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* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
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package org.apache.commons.math3.geometry.partitioning;
import org.apache.commons.math3.geometry.Point;
import org.apache.commons.math3.geometry.Space;
/** This interface represents an hyperplane of a space.
* The most prominent place where hyperplane appears in space
* partitioning is as cutters. Each partitioning node in a {@link
* BSPTree BSP tree} has a cut {@link SubHyperplane sub-hyperplane}
* which is either an hyperplane or a part of an hyperplane. In an
* n-dimensions euclidean space, an hyperplane is an (n-1)-dimensions
* hyperplane (for example a traditional plane in the 3D euclidean
* space). They can be more exotic objects in specific fields, for
* example a circle on the surface of the unit sphere.
*
* Note that this interface is not intended to be implemented
* by Apache Commons Math users, it is only intended to be implemented
* within the library itself. New methods may be added even for minor
* versions, which breaks compatibility for external implementations.
*
* @param Type of the space.
* @since 3.0
*/
public interface Hyperplane {
/** Copy the instance.
* The instance created is completely independant of the original
* one. A deep copy is used, none of the underlying objects are
* shared (except for immutable objects).
* @return a new hyperplane, copy of the instance
*/
Hyperplane copySelf();
/** Get the offset (oriented distance) of a point.
* The offset is 0 if the point is on the underlying hyperplane,
* it is positive if the point is on one particular side of the
* hyperplane, and it is negative if the point is on the other side,
* according to the hyperplane natural orientation.
* @param point point to check
* @return offset of the point
*/
double getOffset(Point point);
/** Project a point to the hyperplane.
* @param point point to project
* @return projected point
* @since 3.3
*/
Point project(Point point);
/** Get the tolerance below which points are considered to belong to the hyperplane.
* @return tolerance below which points are considered to belong to the hyperplane
* @since 3.3
*/
double getTolerance();
/** Check if the instance has the same orientation as another hyperplane.
* This method is expected to be called on parallel hyperplanes. The
* method should not re-check for parallelism, only for
* orientation, typically by testing something like the sign of the
* dot-products of normals.
* @param other other hyperplane to check against the instance
* @return true if the instance and the other hyperplane have
* the same orientation
*/
boolean sameOrientationAs(Hyperplane other);
/** Build a sub-hyperplane covering the whole hyperplane.
* @return a sub-hyperplane covering the whole hyperplane
*/
SubHyperplane wholeHyperplane();
/** Build a region covering the whole space.
* @return a region containing the instance
*/
Region wholeSpace();
}