Triangle.h

/****************************************************************************
 * Copyright 2005 Evan Drumwright
 * This library is distributed under the terms of the GNU General Public 
 * License (found in COPYING).
 ****************************************************************************/

#ifndef _TRIANGLE_H
#define _TRIANGLE_H

#include <ostream>
#include <boost/shared_ptr.hpp>
#include <Physsim/Base.h>
#include <Physsim/Vector3.h>
#include <Physsim/Matrix4.h>

namespace Physsim {

class Triangle : public Base
{
        public:
                Triangle(Vector3ConstPtr a, Vector3ConstPtr b, Vector3ConstPtr c);
                Triangle(const Vector3& a, const Vector3& b, const Vector3& c);
                Triangle() {}
                ~Triangle();
                Triangle(const Triangle& t) : Base() { operator=(t); }
                void operator=(const Triangle& t);
                static bool intersects(const Triangle& t1, const Triangle& t2);
                static Triangle transform(const Triangle& t, const Matrix4& m);
                Vector3ConstPtr get_vertex(unsigned i) const;
                const Vector3& normal() const { return _normal; }
                bool on_vertex(const Vector3& x) const;
                bool on_edge(const Vector3& x) const;
                bool inside(const Vector3& x) const;
                bool strictly_inside(const Vector3& x) const;
                void to_VRML(std::ostream& o, bool wireframe) const;
                void set_a(Vector3ConstPtr a);
                void set_b(Vector3ConstPtr b);
                void set_c(Vector3ConstPtr c);
                void set_a(const Vector3& a) { set_a(Vector3ConstPtr(new Vector3(a))); }
                void set_b(const Vector3& b) { set_b(Vector3ConstPtr(new Vector3(b))); }
                void set_c(const Vector3& c) { set_c(Vector3ConstPtr(new Vector3(c))); }
                Real get_area() const { return _area; }
                void force_normal_update();
                Real calc_distance(const Vector3& point, Vector3& closest_point) const;

                Real get_d() const { return _d; }

//              void transform(const Matrix4& m);
                
                Vector3ConstPtr a() const { return _a; }
                
                Vector3ConstPtr b() const { return _b; }
                
                Vector3ConstPtr c() const { return _c; }

        private:
                Real _area;
                Vector3 _normal;
                Vector3ConstPtr _a, _b, _c;
                Real _d;

                void calc_area();
                void det_params(const Vector3& x, Real& s, Real& t) const;
                static bool project6(const Vector3&, const Vector3&, const Vector3&, const Vector3&, const Vector3&, const Vector3&, const Vector3&);
}; // end class

std::ostream& operator<<(std::ostream& o, const Triangle& t);

} // end namespace Physsim

#endif

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