pal::GeomFunction Class Reference

Pal labeling engine geometry functions. More...

#include <geomfunction.h>

Static Public Member Functions
static bool	computeLineIntersection (double x1, double y1, double x2, double y2, double x3, double y3, double x4, double y4, double *x, double *y)
	Compute the point where two lines intersect.
static bool	containsCandidate (const GEOSPreparedGeometry *geom, double x, double y, double width, double height, double alpha)
	Returns true if a GEOS prepared geometry totally contains a label candidate.
static std::vector< int >	convexHullId (std::vector< int > &id, const std::vector< double > &x, const std::vector< double > &y)
	Compute the convex hull in O(n·log(n)).
static double	cross_product (double x1, double y1, double x2, double y2, double x3, double y3)
static void	findLineCircleIntersection (double cx, double cy, double radius, double x1, double y1, double x2, double y2, double &xRes, double &yRes)
static bool	isSegIntersects (double x1, double y1, double x2, double y2, double x3, double y3, double x4, double y4)
	Returns true if the two segments intersect.
static bool	reorderPolygon (std::vector< double > &x, std::vector< double > &y)
	Reorder points to have cross prod ((x,y)[i], (x,y)[i+1), point) > 0 when point is outside.

Detailed Description

Pal labeling engine geometry functions.

Note

not available in Python bindings

Definition at line 50 of file geomfunction.h.

Member Function Documentation

computeLineIntersection()

bool GeomFunction::computeLineIntersection ( double x1, double y1, double x2, double y2, double x3, double y3, double x4, double y4, double * x, double * y )

static

Compute the point where two lines intersect.

Returns

true if the lines intersect, or false if the lines are parallel

Definition at line 145 of file geomfunction.cpp.

containsCandidate()

bool GeomFunction::containsCandidate ( const GEOSPreparedGeometry * geom, double x, double y, double width, double height, double alpha )

static

Returns true if a GEOS prepared geometry totally contains a label candidate.

Parameters

geom	GEOS prepared geometry
x	candidate x
y	candidate y
width	candidate width
height	candidate height
alpha	candidate angle

Returns

true if candidate is totally contained

Definition at line 306 of file geomfunction.cpp.

convexHullId()

std::vector< int > GeomFunction::convexHullId ( std::vector< int > & id, const std::vector< double > & x, const std::vector< double > & y )

static

Compute the convex hull in O(n·log(n)).

Parameters

id	set of point (i.e. point no 0 is (x,y) = x[id[0]],y[id[0]])
x	x coordinates
y	y coordinates

Returns

convexHull vertex ids

Definition at line 175 of file geomfunction.cpp.

cross_product()

double pal::GeomFunction::cross_product ( double x1, double y1, double x2, double y2, double x3, double y3 )

inlinestatic

Definition at line 63 of file geomfunction.h.

findLineCircleIntersection()

void GeomFunction::findLineCircleIntersection ( double cx, double cy, double radius, double x1, double y1, double x2, double y2, double & xRes, double & yRes )

static

Definition at line 352 of file geomfunction.cpp.

isSegIntersects()

bool GeomFunction::isSegIntersects ( double x1, double y1, double x2, double y2, double x3, double y3, double x4, double y4 )

static

Returns true if the two segments intersect.

Definition at line 138 of file geomfunction.cpp.

reorderPolygon()

bool GeomFunction::reorderPolygon ( std::vector< double > & x, std::vector< double > & y )

static

Reorder points to have cross prod ((x,y)[i], (x,y)[i+1), point) > 0 when point is outside.

Definition at line 268 of file geomfunction.cpp.

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The documentation for this class was generated from the following files:

• /build/qgis-3.99.0+git20251207+21b3aa880ba+99sid/src/core/pal/geomfunction.h
• /build/qgis-3.99.0+git20251207+21b3aa880ba+99sid/src/core/pal/geomfunction.cpp