geos.c File Reference

Vector library - GEOS support. More...

#include <stdlib.h>
#include <grass/vector.h>
#include <grass/glocale.h>

Include dependency graph for geos.c:

Go to the source code of this file.

Functions
GEOSGeometry *	Vect_read_line_geos (struct Map_info *Map, int line, int *type)
	Read vector feature and stores it as GEOSGeometry instance. More...
GEOSGeometry *	Vect_read_area_geos (struct Map_info *Map, int area)
	Read vector area and stores it as GEOSGeometry instance (polygon) More...
GEOSGeometry *	Vect_line_to_geos (const struct line_pnts *points, int type, int with_z)
	Create GEOSGeometry of given type from feature points. More...
GEOSCoordSequence *	Vect_get_area_points_geos (struct Map_info *Map, int area)
	Returns the polygon array of points, i.e. outer ring (shell) More...
GEOSCoordSequence *	Vect_get_isle_points_geos (struct Map_info *Map, int isle)
	Returns the polygon (isle) array of points (inner ring) More...

Detailed Description

Vector library - GEOS support.

Higher level functions for reading/writing/manipulating vectors.

(C) 2009 by the GRASS Development Team

This program is free software under the GNU General Public License (>=v2). Read the file COPYING that comes with GRASS for details.

Author

Martin Landa <landa.martin gmail.com>

Definition in file geos.c.

Function Documentation

Vect_get_area_points_geos()

GEOSCoordSequence* Vect_get_area_points_geos	(	struct Map_info *	Map,
		int	area
	)

Returns the polygon array of points, i.e. outer ring (shell)

You should free allocated memory by GEOSCoordSeq_destroy().

See also Vect_get_area_points().

Parameters

Map	pointer to Map_info
area	area id

Returns

pointer to GEOSCoordSequence

empty GEOSCoordSequence for dead area

NULL on error

Definition at line 401 of file geos.c.

References _, Plus_head::Area, G_debug(), G_warning(), NULL, and Map_info::plus.

Vect_get_isle_points_geos()

GEOSCoordSequence* Vect_get_isle_points_geos	(	struct Map_info *	Map,
		int	isle
	)

Returns the polygon (isle) array of points (inner ring)

You should free allocated memory by GEOSCoordSeq_destroy().

See also Vect_get_isle_points().

Parameters

Map	pointer to Map_info
isle	isel id

Returns

pointer to GEOSGeometry

NULL on error or dead line

Definition at line 432 of file geos.c.

References G_debug(), Plus_head::Isle, and Map_info::plus.

Vect_line_to_geos()

GEOSGeometry* Vect_line_to_geos	(	const struct line_pnts *	points,
		int	type,
		int	with_z
	)

Create GEOSGeometry of given type from feature points.

Supported types:

• GV_POINT -> POINT
• GV_CENTROID -> POINT
• GV_LINE -> LINESTRING
• GV_BOUNDARY -> LINEARRING

You should free allocated memory by GEOSGeom_destroy().

Parameters

points	pointer to line_pnts structure
type	feature type (see supported types)
with_z	Set to 1 if the feature is 3d, 0 otherwise

Returns

pointer to GEOSGeometry instance

NULL on error

Definition at line 132 of file geos.c.

Vect_read_area_geos()

GEOSGeometry* Vect_read_area_geos	(	struct Map_info *	Map,
		int	area
	)

Read vector area and stores it as GEOSGeometry instance (polygon)

You should free allocated memory by GEOSGeom_destroy().

Parameters

Map	pointer to Map_info structure
area	area id

Returns

pointer to GEOSGeometry instance

NULL on error

Definition at line 81 of file geos.c.

Referenced by Vect_read_area_to_wkb(), and Vect_read_area_to_wkt().

Vect_read_line_geos()

GEOSGeometry* Vect_read_line_geos	(	struct Map_info *	Map,
		int	line,
		int *	type
	)

Read vector feature and stores it as GEOSGeometry instance.

Supported feature types:

• GV_POINT -> POINT
• GV_LINE -> LINESTRING
• GV_BOUNDARY -> LINESTRING / LINEARRING

You should free allocated memory by GEOSGeom_destroy().

Parameters

	Map	pointer to Map_info structure
	line	feature id
[out]	type	feature type or NULL

Returns

pointer to GEOSGeometry instance

empty GEOSGeometry for unsupported feature type

NULL on error

Definition at line 45 of file geos.c.