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Straight Rational Lines (rat_line)

Definition

An instance l of the data type rat_line is a directed straight line in the two-dimensional plane.

Creation

rat_line l(rat_point p, rat_point q);
    introduces a variable l of type rat_line. l is initialized to the line passing through points p and q directed form p to q.
Precondition: p != q.
rat_line l(rat_segment s); introduces a variable l of type rat_line. l is initialized to the line supporting segment s.
Precondition: s is nontrivial.

rat_line

l(rat_point p, rat_vector v);
    introduces a variable l of type rat_line. l is initialized to the line passing through points p and p+v.
Precondition: v is a nonzero vector.
rat_line l(rat_ray r); introduces a variable l of type rat_line. l is initialized to the line supporting ray r.

rat_line

l; introduces a variable l of type rat_line.

   

Operations

line l.to_line() returns a floating point approximation of l.
rat_point l.point1() returns a point on l.
rat_point l.point2() returns a second point on l.
rat_segment l.seg() returns a segment on l.
bool l.is_vertical() decides whether l is vertical.
bool l.is_horizontal() decides whether l is horizontal.
bool l.intersection(rat_line g, rat_point& inter)
    returns true if l and g intersect. In case of intersection a common point is returned in inter.
bool l.intersection(rat_segment s, rat_point& inter)
    returns true if l and s intersect. In case of intersection a common point is returned in inter.
rat_line l.translate(rational dx, rational dy)
    returns l translated by vector (dx,dy).
rat_line l.translate(integer dx, integer dy, integer dw)
    returns l translated by vector (dx/dw,dy/dw).
rat_line l.translate(rat_vector v) returns l translated by vector v.
Precondition: v.dim() = 2.
rat_line l + rat_vector v returns l translated by vector v.
rat_line l - rat_vector v returns l translated by vector -v.
rat_line l.rotate90(rat_point q) returns l rotated about q by an angle of 90 degrees.
rat_line l.reflect(rat_point p, rat_point q)
    returns l reflected across the straight line passing through p and q.
rat_line l.reverse() returns l reversed.
rational l.sqr_dist(rat_point q) returns the square of the distance between l and q.
rat_segment l.perpendicular(rat_point p)
    returns the segment perpendicular to l with source p and target on l.
int l.side_of(rat_point p) computes orientation(a, b, p), where a != b and a and b appear in this order on line l.
bool l == g returns true if the l and g are equal as oriented lines.
bool equal_as_sets(rat_line l, rat_line g)
    returns true if the l and g are equal as unoriented lines.

Non-Member Functions

int orientation(rat_line l, rat_point p)
    computes orientation(a, b, p), where a != b and a and b appear in this order on line l.
int cmp_slopes(rat_line l1, rat_line l2)
    returns compare(slope(l_1), slope(l_2)).
rat_line p_bisector(rat_point p, rat_point q)
    returns the perpendicular bisector of p and q. The bisector has p on its left.
Precondition: p != q.


next up previous contents
Next: Rational Polygons (rat_polygon) Up: Basic Data Types for Previous: Rational Rays (rat_ray)
LEDA research project
1998-10-02