OgreEdgeListBuilder.h

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

Copyright (c) 2000-2013 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 __EdgeListBuilder_H__
#define __EdgeListBuilder_H__

#include "OgrePrerequisites.h"
#include "OgreVector4.h"
#include "OgreHardwareVertexBuffer.h"
#include "OgreRenderOperation.h"

namespace Ogre {
    class _OgreExport EdgeData : public EdgeDataAlloc
    {
    public:
        struct Triangle {
            size_t indexSet; 
            size_t vertexSet;
            size_t vertIndex[3];
            size_t sharedVertIndex[3]; 
                                        // duplicates eliminated (this buffer is not exposed)

            Triangle() :indexSet(0), vertexSet(0) {}
        };
        struct Edge {
            size_t triIndex[2];
            size_t vertIndex[2];
            size_t sharedVertIndex[2];
            bool degenerate;
        };

        // Array of 4D vector of triangle face normal, which is unit vector orthogonal
        // to the triangles, plus distance from origin.
        // Use aligned policy here because we are intended to use in SIMD optimised routines .
        typedef std::vector<Vector4, STLAllocator<Vector4, CategorisedAlignAllocPolicy<MEMCATEGORY_GEOMETRY> > > TriangleFaceNormalList;

        // Working vector used when calculating the silhouette.
        // Use std::vector<char> instead of std::vector<bool> which might implemented
        // similar bit-fields causing loss performance.
        typedef vector<char>::type TriangleLightFacingList;

        typedef vector<Triangle>::type TriangleList;
        typedef vector<Edge>::type EdgeList;

        struct EdgeGroup
        {
            size_t vertexSet;
            const VertexData* vertexData;
            size_t triStart;
            size_t triCount;
            EdgeList edges;

        };

        typedef vector<EdgeGroup>::type EdgeGroupList;

        TriangleList triangles;
        TriangleFaceNormalList triangleFaceNormals;
        TriangleLightFacingList triangleLightFacings;
        EdgeGroupList edgeGroups;
        bool isClosed;


        void updateTriangleLightFacing(const Vector4& lightPos);
        void updateFaceNormals(size_t vertexSet, const HardwareVertexBufferSharedPtr& positionBuffer);



        // Debugging method
        void log(Log* log);
        
    };

    class _OgreExport EdgeListBuilder 
    {
    public:

        EdgeListBuilder();
        virtual ~EdgeListBuilder();
        void addVertexData(const VertexData* vertexData);
        void addIndexData(const IndexData* indexData, size_t vertexSet = 0, 
            RenderOperation::OperationType opType = RenderOperation::OT_TRIANGLE_LIST);

        EdgeData* build(void);

        void log(Log* l);
    protected:

        struct CommonVertex {
            Vector3  position;  // location of point in euclidean space
            size_t index;       // place of vertex in common vertex list
            size_t vertexSet;   // The vertex set this came from
            size_t indexSet;    // The index set this was referenced (first) from
            size_t originalIndex; // place of vertex in original vertex set
        };
        struct Geometry {
            size_t vertexSet;           // The vertex data set this geometry data refers to
            size_t indexSet;            // The index data set this geometry data refers to
            const IndexData* indexData; // The index information which describes the triangles.
            RenderOperation::OperationType opType;  // The operation type used to render this geometry
        };
        struct geometryLess {
            bool operator()(const Geometry& a, const Geometry& b) const
            {
                if (a.vertexSet < b.vertexSet) return true;
                if (a.vertexSet > b.vertexSet) return false;
                return a.indexSet < b.indexSet;
            }
        };
        struct vectorLess {
            bool operator()(const Vector3& a, const Vector3& b) const
            {
                if (a.x < b.x) return true;
                if (a.x > b.x) return false;
                if (a.y < b.y) return true;
                if (a.y > b.y) return false;
                return a.z < b.z;
            }
        };

        typedef vector<const VertexData*>::type VertexDataList;
        typedef vector<Geometry>::type GeometryList;
        typedef vector<CommonVertex>::type CommonVertexList;

        GeometryList mGeometryList;
        VertexDataList mVertexDataList;
        CommonVertexList mVertices;
        EdgeData* mEdgeData;
        typedef map<Vector3, size_t, vectorLess>::type CommonVertexMap;
        CommonVertexMap mCommonVertexMap;
        typedef multimap< std::pair<size_t, size_t>, std::pair<size_t, size_t> >::type EdgeMap;
        EdgeMap mEdgeMap;

        void buildTrianglesEdges(const Geometry &geometry);

        size_t findOrCreateCommonVertex(const Vector3& vec, size_t vertexSet, 
            size_t indexSet, size_t originalIndex);
        void connectOrCreateEdge(size_t vertexSet, size_t triangleIndex, size_t vertIndex0, size_t vertIndex1, 
            size_t sharedVertIndex0, size_t sharedVertIndex1);
    };
}
#endif