SpatiaLite  5.0.1
demo2.c

This is a sample C source showing how to manipulate GEOMETRY within Spatialite. It essentially follows on from the functionality shown in the demo1.c example, and covers:

Note that this does not require a database command line argument. Here is a typical run: 

$ ./demo2 
step#1: POINT           Dimension=0 IsValid=1
                        POINT 0/1 x=1.5000 y=2.7500

step#2: LINESTRING      Dimension=1 IsValid=1
                        LINESTRING 0/1 has 5 vertices
                                vertex 0/5 x=1.0000 y=1.0000
                                vertex 1/5 x=2.0000 y=1.0000
                                vertex 2/5 x=2.0000 y=2.0000
                                vertex 3/5 x=100.0000 y=2.0000
                                vertex 4/5 x=100.0000 y=100.0000

step#3: POLYGON Dimension=2 IsValid=1
                        POLYGON 0/1 has 2 holes
                                ExteriorRing has 5 vertices
                                        vertex 0/5 x=0.0000 y=0.0000
                                        vertex 1/5 x=50.0000 y=0.0000
                                        vertex 2/5 x=50.0000 y=50.0000
                                        vertex 3/5 x=0.0000 y=50.0000
                                        vertex 4/5 x=0.0000 y=0.0000
                                InteriorRing 0/2 has 5 vertices
                                        vertex 0/5 x=40.0000 y=40.0000
                                        vertex 1/5 x=41.0000 y=40.0000
                                        vertex 2/5 x=41.0000 y=41.0000
                                        vertex 3/5 x=40.0000 y=41.0000
                                        vertex 4/5 x=40.0000 y=40.0000
                                InteriorRing 1/2 has 5 vertices
                                        vertex 0/5 x=30.0000 y=30.0000
                                        vertex 1/5 x=31.0000 y=30.0000
                                        vertex 2/5 x=31.0000 y=31.0000
                                        vertex 3/5 x=30.0000 y=31.0000
                                        vertex 4/5 x=30.0000 y=30.0000

step#4: MULTIPOINT      Dimension=0 IsValid=1
                        POINT 0/5 x=5.0000 y=5.0000
                        POINT 1/5 x=15.0000 y=5.0000
                        POINT 2/5 x=5.0000 y=15.0000
                        POINT 3/5 x=25.0000 y=5.0000
                        POINT 4/5 x=5.0000 y=25.0000

step#5: MULTILINESTRING Dimension=1 IsValid=1
                        LINESTRING 0/2 has 2 vertices
                                vertex 0/2 x=30.0000 y=10.0000
                                vertex 1/2 x=10.0000 y=30.0000
                        LINESTRING 1/2 has 2 vertices
                                vertex 0/2 x=40.0000 y=50.0000
                                vertex 1/2 x=50.0000 y=40.0000

step#6: MULTIPOLYGON    Dimension=2 IsValid=1
                        POLYGON 0/2 has 0 holes
                                ExteriorRing has 5 vertices
                                        vertex 0/5 x=60.0000 y=60.0000
                                        vertex 1/5 x=70.0000 y=60.0000
                                        vertex 2/5 x=70.0000 y=70.0000
                                        vertex 3/5 x=60.0000 y=70.0000
                                        vertex 4/5 x=60.0000 y=60.0000
                        POLYGON 1/2 has 0 holes
                                ExteriorRing has 5 vertices
                                        vertex 0/5 x=80.0000 y=80.0000
                                        vertex 1/5 x=90.0000 y=80.0000
                                        vertex 2/5 x=90.0000 y=90.0000
                                        vertex 3/5 x=80.0000 y=90.0000
                                        vertex 4/5 x=80.0000 y=80.0000

