QGIS API Documentation
3.22.4-Białowieża (ce8e65e95e)
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Contains various geometry utility functions. More...
#include <qgsgeometryutils.h>
Classes | |
struct | SelfIntersection |
Public Types | |
enum | ComponentType { Vertex , Ring , Part } |
Static Public Member Functions | |
static double | angleBetweenThreePoints (double x1, double y1, double x2, double y2, double x3, double y3) SIP_HOLDGIL |
Calculates the angle between the lines AB and BC, where AB and BC described by points a, b and b, c. More... | |
static bool | angleBisector (double aX, double aY, double bX, double bY, double cX, double cY, double dX, double dY, double &pointX, double &pointY, double &angle) SIP_HOLDGIL |
Returns the point (pointX, pointY) forming the bisector from segment (aX aY) (bX bY) and segment (bX, bY) (dX, dY). More... | |
static bool | angleOnCircle (double angle, double angle1, double angle2, double angle3) SIP_HOLDGIL |
Returns true if an angle is between angle1 and angle3 on a circle described by angle1, angle2 and angle3. More... | |
static double | averageAngle (double a1, double a2) SIP_HOLDGIL |
Averages two angles, correctly handling negative angles and ensuring the result is between 0 and 2 pi. More... | |
static double | averageAngle (double x1, double y1, double x2, double y2, double x3, double y3) SIP_HOLDGIL |
Calculates the average angle (in radians) between the two linear segments from (x1, y1) to (x2, y2) and (x2, y2) to (x3, y3). More... | |
static bool | bisector (double aX, double aY, double bX, double bY, double cX, double cY, double &pointX, double &pointY) SIP_HOLDGIL |
Returns the point (pointX, pointY) forming the bisector from point (aX, aY) to the segment (bX, bY) (cX, cY). More... | |
static double | ccwAngle (double dy, double dx) SIP_HOLDGIL |
Returns the counter clockwise angle between a line with components dx, dy and the line with dx > 0 and dy = 0. More... | |
static bool | circleAngleBetween (double angle, double angle1, double angle2, bool clockwise) SIP_HOLDGIL |
Returns true if, in a circle, angle is between angle1 and angle2. More... | |
static void | circleCenterRadius (const QgsPoint &pt1, const QgsPoint &pt2, const QgsPoint &pt3, double &radius, double ¢erX, double ¢erY) SIP_HOLDGIL |
Returns radius and center of the circle through pt1, pt2, pt3. More... | |
static int | circleCircleInnerTangents (const QgsPointXY ¢er1, double radius1, const QgsPointXY ¢er2, double radius2, QgsPointXY &line1P1, QgsPointXY &line1P2, QgsPointXY &line2P1, QgsPointXY &line2P2) SIP_HOLDGIL |
Calculates the inner tangent points for two circles, centered at center1 and center2 and with radii of radius1 and radius2 respectively. More... | |
static int | circleCircleIntersections (const QgsPointXY ¢er1, double radius1, const QgsPointXY ¢er2, double radius2, QgsPointXY &intersection1, QgsPointXY &intersection2) SIP_HOLDGIL |
Calculates the intersections points between the circle with center center1 and radius radius1 and the circle with center center2 and radius radius2. More... | |
static int | circleCircleOuterTangents (const QgsPointXY ¢er1, double radius1, const QgsPointXY ¢er2, double radius2, QgsPointXY &line1P1, QgsPointXY &line1P2, QgsPointXY &line2P1, QgsPointXY &line2P2) SIP_HOLDGIL |
Calculates the outer tangent points for two circles, centered at center1 and center2 and with radii of radius1 and radius2 respectively. More... | |
static bool | circleClockwise (double angle1, double angle2, double angle3) SIP_HOLDGIL |
Returns true if the circle defined by three angles is ordered clockwise. More... | |
static double | circleLength (double x1, double y1, double x2, double y2, double x3, double y3) SIP_HOLDGIL |
Length of a circular string segment defined by pt1, pt2, pt3. More... | |
static double | circleTangentDirection (const QgsPoint &tangentPoint, const QgsPoint &cp1, const QgsPoint &cp2, const QgsPoint &cp3) SIP_HOLDGIL |
Calculates the direction angle of a circle tangent (clockwise from north in radians) More... | |
static QgsPoint | closestPoint (const QgsAbstractGeometry &geometry, const QgsPoint &point) |
Returns the nearest point on a segment of a geometry for the specified point. More... | |
template<class T > | |
static double | closestSegmentFromComponents (T &container, ComponentType ctype, const QgsPoint &pt, QgsPoint &segmentPt, QgsVertexId &vertexAfter, int *leftOf, double epsilon) |
static int | closestSideOfRectangle (double right, double bottom, double left, double top, double x, double y) |
