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:

Collaboration 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)
Public Member Functions inherited from geos::noding::Noder
virtual	~Noder ()

Private Member Functions
void	snapRound (MCIndexNoder &noder, std::vector< SegmentString * > *segStrings)
void	findInteriorIntersections (MCIndexNoder &noder, std::vector< SegmentString * > *segStrings, std::vector< geom::Coordinate > &intersections)
void	computeIntersectionSnaps (std::vector< geom::Coordinate > &snapPts)
void	computeVertexSnaps (NodedSegmentString *e)
void	checkCorrectness (std::vector< SegmentString * > &inputSegmentStrings)
	MCIndexSnapRounder (const MCIndexSnapRounder &other)=delete
MCIndexSnapRounder &	operator= (const MCIndexSnapRounder &rhs)=delete

Private Attributes
const geom::PrecisionModel &	pm
	externally owned More...
algorithm::LineIntersector	li
double	scaleFactor
std::vector< SegmentString * > *	nodedSegStrings
std::unique_ptr< MCIndexPointSnapper >	pointSnapper

Additional Inherited Members
Protected Member Functions inherited from geos::noding::Noder
	Noder ()

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.

Definition at line 74 of file MCIndexSnapRounder.h.

Constructor & Destructor Documentation

geos::noding::snapround::MCIndexSnapRounder::MCIndexSnapRounder ( const geom::PrecisionModel &  nPm )

inline

Definition at line 78 of file MCIndexSnapRounder.h.

geos::noding::snapround::MCIndexSnapRounder::MCIndexSnapRounder ( const MCIndexSnapRounder &  other )

privatedelete

Member Function Documentation

void geos::noding::snapround::MCIndexSnapRounder::checkCorrectness ( std::vector< SegmentString * > &  inputSegmentStrings )

private

void geos::noding::snapround::MCIndexSnapRounder::computeIntersectionSnaps ( std::vector< geom::Coordinate > &  snapPts )

private

Computes nodes introduced as a result of snapping segments to snap points (hot pixels)

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.

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.

void geos::noding::snapround::MCIndexSnapRounder::computeVertexSnaps ( NodedSegmentString *  e )

private

Performs a brute-force comparison of every segment in each SegmentString. This has n^2 performance.

void geos::noding::snapround::MCIndexSnapRounder::findInteriorIntersections ( MCIndexNoder &  noder, std::vector< SegmentString * > *  segStrings, std::vector< geom::Coordinate > &  intersections  )

private

Computes all interior intersections in the collection of SegmentStrings, and push their Coordinate to the provided vector.

Does NOT node the segStrings.

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.

Implements geos::noding::Noder.

Definition at line 88 of file MCIndexSnapRounder.h.

MCIndexSnapRounder& geos::noding::snapround::MCIndexSnapRounder::operator= ( const MCIndexSnapRounder &  rhs )

privatedelete

void geos::noding::snapround::MCIndexSnapRounder::snapRound ( MCIndexNoder &  noder, std::vector< SegmentString * > *  segStrings  )

private

Member Data Documentation

algorithm::LineIntersector geos::noding::snapround::MCIndexSnapRounder::li

private

Definition at line 110 of file MCIndexSnapRounder.h.

std::vector<SegmentString*>* geos::noding::snapround::MCIndexSnapRounder::nodedSegStrings

private

Definition at line 114 of file MCIndexSnapRounder.h.

const geom::PrecisionModel& geos::noding::snapround::MCIndexSnapRounder::pm

private

externally owned

Definition at line 108 of file MCIndexSnapRounder.h.

std::unique_ptr<MCIndexPointSnapper> geos::noding::snapround::MCIndexSnapRounder::pointSnapper

private

Definition at line 116 of file MCIndexSnapRounder.h.

double geos::noding::snapround::MCIndexSnapRounder::scaleFactor

private

Definition at line 112 of file MCIndexSnapRounder.h.

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

• MCIndexSnapRounder.h