step#7: GEOMETRYCOLLECTION      Dimension=2 IsValid=1
                        POINT 0/2 x=100.0000 y=100.0000
                        POINT 1/2 x=100.0000 y=0.0000
                        LINESTRING 0/2 has 2 vertices
                                vertex 0/2 x=130.0000 y=110.0000
                                vertex 1/2 x=110.0000 y=130.0000
                        LINESTRING 1/2 has 2 vertices
                                vertex 0/2 x=140.0000 y=150.0000
                                vertex 1/2 x=150.0000 y=140.0000
                        POLYGON 0/2 has 0 holes
                                ExteriorRing has 5 vertices
                                        vertex 0/5 x=160.0000 y=160.0000
                                        vertex 1/5 x=170.0000 y=160.0000
                                        vertex 2/5 x=170.0000 y=170.0000
                                        vertex 3/5 x=160.0000 y=170.0000
                                        vertex 4/5 x=160.0000 y=160.0000
                        POLYGON 1/2 has 0 holes
                                ExteriorRing has 5 vertices
                                        vertex 0/5 x=180.0000 y=180.0000
                                        vertex 1/5 x=190.0000 y=180.0000
                                        vertex 2/5 x=190.0000 y=190.0000
                                        vertex 3/5 x=180.0000 y=190.0000
                                        vertex 4/5 x=180.0000 y=180.0000

step#8: checking WKT representations

GEOMETRYCOLLECTION(POINT(1.5 2.75))

GEOMETRYCOLLECTION(LINESTRING(1 1, 2 1, 2 2, 100 2, 100 100))

GEOMETRYCOLLECTION(POLYGON((0 0, 50 0, 50 50, 0 50, 0 0), (40 40, 41 40, 41 41, 40 41, 40 40), (30 30, 31 30, 31 31, 30 31, 30 30)))

GEOMETRYCOLLECTION(POINT(5 5), POINT(15 5), POINT(5 15), POINT(25 5), POINT(5 25))

GEOMETRYCOLLECTION(LINESTRING(30 10, 10 30), LINESTRING(40 50, 50 40))

GEOMETRYCOLLECTION(POLYGON((60 60, 70 60, 70 70, 60 70, 60 60)), POLYGON((80 80, 90 80, 90 90, 80 90, 80 80)))

