GRASS GIS 7 Programmer's Manual  7.5.svn(2017)-r71933
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dgraph.c File Reference

Vector library - intersection (lower level functions) More...

#include <stdlib.h>
#include <string.h>
#include <math.h>
#include <grass/vector.h>
#include <grass/glocale.h>
#include "dgraph.h"
#include "e_intersect.h"
Include dependency graph for dgraph.c:

Go to the source code of this file.


#define LENGTH(DX, DY)   (sqrt((DX*DX)+(DY*DY)))
#define MIN(X, Y)   ((X<Y)?X:Y)
#define MAX(X, Y)   ((X>Y)?X:Y)
#define PI   M_PI


struct seg_intersections * create_si_struct (int segments_count)
void destroy_si_struct (struct seg_intersections *si)
void add_ipoint1 (struct seg_intersection_list *il, int with, double dist, int ip)
void add_ipoint (const struct line_pnts *Points, int first_seg, int second_seg, double x, double y, struct seg_intersections *si)
void sort_intersection_list (struct seg_intersection_list *il)
int compare (const void *a, const void *b)
double get_epsilon (struct line_pnts *Points)
struct seg_intersections * find_all_intersections (const struct line_pnts *Points)
struct planar_graphpg_create_struct (int n, int e)
void pg_destroy_struct (struct planar_graph *pg)
int pg_existsedge (struct planar_graph *pg, int v1, int v2)
void pg_addedge1 (struct pg_vertex *v, struct pg_edge *e)
void pg_addedge (struct planar_graph *pg, int v1, int v2)
struct planar_graphpg_create (const struct line_pnts *Points)

Detailed Description

Vector library - intersection (lower level functions)

Higher level functions for reading/writing/manipulating vectors.

(C) 2008-2009 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.

Rewritten by Rosen Matev (Google Summer of Code 2008)

Definition in file dgraph.c.

Macro Definition Documentation

#define LENGTH (   DX,
)    (sqrt((DX*DX)+(DY*DY)))

Definition at line 24 of file dgraph.c.

Referenced by add_ipoint().

#define MAX (   X,
)    ((X>Y)?X:Y)

Definition at line 29 of file dgraph.c.

Referenced by get_epsilon(), and pg_create_struct().

#define MIN (   X,
)    ((X<Y)?X:Y)

Definition at line 26 of file dgraph.c.

#define PI   M_PI

Definition at line 31 of file dgraph.c.

Function Documentation

void add_ipoint ( const struct line_pnts Points,
int  first_seg,
int  second_seg,
double  x,
double  y,
struct seg_intersections *  si 

Definition at line 120 of file dgraph.c.

References add_ipoint1(), G_debug(), LENGTH, t, x, line_pnts::x, and line_pnts::y.

Referenced by find_all_intersections().

void add_ipoint1 ( struct seg_intersection_list *  il,
int  with,
double  dist,
int  ip 

Definition at line 99 of file dgraph.c.

Referenced by add_ipoint().

int compare ( const void *  a,
const void *  b 
struct seg_intersections* create_si_struct ( int  segments_count)

Definition at line 64 of file dgraph.c.

References NULL.

Referenced by find_all_intersections().

void destroy_si_struct ( struct seg_intersections *  si)

Definition at line 85 of file dgraph.c.

References G_free().

Referenced by pg_create().

struct seg_intersections* find_all_intersections ( const struct line_pnts Points)
double get_epsilon ( struct line_pnts Points)

Definition at line 193 of file dgraph.c.

References MAX, min, line_pnts::n_points, t, x, line_pnts::x, and line_pnts::y.

void pg_addedge1 ( struct pg_vertex v,
struct pg_edge e 

Definition at line 405 of file dgraph.c.

References pg_vertex::eallocated, pg_vertex::ecount, and pg_vertex::edges.

Referenced by pg_addedge().

struct planar_graph* pg_create_struct ( int  n,
int  e 
void pg_destroy_struct ( struct planar_graph pg)
int pg_existsedge ( struct planar_graph pg,
int  v1,
int  v2 

Definition at line 382 of file dgraph.c.

References pg_vertex::ecount, pg_vertex::edges, planar_graph::v, pg_edge::v1, and pg_edge::v2.

Referenced by pg_addedge().

void sort_intersection_list ( struct seg_intersection_list *  il)

Definition at line 151 of file dgraph.c.

References G_debug(), min, and t.

Referenced by find_all_intersections().