#ifndef TRIANGLE_HXX
 #define TRIANGLE_HXX
 
 #include "Primitive.hxx"
 #include "Shader.hxx"
 #include "Box.hxx"
 
 using namespace std;
 
 class Triangle : public Primitive
 {
 	Vec3f a, b, c, edge1, edge2, normal, min, max;
 	Box   box;
 public:
 	Triangle(Vec3f a, Vec3f b, Vec3f c, Shader *shader, PhotonDistributor *photon_distributor)
 		: Primitive(shader, photon_distributor),a(a),b(b),c(c)
 	{
 		// Precomputation general
 		edge1 = b - a;
 		edge2 = c - a;
 
 		// Precomputation normal
 		normal = Cross(edge1, edge2);
 		Normalize(normal);
 
 		// Precomputation bounds
 		box.Extend(a);
 		box.Extend(b);
 		box.Extend(c);
 
 		box.Extend(box.min - Vec3f(Epsilon));
 		box.Extend(box.max + Vec3f(Epsilon));
 	};
 
 	virtual ~Triangle(){};
 
 	virtual bool Intersect(Ray &ray)
 	{
 		const Vec3f pvec = ray.dir ^ edge2;
 
 		const float det = Dot(edge1, pvec);
 		if (fabs(det) < 1E-5)
 			return false;
 
 		const float inv_det = 1.0f / det;
 
 		const Vec3f tvec = ray.org - a;
 		float lambda = Dot(tvec, pvec);
 		lambda *= inv_det;
 
 		if (lambda < 0.0f || lambda > 1.0f)
 			return false;
 
 		const Vec3f qvec = tvec^edge1;
 		float mue = Dot(ray.dir, qvec);
 		mue *= inv_det;
 
 		if (mue < 0.0f || mue + lambda > 1.0f)
 			return false;
 
 		float f = Dot(edge2, qvec);
 		f *= inv_det;
 		if (ray.t <= f || f <  1E-5)
 			return false;
 
 		ray.u = lambda;
 		ray.v = mue;
 
 		ray.t   = f;
 		ray.hit = this;
 
 		return true;
 	};
 
 	virtual Vec3f GetNormal(Ray &ray)
 	{
 		return normal;
 	};
 
 	virtual Box CalcBounds()
 	{
 		return box;
 	}
 };
 
 #endif