GEOMETRYCOLLECTION(POINT(100 100), POINT(100 0), LINESTRING(130 110, 110 130), LINESTRING(140 150, 150 140), POLYGON((160 160, 170 160, 170 170, 160 170, 160 160)), POLYGON((180 180, 190 180, 190 190, 180 190, 180 180)))
/*
demo2.c
Author: Sandro Furieri a.furieri@lqt.it
This software is provided 'as-is', without any express or implied
warranty. In no event will the author be held liable for any
damages arising from the use of this software.
Permission is granted to anyone to use this software for any
purpose, including commercial applications, and to alter it and
redistribute it freely
*/
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <spatialite/gaiaconfig.h>
/*
these headers are required in order to support
SQLite/SpatiaLite
*/
#include <geos_c.h>
#include <sqlite3.h>
#include <spatialite/gaiageo.h>
#include <spatialite.h>
static char *
geom_type (int type)
{
/* utility function returning corresponding GeometryType as a string */
static char *name = "EMPTY / NULL GEOMETRY";
if (type == GAIA_POINT)
name = "POINT";
if (type == GAIA_LINESTRING)
name = "LINESTRING";
if (type == GAIA_POLYGON)
name = "POLYGON";
if (type == GAIA_MULTIPOINT)
name = "MULTIPOINT";
if (type == GAIA_MULTILINESTRING)
name = "MULTILINESTRING";
if (type == GAIA_MULTIPOLYGON)
name = "MULTIPOLYGON";
if (type == GAIA_GEOMETRYCOLLECTION)
name = "GEOMETRYCOLLECTION";
return name;
}
static void
geometry_printout (gaiaGeomCollPtr geom)
{
/* utility function printing a generic Geometry object */
gaiaPointPtr pt;
gaiaLinestringPtr ln;
gaiaPolygonPtr pg;
gaiaRingPtr rng;
int n_pts = 0;
int n_lns = 0;
int n_pgs = 0;
int cnt;
int iv;
int ir;
double x;
double y;
/* we'll now count how many POINTs are there */
pt = geom->FirstPoint;
while (pt)
{
n_pts++;
pt = pt->Next;
}
/* we'll now count how many LINESTRINGs are there */
ln = geom->FirstLinestring;
while (ln)
{
n_lns++;
ln = ln->Next;
}
/* we'll now count how many POLYGONs are there */
pg = geom->FirstPolygon;
while (pg)
{
n_pgs++;
pg = pg->Next;
}
if (n_pts)
{
/* printing POINTs coordinates */
cnt = 0;
pt = geom->FirstPoint;
while (pt)
{
/* we'll now scan the linked list of POINTs */
printf ("\t\t\tPOINT %d/%d x=%1.4f y=%1.4f\n",
cnt, n_pts, pt->X, pt->Y);
cnt++;
pt = pt->Next;
}
}
if (n_lns)
{
/* printing LINESTRINGs coordinates */
cnt = 0;
ln = geom->FirstLinestring;
while (ln)
{
/* we'll now scan the linked list of LINESTRINGs */
printf ("\t\t\tLINESTRING %d/%d has %d vertices\n",
cnt, n_lns, ln->Points);
for (iv = 0; iv < ln->Points; iv++)
{
/* we'll now retrieve coordinates for each vertex */
gaiaGetPoint (ln->Coords, iv, &x, &y);
printf ("\t\t\t\tvertex %d/%d x=%1.4f y=%1.4f\n",
iv, ln->Points, x, y);
}
cnt++;
ln = ln->Next;
}
}
if (n_pgs)
{
/* printing POLYGONs coordinates */
cnt = 0;
pg = geom->FirstPolygon;
while (pg)
{
/* we'll now scan the linked list of POLYGONs */
printf ("\t\t\tPOLYGON %d/%d has %d hole%c\n",
cnt, n_pgs, pg->NumInteriors,
(pg->NumInteriors == 1) ? ' ' : 's');
/*
now we'll print out the Exterior ring
[surely a POLYGON has an Exterior ring
*/
rng = pg->Exterior;
printf ("\t\t\t\tExteriorRing has %d vertices\n", rng->Points);
for (iv = 0; iv < rng->Points; iv++)
