Speed-optimized clipping of a Geometry with a rectangle. More...

#include <RectangleIntersection.h>

Collaboration diagram for geos::operation::intersection::RectangleIntersection:

Static Public Member Functions
static std::unique_ptr< geom::Geometry >	clip (const geom::Geometry &geom, const Rectangle &rect)
	Clip geometry with a rectangle. More...

static std::unique_ptr< geom::Geometry >	clipBoundary (const geom::Geometry &geom, const Rectangle &rect)
	Clip boundary of a geometry with a rectangle. More...

Private Member Functions
	RectangleIntersection (const geom::Geometry &geom, const Rectangle &rect)

std::unique_ptr< geom::Geometry >	clipBoundary ()

std::unique_ptr< geom::Geometry >	clip ()

void	clip_geom (const geom::Geometry *g, RectangleIntersectionBuilder &parts, const Rectangle &rect, bool keep_polygons)

void	clip_point (const geom::Point *g, RectangleIntersectionBuilder &parts, const Rectangle &rect)

void	clip_multipoint (const geom::MultiPoint *g, RectangleIntersectionBuilder &parts, const Rectangle &rect)

void	clip_linestring (const geom::LineString *g, RectangleIntersectionBuilder &parts, const Rectangle &rect)

void	clip_multilinestring (const geom::MultiLineString *g, RectangleIntersectionBuilder &parts, const Rectangle &rect)

void	clip_polygon (const geom::Polygon *g, RectangleIntersectionBuilder &parts, const Rectangle &rect, bool keep_polygons)

void	clip_multipolygon (const geom::MultiPolygon *g, RectangleIntersectionBuilder &parts, const Rectangle &rect, bool keep_polygons)

void	clip_geometrycollection (const geom::GeometryCollection *g, RectangleIntersectionBuilder &parts, const Rectangle &rect, bool keep_polygons)

void	clip_polygon_to_linestrings (const geom::Polygon *g, RectangleIntersectionBuilder &parts, const Rectangle &rect)

void	clip_polygon_to_polygons (const geom::Polygon *g, RectangleIntersectionBuilder &parts, const Rectangle &rect)

bool	clip_linestring_parts (const geom::LineString *gi, RectangleIntersectionBuilder &parts, const Rectangle &rect)
	Clip geometry. More...

Private Attributes
const geom::Geometry &	_geom

const Rectangle &	_rect

const geom::GeometryFactory *	_gf

const geom::CoordinateSequenceFactory *	_csf

Detailed Description

Speed-optimized clipping of a Geometry with a rectangle.

Two different methods are provided. The first performs normal clipping, the second clips the boundaries of polygons, not the polygons themselves. In the first case a polygon will remain a polygon or is completely cut out. In the latter case polygons will be converted to polylines if any vertex is outside the clipping rectangle, or will be cut out completely.

The algorithm works best when the number of intersections is very low. For example, if the geometry is completely to the left of the clipping rectangle, only the x-coordinate of the geometry is ever tested and is only compared with the x-coordinate of the left edge of the rectangle. Hence clipping may be faster than calculating the envelope of the geometry for trivial overlap tests.

The input geometry must be valid. In particular all LinearRings must be properly closed, or the algorithm may not terminate.

Definition at line 75 of file RectangleIntersection.h.

Constructor & Destructor Documentation

geos::operation::intersection::RectangleIntersection::RectangleIntersection	(	const geom::Geometry &	geom,
		const Rectangle &	rect
	)

private

Member Function Documentation

static std::unique_ptr<geom::Geometry> geos::operation::intersection::RectangleIntersection::clip	(	const geom::Geometry &	geom,
		const Rectangle &	rect
	)

static

Clip geometry with a rectangle.