Returns a number representing the closest side of a rectangle defined by /a right, bottom, left, top to the point at (x, y), where the point may be in the interior of the rectangle or outside it. More... | |
static QgsPoint | closestVertex (const QgsAbstractGeometry &geom, const QgsPoint &pt, QgsVertexId &id) |
Returns the closest vertex to a geometry for a specified point. More... | |
static void | coefficients (const QgsPoint &pt1, const QgsPoint &pt2, double &a, double &b, double &c) SIP_HOLDGIL |
Returns the coefficients (a, b, c for equation "ax + by + c = 0") of a line defined by points pt1 and pt2. More... | |
static double | distanceToVertex (const QgsAbstractGeometry &geom, QgsVertexId id) |
Returns the distance along a geometry from its first vertex to the specified vertex. More... | |
static QVector< QgsLineString * > | extractLineStrings (const QgsAbstractGeometry *geom) |
Returns list of linestrings extracted from the passed geometry. More... | |
static double | gradient (const QgsPoint &pt1, const QgsPoint &pt2) SIP_HOLDGIL |
Returns the gradient of a line defined by points pt1 and pt2. More... | |
static double | interpolateArcValue (double angle, double a1, double a2, double a3, double zm1, double zm2, double zm3) SIP_HOLDGIL |
Interpolate a value at given angle on circular arc given values (zm1, zm2, zm3) at three different angles (a1, a2, a3). More... | |
static QgsPoint | interpolatePointOnArc (const QgsPoint &pt1, const QgsPoint &pt2, const QgsPoint &pt3, double distance) SIP_HOLDGIL |
Interpolates a point on an arc defined by three points, pt1, pt2 and pt3. More... | |
static QgsPoint | interpolatePointOnLine (const QgsPoint &p1, const QgsPoint &p2, double fraction) SIP_HOLDGIL |
Interpolates the position of a point a fraction of the way along the line from p1 to p2. More... | |
static QgsPointXY | interpolatePointOnLine (double x1, double y1, double x2, double y2, double fraction) SIP_HOLDGIL |
Interpolates the position of a point a fraction of the way along the line from (x1, y1) to (x2, y2). More... | |
static QgsPointXY | interpolatePointOnLineByValue (double x1, double y1, double v1, double x2, double y2, double v2, double value) SIP_HOLDGIL |
Interpolates the position of a point along the line from (x1, y1) to (x2, y2). More... | |
static int | leftOfLine (const double x, const double y, const double x1, const double y1, const double x2, const double y2) SIP_HOLDGIL |
Returns a value < 0 if the point (x, y) is left of the line from (x1, y1) -> (x2, y2). More... | |
static int | leftOfLine (const QgsPoint &point, const QgsPoint &p1, const QgsPoint &p2) SIP_HOLDGIL |
Returns a value < 0 if the point point is left of the line from p1 -> p2. More... | |
static double | lineAngle (double x1, double y1, double x2, double y2) SIP_HOLDGIL |
Calculates the direction of line joining two points in radians, clockwise from the north direction. More... | |
static bool | lineCircleIntersection (const QgsPointXY ¢er, double radius, const QgsPointXY &linePoint1, const QgsPointXY &linePoint2, QgsPointXY &intersection) SIP_HOLDGIL |
Compute the intersection of a line and a circle. More... | |
static bool | lineIntersection (const QgsPoint &p1, QgsVector v1, const QgsPoint &p2, QgsVector v2, QgsPoint &intersection) SIP_HOLDGIL |
Computes the intersection between two lines. More... | |
static double | linePerpendicularAngle (double x1, double y1, double x2, double y2) SIP_HOLDGIL |
Calculates the perpendicular angle to a line joining two points. More... | |
static bool | linesIntersection3D (const QgsVector3D &La1, const QgsVector3D &La2, const QgsVector3D &Lb1, const QgsVector3D &Lb2, QgsVector3D &intersection) SIP_HOLDGIL |
An algorithm to calculate an (approximate) intersection of two lines in 3D. More... | |
static QgsPoint | midpoint (const QgsPoint &pt1, const QgsPoint &pt2) SIP_HOLDGIL |
Returns a middle point between points pt1 and pt2. More... | |
static double | normalizedAngle (double angle) SIP_HOLDGIL |
Ensures that an angle is in the range 0 <= angle < 2 pi. More... | |
static void | perpendicularOffsetPointAlongSegment (double x1, double y1, double x2, double y2, double proportion, double offset, double *x, double *y) |
Calculates a point a certain proportion of the way along the segment from (x1, y1) to (x2, y2), offset from the segment by the specified offset amount. More... | |
static QgsLineString | perpendicularSegment (const QgsPoint &p, const QgsPoint &s1, const QgsPoint &s2) SIP_HOLDGIL |
Create a perpendicular line segment from p to segment [s1, s2]. More... | |