{
/* we'll now retrieve coordinates for each vertex */
gaiaGetPoint (rng->Coords, iv, &x, &y);
printf ("\t\t\t\t\tvertex %d/%d x=%1.4f y=%1.4f\n",
iv, rng->Points, x, y);
}
for (ir = 0; ir < pg->NumInteriors; ir++)
{
/*
a POLYGON can contain an arbitrary number of Interior rings (including zero)
*/
rng = pg->Interiors + ir;
printf ("\t\t\t\tInteriorRing %d/%d has %d vertices\n",
ir, pg->NumInteriors, rng->Points);
for (iv = 0; iv < rng->Points; iv++)
{
/* we'll now retrieve coordinates for each vertex */
gaiaGetPoint (rng->Coords, iv, &x, &y);
printf
("\t\t\t\t\tvertex %d/%d x=%1.4f y=%1.4f\n",
iv, rng->Points, x, y);
}
}
cnt++;
pg = pg->Next;
}
}
}
int
main (int argc, char *argv[])
{
gaiaGeomCollPtr geo_pt = NULL;
gaiaGeomCollPtr geo_ln = NULL;
gaiaGeomCollPtr geo_pg = NULL;
gaiaGeomCollPtr geo_mpt = NULL;
gaiaGeomCollPtr geo_mln = NULL;
gaiaGeomCollPtr geo_mpg = NULL;
gaiaGeomCollPtr geo_coll = NULL;
gaiaLinestringPtr line;
gaiaPolygonPtr polyg;
gaiaRingPtr ring;
gaiaOutBuffer wkt;
int ret;
sqlite3 *handle;
void *cache;
if (argc > 1 || argv[0] == NULL)
argc = 1; /* silencing stupid compiler warnings */
/*
this demo does not strictly require any DB connection to be established
However you must initialize the SpatiaLite extension [and related]
and you *must* establish a "fake" DB connection in order to
properly initialize SpatiaLite and GEOS libraries
*/
ret = sqlite3_open_v2 (":memory:", &handle, SQLITE_OPEN_READONLY, NULL);
if (ret != SQLITE_OK)
{
printf ("cannot open '%s': %s\n", ":memory:",
sqlite3_errmsg (handle));
sqlite3_close (handle);
return -1;
}
cache = spatialite_alloc_connection ();
spatialite_init_ex (handle, cache, 0);
#ifndef OMIT_GEOS /* GEOS must be enabled */
/*
Step #1
creating and checking a POINT Geometry
*/
/* we'll allocate a Geometry object */
geo_pt = gaiaAllocGeomColl ();
/* then we insert a POINT, directly passing its coordinates */
gaiaAddPointToGeomColl (geo_pt, 1.5, 2.75);
/* now we'll print the main attributes for this geometry */
printf ("step#1: %s\t\tDimension=%d IsValid=%d\n",
geom_type (gaiaGeometryType (geo_pt)),
gaiaDimension (geo_pt), gaiaIsValid_r (cache, geo_pt));
geometry_printout (geo_pt);
/*
Step #2
creating and checking a LINESTRING Geometry
*/
geo_ln = gaiaAllocGeomColl ();
/* then we insert a LINESTRING, specifying how many vertices it contains */
line = gaiaAddLinestringToGeomColl (geo_ln, 5);
/*
we've got a pointer referencing the linestring we've just inserted
now we'll set coordinates for each vertex
*/
gaiaSetPoint (line->Coords, 0, 1.0, 1.0);
gaiaSetPoint (line->Coords, 1, 2.0, 1.0);
gaiaSetPoint (line->Coords, 2, 2.0, 2.0);
gaiaSetPoint (line->Coords, 3, 100.0, 2.0);
gaiaSetPoint (line->Coords, 4, 100.0, 100.0);
printf ("\nstep#2: %s\tDimension=%d IsValid=%d\n",
geom_type (gaiaGeometryType (geo_ln)),
gaiaDimension (geo_ln), gaiaIsValid_r (cache, geo_ln));
geometry_printout (geo_ln);
/*
Step #3
creating and checking a POLYGON Geometry
*/
geo_pg = gaiaAllocGeomColl ();
/*
then we insert a POLYGON, specifying:
- how many vertices have to be allocated for the Exterior Ring
- how many Interior Rings it has
*/
polyg = gaiaAddPolygonToGeomColl (geo_pg, 5, 2);
