GRASS GIS 8 Programmer's Manual
8.2.2dev(2023)-3d2c704037
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Vector library - polygon related fns. More...
#include <math.h>
#include <stdlib.h>
#include <grass/vector.h>
#include <grass/linkm.h>
#include <grass/glocale.h>
Go to the source code of this file.
Functions | |
int | Vect__intersect_y_line_with_poly () |
int | Vect__intersect_x_line_with_poly () |
int | Vect_get_point_in_area (const struct Map_info *Map, int area, double *X, double *Y) |
Get point inside area and outside all islands. More... | |
int | Vect__intersect_y_line_with_poly (const struct line_pnts *Points, double y, struct line_pnts *Inter) |
int | Vect__intersect_x_line_with_poly (const struct line_pnts *Points, double x, struct line_pnts *Inter) |
int | Vect_get_point_in_poly (const struct line_pnts *Points, double *X, double *Y) |
Get point inside polygon. More... | |
int | Vect_find_poly_centroid (const struct line_pnts *points, double *cent_x, double *cent_y) |
Get centroid of polygon. More... | |
int | Vect_get_point_in_poly_isl (const struct line_pnts *Points, const struct line_pnts **IPoints, int n_isles, double *att_x, double *att_y) |
Get point inside polygon but outside the islands specifiled in IPoints. More... | |
int | Vect_point_in_poly (double X, double Y, const struct line_pnts *Points) |
Determines if a point (X,Y) is inside a polygon. More... | |
int | Vect_point_in_area_outer_ring (double X, double Y, const struct Map_info *Map, int area, struct bound_box *box) |
Determines if a point (X,Y) is inside an area outer ring. Islands are not considered. More... | |
int | Vect_point_in_island (double X, double Y, const struct Map_info *Map, int isle, struct bound_box *box) |
Determines if a point (X,Y) is inside an island. More... | |
Vector library - polygon related fns.
Higher level functions for reading/writing/manipulating vectors.
(C) 2001-2009 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.
Definition in file Vlib/poly.c.
int Vect__intersect_x_line_with_poly | ( | ) |
int Vect__intersect_x_line_with_poly | ( | const struct line_pnts * | Points, |
double | x, | ||
struct line_pnts * | Inter | ||
) |
Definition at line 172 of file Vlib/poly.c.
int Vect__intersect_y_line_with_poly | ( | ) |
Referenced by Vect_get_point_in_poly_isl().
int Vect__intersect_y_line_with_poly | ( | const struct line_pnts * | Points, |
double | y, | ||
struct line_pnts * | Inter | ||
) |
Definition at line 128 of file Vlib/poly.c.
int Vect_find_poly_centroid | ( | const struct line_pnts * | points, |
double * | cent_x, | ||
double * | cent_y | ||
) |
Get centroid of polygon.
points | polygon | |
[out] | cent_x,cent_y | centroid coordinates |
Definition at line 363 of file Vlib/poly.c.
References line_pnts::n_points, line_pnts::x, and line_pnts::y.
Referenced by Vect_get_point_in_poly_isl().
int Vect_get_point_in_area | ( | const struct Map_info * | Map, |
int | area, | ||
double * | X, | ||
double * | Y | ||
) |
Get point inside area and outside all islands.
Take a line and intersect it with the polygon and any islands. sort the list of X values from these intersections. This will be a list of segments alternating IN/OUT/IN/OUT of the polygon. Pick the largest IN segment and take the midpoint.
Map | vector map | |
area | area id | |
[out] | X,Y | point coordinateds |
Definition at line 56 of file Vlib/poly.c.
int Vect_get_point_in_poly | ( | const struct line_pnts * | Points, |
double * | X, | ||
double * | Y | ||
) |
Get point inside polygon.
This does NOT consider ISLANDS!
Points | polygon | |
[out] | X,Y | point coordinates |
Definition at line 211 of file Vlib/poly.c.
int Vect_get_point_in_poly_isl | ( | const struct line_pnts * | Points, |
const struct line_pnts ** | IPoints, | ||
int | n_isles, | ||
double * | att_x, | ||
double * | att_y | ||
) |
Get point inside polygon but outside the islands specifiled in IPoints.
Take a line and intersect it with the polygon and any islands. sort the list of X values from these intersections. This will be a list of segments alternating IN/OUT/IN/OUT of the polygon. Pick the largest IN segment and take the midpoint.
Points | polygon (boundary) | |
IPoints | isles (list of isle boundaries) | |
n_isles | number of isles | |
[out] | att_x,att_y | point coordinates |
Definition at line 457 of file Vlib/poly.c.
References G_debug(), max, line_pnts::n_points, Vect__intersect_y_line_with_poly(), Vect_find_poly_centroid(), Vect_new_line_struct(), Vect_point_in_poly(), x, line_pnts::x, and line_pnts::y.
int Vect_point_in_area_outer_ring | ( | double | X, |
double | Y, | ||
const struct Map_info * | Map, | ||
int | area, | ||
struct bound_box * | box | ||
) |
Determines if a point (X,Y) is inside an area outer ring. Islands are not considered.
X,Y | point coordinates |
Map | vector map |
area | area id |
box | area bounding box |
Definition at line 856 of file Vlib/poly.c.
int Vect_point_in_island | ( | double | X, |
double | Y, | ||
const struct Map_info * | Map, | ||
int | isle, | ||
struct bound_box * | box | ||
) |
Determines if a point (X,Y) is inside an island.
X,Y | point coordinates |
Map | vector map |
isle | isle id |
box | isle bounding box |
Definition at line 925 of file Vlib/poly.c.
int Vect_point_in_poly | ( | double | X, |
double | Y, | ||
const struct line_pnts * | Points | ||
) |
Determines if a point (X,Y) is inside a polygon.
X,Y | point coordinates |
Points | polygon |
Definition at line 826 of file Vlib/poly.c.
References G_debug(), and line_pnts::n_points.
Referenced by Vect_get_point_in_poly_isl().