static bool | pointContinuesArc (const QgsPoint &a1, const QgsPoint &a2, const QgsPoint &a3, const QgsPoint &b, double distanceTolerance, double pointSpacingAngleTolerance) SIP_HOLDGIL |
Returns true if point b is on the arc formed by points a1, a2, and a3, but not within that arc portion already described by a1, a2 and a3. More... | |
static QgsPoint | pointOnLineWithDistance (const QgsPoint &startPoint, const QgsPoint &directionPoint, double distance) SIP_HOLDGIL |
Returns a point a specified distance toward a second point. More... | |
static void | pointOnLineWithDistance (double x1, double y1, double x2, double y2, double distance, double &x, double &y, double *z1=nullptr, double *z2=nullptr, double *z=nullptr, double *m1=nullptr, double *m2=nullptr, double *m=nullptr) |
Calculates the point a specified distance from (x1, y1) toward a second point (x2, y2). More... | |
static QgsPointSequence | pointsFromWKT (const QString &wktCoordinateList, bool is3D, bool isMeasure) |
Returns a list of points contained in a WKT string. More... | |
static QDomElement | pointsToGML2 (const QgsPointSequence &points, QDomDocument &doc, int precision, const QString &ns, QgsAbstractGeometry::AxisOrder axisOrder=QgsAbstractGeometry::AxisOrder::XY) |
Returns a gml::coordinates DOM element. More... | |
static QDomElement | pointsToGML3 (const QgsPointSequence &points, QDomDocument &doc, int precision, const QString &ns, bool is3D, QgsAbstractGeometry::AxisOrder axisOrder=QgsAbstractGeometry::AxisOrder::XY) |
Returns a gml::posList DOM element. More... | |
static QString | pointsToJSON (const QgsPointSequence &points, int precision) |
Returns a geoJSON coordinates string. More... | |
static json | pointsToJson (const QgsPointSequence &points, int precision) |
Returns coordinates as json object. More... | |
static void | pointsToWKB (QgsWkbPtr &wkb, const QgsPointSequence &points, bool is3D, bool isMeasure) |
Returns a LinearRing { uint32 numPoints; Point points[numPoints]; }. More... | |
static QString | pointsToWKT (const QgsPointSequence &points, int precision, bool is3D, bool isMeasure) |
Returns a WKT coordinate list. More... | |
static QgsPoint | projectPointOnSegment (const QgsPoint &p, const QgsPoint &s1, const QgsPoint &s2) SIP_HOLDGIL |
Project the point on a segment. More... | |
static bool | segmentIntersection (const QgsPoint &p1, const QgsPoint &p2, const QgsPoint &q1, const QgsPoint &q2, QgsPoint &intersectionPoint, bool &isIntersection, double tolerance=1e-8, bool acceptImproperIntersection=false) SIP_HOLDGIL |
Compute the intersection between two segments. More... | |
static void | segmentizeArc (const QgsPoint &p1, const QgsPoint &p2, const QgsPoint &p3, QgsPointSequence &points, double tolerance=M_PI_2/90, QgsAbstractGeometry::SegmentationToleranceType toleranceType=QgsAbstractGeometry::MaximumAngle, bool hasZ=false, bool hasM=false) |
Convert circular arc defined by p1, p2, p3 (p1/p3 being start resp. More... | |
static bool | segmentMidPoint (const QgsPoint &p1, const QgsPoint &p2, QgsPoint &result, double radius, const QgsPoint &mousePos) SIP_HOLDGIL |
Calculates midpoint on circle passing through p1 and p2, closest to the given coordinate mousePos. More... | |
static QgsPoint | segmentMidPointFromCenter (const QgsPoint &p1, const QgsPoint &p2, const QgsPoint ¢er, bool useShortestArc=true) SIP_HOLDGIL |
Calculates the midpoint on the circle passing through p1 and p2, with the specified center coordinate. More... | |
static int | segmentSide (const QgsPoint &pt1, const QgsPoint &pt3, const QgsPoint &pt2) SIP_HOLDGIL |
For line defined by points pt1 and pt3, find out on which side of the line is point pt3. More... | |
static QVector< SelfIntersection > | selfIntersections (const QgsAbstractGeometry *geom, int part, int ring, double tolerance) |
Find self intersections in a polyline. More... | |
static Q_DECL_DEPRECATED bool | setZValueFromPoints (const QgsPointSequence &points, QgsPoint &point) |
A Z dimension is added to point if one of the point in the list points is in 3D. More... | |
static double | skewLinesDistance (const QgsVector3D &P1, const QgsVector3D &P12, const QgsVector3D &P2, const QgsVector3D &P22) SIP_HOLDGIL |
An algorithm to calculate the shortest distance between two skew lines. More... | |
static bool | skewLinesProjection (const QgsVector3D &P1, const QgsVector3D &P12, const QgsVector3D &P2, const QgsVector3D &P22, QgsVector3D &X1, double epsilon=0.0001) SIP_HOLDGIL |
A method to project one skew line onto another. More... | |
static double | sqrDistance2D (const QgsPoint &pt1, const QgsPoint &pt2) SIP_HOLDGIL |