/*
we've got a pointer referencing the polygon we've just inserted
now we'll get a pointer referencing its Exterior ring
*/
ring = polyg->Exterior;
/* now we'll set coordinates for each Exterior ring vertex */
gaiaSetPoint (ring->Coords, 0, 0.0, 0.0);
gaiaSetPoint (ring->Coords, 1, 50.0, 0.0);
gaiaSetPoint (ring->Coords, 2, 50.0, 50.0);
gaiaSetPoint (ring->Coords, 3, 0.0, 50.0);
/* please note: a Ring is a CLOSED figure, so last and first vertex have to be coincident */
gaiaSetPoint (ring->Coords, 4, 0.0, 0.0);
/*
we'll now get a pointer referencing the FIRST interior ring,
specifying how vertices have to be allocated
*/
ring = gaiaAddInteriorRing (polyg, 0, 5);
/* then setting coordinates for each Interior ring vertex */
gaiaSetPoint (ring->Coords, 0, 40.0, 40.0);
gaiaSetPoint (ring->Coords, 1, 41.0, 40.0);
gaiaSetPoint (ring->Coords, 2, 41.0, 41.0);
gaiaSetPoint (ring->Coords, 3, 40.0, 41.0);
gaiaSetPoint (ring->Coords, 4, 40.0, 40.0);
/*
we'll now get a pointer referencing the SECOND interior ring,
specifying how vertices have to be allocated
*/
ring = gaiaAddInteriorRing (polyg, 1, 5);
/* then setting coordinates for each Interior ring vertex */
gaiaSetPoint (ring->Coords, 0, 30.0, 30.0);
gaiaSetPoint (ring->Coords, 1, 31.0, 30.0);
gaiaSetPoint (ring->Coords, 2, 31.0, 31.0);
gaiaSetPoint (ring->Coords, 3, 30.0, 31.0);
gaiaSetPoint (ring->Coords, 4, 30.0, 30.0);
printf ("\nstep#3: %s\tDimension=%d IsValid=%d\n",
geom_type (gaiaGeometryType (geo_pg)),
gaiaDimension (geo_pg), gaiaIsValid_r (cache, geo_pg));
geometry_printout (geo_pg);
/*
Step #4
creating and checking a MULTIPOINT Geometry
*/
geo_mpt = gaiaAllocGeomColl ();
/* then we'll insert some POINTs */
gaiaAddPointToGeomColl (geo_mpt, 5.0, 5.0);
gaiaAddPointToGeomColl (geo_mpt, 15.0, 5.0);
gaiaAddPointToGeomColl (geo_mpt, 5.0, 15.0);
gaiaAddPointToGeomColl (geo_mpt, 25.0, 5.0);
gaiaAddPointToGeomColl (geo_mpt, 5.0, 25.0);
printf ("\nstep#4: %s\tDimension=%d IsValid=%d\n",
geom_type (gaiaGeometryType (geo_mpt)),
gaiaDimension (geo_mpt), gaiaIsValid_r (cache, geo_mpt));
geometry_printout (geo_mpt);
/*
Step #5
creating and checking a MULTILINESTRING Geometry
*/
geo_mln = gaiaAllocGeomColl ();
/* then we'll insert two LINESTRINGs */
line = gaiaAddLinestringToGeomColl (geo_mln, 2);
gaiaSetPoint (line->Coords, 0, 30.0, 10.0);
gaiaSetPoint (line->Coords, 1, 10.0, 30.0);
line = gaiaAddLinestringToGeomColl (geo_mln, 2);
gaiaSetPoint (line->Coords, 0, 40.0, 50.0);
gaiaSetPoint (line->Coords, 1, 50.0, 40.0);
printf ("\nstep#5: %s\tDimension=%d IsValid=%d\n",
geom_type (gaiaGeometryType (geo_mln)),
gaiaDimension (geo_mln), gaiaIsValid_r (cache, geo_mln));
geometry_printout (geo_mln);
/*
Step #6
creating and checking a MULTIPOLYGON Geometry
*/
geo_mpg = gaiaAllocGeomColl ();
/* then we'll insert two POLYGONs */
polyg = gaiaAddPolygonToGeomColl (geo_mpg, 5, 0);
ring = polyg->Exterior;
gaiaSetPoint (ring->Coords, 0, 60.0, 60.0);
gaiaSetPoint (ring->Coords, 1, 70.0, 60.0);
gaiaSetPoint (ring->Coords, 2, 70.0, 70.0);
gaiaSetPoint (ring->Coords, 3, 60.0, 70.0);
gaiaSetPoint (ring->Coords, 4, 60.0, 60.0);
polyg = gaiaAddPolygonToGeomColl (geo_mpg, 5, 0);
