lwgeom_from_twkb_state()

LWGEOM * lwgeom_from_twkb_state

(

twkb_parse_state *

s

)

Internal function declarations.

Generic handling for TWKB geometries.

The front of every TWKB geometry (including those embedded in collections) is a type byte and metadata byte, then optional size, bbox, etc. Read those, then switch to particular type handling code.

Definition at line 562 of file lwin_twkb.c.

{
        GBOX bbox;
        LWGEOM *geom = NULL;
        uint32_t has_bbox = LW_FALSE;
        int i;
 
        /* Read the first two bytes, and optional */
        /* extended precision info and optional size info */
        header_from_twkb_state(s);
 
        /* Just experienced a geometry header, so now we */
        /* need to reset our coordinate deltas */
        for ( i = 0; i < TWKB_IN_MAXCOORDS; i++ )
        {
                s->coords[i] = 0.0;
        }
 
        /* Read the bounding box, is there is one */
        if ( s->has_bbox )
        {
                /* Initialize */
                has_bbox = s->has_bbox;
                memset(&bbox, 0, sizeof(GBOX));
                bbox.flags = gflags(s->has_z, s->has_m, 0);
 
                /* X */
                bbox.xmin = twkb_parse_state_double(s, s->factor);
                bbox.xmax = bbox.xmin + twkb_parse_state_double(s, s->factor);
                /* Y */
                bbox.ymin = twkb_parse_state_double(s, s->factor);
                bbox.ymax = bbox.ymin + twkb_parse_state_double(s, s->factor);
                /* Z */
                if ( s->has_z )
                {
                        bbox.zmin = twkb_parse_state_double(s, s->factor_z);
                        bbox.zmax = bbox.zmin + twkb_parse_state_double(s, s->factor_z);
                }
                /* M */
                if ( s->has_m )
                {
                        bbox.mmin = twkb_parse_state_double(s, s->factor_m);
                        bbox.mmax = bbox.mmin + twkb_parse_state_double(s, s->factor_m);
                }
        }
 
        /* Switch to code for the particular type we're dealing with */
        switch( s->lwtype )
        {
                case POINTTYPE:
                        geom = lwpoint_as_lwgeom(lwpoint_from_twkb_state(s));
                        break;
                case LINETYPE:
                        geom = lwline_as_lwgeom(lwline_from_twkb_state(s));
                        break;
                case POLYGONTYPE:
                        geom = lwpoly_as_lwgeom(lwpoly_from_twkb_state(s));
                        break;
                case MULTIPOINTTYPE:
                        geom = lwcollection_as_lwgeom(lwmultipoint_from_twkb_state(s));
                        break;
                case MULTILINETYPE:
                        geom = lwcollection_as_lwgeom(lwmultiline_from_twkb_state(s));
                        break;
                case MULTIPOLYGONTYPE:
                        geom = lwcollection_as_lwgeom(lwmultipoly_from_twkb_state(s));
                        break;
                case COLLECTIONTYPE:
                        geom = lwcollection_as_lwgeom(lwcollection_from_twkb_state(s));
                        break;
                /* Unknown type! */
                default:
                        lwerror("Unsupported geometry type: %s [%d]", lwtype_name(s->lwtype), s->lwtype);
                        break;
        }
 
        if ( has_bbox )
        {
                geom->bbox = gbox_clone(&bbox);
        }
 
        return geom;
}

References LWGEOM::bbox, COLLECTIONTYPE, GBOX::flags, gbox_clone(), gflags(), header_from_twkb_state(), LINETYPE, LW_FALSE, lwcollection_as_lwgeom(), lwcollection_from_twkb_state(), lwerror(), lwline_as_lwgeom(), lwline_from_twkb_state(), lwmultiline_from_twkb_state(), lwmultipoint_from_twkb_state(), lwmultipoly_from_twkb_state(), lwpoint_as_lwgeom(), lwpoint_from_twkb_state(), lwpoly_as_lwgeom(), lwpoly_from_twkb_state(), lwtype_name(), GBOX::mmax, GBOX::mmin, MULTILINETYPE, MULTIPOINTTYPE, MULTIPOLYGONTYPE, POINTTYPE, POLYGONTYPE, s, TWKB_IN_MAXCOORDS, twkb_parse_state_double(), GBOX::xmax, GBOX::xmin, GBOX::ymax, GBOX::ymin, GBOX::zmax, and GBOX::zmin.

Referenced by lwcollection_from_twkb_state(), and lwgeom_from_twkb().

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