org.deegree.geometry.validation
Class GeometryValidator

java.lang.Object
  org.deegree.geometry.validation.GeometryValidator

public class GeometryValidator
extends Object

Performs topological validation of Geometry objects.

The tested topological properties depend on the type of geometry:

Points

No constraints, Point geometries are always topologically valid.

Curves

• CURVE_DISCONTINUITY: The end point of a segment n does not coincide with the start point of segment n+1.
• CURVE_SELF_INTERSECTION: Curve intersects itself.

Rings

The above events are also generated for Ring geometries (as they are a generally just closed Curve s). Additionally, the following events may occur:

• RING_NOT_CLOSED: The end point does not coincide with the start point.
• RING_SELF_INTERSECTION: Ring intersects itself.

PolygonPatches (= planar surfaces)

The boundaries of a PolygonPatch are Rings, which are tested and may generate the above events. Additionally, the following events may occur:

• EXTERIOR_RING_CCW: The control points of an exterior ring (i.e. the shell) does not follow counter-clockwise order.
• INTERIOR_RING_CW: The control points of an interior ring (i.e. a hole) of a PolygonPatch does not follow clockwise order.
• INTERIOR_RINGS_TOUCH: Two interior rings touch.
• INTERIOR_RINGS_INTERSECTS: Two interior rings intersect.
• INTERIOR_RINGS_WITHIN: An interior ring lies inside another.
• EXTERIOR_RING_TOUCHES_INTERIOR: An interior ring touches the shell.
• EXTERIOR_RING_INTERSECTS_INTERIOR: An interior ring intersects the shell.
• EXTERIOR_RING_WITHIN_INTERIOR: The exterior ring lies inside an interior ring.

Version:

$Revision:$, $Date:$

Author:

Markus Schneider , last edited by: $Author:$

Constructor Summary

GeometryValidator(GeometryValidationEventHandler eventHandler)
Creates a new GeometryValidator which performs callbacks on the given GeometryValidationEventHandler in case of errors.

Method Summary

boolean

validateGeometry(Geometry geom) Performs a topological validation of the given Geometry.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

GeometryValidator

public GeometryValidator(GeometryValidationEventHandler eventHandler)

Creates a new GeometryValidator which performs callbacks on the given GeometryValidationEventHandler in case of errors.

Parameters:

eventHandler - callback handler for errors

Method Detail

validateGeometry

public boolean validateGeometry(Geometry geom)

Performs a topological validation of the given Geometry.

Contained geometry objects and geometry particles are recursively checked (e.g. the members of a MultiGeometry) and callbacks to the associated GeometryValidationEventHandler are performed for each detected issue.

Parameters:

geom - geometry to be validated

Returns:

true, if the geometry is valid, false otherwise (depends on the GeometryValidationEventHandler implementation)