivate
            tag points (required for weapon / equip systems etc)    as well as resuse of TagPoint instances
            without construction & destruction which avoids memory thrashing.
        */
        TagPointList mActiveTagPoints;

        /** Free tag point list.
        @remarks
            This contains a list of the tag points free for use as new instances
            as required by the set. When a TagPoint instances are deactived, there will are referenced on this
            list. As they get used this list reduces, as they get released back to to the set they get added
            back to the list.
        */
        TagPointList mFreeTagPoints;

        /// TagPoint automatic handles
        unsigned short mNextTagPointAutoHandle;

        void cloneBoneAndChildren(Bone* source, Bone* parent);
        /** Overridden from Skeleton
        */
        void loadImpl(void);
        /** Overridden from Skeleton
        */
        void unloadImpl(void);

    };

}


#endif