LWGEOM *
lwgeom_construct_empty(uint8_t type, int srid, char hasz, char hasm)
{
switch(type)
{
case POINTTYPE:
return lwpoint_as_lwgeom(lwpoint_construct_empty(srid, hasz, hasm));
case LINETYPE:
return lwline_as_lwgeom(lwline_construct_empty(srid, hasz, hasm));
case POLYGONTYPE:
return lwpoly_as_lwgeom(lwpoly_construct_empty(srid, hasz, hasm));
case CURVEPOLYTYPE:
return lwcurvepoly_as_lwgeom(lwcurvepoly_construct_empty(srid, hasz, hasm));
case CIRCSTRINGTYPE:
return lwcircstring_as_lwgeom(lwcircstring_construct_empty(srid, hasz, hasm));
case TRIANGLETYPE:
return lwtriangle_as_lwgeom(lwtriangle_construct_empty(srid, hasz, hasm));
case COMPOUNDTYPE:
case MULTIPOINTTYPE:
case MULTILINETYPE:
case MULTIPOLYGONTYPE:
case COLLECTIONTYPE:
return lwcollection_as_lwgeom(lwcollection_construct_empty(type, srid, hasz, hasm));
default:
lwerror("lwgeom_construct_empty: unsupported geometry type: %s",
lwtype_name(type));
return NULL;
}
}
/**
* Create a new circularstring. Null point array implies empty. Null dimensionality
* implies no specified dimensionality in the WKT.
* Circular strings are just like linestrings, except with slighty different
* validity rules (minpoint == 3, numpoints % 2 == 1).
*/
LWGEOM* wkt_parser_circularstring_new(POINTARRAY *pa, char *dimensionality)
{
uint8_t flags = wkt_dimensionality(dimensionality);
LWDEBUG(4,"entered");
/* No pointarray means it is empty */
if( ! pa )
return lwcircstring_as_lwgeom(lwcircstring_construct_empty(SRID_UNKNOWN, FLAGS_GET_Z(flags), FLAGS_GET_M(flags)));
/* If the number of dimensions is not consistent, we have a problem. */
if( wkt_pointarray_dimensionality(pa, flags) == LW_FALSE )
{
ptarray_free(pa);
SET_PARSER_ERROR(PARSER_ERROR_MIXDIMS);
return NULL;
}
/* Apply check for not enough points, if requested. */
if( (global_parser_result.parser_check_flags & LW_PARSER_CHECK_MINPOINTS) && (pa->npoints < 3) )
{
ptarray_free(pa);
SET_PARSER_ERROR(PARSER_ERROR_MOREPOINTS);
return NULL;
}
/* Apply check for odd number of points, if requested. */
if( (global_parser_result.parser_check_flags & LW_PARSER_CHECK_ODD) && ((pa->npoints % 2) == 0) )
{
ptarray_free(pa);
SET_PARSER_ERROR(PARSER_ERROR_ODDPOINTS);
return NULL;
}
return lwcircstring_as_lwgeom(lwcircstring_construct(SRID_UNKNOWN, NULL, pa));
}
/**
* CIRCULARSTRING
* Read a WKB circularstring, starting just after the endian byte,
* type number and optional srid number. Advance the parse state
* forward appropriately.
* There is only one pointarray in a linestring. Optionally
* check for minimal following of rules (three point minimum,
* odd number of points).
*/
static LWCIRCSTRING* lwcircstring_from_wkb_state(wkb_parse_state *s)
{
POINTARRAY *pa = ptarray_from_wkb_state(s);
if( pa == NULL || pa->npoints == 0 )
return lwcircstring_construct_empty(s->srid, s->has_z, s->has_m);
if( s->check & LW_PARSER_CHECK_MINPOINTS && pa->npoints < 3 )
{
lwerror("%s must have at least three points", lwtype_name(s->lwtype));
return NULL;
}
if( s->check & LW_PARSER_CHECK_ODD && ! (pa->npoints % 2) )
{
lwerror("%s must have an odd number of points", lwtype_name(s->lwtype));
return NULL;
}
return lwcircstring_construct(s->srid, NULL, pa);
}
