com.vividsolutions.jts.operation

Class IsSimpleOp


  • public class IsSimpleOp
extends Object
    Tests whether a Geometry is simple. In general, the SFS specification of simplicity follows the rule:
    • A Geometry is simple if and only if the only self-intersections are at boundary points.
    This definition relies on the definition of boundary points. The SFS uses the Mod-2 rule to determine which points are on the boundary of lineal geometries, but this class supports using other BoundaryNodeRules as well.

    Simplicity is defined for each Geometry subclass as follows:

    • Valid polygonal geometries are simple by definition, so isSimple trivially returns true. (Hint: in order to check if a polygonal geometry has self-intersections, use Geometry.isValid()).
    • Linear geometries are simple iff they do not self-intersect at points other than boundary points. (Using the Mod-2 rule, this means that closed linestrings cannot be touched at their endpoints, since these are interior points, not boundary points).
    • Zero-dimensional geometries (points) are simple iff they have no repeated points.
    • Empty Geometrys are always simple
    See Also:
    BoundaryNodeRule

    • Constructor Detail

      • IsSimpleOp

        public IsSimpleOp()
        Deprecated.  use IsSimpleOp(Geometry)
        Creates a simplicity checker using the default SFS Mod-2 Boundary Node Rule

      • IsSimpleOp

        public IsSimpleOp(Geometry geom)
        Creates a simplicity checker using the default SFS Mod-2 Boundary Node Rule
        Parameters:
        geom - the geometry to test

      • IsSimpleOp

        public IsSimpleOp(Geometry geom,
                  BoundaryNodeRule boundaryNodeRule)
        Creates a simplicity checker using a given BoundaryNodeRule
        Parameters:
        geom - the geometry to test
        boundaryNodeRule - the rule to use.

    • Method Detail

      • isSimple

        public boolean isSimple()
        Tests whether the geometry is simple.
        Returns:
        true if the geometry is simple

      • getNonSimpleLocation

        public Coordinate getNonSimpleLocation()
        Gets a coordinate for the location where the geometry fails to be simple. (i.e. where it has a non-boundary self-intersection). isSimple() must be called before this method is called.
        Returns:
        a coordinate for the location of the non-boundary self-intersection

      • isSimple

        public boolean isSimple(LineString geom)
        Deprecated.  use isSimple()
        Reports whether a LineString is simple.
        Parameters:
        geom - the lineal geometry to test
        Returns:
        true if the geometry is simple

      • isSimple

        public boolean isSimple(MultiLineString geom)
        Deprecated.  use isSimple()
        Reports whether a MultiLineString geometry is simple.
        Parameters:
        geom - the lineal geometry to test
        Returns:
        true if the geometry is simple

      • isSimple

        public boolean isSimple(MultiPoint mp)
        Deprecated.  use isSimple()
        A MultiPoint is simple iff it has no repeated points