/**
 * <p>
 * Interface for boundaries environments for robots.
 * This interface is going to cause a problem, as
 * the methods for storing polygons vs. polyhedra are
 * fundamentally different.
 * A core set of queries can be made which work for any number of dimensions,
 * but some sensors may want access to winged edge representations for 2d
 * or "graph of polygons" representations for 3d boundaries.
 * Also some boundaries may be curved surfaces rather then polytopes.
 * This may be handled by casting to a subtype for 2d boundaries
 * and not worrying about higher dimensionalities, as
 * correct implementation of complex non-convex polyhedral boundaries
 * in 3d is extremely difficult.
 * </p>
 * @author     Michael Schuresko
 * @version    %I%, %G%
 * @since      1.0
*/

public interface IBoundary
{
    /**
     * Mostly just a safety check, since the environment should have
     * this anyway
     */
    public int getNumDimensions();

    /**
     * Inside / outside query.
     */
    public boolean isPointInside(double arrPoint[]);

    /**
     * Finds distance to boundary along a ray from a start point, 
     * returns negative number if outside boundary
     * @param arrRayOrigin origin of ray
     * @param arrRayDir direction of ray
     * @return distance along arrRayDir from arrRayOrigin to boundary, negative if arrRayOrigin is outside boundary
     */
    public double distToBoundary(double arrRayOrigin[], double arrRayDir[]);

    /**
     * Finds the closest point on the boundary to a given point,
     * or a minimally close point if multiple such points exist.
     * @param arrPoint point to find closest point to
     * @return closest point to arrPoint
     */
    public double [] closestBoundaryPoint(double arrPoint[]);

    /**
     * gets bounding box min corner
     * @return min corner of bounding box
     */
    public double [] bboxMinCorner();

    /** 
     * gets bounding box max corner
     * @return max corner of bounding box
     */
    public double [] bboxMaxCorner();
}