source: GTP/trunk/App/Demos/Geom/OgreStuff/include/OgreStaticGeometry.h @ 1812

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

Copyright (c) 2000-2005 The OGRE Team
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.
-----------------------------------------------------------------------------
*/
#ifndef __StaticGeometry_H__
#define __StaticGeometry_H__

#include "OgrePrerequisites.h"
#include "OgreMovableObject.h"
#include "OgreRenderable.h"

namespace Ogre {

        /** Pre-transforms and batches up meshes for efficient use as static
                geometry in a scene.
        @remarks
                Modern graphics cards (GPUs) prefer to receive geometry in large
                batches. It is orders of magnitude faster to render 10 batches
                of 10,000 triangles than it is to render 10,000 batches of 10 
                triangles, even though both result in the same number of on-screen
                triangles.
        @par
                Therefore it is important when you are rendering a lot of geometry to 
                batch things up into as few rendering calls as possible. This
                class allows you to build a batched object from a series of entities 
                in order to benefit from this behaviour.
                Batching has implications of it's own though:
                @li Batched geometry cannot be subdivided; that means that the whole
                        group will be displayed, or none of it will. This obivously has
                        culling issues.
                @li A single world transform must apply to the entire batch. Therefore
                        once you have batched things, you can't move them around relative to
                        each other. That's why this class is most useful when dealing with 
                        static geometry (hence the name). In addition, geometry is 
                        effectively duplicated, so if you add 3 entities based on the same 
                        mesh in different positions, they will use 3 times the geometry 
                        space than the movable version (which re-uses the same geometry). 
                        So you trade memory     and flexibility of movement for pure speed when
                        using this class.
                @li A single material must apply for each batch. In fact this class 
                        allows you to use multiple materials, but you should be aware that 
                        internally this means that there is one batch per material. 
                        Therefore you won't gain as much benefit from the batching if you 
                        use many different materials; try to keep the number down.
        @par
                In order to retain some sort of culling, this class will batch up 
                meshes in localised regions. The size and shape of these blocks is
                controlled by the SceneManager which contructs this object, since it
                makes sense to batch things up in the most appropriate way given the 
                existing partitioning of the scene. 
        @par
                The LOD settings of both the Mesh and the Materials used in 
                constructing this static geometry will be respected. This means that 
                if you use meshes/materials which have LOD, batches in the distance 
                will have a lower polygon count or material detail to those in the 
                foreground. Since each mesh might have different LOD distances, during 
                build the furthest distance at each LOD level from all meshes  
                in that region is used. This means all the LOD levels change at the 
                same time, but at the furthest distance of any of them (so quality is 
                not degraded). Be aware that using Mesh LOD in this class will 
                further increase the memory required. Only generated LOD
                is supported for meshes.
        @par
                There are 2 ways you can add geometry to this class; you can add
                Entity objects directly with predetermined positions, scales and 
                orientations, or you can add an entire SceneNode and it's subtree, 
                including all the objects attached to it. Once you've added everthing
                you need to, you have to call build() the fix the geometry in place. 
        @note
                This class is not a replacement for world geometry (@see 
                SceneManager::setWorldGeometry). The single most efficient way to 
                render large amounts of static geometry is to use a SceneManager which 
                is specialised for dealing with that particular world structure. 
                However, this class does provide you with a good 'halfway house'
                between generalised movable geometry (Entity) which works with all 
                SceneManagers but isn't efficient when using very large numbers, and 
                highly specialised world geometry which is extremely fast but not 
                generic and typically requires custom world editors.
        @par
                You should not construct instances of this class directly; instead, cal 
                SceneManager::createStaticGeometry, which gives the SceneManager the 
                option of providing you with a specialised version of this class if it
                wishes, and also handles the memory management for you like other 
                classes.
        @note
                Warning: this class only works with triangle lists at the moment,
                do not pass it triangle strips, fans or lines / points.
        */
        class _OgreExport StaticGeometry
        {
        public:
                /** Struct holding geometry optimised per SubMesh / lod level, ready
                        for copying to instances. 
                @remarks
                        Since we're going to be duplicating geometry lots of times, it's
                        far more important that we don't have redundant vertex data. If a 
                        SubMesh uses shared geometry, or we're looking at a lower LOD, not
                        all the vertices are being referenced by faces on that submesh.
                        Therefore to duplicate them, potentially hundreds or even thousands
                        of times, would be extremely wasteful. Therefore, if a SubMesh at
                        a given LOD has wastage, we create an optimised version of it's
                        geometry which is ready for copying with no wastage.
                */
                class _OgrePrivate OptimisedSubMeshGeometry
                {
                public:
                        OptimisedSubMeshGeometry() :vertexData(0), indexData(0) {}
                        ~OptimisedSubMeshGeometry() 
                        {
                                delete vertexData;
                                delete indexData;
                        }
                        VertexData *vertexData;
                        IndexData *indexData;
                };
                typedef std::list<OptimisedSubMeshGeometry*> OptimisedSubMeshGeometryList;
                /// Saved link between SubMesh at a LOD and vertex/index data
                /// May point to original or optimised geometry
                struct SubMeshLodGeometryLink
                {
                        VertexData* vertexData;
                        IndexData* indexData;
                };
                typedef std::vector<SubMeshLodGeometryLink> SubMeshLodGeometryLinkList;
                typedef std::map<SubMesh*, SubMeshLodGeometryLinkList*> SubMeshGeometryLookup;
                /// Structure recording a queued submesh for the build
                struct QueuedSubMesh
                {
                        SubMesh* submesh;
                        /// Link to LOD list of geometry, potentially optimised
                        SubMeshLodGeometryLinkList* geometryLodList;
                        String materialName;
                        Vector3 position;
                        Quaternion orientation;
                        Vector3 scale;
                        /// Pre-transformed world AABB 
                        AxisAlignedBox worldBounds;
                };
                typedef std::vector<QueuedSubMesh*> QueuedSubMeshList;
                /// Structure recording a queued geometry for low level builds
                struct QueuedGeometry
                {
                        SubMeshLodGeometryLink* geometry;
                        Vector3 position;
                        Quaternion orientation;
                        Vector3 scale;
                };
                typedef std::vector<QueuedGeometry*> QueuedGeometryList;
                