ring = polyg->Exterior;
gaiaSetPoint (ring->Coords, 0, 80.0, 80.0);
gaiaSetPoint (ring->Coords, 1, 90.0, 80.0);
gaiaSetPoint (ring->Coords, 2, 90.0, 90.0);
gaiaSetPoint (ring->Coords, 3, 80.0, 90.0);
gaiaSetPoint (ring->Coords, 4, 80.0, 80.0);
printf ("\nstep#6: %s\tDimension=%d IsValid=%d\n",
geom_type (gaiaGeometryType (geo_mpg)),
gaiaDimension (geo_mpg), gaiaIsValid_r (cache, geo_mpg));
geometry_printout (geo_mpg);
/*
Step #7
creating and checking a GEOMETRYCOLLECTION Geometry
*/
geo_coll = gaiaAllocGeomColl ();
/* then we'll insert two POINTs */
gaiaAddPointToGeomColl (geo_coll, 100.0, 100.0);
gaiaAddPointToGeomColl (geo_coll, 100.0, 0.0);
/* then we'll insert two LINESTRINGs */
line = gaiaAddLinestringToGeomColl (geo_coll, 2);
gaiaSetPoint (line->Coords, 0, 130.0, 110.0);
gaiaSetPoint (line->Coords, 1, 110.0, 130.0);
line = gaiaAddLinestringToGeomColl (geo_coll, 2);
gaiaSetPoint (line->Coords, 0, 140.0, 150.0);
gaiaSetPoint (line->Coords, 1, 150.0, 140.0);
/* then we'll insert two POLYGONs */
polyg = gaiaAddPolygonToGeomColl (geo_coll, 5, 0);
ring = polyg->Exterior;
gaiaSetPoint (ring->Coords, 0, 160.0, 160.0);
gaiaSetPoint (ring->Coords, 1, 170.0, 160.0);
gaiaSetPoint (ring->Coords, 2, 170.0, 170.0);
gaiaSetPoint (ring->Coords, 3, 160.0, 170.0);
gaiaSetPoint (ring->Coords, 4, 160.0, 160.0);
polyg = gaiaAddPolygonToGeomColl (geo_coll, 5, 0);
ring = polyg->Exterior;
gaiaSetPoint (ring->Coords, 0, 180.0, 180.0);
gaiaSetPoint (ring->Coords, 1, 190.0, 180.0);
gaiaSetPoint (ring->Coords, 2, 190.0, 190.0);
gaiaSetPoint (ring->Coords, 3, 180.0, 190.0);
gaiaSetPoint (ring->Coords, 4, 180.0, 180.0);
printf ("\nstep#7: %s\tDimension=%d IsValid=%d\n",
geom_type (gaiaGeometryType (geo_coll)),
gaiaDimension (geo_coll), gaiaIsValid_r (cache, geo_coll));
geometry_printout (geo_coll);
/*
Step #8
printing each geometry as Well Known Text (WKT)
*/
printf ("\nstep#8: checking WKT representations\n");
/* first we'll get the WKT corresponding to geometry */
gaiaOutBufferInitialize (&wkt);
gaiaOutWkt (&wkt, geo_pt);
/* we have to check wkt is not NULL */
if (wkt.Error == 0 && wkt.Buffer != NULL)
{
/* printing the WKT */
printf ("\n%s\n", wkt.Buffer);
/* finally freeing the wkt temporary storage allocation */
gaiaOutBufferReset (&wkt);
}
gaiaOutBufferInitialize (&wkt);
gaiaOutWkt (&wkt, geo_ln);
if (wkt.Error == 0 && wkt.Buffer != NULL)
{
printf ("\n%s\n", wkt.Buffer);
gaiaOutBufferReset (&wkt);
}
gaiaOutBufferInitialize (&wkt);
gaiaOutWkt (&wkt, geo_pg);
if (wkt.Error == 0 && wkt.Buffer != NULL)
{
printf ("\n%s\n", wkt.Buffer);
gaiaOutBufferReset (&wkt);
}
gaiaOutBufferInitialize (&wkt);
gaiaOutWkt (&wkt, geo_mpt);
if (wkt.Error == 0 && wkt.Buffer != NULL)
{
printf ("\n%s\n", wkt.Buffer);
gaiaOutBufferReset (&wkt);
}
gaiaOutBufferInitialize (&wkt);
gaiaOutWkt (&wkt, geo_mln);
if (wkt.Error == 0 && wkt.Buffer != NULL)
{
printf ("\n%s\n", wkt.Buffer);
gaiaOutBufferReset (&wkt);
}
gaiaOutBufferInitialize (&wkt);
gaiaOutWkt (&wkt, geo_mpg);
if (wkt.Error == 0 && wkt.Buffer != NULL)
{
printf ("\n%s\n", wkt.Buffer);
gaiaOutBufferReset (&wkt);
}
gaiaOutBufferInitialize (&wkt);
gaiaOutWkt (&wkt, geo_coll);
