Uses Snap Rounding to compute a rounded, fully noded arrangement from a set of SegmentString. More...

#include <MCIndexSnapRounder.h>

Inheritance diagram for geos::noding::snapround::MCIndexSnapRounder:

Public Member Functions
	MCIndexSnapRounder (const geom::PrecisionModel &nPm)

std::vector< SegmentString * > *	getNodedSubstrings () const override
	Returns a collection of fully noded SegmentStrings. The SegmentStrings have the same context as their parent. More...

void	computeNodes (std::vector< SegmentString * > *segStrings) override
	Computes the noding for a collection of SegmentStrings. More...

void	computeVertexSnaps (std::vector< SegmentString * > &edges)

Detailed Description

Uses Snap Rounding to compute a rounded, fully noded arrangement from a set of SegmentString.

Implements the Snap Rounding technique described in Hobby, Guibas & Marimont, and Goodrich et al.

Snap Rounding assumes that all vertices lie on a uniform grid (hence the precision model of the input must be fixed precision, and all the input vertices must be rounded to that precision).

This implementation uses a monotone chains and a spatial index to speed up the intersection tests.

This implementation appears to be fully robust using an integer precision model.

It will function with non-integer precision models, but the results are not 100% guaranteed to be correctly noded.

Member Function Documentation

◆ computeNodes()

void geos::noding::snapround::MCIndexSnapRounder::computeNodes ( std::vector< SegmentString * > * segStrings )

overridevirtual

Computes the noding for a collection of SegmentStrings.

Some Noders may add all these nodes to the input SegmentStrings; others may only add some or none at all.

Parameters

segStrings a collection of SegmentStrings to node The caller remains responsible for releasing the memory associated with the container and its elements.

Implements geos::noding::Noder.

◆ computeVertexSnaps()

void geos::noding::snapround::MCIndexSnapRounder::computeVertexSnaps ( std::vector< SegmentString * > & edges )

Computes nodes introduced as a result of snapping segments to vertices of other segments

Parameters

edges the list of segment strings to snap together NOTE: they must be instances of NodedSegmentString, or an assertion will fail.

◆ getNodedSubstrings()

std::vector<SegmentString*>* geos::noding::snapround::MCIndexSnapRounder::getNodedSubstrings ( ) const

inlineoverridevirtual

Returns a collection of fully noded SegmentStrings. The SegmentStrings have the same context as their parent.

Returns: a newly allocated std::vector of newly allocated SegmentStrings (copies of input, if needs be). Caller is responsible to delete container and elements.