/*

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

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 __StaticFaceGroup_H__

#define __StaticFaceGroup_H__

#include "OgrePrerequisites.h"

#include "OgrePlane.h"

#include "OgrePatchSurface.h"

namespace Ogre {

    /** \addtogroup Core

    *  @{

    */

    /** \addtogroup Scene

    *  @{

    */

    /** A type of face group, i.e. face list of procedural etc */

    enum FaceGroupType {

        FGT_FACE_LIST,

        FGT_PATCH,

        FGT_UNKNOWN

    };

    /** Collects a group of static i.e. immovable faces together which have common

        properties like the material they use, the plane they lie on.

        Whilst for discrete geometry (i.e. movable objects) groups of faces are

        held in the SubMesh class, for immovable objects like scenery there

        needs to ba little more flexibility in the grouping since the group is

        likely to be a small part of a huge set of geometry. In addition, because

        the faces are unmoving certain optimisations can be performed, e.g.

        precalculating a world-coordinate bounding box and normal.

        @par

            Exactly how this class is used depends on the format of the large

            static geometry used in the level. An example would be the use of this

            class in the BspNode class for indoor levels.

            For flexibility and efficiency, it is not assumed that this class holds

            details of the vertices itself, or in fact that it holds the vertex indices

            itself. Everything is manipulated via pointers so if you want this

            class to point into a block of geometry data it can.

    */

    struct StaticFaceGroup {

        // Type of face group.

        FaceGroupType fType;

        /// Is this a sky surface?

        bool isSky;

        /** Index into a buffer containing vertex definitions. Because we're

            dealing with subsets of large levels this is likely to be part-way

            through a huge vertex buffer. */

        int vertexStart;

        /** The range of vertices in the buffer this facegroup references.

            This is really for copying purposes only, so that we know which

            subset of vertices to copy from our large-level buffer into the rendering buffer.

        */

        int numVertices;

        /** Index into a buffer containing vertex indices. This buffer

            may be individual to this group or shared for memory allocation

            efficiency.The vertex indexes are relative the the mVertexStart pointer,

            not to the start of the large-level buffer, allowing simple reindexing

            when copying data into rendering buffers.

            This is only applicable to FGT_FACE_LIST face group types.

        */

        int elementStart;

        /** The number of vertex indices.

            This is only applicable to FGT_FACE_LIST face group types.

        */

        int numElements;

        /** Handle to material used by this group.

            Note the use of the material handle rather than the material

            name - this is for efficiency since there will be many of these.

        */

        ResourceHandle materialHandle;

        Plane plane;

        /// Patch surface (only applicable when fType = FGT_PATCH)

        PatchSurface* patchSurf;

        friend std::ostream& operator<<(std::ostream& o, const StaticFaceGroup& s)

        {

            o << "StaticFaceGroup(";

            if (s.fType == FGT_FACE_LIST)

            {

                o << "faceList, numVertices=" << s.numVertices << ", vertexStart=" << s.vertexStart;

                o << ", numElements=" << s.numElements << ", elementStart=" << s.elementStart;

                o << ", normal=" << s.plane.normal;

            }

            else if (s.fType == FGT_PATCH)

            {

                o << "bezierPatch, numVertices=" << s.numVertices << ", vertexStart=" << s.vertexStart;

                // TODO

            }

            o << ", materialHandle=" << s.materialHandle;

            o << ")";

            return o;

        }

    };

    /** @} */

    /** @} */

} // namespace

#endif