                // forward declarations
                class LODBucket;
                class MaterialBucket;
                class Region;

                /** A GeometryBucket is a the lowest level bucket where geometry with 
                        the same vertex & index format is stored. It also acts as the 
                        renderable.
                */
                class _OgreExport GeometryBucket :      public Renderable
                {
                protected:
                        /// Geometry which has been queued up pre-build (not for deallocation)
                        QueuedGeometryList mQueuedGeometry;
                        /// Pointer to parent bucket
                        MaterialBucket* mParent;
                        /// String identifying the vertex / index format
                        String mFormatString;
                        /// Vertex information, includes current number of vertices
                        /// committed to be a part of this bucket
                        VertexData* mVertexData;
                        /// Index information, includes index type which limits the max
                        /// number of vertices which are allowed in one bucket
                        IndexData* mIndexData;
                        /// Size of indexes
                        HardwareIndexBuffer::IndexType mIndexType;
                        /// Maximum vertex indexable
                        size_t mMaxVertexIndex;

                        template<typename T>
                        void copyIndexes(const T* src, T* dst, size_t count, size_t indexOffset)
                        {
                                if (indexOffset == 0)
                                {
                                        memcpy(dst, src, sizeof(T) * count);
                                }
                                else
                                {
                                        while(count--)
                                        {
                                                *dst++ = static_cast<T>(*src++ + indexOffset);
                                        }
                                }
                        }
                public:
                        GeometryBucket(MaterialBucket* parent, const String& formatString, 
                                const VertexData* vData, const IndexData* iData);
                        virtual ~GeometryBucket();
                        MaterialBucket* getParent(void) { return mParent; }
                        /// Get the vertex data for this geometry 
                        const VertexData* getVertexData(void) const { return mVertexData; }
                        /// Get the index data for this geometry 
                        const IndexData* getIndexData(void) const { return mIndexData; }
                        /// @copydoc Renderable::getMaterial
                        const MaterialPtr& getMaterial(void) const;
                        Technique* getTechnique(void) const;
                        void getRenderOperation(RenderOperation& op);
                void getWorldTransforms(Matrix4* xform) const;
                const Quaternion& getWorldOrientation(void) const;
                const Vector3& getWorldPosition(void) const;
                        Real getSquaredViewDepth(const Camera* cam) const;
                const LightList& getLights(void) const;
                        bool getCastsShadows(void) const;
                        
