PostGIS 3.7.0dev-r@@SVN_REVISION@@
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◆ lwgeom_length_spheroid()

double lwgeom_length_spheroid ( const LWGEOM geom,
const SPHEROID s 
)

Calculate the geodetic length of a lwgeom on the unit sphere.

The result will have to by multiplied by the real radius to get the real length.

Definition at line 3145 of file lwgeodetic.c.

3146{
3147 int type;
3148 uint32_t i = 0;
3149 double length = 0.0;
3150
3151 assert(geom);
3152
3153 /* No area in nothing */
3154 if ( lwgeom_is_empty(geom) )
3155 return 0.0;
3156
3157 type = geom->type;
3158
3159 if ( type == POINTTYPE || type == MULTIPOINTTYPE )
3160 return 0.0;
3161
3162 if ( type == LINETYPE )
3163 return ptarray_length_spheroid(((LWLINE*)geom)->points, s);
3164
3165 if ( type == POLYGONTYPE )
3166 {
3167 LWPOLY *poly = (LWPOLY*)geom;
3168 for ( i = 0; i < poly->nrings; i++ )
3169 {
3170 length += ptarray_length_spheroid(poly->rings[i], s);
3171 }
3172 return length;
3173 }
3174
3175 if ( type == TRIANGLETYPE )
3176 return ptarray_length_spheroid(((LWTRIANGLE*)geom)->points, s);
3177
3178 if ( lwtype_is_collection( type ) )
3179 {
3180 LWCOLLECTION *col = (LWCOLLECTION*)geom;
3181
3182 for ( i = 0; i < col->ngeoms; i++ )
3183 {
3184 length += lwgeom_length_spheroid(col->geoms[i], s);
3185 }
3186 return length;
3187 }
3188
3189 lwerror("unsupported type passed to lwgeom_length_sphere");
3190 return 0.0;
3191}
char * s
Definition cu_in_wkt.c:23
#define LINETYPE
Definition liblwgeom.h:103
#define MULTIPOINTTYPE
Definition liblwgeom.h:105
int lwtype_is_collection(uint8_t type)
Determine whether a type number is a collection or not.
Definition lwgeom.c:1196
#define POINTTYPE
LWTYPE numbers, used internally by PostGIS.
Definition liblwgeom.h:102
#define POLYGONTYPE
Definition liblwgeom.h:104
#define TRIANGLETYPE
Definition liblwgeom.h:115
double ptarray_length_spheroid(const POINTARRAY *pa, const SPHEROID *s)
double lwgeom_length_spheroid(const LWGEOM *geom, const SPHEROID *s)
Calculate the geodetic length of a lwgeom on the unit sphere.
void void lwerror(const char *fmt,...) __attribute__((format(printf
Write a notice out to the error handler.
static int lwgeom_is_empty(const LWGEOM *geom)
Return true or false depending on whether a geometry is an "empty" geometry (no vertices members)
Definition lwinline.h:199
uint32_t ngeoms
Definition liblwgeom.h:580
LWGEOM ** geoms
Definition liblwgeom.h:575
uint8_t type
Definition liblwgeom.h:462
POINTARRAY ** rings
Definition liblwgeom.h:519
uint32_t nrings
Definition liblwgeom.h:524

References LWCOLLECTION::geoms, LINETYPE, lwerror(), lwgeom_is_empty(), lwgeom_length_spheroid(), lwtype_is_collection(), MULTIPOINTTYPE, LWCOLLECTION::ngeoms, LWPOLY::nrings, POINTTYPE, POLYGONTYPE, ptarray_length_spheroid(), LWPOLY::rings, s, TRIANGLETYPE, and LWGEOM::type.

Referenced by geography_length(), geography_perimeter(), LWGEOM_length2d_ellipsoid(), LWGEOM_length_ellipsoid_linestring(), and lwgeom_length_spheroid().

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