source: GTP/trunk/App/Demos/Illum/PathMap/TriangleMesh.h @ 896

#pragma once
#include "Intersectable.hpp"
#include "KDTree.hpp"
#include <iostream>

class Radion;

#ifndef D3DVERTEX__DEFINED
struct D3DVERTEX{
        D3DXVECTOR3 pos;
        D3DXVECTOR3 normal;
        D3DXVECTOR2 tex0;
};
#define D3DVERTEX__DEFINED
#endif

/*!
\brief ray-tracable representaion of a mesh
TriangleMesh encapsulates a kd-tree containing triangles. It can be constructed using the vertex and index
buffers of a mesh. Ray-intersection and random surface sampling are supported.
*/
class TriangleMesh :
        public Intersectable
{
//      const Material*         material;
        KDTree* meshTree;

        Vector* meshVertices;
        Vector* normals;
        Vector* texCoords;
        unsigned int nMeshVertices;

        /*!
        \brief A triangle with ray-intersection.
        */
        class Patch : public Intersectable{
                public:
                static Vector*  meshVertices;   //!< a temporary reference to the owner TriangleMesh's vertex array
                static Vector*  meshNormals;    //!< a temporary reference to the owner TriangleMesh's normal array
                static Vector*  meshTexCoords;  //!< a temporary reference to the owner TriangleMesh's texcoord array
                Vector                  flatNormal;                                     //!< triangle normal
                float                   hyperPlaneShiftOffset;          //!< triangle plane offset
                Vector                  inverseVertexMatrix[3];         //!< Descartes to barycentric matrix
                unsigned short vertexIndices[3];                        //!< triangle vertex indices
                bool intersect(const Ray& ray, float& depth, float rayMin, float rayMax);
                bool intersectBackSide(const Ray& ray, float& depth, float rayMin, float rayMax);
                void sampleSurface(Radion& radion); //power = brdf
        } *meshPatches; //!< mesh triangles array

        unsigned int nMeshPatches;                      //!< number of mesh triangles
        unsigned int nAreaTreeNodes;            //!< number of nodes in area tree (for selection ~ area)
        double getPatchArea(unsigned int index);

        double surfaceArea;                                     //!< total surface
        double* areaTree;                                       //!< area tree nodes array
        void buildAreaTree();                           //!< build area tree from root
        double buildAreaTree(unsigned int u);   //!< build area tree from given node (recursively)
public:
        float getSurfaceArea();                                 //!< return total surface area
        void sampleSurface(Radion& radion);             //!< return random surface radion
private:
        void sampleSurface(unsigned int u, double rnd, Radion& radion); //!< return random surface radion from area subtree under node u (recursive)
public:
        TriangleMesh(std::istream& isc, Material** materialTable, int nMaterials);
        void getTransformedBoundingBox(const Transformation& tf, BoundingBox& bb);
        bool intersectBackSide(const Ray& ray, float& depth, float rayMin, float rayMax);
        bool intersect(const Ray& ray, float& depth, float rayMin, float rayMax);
        ~TriangleMesh(void);

        //! constructor to build a TriangleMesh from mesh buffers. Vertex format has to be per struct D3DVERTEX.
        TriangleMesh(Material* material, unsigned short* indexBuffer, unsigned int nFaces,
                                                   D3DVERTEX* vertexBuffer, unsigned int nVertices);

};