                        /** Try to assign geometry to this bucket.
                        @returns false if there is no room left in this bucket
                        */
                        bool assign(QueuedGeometry* qsm);
                        /// Build
                        void build(bool stencilShadows);
                        /// Dump contents for diagnostics
                        void dump(std::ofstream& of) const;
                };
                /** A MaterialBucket is a collection of smaller buckets with the same 
                        Material (and implicitly the same LOD). */
                class _OgreExport MaterialBucket
                {
                public:
                        /// list of Geometry Buckets in this region
                        typedef std::vector<GeometryBucket*> GeometryBucketList;
                protected:
                        /// Pointer to parent LODBucket
                        LODBucket* mParent;
                        /// Material being used
                        String mMaterialName;
                        /// Pointer to material being used
                        MaterialPtr mMaterial;
                        /// Active technique
                        Technique* mTechnique;

                        /// list of Geometry Buckets in this region
                        GeometryBucketList mGeometryBucketList;
                        // index to current Geometry Buckets for a given geometry format
                        typedef std::map<String, GeometryBucket*> CurrentGeometryMap;
                        CurrentGeometryMap mCurrentGeometryMap;
                        /// Get a packed string identifying the geometry format
                        String getGeometryFormatString(SubMeshLodGeometryLink* geom);
                        
                public:
                        MaterialBucket(LODBucket* parent, const String& materialName);
                        virtual ~MaterialBucket();
                        LODBucket* getParent(void) { return mParent; }
                        /// Get the material name
                        const String& getMaterialName(void) const { return mMaterialName; }
                        /// Assign geometry to this bucket
                        void assign(QueuedGeometry* qsm);
                        /// Build
                        void build(bool stencilShadows);
                        /// Add children to the render queue
                        void addRenderables(RenderQueue* queue, uint8 group, 
                                Real camSquaredDist);
                        /// Get the material for this bucket
                        const MaterialPtr& getMaterial(void) const { return mMaterial; }
                        /// Iterator over geometry
                        typedef VectorIterator<GeometryBucketList> GeometryIterator;
                        /// Get an iterator over the contained geometry
                        GeometryIterator getGeometryIterator(void);
                        /// Get the current Technique
                        Technique* getCurrentTechnique(void) const { return mTechnique; }
                        /// Dump contents for diagnostics
                        void dump(std::ofstream& of) const;
                };
                /** A LODBucket is a collection of smaller buckets with the same LOD. 
                @remarks
                        LOD refers to Mesh LOD here. Material LOD can change separately
                        at the next bucket down from this.
                */
                class _OgreExport LODBucket
                {
                public:
                        /// Lookup of Material Buckets in this region
                        typedef std::map<String, MaterialBucket*> MaterialBucketMap;
                protected:
                        /// Pointer to parent region
                        Region* mParent;
                        /// LOD level (0 == full LOD)
                        unsigned short mLod;
                        /// distance at which this LOD starts to apply (squared)
                        Real mSquaredDistance;
                        /// Lookup of Material Buckets in this region
                        MaterialBucketMap mMaterialBucketMap;
                        /// Geometry queued for a single LOD (deallocated here)
                        QueuedGeometryList mQueuedGeometryList;
                public:
                        LODBucket(Region* parent, unsigned short lod, Real lodDist);
                        virtual ~LODBucket();
                        Region* getParent(void) { return mParent; }
                        /// Get the lod index
                        ushort getLod(void) const { return mLod; }
                        /// Get the lod squared distance
                        Real getSquaredDistance(void) const { return mSquaredDistance; }
                        /// Assign a queued submesh to this bucket, using specified mesh LOD
                        void assign(QueuedSubMesh* qsm, ushort atLod);
                        /// Build
                        void build(bool stencilShadows);
                        /// Add children to the render queue
                        void addRenderables(RenderQueue* queue, uint8 group, 
                                Real camSquaredDistance);
                        /// Iterator over the materials in this LOD
                        typedef MapIterator<MaterialBucketMap> MaterialIterator;
                        /// Get an iterator over the materials in this LOD
                        MaterialIterator getMaterialIterator(void);
                        /// Dump contents for diagnostics
                        void dump(std::ofstream& of) const;
                        
