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;
}
}
LWGEOM* wkt_parser_triangle_new(POINTARRAY *pa, char *dimensionality)
{
uint8_t flags = wkt_dimensionality(dimensionality);
LWDEBUG(4,"entered");
/* No pointarray means it is empty */
if( ! pa )
return lwtriangle_as_lwgeom(lwtriangle_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;
}
/* Triangles need four points. */
if( (pa->npoints != 4) )
{
ptarray_free(pa);
SET_PARSER_ERROR(PARSER_ERROR_TRIANGLEPOINTS);
return NULL;
}
/* Triangles need closure. */
if( ! ptarray_isclosed(pa) )
{
ptarray_free(pa);
SET_PARSER_ERROR(PARSER_ERROR_UNCLOSED);
return NULL;
}
return lwtriangle_as_lwgeom(lwtriangle_construct(SRID_UNKNOWN, NULL, pa));
}
/**
* TRIANGLE
* Read a WKB triangle, starting just after the endian byte,
* type number and optional srid number. Advance the parse state
* forward appropriately.
* Triangles are encoded like polygons in WKB, but more like linestrings
* as lwgeometries.
*/
static LWTRIANGLE* lwtriangle_from_wkb_state(wkb_parse_state *s)
{
uint32_t nrings = integer_from_wkb_state(s);
LWTRIANGLE *tri = lwtriangle_construct_empty(s->srid, s->has_z, s->has_m);
POINTARRAY *pa = NULL;
/* Empty triangle? */
if( nrings == 0 )
return tri;
/* Should be only one ring. */
if ( nrings != 1 )
lwerror("Triangle has wrong number of rings: %d", nrings);
/* There's only one ring, we hope? */
pa = ptarray_from_wkb_state(s);
/* If there's no points, return an empty triangle. */
if( pa == NULL )
return tri;
/* Check for at least four points. */
if( s->check & LW_PARSER_CHECK_MINPOINTS && pa->npoints < 4 )
{
LWDEBUGF(2, "%s must have at least four points", lwtype_name(s->lwtype));
lwerror("%s must have at least four points", lwtype_name(s->lwtype));
return NULL;
}
if( s->check & LW_PARSER_CHECK_CLOSURE && ! ptarray_is_closed(pa) )
{
lwerror("%s must have closed rings", lwtype_name(s->lwtype));
return NULL;
}
if( s->check & LW_PARSER_CHECK_ZCLOSURE && ! ptarray_is_closed_z(pa) )
{
lwerror("%s must have closed rings", lwtype_name(s->lwtype));
return NULL;
}
/* Empty TRIANGLE starts w/ empty POINTARRAY, free it first */
if (tri->points)
ptarray_free(tri->points);
tri->points = pa;
return tri;
}
