#include <LineSegment.h>
Inheritance diagram for geos::geom::LineSegment:
Public Member Functions | |
LineSegment () | |
Segemnt end. | |
LineSegment (const LineSegment &ls) | |
LineSegment (const Coordinate &c0, const Coordinate &c1) | |
Constructs a LineSegment with the given start and end Coordinates. | |
LineSegment (double x0, double y0, double x1, double y1) | |
void | setCoordinates (const Coordinate &c0, const Coordinate &c1) |
const Coordinate & | operator[] (size_t i) const |
Coordinate & | operator[] (size_t i) |
void | setCoordinates (const LineSegment &ls) |
double | getLength () const |
Computes the length of the line segment. | |
bool | isHorizontal () const |
Tests whether the segment is horizontal. | |
bool | isVertical () const |
Tests whether the segment is vertical. | |
int | orientationIndex (const LineSegment &seg) const |
int | orientationIndex (const LineSegment *seg) const |
int | orientationIndex (const Coordinate &p) const |
Determines the orientation index of a Coordinate relative to this segment. | |
void | reverse () |
Reverses the direction of the line segment. | |
void | normalize () |
Puts the line segment into a normalized form. | |
double | angle () const |
the angle this segment makes with the x-axis (in radians) | |
void | midPoint (Coordinate &ret) const |
Computes the midpoint of the segment. | |
double | distance (const LineSegment &ls) const |
Computes the distance between this line segment and another one. | |
double | distance (const Coordinate &p) const |
Computes the distance between this line segment and a point. | |
double | distancePerpendicular (const Coordinate &p) const |
Computes the perpendicular distance between the (infinite) line defined by this line segment and a point. | |
void | pointAlong (double segmentLengthFraction, Coordinate &ret) const |
Computes the Coordinate that lies a given fraction along the line defined by this segment. | |
void | pointAlongOffset (double segmentLengthFraction, double offsetDistance, Coordinate &ret) const |
Computes the Coordinate that lies a given fraction along the line defined by this segment and offset from the segment by a given distance. | |
double | projectionFactor (const Coordinate &p) const |
Compute the projection factor for the projection of the point p onto this LineSegment. | |
double | segmentFraction (const Coordinate &inputPt) const |
Computes the fraction of distance (in [0.0, 1.0] ) that the projection of a point occurs along this line segment. | |
void | project (const Coordinate &p, Coordinate &ret) const |
Compute the projection of a point onto the line determined by this line segment. | |
bool | project (const LineSegment &seg, LineSegment &ret) const |
Project a line segment onto this line segment and return the resulting line segment. | |
void | closestPoint (const Coordinate &p, Coordinate &ret) const |
Computes the closest point on this line segment to another point. | |
int | compareTo (const LineSegment &other) const |
Compares this object with the specified object for order. | |
bool | equalsTopo (const LineSegment &other) const |
Returns true if other is topologically equal to this LineSegment (e.g. irrespective of orientation). | |
CoordinateSequence * | closestPoints (const LineSegment &line) |
CoordinateSequence * | closestPoints (const LineSegment *line) |
bool | intersection (const LineSegment &line, Coordinate &coord) const |
bool | lineIntersection (const LineSegment &line, Coordinate &coord) const |
Computes the intersection point of the lines defined by two segments, if there is one. | |
std::auto_ptr< LineString > | toGeometry (const GeometryFactory &gf) const |
Public Attributes | |
Coordinate | p0 |
Coordinate | p1 |
Segment start. | |
Friends | |
std::ostream & | operator<< (std::ostream &o, const LineSegment &l) |
This class is designed to be easily mutable (to the extent of having its contained points public). This supports a common pattern of reusing a single LineSegment object as a way of computing segment properties on the segments defined by arrays or lists of Coordinates.
TODO: have this class keep pointers rather then real Coordinates ?
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Computes the closest point on this line segment to another point.
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Computes the closest points on two line segments.
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Compares this object with the specified object for order. Uses the standard lexicographic ordering for the points in the LineSegment.
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Returns
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Computes an intersection point between two segments, if there is one. There may be 0, 1 or many intersection points between two segments. If there are 0, null is returned. If there is 1 or more, a single one is returned (chosen at the discretion of the algorithm). If more information is required about the details of the intersection, the LineIntersector class should be used.
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Tests whether the segment is horizontal.
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Tests whether the segment is vertical.
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Computes the intersection point of the lines defined by two segments, if there is one.
There may be 0, 1 or an infinite number of intersection points between two lines. If there is a unique intersection point, it is returned. Otherwise,
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Computes the midpoint of the segment.
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Puts the line segment into a normalized form. This is useful for using line segments in maps and indexes when topological equality rather than exact equality is desired. |
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Determines the orientation index of a Coordinate relative to this segment. The orientation index is as defined in CGAlgorithms::computeOrientation.
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Determines the orientation of a LineSegment relative to this segment. The concept of orientation is specified as follows: Given two line segments A and L, <ul A is to the left of a segment L if A lies wholly in the closed half-plane lying to the left of L A is to the right of a segment L if A lies wholly in the closed half-plane lying to the right of L otherwise, A has indeterminate orientation relative to L. This happens if A is collinear with L or if A crosses the line determined by L.
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Computes the Coordinate that lies a given fraction along the line defined by this segment.
A fraction of
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Computes the Coordinate that lies a given fraction along the line defined by this segment and offset from the segment by a given distance.
A fraction of The computed point is offset to the left of the line if the offset distance is positive, to the right if negative.
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Project a line segment onto this line segment and return the resulting line segment. The returned line segment will be a subset of the target line line segment. This subset may be null, if the segments are oriented in such a way that there is no projection. Note that the returned line may have zero length (i.e. the same endpoints). This can happen for instance if the lines are perpendicular to one another.
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Compute the projection of a point onto the line determined by this line segment. Note that the projected point may lie outside the line segment. If this is the case, the projection factor will lie outside the range [0.0, 1.0]. |
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Compute the projection factor for the projection of the point p onto this LineSegment. The projection factor is the constant r by which the vector for this segment must be multiplied to equal the vector for the projection of p on the line defined by this segment. The projection factor returned will be in the range (-inf, +inf)
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Computes the fraction of distance (in
If the point is beyond either ends of the line segment, the closest fractional value (
Essentially, this is the projectionFactor clamped to the range
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Creates a LineString with the same coordinates as this segment
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