lwtriangle_from_wkb_state()

static LWTRIANGLE * lwtriangle_from_wkb_state ( wkb_parse_state *  s )

static

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.

Definition at line 603 of file lwin_wkb.c.

{
        uint32_t nrings = integer_from_wkb_state(s);
        if (s->error)
                return NULL;
 
        /* Empty triangle? */
        if( nrings == 0 )
                return lwtriangle_construct_empty(s->srid, s->has_z, s->has_m);
 
        /* Should be only one ring. */
        if (nrings != 1)
        {
                lwerror("Triangle has wrong number of rings: %d", nrings);
        }
 
        /* There's only one ring, we hope? */
        POINTARRAY *pa = ptarray_from_wkb_state(s);
 
        /* If there's no points, return an empty triangle. */
        if (pa == NULL)
                return lwtriangle_construct_empty(s->srid, s->has_z, s->has_m);
 
        /* Check for at least four points. */
        if (s->check & LW_PARSER_CHECK_MINPOINTS && pa->npoints < 4)
        {
                ptarray_free(pa);
                lwerror("%s must have at least four points", lwtype_name(s->lwtype));
                return NULL;
        }
 
        if (s->check & LW_PARSER_CHECK_ZCLOSURE && !ptarray_is_closed_z(pa))
        {
                ptarray_free(pa);
                lwerror("%s must have closed rings", lwtype_name(s->lwtype));
                return NULL;
        }
 
        /* Empty TRIANGLE starts w/ empty POINTARRAY, free it first */
        return lwtriangle_construct(s->srid, NULL, pa);
}

References integer_from_wkb_state(), LW_PARSER_CHECK_MINPOINTS, LW_PARSER_CHECK_ZCLOSURE, lwerror(), lwtriangle_construct(), lwtriangle_construct_empty(), lwtype_name(), POINTARRAY::npoints, ptarray_free(), ptarray_from_wkb_state(), ptarray_is_closed_z(), and s.

Referenced by lwgeom_from_wkb_state().

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