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.
Macros | |
| #define | FP_AVG(A, B) |
Detailed Description
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.
Macro Definition Documentation
◆ FP_AVG
| #define FP_AVG | ( | A, | |
| B | |||
| ) |
Definition at line 25 of file Vlib/poly.c.
Function Documentation
◆ 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 187 of file Vlib/poly.c.
References b, line_pnts::n_points, Vect_append_point(), line_pnts::x, and line_pnts::y.
Referenced by Vect_get_point_in_poly_isl().
◆ Vect__intersect_y_line_with_poly()
| int Vect__intersect_y_line_with_poly | ( | const struct line_pnts * | Points, |
| double | y, | ||
| struct line_pnts * | Inter | ||
| ) |
Definition at line 132 of file Vlib/poly.c.
References b, line_pnts::n_points, Vect_append_point(), line_pnts::x, and line_pnts::y.
Referenced by Vect_get_point_in_poly_isl().
◆ Vect_find_poly_centroid()
Get centroid of polygon.
- Parameters
-
points polygon [out] cent_x,cent_y centroid coordinates
- Returns
- 0 on success
- -1 on error
Definition at line 385 of file Vlib/poly.c.
References line_pnts::n_points, line_pnts::x, and line_pnts::y.
Referenced by Vect_get_point_in_poly(), and Vect_get_point_in_poly_isl().
◆ Vect_find_poly_centroid_cog()
| int Vect_find_poly_centroid_cog | ( | const struct line_pnts * | Points, |
| const struct line_pnts ** | IPoints, | ||
| int | n_isles, | ||
| double * | cent_x, | ||
| double * | cent_y | ||
| ) |
Get centroid of polygon.
Calculate the center of gravity of the area considering any islands
- Parameters
-
Points polygon IPoints isles (list of isle boundaries) n_isles number of isles [out] cent_x,cent_y centroid coordinates
- Returns
- 0 on success
- -1 on error
- Since
- version 8.6
Definition at line 439 of file Vlib/poly.c.
References bound_box::E, bound_box::N, line_pnts::n_points, bound_box::S, Vect_line_box(), bound_box::W, line_pnts::x, x, and line_pnts::y.
Referenced by Vect_get_point_in_poly_isl().
◆ Vect_get_point_in_area()
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.
- Parameters
-
Map vector map area area id [out] X,Y point coordinateds
- Returns
- 0 on success
- -1 on error
Definition at line 61 of file Vlib/poly.c.
References G_debug(), G_realloc, NULL, Vect_get_area_isle(), Vect_get_area_num_isles(), Vect_get_area_points(), Vect_get_isle_points(), Vect_get_point_in_poly_isl(), Vect_new_line_struct(), X, and Y.
◆ Vect_get_point_in_poly()
Get point inside polygon.
This does NOT consider ISLANDS!
- Parameters
-
Points polygon [out] X,Y point coordinates
- Returns
- 0 on success
- -1 on error
Definition at line 238 of file Vlib/poly.c.
References _, G_debug(), G_warning(), link_exit_on_error(), link_init(), link_new(), line_pnts::n_points, NULL, Vect_find_poly_centroid(), Vect_point_in_poly(), X, line_pnts::x, x, and Y.
Referenced by V2_write_line_sfa().
◆ Vect_get_point_in_poly_isl()
| 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.
- Parameters
-
Points polygon (boundary) IPoints isles (list of isle boundaries) n_isles number of isles [out] att_x,att_y point coordinates
- Returns
- 0 on success
- -1 on error
Definition at line 547 of file Vlib/poly.c.
References FP_AVG, G_debug(), G_warning(), max, line_pnts::n_points, Vect__intersect_x_line_with_poly(), Vect__intersect_y_line_with_poly(), Vect_find_poly_centroid(), Vect_find_poly_centroid_cog(), Vect_new_line_struct(), Vect_point_in_poly(), line_pnts::x, and line_pnts::y.
Referenced by Vect_get_point_in_area().
◆ Vect_point_in_area_outer_ring()
| int Vect_point_in_area_outer_ring | ( | double | X, |
| double | Y, | ||
| 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.
- Parameters
-
X,Y point coordinates Map vector map area area id box area bounding box
- Returns
- 0 - outside
- 1 - inside
- 2 - on the boundary
Definition at line 1009 of file Vlib/poly.c.
References bound_box::E, G_debug(), bound_box::N, Vect_get_area_points(), Vect_new_line_struct(), Vect_point_in_poly(), W, X, and Y.
Referenced by Vect_find_area(), Vect_isle_find_area(), and Vect_point_in_area().
◆ Vect_point_in_island()
| int Vect_point_in_island | ( | double | X, |
| double | Y, | ||
| struct Map_info * | Map, | ||
| int | isle, | ||
| struct bound_box * | box | ||
| ) |
Determines if a point (X,Y) is inside an island.
- Parameters
-
X,Y point coordinates Map vector map isle isle id box isle bounding box
- Returns
- 0 - outside
- 1 - inside
- 2 - on the boundary
Definition at line 1047 of file Vlib/poly.c.
References bound_box::E, G_debug(), bound_box::N, Vect_get_isle_points(), Vect_new_line_struct(), Vect_point_in_poly(), W, X, and Y.
Referenced by Vect_find_area(), Vect_find_island(), and Vect_point_in_area().
◆ Vect_point_in_poly()
Determines if a point (X,Y) is inside a polygon.
- Parameters
-
X,Y point coordinates Points polygon
- Returns
- 0 - outside
- 1 - inside
- 2 - on the boundary
Definition at line 979 of file Vlib/poly.c.
References G_debug(), line_pnts::n_points, X, and Y.
Referenced by Vect_get_point_in_poly(), Vect_get_point_in_poly_isl(), Vect_point_in_area_outer_ring(), Vect_point_in_island(), and Vect_select_lines_by_polygon().
