vector/Vlib/write.c File Reference

Vector library - write vector features. More...

#include <sys/types.h>
#include <grass/glocale.h>
#include <grass/vector.h>

Include dependency graph for vector/Vlib/write.c:

Go to the source code of this file.

Functions
off_t	Vect_write_line (struct Map_info *Map, int type, const struct line_pnts *points, const struct line_cats *cats)
	Writes a new feature. More...
off_t	Vect_rewrite_line (struct Map_info *Map, off_t line, int type, const struct line_pnts *points, const struct line_cats *cats)
	Rewrites existing feature (topological level required) More...
int	Vect_delete_line (struct Map_info *Map, off_t line)
	Delete existing feature (topological level required) More...
int	Vect_restore_line (struct Map_info *Map, off_t offset, off_t line)
	Restore previously deleted feature (topological level required) More...

Detailed Description

Vector library - write vector features.

Higher level functions for reading/writing/manipulating vectors.

Supported operations:

• Write a new feature
• Rewrite existing feature
• Delete existing feature
• Restore deleted feature

(C) 2001-2010, 2012-2013 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

Radim Blazek

Updated by Martin Landa <landa.martin gmail.com> (restore lines, OGR & PostGIS support)

Definition in file vector/Vlib/write.c.

Function Documentation

Vect_delete_line()

int Vect_delete_line	(	struct Map_info *	Map,
		off_t	line
	)

Delete existing feature (topological level required)

Note: Topology must be built at level >= GV_BUILD_BASE

A warning is printed on error.

Parameters

Map	pointer to Map_info structure
line	feature id (level 2) or feature offset (level 1)

Returns

0 on success

-1 on error

Definition at line 253 of file vector/Vlib/write.c.

Vect_restore_line()

int Vect_restore_line	(	struct Map_info *	Map,
		off_t	offset,
		off_t	line
	)

Restore previously deleted feature (topological level required)

Note: Topology must be built at level >= GV_BUILD_BASE

A warning is printed on error.

Parameters

Map	pointer to Map_info structure
offset	feature offset to be restored
line	feature id to be restored (used only on level 2)

Returns

0 on success

-1 on error

Definition at line 286 of file vector/Vlib/write.c.

Vect_rewrite_line()

off_t Vect_rewrite_line	(	struct Map_info *	Map,
		off_t	line,
		int	type,
		const struct line_pnts *	points,
		const struct line_cats *	cats
	)

Rewrites existing feature (topological level required)

Note: Topology must be built at level >= GV_BUILD_BASE

A warning is printed on error.

The number of points or cats or type may change. If necessary, the old feature is deleted and new is written.

Parameters

Map	pointer to Map_info structure
line	feature id (level 2) or feature offset (level 1)
type	feature type (GV_POINT, GV_LINE, ...)
points	feature geometry
cats	feature categories

Returns

new feature id (on level 2) (or 0 when build level < GV_BUILD_BASE)

offset into file where the feature starts (on level 1)

-1 on error

Definition at line 220 of file vector/Vlib/write.c.

Vect_write_line()

off_t Vect_write_line	(	struct Map_info *	Map,
		int	type,
		const struct line_pnts *	points,
		const struct line_cats *	cats
	)

Writes a new feature.

New feature is written to the end of file (in the case of native format). Topological level is not required.

A warning is printed on error.

Parameters

Map	pointer to Map_info structure
type	feature type (see dig_defines.h for supported types)
points	pointer to line_pnts structure (feature geometry)
cats	pointer to line_cats structure (feature categories)

Returns

new feature id (on level 2) (or 0 when build level < GV_BUILD_BASE)

offset into file where the feature starts (on level 1)

-1 on error

Definition at line 178 of file vector/Vlib/write.c.