GRASS GIS 7 Programmer's Manual  7.7.svn(2018)-r73570
 All Data Structures Files Functions Variables Typedefs Enumerations Enumerator Friends Macros Pages
chtype.c
Go to the documentation of this file.
1 /*!
2  \file vector/vedit/chtype.c
3 
4  \brief Vedit library - change primitives type
5 
6  (C) 2008 by the GRASS Development Team
7 
8  This program is free software under the GNU General Public License
9  (>=v2). Read the file COPYING that comes with GRASS for details.
10 
11  \author Martin Landa <landa.martin gmail.com>
12 */
13 
14 #include <grass/vedit.h>
15 
16 /*!
17  \brief Change primitive type
18 
19  Supported conversions:
20  - point <-> centroid
21  - line <-> boundary
22 
23  \param Map pointer to Map_info
24  \param List list of selected primitives
25 
26  \return number of modified primitives
27  \return -1 on error
28 */
29 int Vedit_chtype_lines(struct Map_info *Map, struct ilist *List)
30 {
31  int i;
32  int nret, line;
33  int type, newtype;
34  struct line_pnts *Points;
35  struct line_cats *Cats;
36 
37  nret = 0;
38 
39  Points = Vect_new_line_struct();
40  Cats = Vect_new_cats_struct();
41 
42  for (i = 0; i < List->n_values; i++) {
43  line = List->value[i];
44  if (!Vect_line_alive(Map, line))
45  continue;
46  type = Vect_read_line(Map, Points, Cats, line);
47  if (type < 0) {
48  return -1;
49  }
50  switch (type) {
51  case GV_POINT:
52  newtype = GV_CENTROID;
53  break;
54  case GV_CENTROID:
55  newtype = GV_POINT;
56  break;
57  case GV_LINE:
58  newtype = GV_BOUNDARY;
59  break;
60  case GV_BOUNDARY:
61  newtype = GV_LINE;
62  break;
63  default:
64  newtype = -1;
65  break;
66  }
67 
68  G_debug(3, "Vedit_chtype_lines(): line=%d, from_type=%d, to_type=%d",
69  line, type, newtype);
70 
71  if (newtype > 0) {
72  if (Vect_rewrite_line(Map, line, newtype, Points, Cats) < 0) {
73  return -1;
74  }
75  nret++;
76  }
77  }
78 
81 
82  return nret;
83 }
off_t Vect_rewrite_line(struct Map_info *Map, off_t line, int type, const struct line_pnts *points, const struct line_cats *cats)
Rewrites existing feature (topological level required)
struct line_pnts * Vect_new_line_struct()
Creates and initializes a line_pnts structure.
Definition: line.c:45
#define GV_CENTROID
Definition: dig_defines.h:185
int Vect_line_alive(const struct Map_info *Map, int line)
Check if feature is alive or dead (topological level required)
int n_values
Number of values in the list.
Definition: gis.h:676
void Vect_destroy_line_struct(struct line_pnts *p)
Frees all memory associated with a line_pnts structure, including the structure itself.
Definition: line.c:77
void Vect_destroy_cats_struct(struct line_cats *p)
Frees all memory associated with line_cats structure, including the struct itself.
#define GV_POINT
Feature types used in memory on run time (may change)
Definition: dig_defines.h:182
Feature category info.
Definition: dig_structs.h:1702
#define GV_LINE
Definition: dig_defines.h:183
Feature geometry info - coordinates.
Definition: dig_structs.h:1675
int Vedit_chtype_lines(struct Map_info *Map, struct ilist *List)
Change primitive type.
Definition: chtype.c:29
int G_debug(int level, const char *msg,...)
Print debugging message.
Definition: debug.c:65
#define GV_BOUNDARY
Definition: dig_defines.h:184
Vector map info.
Definition: dig_structs.h:1259
struct line_cats * Vect_new_cats_struct()
Creates and initializes line_cats structure.
List of integers.
Definition: gis.h:667
int Vect_read_line(const struct Map_info *Map, struct line_pnts *line_p, struct line_cats *line_c, int line)
Read vector feature (topological level required)
int * value
Array of values.
Definition: gis.h:672