Returns the squared 2D distance between two points. More... | |
static double | sqrDistToLine (double ptX, double ptY, double x1, double y1, double x2, double y2, double &minDistX, double &minDistY, double epsilon) SIP_HOLDGIL |
Returns the squared distance between a point and a line. More... | |
static double | sweepAngle (double centerX, double centerY, double x1, double y1, double x2, double y2, double x3, double y3) SIP_HOLDGIL |
Calculates angle of a circular string part defined by pt1, pt2, pt3. More... | |
static bool | tangentPointAndCircle (const QgsPointXY ¢er, double radius, const QgsPointXY &p, QgsPointXY &pt1, QgsPointXY &pt2) SIP_HOLDGIL |
Calculates the tangent points between the circle with the specified center and radius and the point p. More... | |
static bool | transferFirstMValueToPoint (const QgsPointSequence &points, QgsPoint &point) |
A M dimension is added to point if one of the points in the list points contains an M value. More... | |
static bool | transferFirstZOrMValueToPoint (const QgsGeometry &geom, QgsPoint &point) |
A Z or M dimension is added to point if one of the points in the list points contains Z or M value. More... | |
static bool | transferFirstZOrMValueToPoint (const QgsPointSequence &points, QgsPoint &point) |
A Z or M dimension is added to point if one of the points in the list points contains Z or M value. More... | |
template<class Iterator > | |
static bool | transferFirstZOrMValueToPoint (Iterator verticesBegin, Iterator verticesEnd, QgsPoint &point) |
A Z or M dimension is added to point if one of the points in the list points contains Z or M value. More... | |
static bool | transferFirstZValueToPoint (const QgsPointSequence &points, QgsPoint &point) |
A Z dimension is added to point if one of the point in the list points is in 3D. More... | |
static double | triangleArea (double aX, double aY, double bX, double bY, double cX, double cY) SIP_HOLDGIL |
Returns the area of the triangle denoted by the points (aX, aY), (bX, bY) and (cX, cY). More... | |
static bool | verticesAtDistance (const QgsAbstractGeometry &geometry, double distance, QgsVertexId &previousVertex, QgsVertexId &nextVertex) |
Retrieves the vertices which are before and after the interpolated point at a specified distance along a linestring (or polygon boundary). More... | |
static void | weightedPointInTriangle (double aX, double aY, double bX, double bY, double cX, double cY, double weightB, double weightC, double &pointX, double &pointY) SIP_HOLDGIL |
Returns a weighted point inside the triangle denoted by the points (aX, aY), (bX, bY) and (cX, cY). More... | |
static QStringList | wktGetChildBlocks (const QString &wkt, const QString &defaultType=QString()) |
Parses a WKT string and returns of list of blocks contained in the WKT. More... | |
static QPair< QgsWkbTypes::Type, QString > | wktReadBlock (const QString &wkt) |
Parses a WKT block of the format "TYPE( contents )" and returns a pair of geometry type to contents ("Pair(wkbType, "contents")") More... | |
Contains various geometry utility functions.
Definition at line 38 of file qgsgeometryutils.h.
Enumerator | |
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Vertex | |
Ring | |
Part |
Definition at line 957 of file qgsgeometryutils.h.
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Calculates the angle between the lines AB and BC, where AB and BC described by points a, b and b, c.
x1 | x-coordinate of point a |
y1 | y-coordinate of point a |
x2 | x-coordinate of point b |
y2 | y-coordinate of point b |
x3 | x-coordinate of point c |
y3 | y-coordinate of point c |
Definition at line 1615 of file qgsgeometryutils.cpp.
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Returns the point (pointX, pointY) forming the bisector from segment (aX aY) (bX bY) and segment (bX, bY) (dX, dY).
The bisector segment of AB-CD is (point, projection of point by angle)
aX | x-coordinate of first vertex of the segment ab |
aY | y-coordinate of first vertex of the segment ab |
bX | x-coordinate of second vertex of the segment ab |
bY | y-coordinate of second vertex of the segment ab |
cX | x-coordinate of first vertex of the segment cd |
cY | y-coordinate of first vertex of the segment cd |
dX | x-coordinate of second vertex of the segment cd |
dY | y-coordinate of second vertex of the segment cd |
pointX | x-coordinate of generated point |
pointY | y-coordinate of generated point |
angle | angle of the bisector from pointX, pointY origin on [ab-cd] |
true
if the bisector exists (A B and C D are not collinear)Definition at line 1847 of file qgsgeometryutils.cpp.
