#ifndef TRI_MESH_H
#define TRI_MESH_H

#include <vector>

#include "lin_alg.h"
#include "entity.h"
#include "triangle.h"
#include "texture_eval.h"

struct tri_struct
{
	tri_struct(int x, int y, int z) {a=x; b=y; c=z;}
	vector3d norm;
	int a, b, c;
};

struct tri_mesh : Entity
{
	tri_mesh(){phong = false; texture = 0;}
	tri_mesh(const char*file) {load(file); texture = 0;}
	virtual ~tri_mesh(){}
	void load(const char*file);
	std::vector<vector3d> pts;
	std::vector<tri_struct> tris;
	std::vector<vector3d> norms;
	bool phong;
	TextureEval * texture;

	virtual RayIntersect CalcRayIntersect(Ray ray, int flags, int special=-1);
	virtual vector3d CalcNormal(Ray ray, RayIntersect& ri)
		{
			tri_struct & ts = tris[ri.special];
			if(phong)
			{
				double aa = ri.special0;
				double bb = ri.special1;
				double cc = 1 - aa - bb;
				return (norms[ts.a] * aa + norms[ts.b] * bb +
					norms[ts.c] * cc).ret_unit();
			}
			else
			{
				return ts.norm;
			}
		}
	virtual void PathCompress(const Transform&,
				  queue<pair<Entity*, Transform> >&,
				  vector<Entity*>&);
	virtual int IntersectionTest(Ray ray, int flags, int special=-1);
	virtual void GridCollect(vector<EntityWrapBound>& vec);
	virtual Color GetTextureColor(Ray ray, RayIntersect& ri)
		{
			if(!texture)
				return Color();

			Color c;
			c.rgb = texture->Eval(ray.o + ray.d * ri.param_t);
			return c;
		}
	virtual bool HasTexture() {return (bool)texture;}
	void SetTexture(TextureEval * t) {texture = t;}

	void CalcNorms();
};

#endif