                };
                /** The details of a topological region which is the highest level of
                        partitioning for this class.
                @remarks
                        The size & shape of regions entirely depends on the SceneManager
                        specific implementation. It is a MovableObject since it will be
                        attached to a node based on the local centre - in practice it
                        won't actually move (although in theory it could).
                */
                class _OgreExport Region : public MovableObject
                {
                public:
                        /// list of LOD Buckets in this region
                        typedef std::vector<LODBucket*> LODBucketList;
                protected:
                        /** Nested class to allow region shadows. */
                        class _OgreExport RegionShadowRenderable : public ShadowRenderable
                        {
                        protected:
                                Region* mParent;
                                // Shared link to position buffer
                                HardwareVertexBufferSharedPtr mPositionBuffer;
                                // Shared link to w-coord buffer (optional)
                                HardwareVertexBufferSharedPtr mWBuffer;

                        public:
                                RegionShadowRenderable(Region* parent, 
                                        HardwareIndexBufferSharedPtr* indexBuffer, const VertexData* vertexData, 
                                        bool createSeparateLightCap, bool isLightCap = false);
                                ~RegionShadowRenderable();
                                /// Overridden from ShadowRenderable
                                void getWorldTransforms(Matrix4* xform) const;
                                /// Overridden from ShadowRenderable
                                const Quaternion& getWorldOrientation(void) const;
                                /// Overridden from ShadowRenderable
                                const Vector3& getWorldPosition(void) const;
                                HardwareVertexBufferSharedPtr getPositionBuffer(void) { return mPositionBuffer; }
                                HardwareVertexBufferSharedPtr getWBuffer(void) { return mWBuffer; }

                        };
                        /// Parent static geometry
                        StaticGeometry* mParent;
                        /// Scene manager link
                        SceneManager* mSceneMgr;
                        /// Scene node
                        SceneNode* mNode;
                        /// Local list of queued meshes (not used for deallocation)
                        QueuedSubMeshList mQueuedSubMeshes;
                        /// Unique identifier for the region
                        uint32 mRegionID;
                        /// Center of the region
                        Vector3 mCentre;
                        /// LOD distances (squared) as built up - use the max at each level
                        std::vector<Real> mLodSquaredDistances;
                        /// Local AABB relative to region centre
                        AxisAlignedBox mAABB;
                        /// Local bounding radius
                        Real mBoundingRadius;
                        /// The current lod level, as determined from the last camera
                        ushort mCurrentLod;
                        /// Current camera distance, passed on to do material lod later
                        Real mCamDistanceSquared;
                        /// List of LOD buckets                 
                        LODBucketList mLodBucketList;
                        /// List of lights for this region
                        mutable LightList mLightList;
                        /// The last frame that this light list was updated in
                        mutable ulong mLightListUpdated;
                        /// Edge list, used if stencil shadow casting is enabled 
                        EdgeData* mEdgeList;
                        /// List of shadow renderables
                        ShadowRenderableList mShadowRenderables;
                        /// Is a vertex program in use somewhere in this region?
                        bool mVertexProgramInUse;



                public:
                        Region(StaticGeometry* parent, const String& name, SceneManager* mgr, 
                                uint32 regionID, const Vector3& centre);
                        virtual ~Region();
                        // more fields can be added in subclasses
                        StaticGeometry* getParent(void) const { return mParent;}
                        /// Assign a queued mesh to this region, read for final build
                        void assign(QueuedSubMesh* qmesh);
                        /// Build this region
                        void build(bool stencilShadows);
                        /// Get the region ID of this region
                        uint32 getID(void) const { return mRegionID; }
                        /// Get the centre point of the region
                        const Vector3& getCentre(void) const { return mCentre; }
                        const String& getMovableType(void) const;
                        void _notifyCurrentCamera(Camera* cam);
                        const AxisAlignedBox& getBoundingBox(void) const;
                        Real getBoundingRadius(void) const;
                        void _updateRenderQueue(RenderQueue* queue);
                        bool isVisible(void) const;
                        uint32 getTypeFlags(void) const;