if (wkt.Error == 0 && wkt.Buffer != NULL)
{
printf ("\n%s\n", wkt.Buffer);
gaiaOutBufferReset (&wkt);
}
#else
printf ("no GEOS support available: skipping any test\n");
#endif /* GEOS enabled/disabled */
/*
memory cleanup
we have to destroy each object using temporary storage before exit
*/
if (geo_pt)
gaiaFreeGeomColl (geo_pt);
if (geo_ln)
gaiaFreeGeomColl (geo_ln);
if (geo_pg)
gaiaFreeGeomColl (geo_pg);
if (geo_mpt)
gaiaFreeGeomColl (geo_mpt);
if (geo_mln)
gaiaFreeGeomColl (geo_mln);
if (geo_mpg)
gaiaFreeGeomColl (geo_mpg);
if (geo_coll)
gaiaFreeGeomColl (geo_coll);
sqlite3_close (handle);
spatialite_cleanup_ex (cache);
spatialite_shutdown ();
return 0;
}
GAIA_GEOMETRYCOLLECTION
#define GAIA_GEOMETRYCOLLECTION
BLOB-Geometry CLASS: GEOMETRYCOLLECTION.
Definition: gg_const.h:160
spatialite_alloc_connection
SPATIALITE_DECLARE void * spatialite_alloc_connection(void)
Initializes the internal memory block supporting each connection.
gaiaLinestringStruct::Points
int Points
number of points [aka vertices]
Definition: gg_structs.h:132
gaiaPolygonStruct::Interiors
gaiaRingPtr Interiors
array of interior rings
Definition: gg_structs.h:200
gaiaFreeGeomColl
GAIAGEO_DECLARE void gaiaFreeGeomColl(gaiaGeomCollPtr geom)
Destroys a Geometry object.
gaiaPolygonStruct
Container for OGC POLYGON Geometry.
Definition: gg_structs.h:193
gaiaGeometryType
GAIAGEO_DECLARE int gaiaGeometryType(gaiaGeomCollPtr geom)
Determines the corresponding Type for a Geometry object.
gaiaRingStruct::Coords
double * Coords
COORDs mem-array.
Definition: gg_structs.h:164
gaiaPointStruct::Y
double Y
Y coordinate.
Definition: gg_structs.h:84
gaiaAllocGeomColl
GAIAGEO_DECLARE gaiaGeomCollPtr gaiaAllocGeomColl(void)
Allocates a 2D Geometry [XY].
gaiaOutBufferStruct
Container for dynamically growing output buffer.
Definition: gg_structs.h:497
gaiaGeomCollStruct::FirstLinestring
gaiaLinestringPtr FirstLinestring
pointer to first LINESTRING [linked list]; may be NULL
Definition: gg_structs.h:246
gaiaOutBufferReset
GAIAGEO_DECLARE void gaiaOutBufferReset(gaiaOutBufferPtr buf)
Resets a dynamically growing Text output buffer to its initial (empty) state.
spatialite_init_ex
SPATIALITE_DECLARE void spatialite_init_ex(sqlite3 *db_handle, const void *ptr, int verbose)
Initializes a SpatiaLite connection.
gaiaAddPointToGeomColl
GAIAGEO_DECLARE void gaiaAddPointToGeomColl(gaiaGeomCollPtr p, double x, double y)
Creates a new 2D Point [XY] object into a Geometry object.
gaiaRingStruct::Points
int Points
number of points [aka vertices]
Definition: gg_structs.h:162
gaiaAddPolygonToGeomColl
GAIAGEO_DECLARE gaiaPolygonPtr gaiaAddPolygonToGeomColl(gaiaGeomCollPtr p, int vert, int interiors)
Creates a new Polygon object into a Geometry object.
gaiaOutBufferInitialize
GAIAGEO_DECLARE void gaiaOutBufferInitialize(gaiaOutBufferPtr buf)
Initializes a dynamically growing Text output buffer.
gaiaPointStruct::X
double X
X coordinate.
Definition: gg_structs.h:82
gaiaPointStruct::Next
struct gaiaPointStruct * Next
pointer to next item [double linked list]
Definition: gg_structs.h:92
gaiaGetPoint
#define gaiaGetPoint(xy, v, x, y)
macro extracting XY coordinates
Definition: gg_const.h:462