Parameters

geom	a Geometry
rect	a Rectangle

Returns: the clipped geometry; NULL if the geometry is outside the Rectangle

std::unique_ptr<geom::Geometry> geos::operation::intersection::RectangleIntersection::clip ( )

private

void geos::operation::intersection::RectangleIntersection::clip_geom	(	const geom::Geometry *	g,
		RectangleIntersectionBuilder &	parts,
		const Rectangle &	rect,
		bool	keep_polygons
	)

private

void geos::operation::intersection::RectangleIntersection::clip_geometrycollection	(	const geom::GeometryCollection *	g,
		RectangleIntersectionBuilder &	parts,
		const Rectangle &	rect,
		bool	keep_polygons
	)

private

void geos::operation::intersection::RectangleIntersection::clip_linestring	(	const geom::LineString *	g,
		RectangleIntersectionBuilder &	parts,
		const Rectangle &	rect
	)

private

bool geos::operation::intersection::RectangleIntersection::clip_linestring_parts	(	const geom::LineString *	gi,
		RectangleIntersectionBuilder &	parts,
		const Rectangle &	rect
	)

private

Clip geometry.

Returns true if the geometry was fully inside, and does not output anything to RectangleIntersectionBuilder.

void geos::operation::intersection::RectangleIntersection::clip_multilinestring	(	const geom::MultiLineString *	g,
		RectangleIntersectionBuilder &	parts,
		const Rectangle &	rect
	)

private

void geos::operation::intersection::RectangleIntersection::clip_multipoint	(	const geom::MultiPoint *	g,
		RectangleIntersectionBuilder &	parts,
		const Rectangle &	rect
	)

private

void geos::operation::intersection::RectangleIntersection::clip_multipolygon	(	const geom::MultiPolygon *	g,
		RectangleIntersectionBuilder &	parts,
		const Rectangle &	rect,
		bool	keep_polygons
	)

private

void geos::operation::intersection::RectangleIntersection::clip_point	(	const geom::Point *	g,
		RectangleIntersectionBuilder &	parts,
		const Rectangle &	rect
	)

private

void geos::operation::intersection::RectangleIntersection::clip_polygon	(	const geom::Polygon *	g,
		RectangleIntersectionBuilder &	parts,
		const Rectangle &	rect,
		bool	keep_polygons
	)

private

void geos::operation::intersection::RectangleIntersection::clip_polygon_to_linestrings	(	const geom::Polygon *	g,
		RectangleIntersectionBuilder &	parts,
		const Rectangle &	rect
	)

private

void geos::operation::intersection::RectangleIntersection::clip_polygon_to_polygons	(	const geom::Polygon *	g,
		RectangleIntersectionBuilder &	parts,
		const Rectangle &	rect
	)

private

static std::unique_ptr<geom::Geometry> geos::operation::intersection::RectangleIntersection::clipBoundary	(	const geom::Geometry &	geom,
		const Rectangle &	rect
	)

static

Clip boundary of a geometry with a rectangle.

Any polygon which intersects the rectangle will be converted to a polyline or a multipolyline - including the holes.

Parameters

geom	a Geometry
rect	a Rectangle

Returns: the clipped geometry; NULL if the geometry is outside the Rectangle

std::unique_ptr<geom::Geometry> geos::operation::intersection::RectangleIntersection::clipBoundary ( )

private

Member Data Documentation

const geom::CoordinateSequenceFactory* geos::operation::intersection::RectangleIntersection::_csf

private

Definition at line 114 of file RectangleIntersection.h.

const geom::Geometry& geos::operation::intersection::RectangleIntersection::_geom

private

Definition at line 111 of file RectangleIntersection.h.

const geom::GeometryFactory* geos::operation::intersection::RectangleIntersection::_gf

private

Definition at line 113 of file RectangleIntersection.h.

const Rectangle& geos::operation::intersection::RectangleIntersection::_rect

private

Definition at line 112 of file RectangleIntersection.h.

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

RectangleIntersection.h

Static Public Member Functions

Private Member Functions

Private Attributes

Detailed Description

Constructor & Destructor Documentation

Member Function Documentation

Member Data Documentation