/**
* LINESTRING
* Read a WKB linestring, 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 (two point minimum).
*/
static LWLINE* lwline_from_wkb_state(wkb_parse_state *s)
{
POINTARRAY *pa = ptarray_from_wkb_state(s);
if( pa == NULL || pa->npoints == 0 )
return lwline_construct_empty(s->srid, s->has_z, s->has_m);
if( s->check & LW_PARSER_CHECK_MINPOINTS && pa->npoints < 2 )
{
lwerror("%s must have at least two points", lwtype_name(s->lwtype));
return NULL;
}
return lwline_construct(s->srid, 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;
}
/**
* POLYGON
* Read a WKB polygon, starting just after the endian byte,
* type number and optional srid number. Advance the parse state
* forward appropriately.
* First read the number of rings, then read each ring
* (which are structured as point arrays)
*/
static LWPOLY* lwpoly_from_wkb_state(wkb_parse_state *s)
{
uint32_t nrings = integer_from_wkb_state(s);
int i = 0;
LWPOLY *poly = lwpoly_construct_empty(s->srid, s->has_z, s->has_m);
LWDEBUGF(4,"Polygon has %d rings", nrings);
/* Empty polygon? */
if( nrings == 0 )
return poly;
for( i = 0; i < nrings; i++ )
{
POINTARRAY *pa = ptarray_from_wkb_state(s);
if( pa == NULL )
continue;
/* 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 in each ring", lwtype_name(s->lwtype));
lwerror("%s must have at least four points in each ring", lwtype_name(s->lwtype));
return NULL;
}
/* Check that first and last points are the same. */
if( s->check & LW_PARSER_CHECK_CLOSURE && ! ptarray_is_closed_2d(pa) )
{
LWDEBUGF(2, "%s must have closed rings", lwtype_name(s->lwtype));
lwerror("%s must have closed rings", lwtype_name(s->lwtype));
return NULL;
}
/* Add ring to polygon */
if ( lwpoly_add_ring(poly, pa) == LW_FAILURE )
{
LWDEBUG(2, "Unable to add ring to polygon");
lwerror("Unable to add ring to polygon");
}
}
return poly;
}
/**
* 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);
}
