GRASS GIS 7 Programmer's Manual  7.5.svn(2018)-r72993
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overlap.c
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1 /*!
2  \file lib/vector/Vlib/overlap.c
3 
4  \brief Vector library - region/window overlap
5 
6  Higher level functions for reading/writing/manipulating vectors.
7 
8  (C) 2001-2009 by the GRASS Development Team
9 
10  This program is free software under the GNU General Public License
11  (>=v2). Read the file COPYING that comes with GRASS for details.
12 
13  \author Original author CERL, probably Dave Gerdes or Mike Higgins.
14  \author Update to GRASS 5.7 Radim Blazek and David D. Gray.
15  */
16 
17 #include <grass/vector.h>
18 
19 /*!
20  Check if region overlaps with map extent.
21 
22  \param Map vector map
23  \param n,s,e,w region bounding box
24 
25  \return 1 if regions overlap
26  \return 0 if not
27 */
28 int
29 V__map_overlap(struct Map_info *Map, double n, double s, double e, double w)
30 {
31  struct Cell_head W;
32 
33  /* updated for Lat lon support 21 Jun 91 */
34  W.north = Map->constraint.box.N;
35  W.south = Map->constraint.box.S;
36  W.east = Map->constraint.box.E;
37  W.west = Map->constraint.box.W;
38  W.proj = Map->head.proj;
39 
40  return G_window_overlap(&W, n, s, e, w);
41 }
int V__map_overlap(struct Map_info *Map, double n, double s, double e, double w)
Definition: overlap.c:29
double W
West.
Definition: dig_structs.h:82
2D/3D raster map header (used also for region)
Definition: gis.h:390
double west
Extent coordinates (west)
Definition: gis.h:442
double E
East.
Definition: dig_structs.h:78
double N
North.
Definition: dig_structs.h:70
double north
Extent coordinates (north)
Definition: gis.h:436
struct Map_info::@11 constraint
Constraints for sequential feature access.
double south
Extent coordinates (south)
Definition: gis.h:438
int proj
Projection code.
Definition: gis.h:422
struct bound_box box
Region (bbox) constraint.
Definition: dig_structs.h:1366
struct dig_head head
Header info.
Definition: dig_structs.h:1403
Vector map info.
Definition: dig_structs.h:1259
double S
South.
Definition: dig_structs.h:74
double east
Extent coordinates (east)
Definition: gis.h:440
int G_window_overlap(const struct Cell_head *window, double N, double S, double E, double W)
Determines if a box overlays a map window.
Definition: wind_overlap.c:37