GEOS  3.8.0dev
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geos::noding::snapround::MCIndexSnapRounder Class Reference

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:
geos::noding::Noder

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

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
segStringsa collection of SegmentStrings to node

Implements geos::noding::Noder.

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
edgesthe list of segment strings to snap together NOTE: they must be instances of NodedSegmentString, or an assertion will fail.
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 const SegmentStrings. Caller is responsible to delete container and elements.

Implements geos::noding::Noder.


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