                        typedef VectorIterator<LODBucketList> LODIterator;
                        /// Get an iterator over the LODs in this region
                        LODIterator getLODIterator(void);
                        /// Shared set of lights for all GeometryBuckets
                        const LightList& getLights(void) const;
                        /// @copydoc ShadowCaster::getShadowVolumeRenderableIterator
                        ShadowRenderableListIterator getShadowVolumeRenderableIterator(
                                ShadowTechnique shadowTechnique, const Light* light, 
                                HardwareIndexBufferSharedPtr* indexBuffer, 
                                bool extrudeVertices, Real extrusionDistance, unsigned long flags = 0 );
                        /// Overridden from MovableObject
                        EdgeData* getEdgeList(void);


                        /// Dump contents for diagnostics
                        void dump(std::ofstream& of) const;
                        
                };
                /** Indexed region map based on packed x/y/z region index, 10 bits for
                        each axis.
                @remarks
                        Regions are indexed 0-1023 in all axes, where for example region 
                        0 in the x axis begins at mOrigin.x + (mRegionDimensions.x * -512), 
                        and region 1023 ends at mOrigin + (mRegionDimensions.x * 512).
                */
                typedef std::map<uint32, Region*> RegionMap;
        protected:
                // General state & settings
                SceneManager* mOwner;
                String mName;
                bool mBuilt;
                Real mUpperDistance;
                Real mSquaredUpperDistance;
                bool mCastShadows;
                Vector3 mRegionDimensions;
                Vector3 mHalfRegionDimensions;
                Vector3 mOrigin;
                bool mVisible;
        /// The render queue to use when rendering this object
        uint8 mRenderQueueID;
                /// Flags whether the RenderQueue's default should be used.
                bool mRenderQueueIDSet;

                QueuedSubMeshList mQueuedSubMeshes;

                /// List of geometry which has been optimised for SubMesh use
                /// This is the primary storage used for cleaning up later
                OptimisedSubMeshGeometryList mOptimisedSubMeshGeometryList;

                /** Cached links from SubMeshes to (potentially optimised) geometry
                        This is not used for deletion since the lookup may reference
                        original vertex data
                */
                SubMeshGeometryLookup mSubMeshGeometryLookup;
                        
                /// Map of regions
                RegionMap mRegionMap;

                /** Virtual method for getting a region most suitable for the
                        passed in bounds. Can be overridden by subclasses.
                */
                virtual Region* getRegion(const AxisAlignedBox& bounds, bool autoCreate);
                /** Get the region within which a point lies */
                virtual Region* getRegion(const Vector3& point, bool autoCreate);
                /** Get the region using indexes */
                virtual Region* getRegion(ushort x, ushort y, ushort z, bool autoCreate);
                /** Get the region using a packed index, returns null if it doesn't exist. */
                virtual Region* getRegion(uint32 index);
                /** Get the region indexes for a point.
                */
                virtual void getRegionIndexes(const Vector3& point, 
                        ushort& x, ushort& y, ushort& z);
                /** Pack 3 indexes into a single index value
                */
                virtual uint32 packIndex(ushort x, ushort y, ushort z);
                /** Get the volume intersection for an indexed region with some bounds.
                */
                virtual Real getVolumeIntersection(const AxisAlignedBox& box,  
                        ushort x, ushort y, ushort z);
                /** Get the bounds of an indexed region.
                */
                virtual AxisAlignedBox getRegionBounds(ushort x, ushort y, ushort z);
                /** Get the centre of an indexed region.
                */
                virtual Vector3 getRegionCentre(ushort x, ushort y, ushort z);
                /** Calculate world bounds from a set of vertex data. */
                virtual AxisAlignedBox calculateBounds(VertexData* vertexData, 
                        const Vector3& position, const Quaternion& orientation, 
                        const Vector3& scale);
                /** Look up or calculate the geometry data to use for this SubMesh */
                SubMeshLodGeometryLinkList* determineGeometry(SubMesh* sm);
                /** Split some shared geometry into dedicated geometry. */
                void splitGeometry(VertexData* vd, IndexData* id, 
                        SubMeshLodGeometryLink* targetGeomLink);

