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 49 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 143 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 304 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 173 of file geomfunction.cpp.

cross_product()

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

inlinestatic

Definition at line 62 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 350 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 136 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 266 of file geomfunction.cpp.

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

• /build/qgis-3.41.0+git20241225+af5edcb665c+99sid/src/core/pal/geomfunction.h
• /build/qgis-3.41.0+git20241225+af5edcb665c+99sid/src/core/pal/geomfunction.cpp