frink.graphics

Class Plane3DFloat

java.lang.Object

frink.graphics.Plane3DFloat

public class Plane3DFloat
extends java.lang.Object

This represents a plane in 3-D. The plane takes the form: A x + B y + C z + D = 0 Points where A x + B y + C z + D < 0 are considered "inside" the object and A x + B y + C z + D > 0 are considered "outside" the object. The normal vector pointing "outside" the plane are given by (A, B, C) but this is not necessarily normalized, but you can get the normal unit vector by calling getNormal().

Author:

Alan Eliasen, eliasen@mindspring.com

Field Summary

Fields

Modifier and Type	Field and Description
private float	A The coefficients of the plane.
private float	B The coefficients of the plane.
private float	C The coefficients of the plane.
private float	D The coefficients of the plane.
private Point3DFloat	normal The normalized normal vector.

Constructor Summary

Constructors

Constructor and Description
Plane3DFloat(float A, float B, float C, float D) Construct a Plane3DFloat using the coefficients A, B, C, D
Plane3DFloat(float x, float y, float z, float A, float B, float C) Construct a Plane3DFloat using a point [x, y, z] and a normal direction A, B, C.
Plane3DFloat(Point3DFloat p, Point3DFloat n) Construct a Plane3DFloat using a point p and a normal direction n.
Plane3DFloat(Point3DFloat p1, Point3DFloat p2, Point3DFloat p3) Construct a Plane3DFloat from 3 points, listed in the counterclockwise direction as seen from outside the object.

Method Summary

Modifier and Type	Method and Description
Point3DFloat	getNormal() Returns the normalized unit normal of the plane.
boolean	isInside(float x, float y, float z) Returns true if the specified point is "inside" the plane.
boolean	isInside(Point3DFloat p) Returns true if the specified point is "inside" the plane.
float	signedDistanceFloat(float x, float y, float z) Signed distance to plane from point.
java.lang.String	toString() Returns a String representation of this plane.

Methods inherited from class java.lang.Object

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

Field Detail

A

private float A

The coefficients of the plane. These are currently private to indicate that they can't be changed after construction. They are not normalized. This may change.

B

private float B

The coefficients of the plane. These are currently private to indicate that they can't be changed after construction. They are not normalized. This may change.

C

private float C

The coefficients of the plane. These are currently private to indicate that they can't be changed after construction. They are not normalized. This may change.

D

private float D

The coefficients of the plane. These are currently private to indicate that they can't be changed after construction. They are not normalized. This may change.

normal

private Point3DFloat normal

The normalized normal vector.

Constructor Detail

Plane3DFloat

public Plane3DFloat(float A,
                    float B,
                    float C,
                    float D)

Construct a Plane3DFloat using the coefficients A, B, C, D

Plane3DFloat

public Plane3DFloat(float x,
                    float y,
                    float z,
                    float A,
                    float B,
                    float C)

Construct a Plane3DFloat using a point [x, y, z] and a normal direction A, B, C.

Plane3DFloat

public Plane3DFloat(Point3DFloat p,
                    Point3DFloat n)

Construct a Plane3DFloat using a point p and a normal direction n.

Plane3DFloat

public Plane3DFloat(Point3DFloat p1,
                    Point3DFloat p2,
                    Point3DFloat p3)

Construct a Plane3DFloat from 3 points, listed in the counterclockwise direction as seen from outside the object.

Method Detail

getNormal

public Point3DFloat getNormal()

Returns the normalized unit normal of the plane.

signedDistanceFloat

public float signedDistanceFloat(float x,
                                 float y,
                                 float z)

Signed distance to plane from point. If the point is "outside" the plane, this returns a positive value, negative otherwise.

isInside

public boolean isInside(float x,
                        float y,
                        float z)

Returns true if the specified point is "inside" the plane. That is, points where: A x + B y + C z + D < 0 are considered "inside" the object and A x + B y + C z + D > 0 are considered "outside" the object.

isInside

public boolean isInside(Point3DFloat p)

Returns true if the specified point is "inside" the plane. That is, points where: A x + B y + C z + D < 0 are considered "inside" the object and A x + B y + C z + D > 0 are considered "outside" the object.

toString

public java.lang.String toString()

Returns a String representation of this plane.

Overrides:

toString in class java.lang.Object