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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.

## ◆ 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.

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