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Returns true
if an angle is between angle1 and angle3 on a circle described by angle1, angle2 and angle3.
Definition at line 766 of file qgsgeometryutils.cpp.
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Averages two angles, correctly handling negative angles and ensuring the result is between 0 and 2 pi.
a1 | first angle (in radians) |
a2 | second angle (in radians) |
Definition at line 1637 of file qgsgeometryutils.cpp.
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Calculates the average angle (in radians) between the two linear segments from (x1, y1) to (x2, y2) and (x2, y2) to (x3, y3).
Definition at line 1629 of file qgsgeometryutils.cpp.
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Returns the point (pointX, pointY) forming the bisector from point (aX, aY) to the segment (bX, bY) (cX, cY).
The bisector segment of ABC is (A-point)
aX | x-coordinate of first vertex in triangle |
aY | y-coordinate of first vertex in triangle |
bX | x-coordinate of second vertex in triangle |
bY | y-coordinate of second vertex in triangle |
cX | x-coordinate of third vertex in triangle |
cY | y-coordinate of third vertex in triangle |
pointX | x-coordinate of generated point |
pointY | y-coordinate of generated point |
true
if the bisector exists (A B and C are not collinear)Definition at line 1866 of file qgsgeometryutils.cpp.
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Returns the counter clockwise angle between a line with components dx, dy and the line with dx > 0 and dy = 0.
Definition at line 676 of file qgsgeometryutils.cpp.
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Returns true
if, in a circle, angle is between angle1 and angle2.
Definition at line 740 of file qgsgeometryutils.cpp.
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Returns radius and center of the circle through pt1, pt2, pt3.
Definition at line 690 of file qgsgeometryutils.cpp.
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Calculates the inner tangent points for two circles, centered at center1 and center2 and with radii of radius1 and radius2 respectively.
The inner tangent points correspond to the points at which the two lines which are drawn so that they are tangential to both circles and are crossing each other.
The first tangent line is described by the points stored in line1P1 and line1P2, and the second line is described by the points stored in line2P1 and line2P2.
Returns the number of tangents (either 0 or 2).
Definition at line 499 of file qgsgeometryutils.cpp.
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Calculates the intersections points between the circle with center center1 and radius radius1 and the circle with center center2 and radius radius2.
If found, the intersection points will be stored in intersection1 and intersection2.
Definition at line 375 of file qgsgeometryutils.cpp.
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Calculates the outer tangent points for two circles, centered at center1 and center2 and with radii of radius1 and radius2 respectively.
The outer tangent points correspond to the points at which the two lines which are drawn so that they are tangential to both circles touch the circles.
The first tangent line is described by the points stored in line1P1 and line1P2, and the second line is described by the points stored in line2P1 and line2P2.
Returns the number of tangents (either 0 or 2).
Definition at line 463 of file qgsgeometryutils.cpp.
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Returns true
if the circle defined by three angles is ordered clockwise.
The angles are defined counter-clockwise from the origin, i.e. using Euclidean angles as opposed to geographic "North up" angles.
Definition at line 728 of file qgsgeometryutils.cpp.
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Length of a circular string segment defined by pt1, pt2, pt3.
Definition at line 772 of file qgsgeometryutils.cpp.
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Calculates the direction angle of a circle tangent (clockwise from north in radians)
Definition at line 870 of file qgsgeometryutils.cpp.
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Returns the nearest point on a segment of a geometry for the specified point.
The z and m values will be linearly interpolated between the two neighbouring vertices.
Definition at line 101 of file qgsgeometryutils.cpp.
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Definition at line 965 of file qgsgeometryutils.h.
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Returns a number representing the closest side of a rectangle defined by /a right, bottom, left, top to the point at (x, y), where the point may be in the interior of the rectangle or outside it.
The returned value may be:
Definition at line 1407 of file qgsgeometryutils.cpp.
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Returns the closest vertex to a geometry for a specified point.
On error null point will be returned and "id" argument will be invalid.
Definition at line 67 of file qgsgeometryutils.cpp.
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Returns the coefficients (a, b, c for equation "ax + by + c = 0") of a line defined by points pt1 and pt2.
pt1 | first point. |
pt2 | second point. |
a | Output parameter, a coefficient of the equation. |
b | Output parameter, b coefficient of the equation. |
c | Output parameter, c coefficient of the equation. |
Definition at line 1547 of file qgsgeometryutils.cpp.
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Returns the distance along a geometry from its first vertex to the specified vertex.
geom | geometry |
id | vertex id to find distance to |
Definition at line 134 of file qgsgeometryutils.cpp.
