geomview_stream.h

很多二维 三维几何计算算法 C++ 类库

    output_segment(gv, segment);
    return gv;
}
#endif

#if defined CGAL_SEGMENT_3_H && \
   !defined CGAL_GV_OUT_SEGMENT_3_H
#define CGAL_GV_OUT_SEGMENT_3_H
template < class R >
Geomview_stream&
operator<<(Geomview_stream &gv, const Segment_3<R> &segment)
{
    output_segment(gv, segment);
    return gv;
}
#endif

// The following code is the same for Triangle_2 and Triangle_3.
template < class Triangle >
void
output_triangle(Geomview_stream &gv, const Triangle &triangle)
{
    bool ascii_bak = gv.set_ascii_mode();
    gv << "(geometry " << gv.get_new_id("Tr")
       << " {appearance {+edge material {edgecolor "
       << gv.ecr()  << gv.ecg()  << gv.ecb() <<  " } shading constant}{ ";
    gv.set_binary_mode();
    // it's a planar polygon
    gv << "OFF BINARY\n"

    // it has 3 vertices, 1 face and 3 edges
       << 3 << 1 << 3;

    bool raw_bak = gv.set_raw(true);
    for(int i=0; i<3; i++)
        gv << triangle[i];
    gv.set_raw(raw_bak);

    // the face
    gv << 3 << 0 << 1 << 2 << 4 << gv.fcr() << gv.fcg() << gv.fcb() << 1.0
       << "}})";
    gv.set_ascii_mode(ascii_bak);
}

// Draws a set of triangles as OFF format (it's faster than one by one).
template < class InputIterator >
void
Geomview_stream::draw_triangles(InputIterator begin, InputIterator end)
{
    typedef typename std::iterator_traits<InputIterator>::value_type  Triangle;
    typedef typename Kernel_traits<Triangle>::Kernel                  Kernel;
    typedef typename Kernel::Point_3                                  Point;
    typedef typename Kernel::Less_xyz_3                               Comp;

    // We first copy everything in a vector to only require an InputIterator.
    std::vector<Triangle> triangles(begin, end);
    typedef typename std::vector<Triangle>::const_iterator            Tit;

    // Put the points in a map and a vector.
    // The index of a point in the vector is the value associated
    // to it in the map.
    typedef std::map<Point, int, Comp>  Point_map;
    Point_map           point_map(Kernel().less_xyz_3_object());
    std::vector<Point>  points;
    for (Tit i = triangles.begin(); i != triangles.end(); ++i)
        for (int j = 0; j < 3; ++j)
	    if (point_map.insert(typename Point_map::value_type(i->vertex(j),
					        points.size())).second)
                points.push_back(i->vertex(j));

    bool ascii_bak = get_ascii_mode();
    bool raw_bak = set_raw(true);

    // Header.
    set_binary_mode();
    (*this) << "(geometry " << get_new_id("triangles")
            << " {appearance {}{ OFF BINARY\n"
            << points.size() << triangles.size() << 0;

    // Points coordinates.
    std::copy(points.begin(), points.end(),
              Ostream_iterator<Point, Geomview_stream>(*this));

    // Triangles vertices indices.
    for (Tit tit = triangles.begin(); tit != triangles.end(); ++tit) {
        (*this) << 3;
	for (int j = 0; j < 3; ++j)
	    (*this) << point_map[tit->vertex(j)];
        (*this) << 0; // without color.
    }
    // Footer.
    (*this) << "}})";

    set_raw(raw_bak);
    set_ascii_mode(ascii_bak);
}

#if defined CGAL_TRIANGLE_2_H && \
   !defined CGAL_GV_OUT_TRIANGLE_2_H
#define CGAL_GV_OUT_TRIANGLE_2_H
template < class R >
Geomview_stream&
operator<<(Geomview_stream &gv, const Triangle_2<R> &triangle)
{
    output_triangle(gv, triangle);
    return gv;
}
#endif

#if defined CGAL_TRIANGLE_3_H && \
   !defined CGAL_GV_OUT_TRIANGLE_3_H
#define CGAL_GV_OUT_TRIANGLE_3_H
template < class R >
Geomview_stream&
operator<<(Geomview_stream &gv, const Triangle_3<R> &triangle)
{
    output_triangle(gv, triangle);
    return gv;
}
#endif

#if defined CGAL_TETRAHEDRON_3_H && \
   !defined CGAL_GV_OUT_TETRAHEDRON_3_H
#define CGAL_GV_OUT_TETRAHEDRON_3_H
template < class R >
Geomview_stream&
operator<<(Geomview_stream &gv, const Tetrahedron_3<R> &t)
{
    bool ascii_bak = gv.set_ascii_mode();
    gv << "(geometry " << gv.get_new_id("Tetra")
       << " {appearance {}{ ";
    gv.set_binary_mode();
    gv << "OFF BINARY\n"

    // it has 4 vertices, 4 face and 6 edges
       << 4 << 4 << 6 ;

    // the vertices
    bool raw_bak = gv.set_raw(true);
    for(int i=0; i<4; i++)
        gv << t[i];
    gv.set_raw(raw_bak);

