/Users/jab/Documents/Teaching/02585/GEL2_and_demos/GEL/src/Geometry/Triangle.h

#ifndef __GEOMETRY_TRIANGLE_H
#define __GEOMETRY_TRIANGLE_H

#include "CGLA/Vec2f.h"
#include "CGLA/Vec3f.h"
#include "CGLA/Mat3x3f.h"

#define COMPUTE_SIGN

namespace Geometry
{

class Triangle
{
        CGLA::Vec3f vert[3];
        CGLA::Vec3f edge[3];

#ifdef COMPUTE_SIGN
        CGLA::Vec3f vert_norm[3];
        CGLA::Vec3f edge_norm[3];
#endif
        CGLA::Vec3f face_norm;

        CGLA::Vec3f tri_plane_edge_norm[3];
        float edge_len[3];
        
 public:

        Triangle() {}
        
        Triangle(const CGLA::Vec3f& _v0, 
                                         const CGLA::Vec3f& _v1, 
                                         const CGLA::Vec3f& _v2,

                                         const CGLA::Vec3f& _vn0,
                                         const CGLA::Vec3f& _vn1,
                                         const CGLA::Vec3f& _vn2,

                                         const CGLA::Vec3f& _en0,
                                         const CGLA::Vec3f& _en1,
                                         const CGLA::Vec3f& _en2);

        bool intersect(const CGLA::Vec3f&, const CGLA::Vec3f&, float&) const;

        const CGLA::Vec3f get_pmin() const 
        {
                return v_min(vert[0],v_min(vert[1],vert[2]));
        }

        const CGLA::Vec3f get_pmax() const 
        {
                return v_max(vert[0],v_max(vert[1],vert[2]));
        }

        const CGLA::Vec3f centre() const
                {
                        return (vert[0]+vert[1]+vert[2])/3.0f;
                }

        const float area() const 
                {
                        return 0.5 * (cross(edge[0],-edge[2])).length();
                }

        const CGLA::Vec3f get_centre() const 
        {
                CGLA::Vec3f pmin = get_pmin();
                CGLA::Vec3f pmax = get_pmax();
                return (pmax-pmin)/2.0f+pmin;
        }

        bool signed_distance(const CGLA::Vec3f& p, float& sq_dist, float& sgn) const;

        CGLA::Vec3f get_v0() const {return vert[0];}
        CGLA::Vec3f get_v1() const {return vert[1];}
        CGLA::Vec3f get_v2() const {return vert[2];}

        const CGLA::Vec3f& get_edge(int i) const {return edge[i];}

        const CGLA::Vec3f& get_face_norm() const {return face_norm;}
        
};      

}
#endif