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Returns list of linestrings extracted from the passed geometry.
The returned objects have to be deleted by the caller.
Definition at line 31 of file qgsgeometryutils.cpp.
Returns the gradient of a line defined by points pt1 and pt2.
pt1 | first point. |
pt2 | second point. |
Definition at line 1535 of file qgsgeometryutils.cpp.
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Interpolate a value at given angle on circular arc given values (zm1, zm2, zm3) at three different angles (a1, a2, a3).
Definition at line 1096 of file qgsgeometryutils.cpp.
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Interpolates a point on an arc defined by three points, pt1, pt2 and pt3.
The arc will be interpolated by the specified distance from pt1.
Any z or m values present in the points will also be linearly interpolated in the output.
Definition at line 651 of file qgsgeometryutils.cpp.
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Interpolates the position of a point a fraction of the way along the line from p1 to p2.
Usually the fraction should be between 0 and 1, where 0 represents the point at the start of the line (p1) and 1 represents the end of the line (p2). However, it is possible to use a fraction < 0 or > 1, in which case the returned point is extrapolated from the supplied line.
Any Z or M values present in the input points will also be interpolated and present in the returned point.
Definition at line 1509 of file qgsgeometryutils.cpp.
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Interpolates the position of a point a fraction of the way along the line from (x1, y1) to (x2, y2).
Usually the fraction should be between 0 and 1, where 0 represents the point at the start of the line (x1, y1) and 1 represents the end of the line (x2, y2). However, it is possible to use a fraction < 0 or > 1, in which case the returned point is extrapolated from the supplied line.
Definition at line 1519 of file qgsgeometryutils.cpp.
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Interpolates the position of a point along the line from (x1, y1) to (x2, y2).
The position is interpolated using a supplied target value and the value at the start of the line (v1) and end of the line (v2). The returned point will be linearly interpolated to match position corresponding to the target value.
Definition at line 1526 of file qgsgeometryutils.cpp.
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Returns a value < 0 if the point (x, y) is left of the line from (x1, y1) -> (x2, y2).
A positive return value indicates the point is to the right of the line.
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.
Definition at line 589 of file qgsgeometryutils.cpp.
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Returns a value < 0 if the point point is left of the line from p1 -> p2.
A positive return value indicates the point is to the right of the line.
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.
Definition at line 584 of file qgsgeometryutils.cpp.
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Calculates the direction of line joining two points in radians, clockwise from the north direction.
x1 | x-coordinate of line start |
y1 | y-coordinate of line start |
x2 | x-coordinate of line end |
y2 | y-coordinate of line end |
Definition at line 1608 of file qgsgeometryutils.cpp.
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Compute the intersection of a line and a circle.
If the intersection has two solutions (points), the closest point to the initial intersection point is returned.
center | the center of the circle |
radius | the radius of the circle |
linePoint1 | a first point on the line |
linePoint2 | a second point on the line |
intersection | the initial point and the returned intersection point |
true
if an intersection has been found Definition at line 321 of file qgsgeometryutils.cpp.
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Computes the intersection between two lines.
Z dimension is supported and is retrieved from the first 3D point amongst p1 and p2.
p1 | Point on the first line |
v1 | Direction vector of the first line |
p2 | Point on the second line |
v2 | Direction vector of the second line |
intersection | Output parameter, the intersection point |
Definition at line 242 of file qgsgeometryutils.cpp.
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Calculates the perpendicular angle to a line joining two points.
Returned angle is in radians, clockwise from the north direction.
x1 | x-coordinate of line start |
y1 | y-coordinate of line start |
x2 | x-coordinate of line end |
y2 | y-coordinate of line end |
Definition at line 1622 of file qgsgeometryutils.cpp.
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An algorithm to calculate an (approximate) intersection of two lines in 3D.
La1 | is the first point on the first line, |
La2 | is the second point on the first line, |
Lb1 | is the first point on the second line, |
Lb2 | is the second point on the second line, |
intersection | is the result intersection, of it can be found. |
true
if the intersection can be found, false
- otherwise.Definition at line 1718 of file qgsgeometryutils.cpp.
Returns a middle point between points pt1 and pt2.
Z value is computed if one of this point have Z. M value is computed if one of this point have M.
pt1 | first point. |
pt2 | second point. |
Definition at line 1484 of file qgsgeometryutils.cpp.
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Ensures that an angle is in the range 0 <= angle < 2 pi.
angle | angle in radians |
Definition at line 1321 of file qgsgeometryutils.cpp.