    // the faces
    double r = gv.fcr(),
           g = gv.fcg(),
           b = gv.fcb();
    gv << 3 << 0 << 1 << 2 << 4 << r << g << b << 1.0
       << 3 << 3 << 0 << 1 << 4 << r << g << b << 1.0
       << 3 << 3 << 1 << 2 << 4 << r << g << b << 1.0
       << 3 << 3 << 0 << 2 << 4 << r << g << b << 1.0
       << "}})";
    gv.set_ascii_mode(ascii_bak);
    return gv;
}
#endif

#if defined CGAL_SPHERE_3_H && \
   !defined CGAL_GV_OUT_SPHERE_3_H
#define CGAL_GV_OUT_SPHERE_3_H
template < class R >
Geomview_stream&
operator<<(Geomview_stream &gv, const Sphere_3<R> &S)
{
    bool ascii_bak = gv.set_ascii_mode();
    gv << "(geometry " << gv.get_new_id("Sph")
       << " {appearance {+edge material {edgecolor "
       << gv.ecr()  << gv.ecg()  << gv.ecb() <<  "} shading constant}{ "
       << "SPHERE\n"
       << CGAL_CLIB_STD::sqrt(CGAL::to_double(S.squared_radius())) << "\n";

    bool raw_bak = gv.set_raw(true);
    gv << Point_3<R>(S.center()) << "}})";
    gv.set_raw(raw_bak);
    gv.set_ascii_mode(ascii_bak);

    return gv;
}
#endif

#if defined CGAL_RAY_2_H && \
   !defined CGAL_GV_OUT_RAY_2_H
#define CGAL_GV_OUT_RAY_2_H
template < class R >
Geomview_stream&
operator<<(Geomview_stream &gv, const Ray_2<R> &r)
{
    // Note: it won't work if double is not convertible to an RT...
    const Bbox_3 & bb = gv.get_bbox();
    Object result = intersection(Iso_rectangle_2<R>(
		                    Point_2<R>(bb.xmin(), bb.ymin()),
		                    Point_2<R>(bb.xmax(), bb.ymax())), r);
    Point_2<R> ipoint;
    Segment_2<R> iseg;
    if (assign(ipoint, result))
	gv << ipoint;
    else if (assign(iseg, result))
	gv << iseg;
    return gv;
}
#endif

#if defined CGAL_LINE_2_H && \
   !defined CGAL_GV_OUT_LINE_2_H
#define CGAL_GV_OUT_LINE_2_H
template < class R >
Geomview_stream&
operator<<(Geomview_stream &gv, const Line_2<R> &r)
{
    // Note: it won't work if double is not convertible to an RT...
    const Bbox_3 & bb = gv.get_bbox();
    Object result = intersection(Iso_rectangle_2<R>(
		                    Point_2<R>(bb.xmin(), bb.ymin()),
		                    Point_2<R>(bb.xmax(), bb.ymax())), r);
    Point_2<R> ipoint;
    Segment_2<R> iseg;
    if (assign(ipoint, result))
	gv << ipoint;
    else if (assign(iseg, result))
	gv << iseg;
    return gv;
}
#endif

// Ray and Line drawing should be done by intersecting them with the BBox
// of the Geomview_stream.  But for now we take the easy approach.

#if defined CGAL_RAY_3_H && \
   !defined CGAL_GV_OUT_RAY_3_H
#define CGAL_GV_OUT_RAY_3_H
template < class R >
Geomview_stream&
operator<<(Geomview_stream &gv, const Ray_3<R> &r)
{
    typename R::Segment_3 s(r.source(), r.point(1));
    gv << s;
    return gv;
}
#endif

#if defined CGAL_LINE_3_H && \
   !defined CGAL_GV_OUT_LINE_3_H
#define CGAL_GV_OUT_LINE_3_H
template < class R >
Geomview_stream&
operator<<(Geomview_stream &gv, const Line_3<R> &r)
{
    typename R::Segment_3 s(r.point(-1), r.point(1));
    gv << s;
    return gv;
}
#endif

Geomview_stream&
operator<<(Geomview_stream &gv, const Bbox_2 &bbox);

Geomview_stream&
operator<<(Geomview_stream &gv, const Bbox_3 &bbox);

#if defined CGAL_POINT_3_H && !defined CGAL_GV_IN_POINT_3_H
#define CGAL_GV_IN_POINT_3_H
template < class R >
Geomview_stream&
operator>>(Geomview_stream &gv, Point_3<R> &point)
{
    const char *gclpick =
	"(pick world pickplane * nil nil nil nil nil nil nil)";

    bool ascii_bak = gv.set_ascii_mode();
    gv << "(pickable pickplane yes) (ui-target pickplane yes)"
       << "(interest " << gclpick << ")";

    char sexpr[1024];
    gv >> sexpr;  // this reads a gcl expression

    const char* pickpoint = Geomview_stream::nth(sexpr, 3);
    // this gives something as: (0.0607123 0.0607125 4.76837e-07 0.529628)
    double x, y, z, w;
    Geomview_stream::parse_point(pickpoint, x, y, z, w);
    point = Point_3<R>(x, y, z, w);

    // we echo the input
    if (gv.get_echo())
	gv << point;

    // we are done and tell geomview to stop sending pick events
    gv << "(uninterest " << gclpick << ") (pickable pickplane no)";
    gv.set_ascii_mode(ascii_bak);

    return gv;
}
#endif

CGAL_END_NAMESPACE

#endif // CGAL_GEOMVIEW_STREAM_H