Vlib/poly.c File Reference

#include <math.h>
#include <stdlib.h>
#include <grass/Vect.h>
#include <grass/gis.h>
#include <grass/linkm.h>
#include <grass/glocale.h>
Include dependency graph for Vlib/poly.c:

Go to the source code of this file.

Data Structures

struct  Slink

Functions

int Vect__intersect_line_with_poly ()
int Vect_get_point_in_area (struct Map_info *Map, int area, double *X, double *Y)
 Get point inside area and outside all islands.
int Vect__intersect_line_with_poly (struct line_pnts *Points, double y, struct line_pnts *Inter)
int Vect_get_point_in_poly (struct line_pnts *Points, double *X, double *Y)
 Get point inside polygon.
int Vect_find_poly_centroid (struct line_pnts *points, double *cent_x, double *cent_y)
 Get centroid of polygon.
int Vect_get_point_in_poly_isl (struct line_pnts *Points, struct line_pnts **IPoints, int n_isles, double *att_x, double *att_y)
 Get point inside polygon but outside the islands specifiled in IPoints.
int Vect_point_in_poly (double X, double Y, struct line_pnts *Points)
 Determines if a point (X,Y) is inside a polygon.
int Vect_point_in_area_outer_ring (double X, double Y, struct Map_info *Map, int area)
 Determines if a point (X,Y) is inside an area outer ring. Islands are not considered.
int Vect_point_in_island (double X, double Y, struct Map_info *Map, int isle)
 Determines if a point (X,Y) is inside an island.

Function Documentation

int Vect__intersect_line_with_poly ( struct line_pnts *  Points,
double  y,
struct line_pnts *  Inter 
)

Definition at line 141 of file Vlib/poly.c.

References Vect_append_point().

int Vect__intersect_line_with_poly (  ) 
int Vect_find_poly_centroid ( struct line_pnts *  points,
double *  cent_x,
double *  cent_y 
)

Get centroid of polygon.

Parameters:
points polygon
[out] cent_x,cent_y centroid coordinates
Returns:
0 on success
-1 on error

Definition at line 330 of file Vlib/poly.c.

Referenced by Vect_get_point_in_poly(), and Vect_get_point_in_poly_isl().

int Vect_get_point_in_area ( 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.

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 Vect_get_area_isle(), Vect_get_area_num_isles(), Vect_get_area_points(), Vect_get_isle_points(), Vect_get_point_in_poly_isl(), and Vect_new_line_struct().

int Vect_get_point_in_poly ( struct line_pnts *  Points,
double *  X,
double *  Y 
)

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 180 of file Vlib/poly.c.

References Slink::next, Vect_find_poly_centroid(), Vect_point_in_poly(), and Slink::x.

int Vect_get_point_in_poly_isl ( struct line_pnts *  Points,
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
IPoints isles
n_isles number of isles
[out] att_x,att_y point coordinates
Returns:
0 on success
-1 on error

Definition at line 424 of file Vlib/poly.c.

References Vect__intersect_line_with_poly(), Vect_find_poly_centroid(), Vect_new_line_struct(), and Vect_point_in_poly().

Referenced by Vect_get_point_in_area().

int Vect_point_in_area_outer_ring ( double  X,
double  Y,
struct Map_info *  Map,
int  area 
)

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
Returns:
0 - outside
1 - inside
2 - on the boundary (exactly may be said only for vertex of vertical/horizontal line)

Definition at line 695 of file Vlib/poly.c.

References Vect_new_line_struct(), and Vect_read_line().

Referenced by Vect_isle_find_area(), and Vect_point_in_area().

int Vect_point_in_island ( double  X,
double  Y,
struct Map_info *  Map,
int  isle 
)

Determines if a point (X,Y) is inside an island.

Parameters:
X,Y point coordinates
Map vector map
isle isle id
Returns:
0 - outside
1 - inside
2 - on the boundary (exactly may be said only for vertex of vertical/horizontal line)

Definition at line 760 of file Vlib/poly.c.

References Vect_new_line_struct(), and Vect_read_line().

Referenced by Vect_find_island(), and Vect_point_in_area().

int Vect_point_in_poly ( double  X,
double  Y,
struct line_pnts *  Points 
)

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 (exactly may be said only for vertex of vertical/horizontal line)

Definition at line 665 of file Vlib/poly.c.

Referenced by Vect_get_point_in_poly(), Vect_get_point_in_poly_isl(), and Vect_select_lines_by_polygon().


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