Module: RGeo::Feature::Polygon

Extended by:
Type
Includes:
Enumerable, Surface
Included in:
Cartesian::PolygonImpl, Geographic::ProjectedPolygonImpl, Geographic::SphericalPolygonImpl
Defined in:
lib/rgeo/feature/polygon.rb

Overview

SFS 1.1 Description

A Polygon is a planar Surface defined by 1 exterior boundary and 0 or more interior boundaries. Each interior boundary defines a hole in the Polygon.

The assertions for Polygons (the rules that define valid Polygons) are as follows:

(a) Polygons are topologically closed;

(b) The boundary of a Polygon consists of a set of LinearRings that make up its exterior and interior boundaries;

© No two Rings in the boundary cross and the Rings in the boundary of a Polygon may intersect at a Point but only as a tangent;

(d) A Polygon may not have cut lines, spikes or punctures;

(e) The interior of every Polygon is a connected point set;

(f) The exterior of a Polygon with 1 or more holes is not connected. Each hole defines a connected component of the exterior.

In the above assertions, interior, closure and exterior have the standard topological definitions. The combination of (a) and © make a Polygon a regular closed Point set.

Polygons are simple geometric objects.

Notes

Polygon is defined as a module and is provided primarily for the sake of documentation. Implementations need not necessarily include this module itself. Therefore, you should not depend on the kind_of? method to check type. Instead, use the provided check_type class method (or === operator) defined in the Type module.

Constant Summary

Constants included from Type

Type::Instance

Instance Method Summary collapse

Methods included from Type

check_type, subtype_of?, type_name

Methods included from Surface

#area, #centroid, #point_on_surface

Methods included from Geometry

#*, #+, #-, #==, #as_binary, #as_text, #boundary, #buffer, #contains?, #convex_hull, #crosses?, #difference, #dimension, #disjoint?, #distance, #envelope, #eql?, #equals?, #factory, #geometry_type, #intersection, #intersects?, #is_empty?, #is_simple?, #overlaps?, #relate, #srid, #sym_difference, #touches?, #union, #within?

Instance Method Details

#exterior_ring ⇒ Object

SFS 1.1 Description

Returns the exterior ring of this Polygon.

Notes

Returns an object that supports the LinearRing interface.

Raises:



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# File 'lib/rgeo/feature/polygon.rb', line 96

def exterior_ring
  raise Error::UnsupportedOperation, "Method Polygon#exterior_ring not defined."
end

#interior_ring_n(n_) ⇒ Object

SFS 1.1 Description

Returns the Nth interiorRing for this Polygon as a LineString.

Notes

Returns an object that supports the LinearRing interface, or nil if the given n is out of range.

Raises:



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# File 'lib/rgeo/feature/polygon.rb', line 123

def interior_ring_n(n_)
  raise Error::UnsupportedOperation, "Method Polygon#interior_ring_n not defined."
end

#interior_rings ⇒ Object

Returns the interior rings as a (possibly empty) array of objects that support the LinearRing interface.

Raises:



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# File 'lib/rgeo/feature/polygon.rb', line 131

def interior_rings
  raise Error::UnsupportedOperation, "Method Polygon#interior_rings not defined."
end

#num_interior_rings ⇒ Object

SFS 1.1 Description

Returns the number of interiorRings in this Polygon.

Notes

Returns an integer.

Raises:



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# File 'lib/rgeo/feature/polygon.rb', line 109

def num_interior_rings
  raise Error::UnsupportedOperation, "Method Polygon#num_interior_rings not defined."
end