cgal/Core/include/CGAL/CORE/geom3d/triangle3d.h

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/****************************************************************************
* Core Library Version 1.7, August 2004
* Copyright (c) 1995-2004 Exact Computation Project
* All rights reserved.
*
* This file is part of CORE (http://cs.nyu.edu/exact/core/).
* You can redistribute it and/or modify it under the terms of the GNU
* General Public License as published by the Free Software Foundation,
* either version 3 of the License, or (at your option) any later version.
*
* Licensees holding a valid commercial license may use this file in
* accordance with the commercial license agreement provided with the
* software.
*
* This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
* WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
*
*
* $URL$
* $Id$
***************************************************************************/
/*****************************************************************
* File: triangle3d.h
* Synopsis:
* Basic 3-dimensional geometry
* Author: Shubin Zhao (shubinz@cs.nyu.edu), 2001.
*
*****************************************************************
* CORE Library Version 1.4 (July 2001)
* Chee Yap <yap@cs.nyu.edu>
* Chen Li <chenli@cs.nyu.edu>
* Zilin Du <zilin@cs.nyu.edu>
*
* Copyright (c) 1995, 1996, 1998, 1999, 2000, 2001 Exact Computation Project
*
* WWW URL: http://cs.nyu.edu/exact/
* Email: exact@cs.nyu.edu
*
* $Id$
*****************************************************************/
#ifndef _TRIANGLE3D_H_
#define _TRIANGLE3D_H_
#include <CGAL/CORE/geom3d/point3d.h>
#include <CGAL/CORE/geom3d/line3d.h>
#include <CGAL/CORE/geom3d/segment3d.h>
#include <CGAL/CORE/geom3d/plane3d.h>
#include <CGAL/CORE/geom3d/polygon3d.h>
class Triangle3d : public GeomObj{
private:
// three vertices
Point3d p0;
Point3d p1;
Point3d p2;
public:
/************************************************************
* constructors
************************************************************/
Triangle3d(const Point3d& v1, const Point3d& v2, const Point3d& v3);
// given three vertices
Triangle3d(const Triangle3d& T);
// given a triangle
Triangle3d(): p0(ORIGIN_3D), p1(ORIGIN_3D), p2(ORIGIN_3D) {}
//trivial triangle
virtual ~Triangle3d() {}
/************************************************************
* member functions
************************************************************/
// view a triangle as a surface
virtual int dim() const { return 2; }
Point3d V1() const { return p0; }
Point3d V2() const { return p1; }
Point3d V3() const { return p2; }
Vector normal() const { return (p1 - p0).cross( p2 - p0); }
// return normal of the plane containing this triangle
Plane3d toPlane() const { return Plane3d(p0,p1,p2); }
Polygon3d* toPolygon() const;
/************************************************************
* predicates
************************************************************/
inline bool isCoplanar( const Point3d& p ) const {
return orientation3d(p0, p1, p2, p) == 0; }
inline bool isCoplanar( const Segment3d& s ) const {
return isCoplanar(s.startPt()) && isCoplanar(s.stopPt()); }
inline bool isCoplanar( const Line3d& l ) const {
return isCoplanar(l.startPt()) && isCoplanar(l.stopPt()); }
inline bool isCoplanar( const Triangle3d& T ) const {
return isCoplanar(T.V1()) && isCoplanar(T.V2()) && isCoplanar(T.V3()); }
inline bool isCoplanar( const Plane3d& pl ) const {
return pl.contains(p0) && pl.contains(p1) && pl.contains(p2); }
// test if p is on triangle
bool contains( const Point3d& p ) const;
// test if s is on triangle
inline bool contains( const Segment3d& s ) const {
return contains( s.startPt() ) && contains( s.stopPt() ); }
// test if T is on triangle
inline bool contains( const Triangle3d& T ) const {
return contains( T.V1() ) && contains( T.V2() ) && contains( T.V3() ); }
bool isOnEdge( const Point3d& p ) const;
// test if p is on the edge
bool inside( const Point3d& p ) const;
// test if p is inside the triangle
/************************************************************
* Intersection
************************************************************/
/** all intersect predicates return the dimension of the intersection
* -1 if disjoint (i.e., parallel but distinct lines)
* 0 if coincident
* 0 if intersect in a point. In this case, the
*
// -1 if disjoint (i.e., parallel but distinct lines)
// 1 if coincident
// 0 if intersect in a point. In this case, the
// intersection point is assigned to p if this is available.
**/
// intersect predicates
bool do_intersect( const Segment3d& s ) const;
bool do_intersect( const Line3d& l ) const;
bool do_intersect( const Plane3d& pl ) const;
bool do_intersect( const Triangle3d& t ) const;
// these are consistent with other classes
// they return the dimension of the intersection
// return -1 if no intersection
int intersects( const Segment3d& s ) const;
int intersects( const Line3d& l ) const;
int intersects( const Plane3d& pl ) const;
int intersects( const Triangle3d& T ) const;
// general intersections
GeomObj* intersection( const Segment3d& s ) const;
GeomObj* intersection( const Line3d& l ) const;
GeomObj* intersection( const Plane3d& pl ) const;
GeomObj* intersection( const Triangle3d& t ) const;
// coplanar intersections
GeomObj* coplanar_intersection( const Segment3d& s ) const;
GeomObj* coplanar_intersection( const Line3d& l ) const;
GeomObj* coplanar_intersection( const Triangle3d& T ) const;
Polygon3d* in_half_plane( const Point3d& pa,
const Point3d& pb,
const Point3d& pSide,
Polygon3d& plg ) const;
int coplanar_orientation( const Point3d& pa, const Point3d& pb,
const Point3d& ps, const Point3d& p ) const;
/************************************************************
* I/O
************************************************************/
friend std::istream& operator>>(std::istream& in, Triangle3d& T);
friend std::ostream& operator<<(std::ostream & out, const Triangle3d & T);
}; //class Triangle3d
#endif