Version 5.0 The LEDA User Manual

16.4 Straight Lines in 3D-Space ( d3 line )
1. Definition
An instance l of the data type d3 line is a directed straight line in three-dimensional
space.
#include < LEDA/geo/d3 line.h >
2. Creation
d3 line l(const d3 point& p1 , const d3 point& p2 );
d3 line l(const d3 segment& s);
introduces a variable l of type d3 line. l is initialized to the line
through points p1 , p2 .
Precondition : p1 != p2 .
introduces a variable l of type d3 line. l is initialized to the line
supporting segment s.
Precondition : s is not trivial.
d3 line l;
introduces a variable l of type d3 line. l is initialized to the line
through points (0, 0, 0) and (1, 0, 0).
3. Operations
bool l.contains(const d3 point& p)
returns true if p lies on l.
d3 point l.point1( ) returns a point on l.
d3 point l.point2( ) returns a second point on l.
d3 segment l.seg( ) returns a non-trivial segment on l with the same direction.
bool
bool
bool
l.project xy(line& m) if the projection of l into the xy plane is not a point,
the function returns true and assignes the projection
to m. Otherwise false is returned.
l.project xz(line& m) if the projection of l into the xz plane is not a point,
the function returns true and assignes the projection
to m. Otherwise false is returned.
l.project yz(line& m) if the projection of l into the yz plane is not a point,
the function returns true and assignes the projection
to m. Otherwise false is returned.