lwgeom_is_clockwise()

int lwgeom_is_clockwise

(

LWGEOM *

lwgeom

)

Check clockwise orientation on LWGEOM polygons.

Ensure the outer ring is clockwise oriented and all inner rings are counter-clockwise.

Definition at line 65 of file lwgeom.c.

{
        switch (lwgeom->type)
        {
                case POLYGONTYPE:
                        return lwpoly_is_clockwise((LWPOLY *)lwgeom);
 
                case TRIANGLETYPE:
                        return lwtriangle_is_clockwise((LWTRIANGLE *)lwgeom);
 
                case MULTIPOLYGONTYPE:
                case COLLECTIONTYPE:
                {
                        uint32_t i;
                        LWCOLLECTION* coll = (LWCOLLECTION *)lwgeom;
 
                        for (i=0; i < coll->ngeoms; i++)
                                if (!lwgeom_is_clockwise(coll->geoms[i]))
                                        return LW_FALSE;
                        return LW_TRUE;
                }
                default:
                        return LW_TRUE;
                return LW_FALSE;
        }
}

References COLLECTIONTYPE, LWCOLLECTION::geoms, LW_FALSE, LW_TRUE, lwgeom_is_clockwise(), lwpoly_is_clockwise(), lwtriangle_is_clockwise(), MULTIPOLYGONTYPE, LWCOLLECTION::ngeoms, POLYGONTYPE, TRIANGLETYPE, and LWGEOM::type.

Referenced by lwgeom_is_clockwise(), ST_IsPolygonCCW(), ST_IsPolygonCW(), and test_lwgeom_force_clockwise().

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