GAIA_MULTIPOINT
#define GAIA_MULTIPOINT
BLOB-Geometry CLASS: MULTIPOINT.
Definition: gg_const.h:154
GAIA_MULTILINESTRING
#define GAIA_MULTILINESTRING
BLOB-Geometry CLASS: MULTILINESTRING.
Definition: gg_const.h:156
spatialite_shutdown
SPATIALITE_DECLARE void spatialite_shutdown(void)
Finalizes the library.
gaiaIsValid_r
GAIAGEO_DECLARE int gaiaIsValid_r(const void *p_cache, gaiaGeomCollPtr geom)
Checks if a Geometry object represents an OGC Valid Geometry.
gaiaPointStruct
Container for OGC POINT Geometry.
Definition: gg_structs.h:79
GAIA_MULTIPOLYGON
#define GAIA_MULTIPOLYGON
BLOB-Geometry CLASS: MULTIPOLYGON.
Definition: gg_const.h:158
gaiaDimension
GAIAGEO_DECLARE int gaiaDimension(gaiaGeomCollPtr geom)
Determines OGC dimensions for a Geometry object.
gaiaRingStruct
Container for OGC RING Geometry.
Definition: gg_structs.h:159
gaiaLinestringStruct
Container for OGC LINESTRING Geometry.
Definition: gg_structs.h:129
gaiaPolygonStruct::NumInteriors
int NumInteriors
number of interior rings (may be, none)
Definition: gg_structs.h:198
gaiaAddInteriorRing
GAIAGEO_DECLARE gaiaRingPtr gaiaAddInteriorRing(gaiaPolygonPtr p, int pos, int vert)
Creates a new Interior Ring object into a Polygon object.
gaiaOutWkt
GAIAGEO_DECLARE void gaiaOutWkt(gaiaOutBufferPtr out_buf, gaiaGeomCollPtr geom)
Encodes a Geometry object into WKT notation.
spatialite_cleanup_ex
SPATIALITE_DECLARE void spatialite_cleanup_ex(const void *ptr)
Cleanup a SpatiaLite connection.
gaiaGeomCollStruct::FirstPolygon
gaiaPolygonPtr FirstPolygon
pointer to first POLYGON [linked list]; may be NULL
Definition: gg_structs.h:250
GAIA_LINESTRING
#define GAIA_LINESTRING
BLOB-Geometry CLASS: LINESTRING.
Definition: gg_const.h:150
gaiageo.h
Geometry handling functions and constants.
GAIA_POLYGON
#define GAIA_POLYGON
BLOB-Geometry CLASS: POLYGON.
Definition: gg_const.h:152
gaiaLinestringStruct::Next
struct gaiaLinestringStruct * Next
pointer to next item [linked list]
Definition: gg_structs.h:146
gaiaGeomCollStruct::FirstPoint
gaiaPointPtr FirstPoint
pointer to first POINT [linked list]; may be NULL
Definition: gg_structs.h:242
GAIA_POINT
#define GAIA_POINT
BLOB-Geometry CLASS: POINT.
Definition: gg_const.h:148
gaiaPolygonStruct::Exterior
gaiaRingPtr Exterior
the exterior ring (mandatory)
Definition: gg_structs.h:196
gaiaOutBufferStruct::Error
int Error
validity flag
Definition: gg_structs.h:506
gaiaGeomCollStruct
Container for OGC GEOMETRYCOLLECTION Geometry.
Definition: gg_structs.h:227
gaiaLinestringStruct::Coords
double * Coords
COORDs mem-array.
Definition: gg_structs.h:134
gaiaOutBufferStruct::Buffer
char * Buffer
current buffer
Definition: gg_structs.h:500
spatialite.h
Main SpatiaLite header file.
gaiaSetPoint
#define gaiaSetPoint(xy, v, x, y)
macro setting XY coordinates
Definition: gg_const.h:479
gaiaPolygonStruct::Next
struct gaiaPolygonStruct * Next
pointer to next item [linked list]
Definition: gg_structs.h:214
gaiaAddLinestringToGeomColl
GAIAGEO_DECLARE gaiaLinestringPtr gaiaAddLinestringToGeomColl(gaiaGeomCollPtr p, int vert)
Creates a new Linestring object into a Geometry object.
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