                typedef std::map<size_t, size_t> IndexRemap;
                /** Method for figuring out which vertices are used by an index buffer
                        and calculating a remap lookup for a vertex buffer just containing
                        those vertices. 
                */
                template <typename T>
                void buildIndexRemap(T* pBuffer, size_t numIndexes, IndexRemap& remap)
                {
                        remap.clear();
                        for (size_t i = 0; i < numIndexes; ++i)
                        {
                                // use insert since duplicates are silently discarded
                                remap.insert(IndexRemap::value_type(*pBuffer++, remap.size()));
                                // this will have mapped oldindex -> new index IF oldindex
                                // wasn't already there
                        }
                }
                /** Method for altering indexes based on a remap. */
                template <typename T>
                void remapIndexes(T* src, T* dst, const IndexRemap& remap, 
                                size_t numIndexes)
                {
                        for (size_t i = 0; i < numIndexes; ++i)
                        {
                                // look up original and map to target
                                IndexRemap::const_iterator ix = remap.find(*src++);
                                assert(ix != remap.end());
                                *dst++ = static_cast<T>(ix->second);
                        }
                }
                
        public:
                /// Constructor; do not use directly (@see SceneManager::createStaticGeometry)
                StaticGeometry(SceneManager* owner, const String& name);
                /// Destructor
                virtual ~StaticGeometry();

                /// Get the name of this object
                const String& getName(void) const { return mName; }
                /** Adds an Entity to the static geometry.
                @remarks
                        This method takes an existing Entity and adds its details to the 
                        list of elements to include when building. Note that the Entity
                        itself is not copied or referenced in this method; an Entity is 
                        passed simply so that you can change the materials of attached 
                        SubEntity objects if you want. You can add the same Entity 
                        instance multiple times with different material settings 
                        completely safely, and destroy the Entity before destroying 
                        this StaticGeometry if you like. The Entity passed in is simply 
                        used as a definition.
                @note Must be called before 'build'.
                @param ent The Entity to use as a definition (the Mesh and Materials 
                        referenced will be recorded for the build call).
                @param position The world position at which to add this Entity
                @param orientation The world orientation at which to add this Entity
                @param scale The scale at which to add this entity
                */
                virtual void addEntity(Entity* ent, const Vector3& position,
                        const Quaternion& orientation = Quaternion::IDENTITY, 
                        const Vector3& scale = Vector3::UNIT_SCALE);

                /** Adds all the Entity objects attached to a SceneNode and all it's
                        children to the static geometry.
                @remarks
                        This method performs just like addEntity, except it adds all the 
                        entities attached to an entire sub-tree to the geometry. 
                        The position / orientation / scale parameters are taken from the
                        node structure instead of being specified manually. 
                @note
                        The SceneNode you pass in will not be automatically detached from 
                        it's parent, so if you have this node already attached to the scene
                        graph, you will need to remove it if you wish to avoid the overhead
                        of rendering <i>both</i> the original objects and their new static
                        versions! We don't do this for you incase you are preparing this 
                        in advance and so don't want the originals detached yet. 
                @note Must be called before 'build'.
                @param node Pointer to the node to use to provide a set of Entity 
                        templates
                */
                virtual void addSceneNode(const SceneNode* node);

                /** Build the geometry. 
                @remarks
                        Based on all the entities which have been added, and the batching 
                        options which have been set, this method constructs     the batched 
                        geometry structures required. The batches are added to the scene 
                        and will be rendered unless you specifically hide them.
                @note
                        Once you have called this method, you can no longer add any more 
                        entities.
                */
                virtual void build(void);

                /** Destroys all the built geometry state (reverse of build). 
                @remarks
                        You can call build() again after this and it will pick up all the
                        same entities / nodes you queued last time.
                */
                virtual void destroy(void);

                /** Clears any of the entities / nodes added to this geometry and 
                        destroys anything which has already been built.
                */
                virtual void reset(void);

