QgsLineSegment2D class

Represents a single 2D line segment, consisting of a 2D start and end vertex only.

Reference
- Constructors, destructors, conversion operators
- Public functions

Constructors, destructors, conversion operators

QgsLineSegment2D(const QgsPointXY& start, const QgsPointXY& end): Constructor for a QgsLineSegment2D from the specified start point to the end point.
QgsLineSegment2D(double x1, double y1, double x2, double y2): Constructor for a QgsLineSegment2D from the point (x1, y2) to (x2, y2).

Public functions

auto end() const -> QgsPointXY: Returns the segment's end point.
auto endX() const -> double: Returns the segment's end x-coordinate.
auto endY() const -> double: Returns the segment's end y-coordinate.
auto length() const -> double: Returns the length of the segment.
auto lengthSquared() const -> double: Returns the squared length of the segment.
auto operator!=(const QgsLineSegment2D& other) const -> bool: Inequality operator.
auto operator==(const QgsLineSegment2D& other) const -> bool: Equality operator.
auto pointLeftOfLine(const QgsPointXY& point) const -> int: Tests if a point is to the left of the line segment.
void reverse(): Reverses the line segment, so that the start and end points are flipped.
void setEnd(const QgsPointXY& end): Sets the segment's end point.
void setEndX(double x): Sets the segment's end x coordinate.
void setEndY(double y): Sets the segment's end y coordinate.
void setStart(const QgsPointXY& start): Sets the segment's start point.
void setStartX(double x): Sets the segment's start x coordinate.
void setStartY(double y): Sets the segment's start y coordinate.
auto start() const -> QgsPointXY: Returns the segment's start point.
auto startX() const -> double: Returns the segment's start x-coordinate.
auto startY() const -> double: Returns the segment's start y-coordinate.

Function documentation

QgsPointXY QgsLineSegment2D::end() const

Returns the segment's end point.

double QgsLineSegment2D::endX() const

Returns the segment's end x-coordinate.

double QgsLineSegment2D::endY() const

Returns the segment's end y-coordinate.

double QgsLineSegment2D::length() const

Returns the length of the segment.

double QgsLineSegment2D::lengthSquared() const

Returns the squared length of the segment.

int QgsLineSegment2D::pointLeftOfLine(const QgsPointXY& point) const

Tests if a point is to the left of the line segment.

Returns -1 if the point falls to the left of the line, or +1 if the point is to the right.

If the return value is 0, then the test was unsuccessful (e.g. due to testing a point exactly on the line, or exactly in line with the segment) and the result is undefined.

void QgsLineSegment2D::setEnd(const QgsPointXY& end)

Sets the segment's end point.

void QgsLineSegment2D::setEndX(double x)

Sets the segment's end x coordinate.

void QgsLineSegment2D::setEndY(double y)

Sets the segment's end y coordinate.

void QgsLineSegment2D::setStart(const QgsPointXY& start)

Sets the segment's start point.

void QgsLineSegment2D::setStartX(double x)

Sets the segment's start x coordinate.

void QgsLineSegment2D::setStartY(double y)

Sets the segment's start y coordinate.

QgsPointXY QgsLineSegment2D::start() const

Returns the segment's start point.

double QgsLineSegment2D::startX() const

Returns the segment's start x-coordinate.

double QgsLineSegment2D::startY() const

Returns the segment's start y-coordinate.