read_ogr.c File Reference

Vector library - reading data (OGR format) More...

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

Include dependency graph for read_ogr.c:

Go to the source code of this file.

Functions
int	V1_read_next_line_ogr (struct Map_info *Map, struct line_pnts *line_p, struct line_cats *line_c)
	Read next feature from OGR layer. Skip empty features (level 1 without topology). More...
int	V2_read_next_line_ogr (struct Map_info *Map, struct line_pnts *line_p, struct line_cats *line_c)
	Read next feature from OGR layer on topological level. More...
int	V1_read_line_ogr (struct Map_info *Map, struct line_pnts *line_p, struct line_cats *line_c, off_t offset)
	Read feature from OGR layer at given offset (level 1 without topology) More...

Detailed Description

Vector library - reading data (OGR format)

Higher level functions for reading/writing/manipulating vectors.

(C) 2001-2011 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, Piero Cavalieri

Martin Landa <landa.martin gmail.com>

Definition in file read_ogr.c.

Function Documentation

V1_read_line_ogr()

int V1_read_line_ogr	(	struct Map_info *	Map,
		struct line_pnts *	line_p,
		struct line_cats *	line_c,
		off_t	offset
	)

Read feature from OGR layer at given offset (level 1 without topology)

This function implements random access on level 1.

Parameters

	Map	pointer to Map_info structure
[out]	line_p	container used to store line points within (pointer line_pnts struct)
[out]	line_c	container used to store line categories within (pointer line_cats struct)
	offset	given offset

Returns

line type

0 dead line

-2 no more features

-1 on failure

Definition at line 179 of file read_ogr.c.

V1_read_next_line_ogr()

int V1_read_next_line_ogr	(	struct Map_info *	Map,
		struct line_pnts *	line_p,
		struct line_cats *	line_c
	)

Read next feature from OGR layer. Skip empty features (level 1 without topology).

This function implements sequential access.

The action of this routine can be modified by:

• Vect_read_constraint_region()
• Vect_read_constraint_type()
• Vect_remove_constraints()

Parameters

	Map	pointer to Map_info structure
[out]	line_p	container used to store line points within
[out]	line_c	container used to store line categories within

Returns

feature type

-2 no more features (EOF)

-1 out of memory

Definition at line 50 of file read_ogr.c.

V2_read_next_line_ogr()

int V2_read_next_line_ogr	(	struct Map_info *	Map,
		struct line_pnts *	line_p,
		struct line_cats *	line_c
	)

Read next feature from OGR layer on topological level.

This function implements sequential access.

Parameters

	Map	pointer to Map_info structure
[out]	line_p	container used to store line points within (pointer to line_pnts struct)
[out]	line_c	container used to store line categories within (pointer to line_cats struct)

Returns

feature type

-2 no more features (EOF)

-1 on failure

Definition at line 76 of file read_ogr.c.