                /** Sets the distance at which batches are no longer rendered.
                @remarks
                        This lets you turn off batches at a given distance. This can be 
                        useful for things like detail meshes (grass, foliage etc) and could
                        be combined with a shader which fades the geometry out beforehand 
                        to lessen the effect.
                @param dist Distance beyond which the batches will not be rendered 
                        (the default is 0, which means batches are always rendered).
                */
                virtual void setRenderingDistance(Real dist) { 
                        mUpperDistance = dist; 
                        mSquaredUpperDistance = mUpperDistance * mUpperDistance;
                }

                /** Gets the distance at which batches are no longer rendered. */
                virtual Real getRenderingDistance(void) const { return mUpperDistance; }

                /** Gets the squared distance at which batches are no longer rendered. */
                virtual Real getSquaredRenderingDistance(void) const 
                { return mSquaredUpperDistance; }

                /** Hides or shows all the batches. */
                virtual void setVisible(bool visible);

                /** Are the batches visible? */
                virtual bool isVisible(void) const { return mVisible; }

                /** Sets whether this geometry should cast shadows.
                @remarks
                        No matter what the settings on the original entities,
                        the StaticGeometry class defaults to not casting shadows. 
                        This is because, being static, unless you have moving lights
                        you'd be better to use precalculated shadows of some sort.
                        However, if you need them, you can enable them using this
                        method. If the SceneManager is set up to use stencil shadows,
                        edge lists will be copied from the underlying meshes on build.
                        It is essential that all meshes support stencil shadows in this
                        case.
                @note If you intend to use stencil shadows, you must set this to 
                        true before calling 'build' as well as making sure you set the
                        scene's shadow type (that should always be the first thing you do
                        anyway). You can turn shadows off temporarily but they can never 
                        be turned on if they were not at the time of the build. 
                */
                virtual void setCastShadows(bool castShadows);
                /// Will the geometry from this object cast shadows?
                virtual bool getCastShadows(void) { return mCastShadows; }

                /** Sets the size of a single region of geometry.
                @remarks
                        This method allows you to configure the physical world size of 
                        each region, so you can balance culling against batch size. Entities
                        will be fitted within the batch they most closely fit, and the 
                        eventual bounds of each batch may well be slightly larger than this
                        if they overlap a little. The default is Vector3(1000, 1000, 1000).
                @note Must be called before 'build'.
                @param size Vector3 expressing the 3D size of each region.
                */
                virtual void setRegionDimensions(const Vector3& size) { 
                        mRegionDimensions = size; 
                        mHalfRegionDimensions = size * 0.5;
                }
                /** Gets the size of a single batch of geometry. */
                virtual const Vector3& getRegionDimensions(void) const { return mRegionDimensions; }
                /** Sets the origin of the geometry.
                @remarks
                        This method allows you to configure the world centre of the geometry,
                        thus the place which all regions surround. You probably don't need 
                        to mess with this unless you have a seriously large world, since the
                        default set up can handle an area 1024 * mRegionDimensions, and 
                        the sparseness of population is no issue when it comes to rendering.
                        The default is Vector3(0,0,0).
                @note Must be called before 'build'.
                @param size Vector3 expressing the 3D origin of the geometry.
                */
                virtual void setOrigin(const Vector3& origin) { mOrigin = origin; }
                /** Gets the origin of this geometry. */
                virtual const Vector3& getOrigin(void) const { return mOrigin; }

        /** Sets the render queue group this object will be rendered through.
        @remarks
            Render queues are grouped to allow you to more tightly control the ordering
            of rendered objects. If you do not call this method, all  objects default
            to the default queue (RenderQueue::getDefaultQueueGroup), which is fine for 
                        most objects. You may want to alter this if you want to perform more complex
                        rendering.
        @par
            See RenderQueue for more details.
        @param queueID Enumerated value of the queue group to use.
        */
        virtual void setRenderQueueGroup(uint8 queueID);

        /** Gets the queue group for this entity, see setRenderQueueGroup for full details. */
        virtual uint8 getRenderQueueGroup(void) const;
                
                /// Iterator for iterating over contained regions
                typedef MapIterator<RegionMap> RegionIterator;
                /// Get an iterator over the regions in this geometry
                RegionIterator getRegionIterator(void);

                /** Dump the contents of this StaticGeometry to a file for diagnostic
                        purposes.
                */
                virtual void dump(const String& filename) const;


        };

}

#endif