geos.GEOSPolygonize ⇒ number ⏏ ​

Polygonizes a set of Geometries which contain linework that represents the edges of a planar graph.

All types of Geometry are accepted as input; the constituent linework is extracted as the edges to be polygonized.

The edges must be correctly noded; that is, they must only meet at their endpoints and not overlap anywhere. If your edges are not already noded, run them through GEOSUnaryUnion() first. Polygonization will accept incorrectly noded input but will not form polygons from non-noded edges, and reports them as errors.

The Polygonizer reports the following kinds of errors:

• Dangles - edges which have one or both ends which are not incident on another edge endpoint
• Cut Edges - edges which are connected at both ends but which do not form part of a polygon
• Invalid Ring Lines - edges which form rings which are invalid (e.g. the component lines contain a self-intersection) Errors are reported to output parameters "cuts", "dangles" and "invalid" (if not-null). Formed polygons are returned as a collection. NULL is returned on exception. All returned geometries must be destroyed by caller.

The GEOSPolygonize_valid() variant allows extracting only polygons which form a valid polygonal result. The set of extracted polygons is guaranteed to be edge-disjoint. This is useful when it is known that the input lines form a valid polygonal geometry (which may include holes or nested polygons).

Kind: Exported member
Returns: number - A pointer to a GEOS geometry object representing the polygonized geometry, or NULL on error.
See: https://libgeos.org/doxygen/geos__c_8h.html#a9d98e448d3b846d591c726d1c0000d25

geos.GEOSPolygonize_full ⇒ number ⏏ ​

Polygonizes a set of Geometrys which contain linework that represents the edges of a planar graph. All types of Geometry are accepted as input; the constituent linework is extracted as the edges to be polygonized. The processed edges must be correctly noded; that is, they must only meet at their endpoints. The Polygonizer will run on incorrectly noded input but will not form polygons from non-noded edges, and will report them as errors.

The Polygonizer reports the follow kinds of errors:

• Dangles - edges which have one or both ends which are not incident on another edge endpoint
• Cut Edges - edges which are connected at both ends but which do not form part of a polygon
• Invalid Ring Lines - edges which form rings which are invalid (e.g. the component lines contain a self-intersection)

The returned geometry is a collection containing valid polygonal geometry.

Kind: Exported member
Returns: number - a pointer to a collection containing the polygons formed by the polygonization
See: https://libgeos.org/doxygen/geos__c_8h.html#a0f0a7f5c9a3b6d7f9b4d1c8e2a0d4f5a

geos.GEOSPolygonize_full_r ⇒ number ⏏ ​

Polygonizes a set of Geometrys which contain linework that represents the edges of a planar graph. All types of Geometry are accepted as input; the constituent linework is extracted as the edges to be polygonized. The processed edges must be correctly noded; that is, they must only meet at their endpoints. The Polygonizer will run on incorrectly noded input but will not form polygons from non-noded edges, and will report them as errors.

The Polygonizer reports the follow kinds of errors:

• Dangles - edges which have one or both ends which are not incident on another edge endpoint
• Cut Edges - edges which are connected at both ends but which do not form part of a polygon
• Invalid Ring Lines - edges which form rings which are invalid (e.g. the component lines contain a self-intersection)

The returned geometry is a collection containing valid polygonal geometry.

Kind: Exported member
Returns: number - a pointer to a collection containing the polygons formed by the polygonization
See: https://libgeos.org/doxygen/geos__c_8h.html#a1b2a8f7c3b2b6d9a3a0b4c6e1d0f9e1f

geos.GEOSPolygonize_r ⇒ number ⏏ ​

Polygonizes a set of Geometries which contain linework that represents the edges of a planar graph.

All types of Geometry are accepted as input; the constituent linework is extracted as the edges to be polygonized.

The edges must be correctly noded; that is, they must only meet at their endpoints and not overlap anywhere. If your edges are not already noded, run them through GEOSUnaryUnion() first. Polygonization will accept incorrectly noded input but will not form polygons from non-noded edges, and reports them as errors.

The Polygonizer reports the following kinds of errors:

• Dangles - edges which have one or both ends which are not incident on another edge endpoint
• Cut Edges - edges which are connected at both ends but which do not form part of a polygon
• Invalid Ring Lines - edges which form rings which are invalid (e.g. the component lines contain a self-intersection) Errors are reported to output parameters "cuts", "dangles" and "invalid" (if not-null). Formed polygons are returned as a collection. NULL is returned on exception. All returned geometries must be destroyed by caller.

The GEOSPolygonize_valid() variant allows extracting only polygons which form a valid polygonal result. The set of extracted polygons is guaranteed to be edge-disjoint. This is useful when it is known that the input lines form a valid polygonal geometry (which may include holes or nested polygons).

Kind: Exported member
Returns: number - A GeometryCollection containing the polygons formed by the polygonization.

geos.GEOSPolygonize_valid ⇒ number ⏏ ​

Polygonizes a set of valid Geometrys which contain linework that represents the edges of a planar graph. All types of Geometry are accepted as input; the constituent linework is extracted as the edges to be polygonized. The processed edges must be correctly noded; that is, they must only meet at their endpoints. The Polygonizer will run on incorrectly noded input but will not form polygons from non-noded edges, and will report them as errors.

Kind: Exported member
Returns: number - A GeometryCollection containing the polygons formed by the polygonization.

geos.GEOSPolygonize_valid_r ⇒ string ⏏ ​

Polygonizes a set of valid Geometrys which contain linework that represents the edges of a planar graph, using a GEOS context handle. All types of Geometry are accepted as input; the constituent linework is extracted as the edges to be polygonized. The processed edges must be correctly noded; that is, they must only meet at their endpoints. The Polygonizer will run on incorrectly noded input but will not form polygons from non-noded edges, and will report them as errors.

Kind: Exported member
Returns: string - A GeometryCollection containing the polygons formed by the polygonization.

geos.GEOSPolygonizer_getCutEdges ⇒ string ⏏ ​

Gets the list of line segments forming the boundary between inside and outside portions of a set of Geometrys which contain linework that represents the edges of a planar graph.

Kind: Exported member
Returns: string - A MultiLineString containing the boundary segments.

geos.GEOSPolygonizer_getCutEdges_r ⇒ string ⏏ ​

Gets the list of line segments forming the boundary between inside and outside portions of a set of Geometrys which contain linework that represents the edges of a planar graph, using a GEOS context handle.

Kind: Exported member
Returns: string - A MultiLineString containing the boundary segments.