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Calculates a point a certain proportion of the way along the segment from (x1, y1) to (x2, y2), offset from the segment by the specified offset amount.
x1 | x-coordinate of start of segment |
y1 | y-coordinate of start of segment |
x2 | x-coordinate of end of segment |
y2 | y-coordinate of end of segment |
proportion | proportion of the segment's length at which to place the point (between 0.0 and 1.0) |
offset | perpendicular offset from segment to apply to point. A negative offset shifts the point to the left of the segment, while a positive offset will shift it to the right of the segment. |
x | calculated point x-coordinate |
y | calculated point y-coordinate |
Definition at line 634 of file qgsgeometryutils.cpp.
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Create a perpendicular line segment from p to segment [s1, s2].
p | The point |
s1 | The segment start point |
s2 | The segment end point |
Definition at line 1570 of file qgsgeometryutils.cpp.
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Returns true
if point b is on the arc formed by points a1, a2, and a3, but not within that arc portion already described by a1, a2 and a3.
The distanceTolerance specifies the maximum deviation allowed between the original location of point and where it would fall on the candidate arc.
This method only consider a segments as continuing an arc if the points are all regularly spaced on the candidate arc. The pointSpacingAngleTolerance parameter specifies the maximum angular deviation (in radians) allowed when testing for regular point spacing.
Definition at line 895 of file qgsgeometryutils.cpp.
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Returns a point a specified distance toward a second point.
Definition at line 600 of file qgsgeometryutils.cpp.
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Calculates the point a specified distance from (x1, y1) toward a second point (x2, y2).
Optionally, interpolated z and m values can be obtained by specifying the z1, z2 and z arguments and/or the m1, m2, m arguments.
Definition at line 607 of file qgsgeometryutils.cpp.
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Returns a list of points contained in a WKT string.
Definition at line 1116 of file qgsgeometryutils.cpp.
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Returns a gml::coordinates DOM element.
Definition at line 1239 of file qgsgeometryutils.cpp.
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Returns a gml::posList DOM element.
Definition at line 1266 of file qgsgeometryutils.cpp.
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Returns a geoJSON coordinates string.
Definition at line 1288 of file qgsgeometryutils.cpp.
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Returns coordinates as json object.
Definition at line 1304 of file qgsgeometryutils.cpp.
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Returns a LinearRing { uint32 numPoints; Point points[numPoints]; }.
Definition at line 1203 of file qgsgeometryutils.cpp.
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Returns a WKT coordinate list.
Definition at line 1220 of file qgsgeometryutils.cpp.
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Project the point on a segment.
p | The point |
s1 | The segment start point |
s2 | The segment end point |
Definition at line 239 of file qgsgeometryutils.h.
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Compute the intersection between two segments.
p1 | First segment start point |
p2 | First segment end point |
q1 | Second segment start point |
q2 | Second segment end point |
intersectionPoint | Output parameter, the intersection point |
isIntersection | Output parameter, return true if an intersection is found |
tolerance | The tolerance to use |
acceptImproperIntersection | By default, this method returns true only if segments have proper intersection. If set true, returns also TRUE if segments have improper intersection (end of one segment on other segment ; continuous segments). |
Definition at line 261 of file qgsgeometryutils.cpp.
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Convert circular arc defined by p1, p2, p3 (p1/p3 being start resp.
end point, p2 lies on the arc) into a sequence of points.
Definition at line 954 of file qgsgeometryutils.cpp.
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Calculates midpoint on circle passing through p1 and p2, closest to the given coordinate mousePos.
Z dimension is supported and is retrieved from the first 3D point amongst p1 and p2.
Definition at line 814 of file qgsgeometryutils.cpp.
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Calculates the midpoint on the circle passing through p1 and p2, with the specified center coordinate.
If useShortestArc is true
, then the midpoint returned will be that corresponding to the shorter arc from p1 to p2. If it is false
, the longer arc from p1 to p2 will be used (i.e. winding the other way around the circle).
Definition at line 861 of file qgsgeometryutils.cpp.
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For line defined by points pt1 and pt3, find out on which side of the line is point pt3.
Returns -1 if pt3 on the left side, 1 if pt3 is on the right side or 0 if pt3 lies on the line.
Definition at line 1075 of file qgsgeometryutils.cpp.
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Find self intersections in a polyline.
geom | The geometry to check |
part | The part of the geometry to check |
ring | The ring of the geometry part to check |
tolerance | The tolerance to use |
Definition at line 544 of file qgsgeometryutils.cpp.
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A Z dimension is added to point if one of the point in the list points is in 3D.
Moreover, the Z value of point is updated with the first Z value found in list points even if point already contains a Z value.
points | List of points in which a 3D point is searched. |
point | The point to update with Z dimension and value. |
true
if the point is updated, false
otherwiseDefinition at line 788 of file qgsgeometryutils.h.
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An algorithm to calculate the shortest distance between two skew lines.
