#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);

};