P1 | is the first point of the first line, |
P12 | is the second point on the first line, |
P2 | is the first point on the second line, |
P22 | is the second point on the second line. |
Definition at line 1664 of file qgsgeometryutils.cpp.
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A method to project one skew line onto another.
P1 | is a first point that belonds to first skew line, |
P12 | is the second point that belongs to first skew line, |
P2 | is the first point that belongs to second skew line, |
P22 | is the second point that belongs to second skew line, |
X1 | is the result projection point of line P2P22 onto line P1P12, |
epsilon | the tolerance to use. |
true
if such point exists, false
- otherwise. Definition at line 1676 of file qgsgeometryutils.cpp.
Returns the squared 2D distance between two points.
Definition at line 198 of file qgsgeometryutils.cpp.
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Returns the squared distance between a point and a line.
Definition at line 203 of file qgsgeometryutils.cpp.
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Calculates angle of a circular string part defined by pt1, pt2, pt3.
Definition at line 784 of file qgsgeometryutils.cpp.
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Calculates the tangent points between the circle with the specified center and radius and the point p.
If found, the tangent points will be stored in pt1 and pt2.
Definition at line 439 of file qgsgeometryutils.cpp.
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A M dimension is added to point if one of the points in the list points contains an M value.
Moreover, the M value of point is updated with the first M value found in list points even if point already contains a M value.
points | List of points in which a M point is searched. |
point | The point to update with M dimension and value. |
true
if the point is updated, false
otherwiseDefinition at line 1811 of file qgsgeometryutils.cpp.
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A Z or M dimension is added to point if one of the points in the list points contains Z or M value.
This method is equivalent to successively calling Z and M but avoiding looping twice over the set of points.
geom | geometry in which a M point is searched. |
point | The point to update with Z or M dimension and value. |
true
if the point is updated, false
otherwiseDefinition at line 908 of file qgsgeometryutils.h.
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inlinestatic |
A Z or M dimension is added to point if one of the points in the list points contains Z or M value.
This method is equivalent to successively calling Z and M but avoiding looping twice over the set of points.
points | List of points in which a M point is searched. |
point | The point to update with Z or M dimension and value. |
true
if the point is updated, false
otherwiseDefinition at line 887 of file qgsgeometryutils.h.
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A Z or M dimension is added to point if one of the points in the list points contains Z or M value.
This method is equivalent to successively calling Z and M but avoiding looping twice over the set of points.
verticesBegin | begin vertex which a Z or M point is searched. |
verticesEnd | end vertex which a Z or M point is searched. |
point | The point to update with Z or M dimension and value. |
true
if the point is updated, false
otherwiseDefinition at line 845 of file qgsgeometryutils.h.
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A Z dimension is added to point if one of the point in the list points is in 3D.
Moreover, the Z value of point is updated with the first Z value found in list points even if point already contains a Z value.
points | List of points in which a 3D point is searched. |
point | The point to update with Z dimension and value. |
true
if the point is updated, false
otherwiseDefinition at line 1829 of file qgsgeometryutils.cpp.
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Returns the area of the triangle denoted by the points (aX, aY), (bX, bY) and (cX, cY).
Definition at line 1787 of file qgsgeometryutils.cpp.
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Retrieves the vertices which are before and after the interpolated point at a specified distance along a linestring (or polygon boundary).
geometry | line or polygon geometry |
distance | distance to traverse along geometry |
previousVertex | will be set to previous vertex ID |
nextVertex | will be set to next vertex ID |
true
if vertices were successfully retrieved Definition at line 153 of file qgsgeometryutils.cpp.
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Returns a weighted point inside the triangle denoted by the points (aX, aY), (bX, bY) and (cX, cY).
aX | x-coordinate of first vertex in triangle |
aY | y-coordinate of first vertex in triangle |
bX | x-coordinate of second vertex in triangle |
bY | y-coordinate of second vertex in triangle |
cX | x-coordinate of third vertex in triangle |
cY | y-coordinate of third vertex in triangle |
weightB | weighting factor along axis A-B (between 0 and 1) |
weightC | weighting factor along axis A-C (between 0 and 1) |
pointX | x-coordinate of generated point |
pointY | y-coordinate of generated point |
Definition at line 1792 of file qgsgeometryutils.cpp.
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Parses a WKT string and returns of list of blocks contained in the WKT.
wkt | WKT string in the format "TYPE1 (contents1), TYPE2 (TYPE3 (contents3), TYPE4 (contents4))" |
defaultType | default geometry type for children |
Definition at line 1367 of file qgsgeometryutils.cpp.
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Parses a WKT block of the format "TYPE( contents )" and returns a pair of geometry type to contents ("Pair(wkbType, "contents")")
Definition at line 1335 of file qgsgeometryutils.cpp.