VolumeJ
Class VJPlane

java.lang.Object
  |
  +--VolumeJ.VJPlane

public class VJPlane

extends java.lang.Object

VJPlane. Defines a 3D plane equation and methods to create and operate on it. Copyright (c) 1999-2002, Michael Abramoff. All rights reserved.

Constructor Summary

VJPlane(float[] p, float[] q, float[] r)
Create a new plane through 3 points p, q, r.

VJPlane(float[] p, float[] q, float[] r, VJMatrix m)
Create a new plane through 3 homogenuous coordinates p, q, r defined in a coordinate system, but define the plane in a transformation of that coordinate system defined by m.

VJPlane(VJPlane p)
Create a new plane from another plane.

VJPlane(VJPlane p, float[] q)
Create a new plane parallel to a plane p through a point q.

Method Summary

static float	check(float x, float y, float z, float a, float b, float c, float d) Return the result of a plane equation with a,b,c,d with a point x,y,z filled in.
float	getA() Get the A for the plane equation Ax+By+C+D=0 of this plane
float	getB() Get the B for the plane equation Ax+By+C+D=0 of this plane
float	getC() Get the D for the plane equation Ax+By+C+D=0 of this plane
float	getD() Get the D for the plane equation Ax+By+C+D=0 of this plane
VJGradient	getGradient() Return the gradient of a plane (the normal vector) as a VJGradient.
float	intersectRay(float x0, float y0) Optimization for finding intersection of this plane with a ray running through x0, y0, 0 with derivative 0,0,1.
void	setD(float d) Set the D for the plane equation Ax+By+C+D=0 of this plane
java.lang.String	toString()

Methods inherited from class java.lang.Object

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

Constructor Detail

VJPlane

public VJPlane(float[] p,
               float[] q,
               float[] r)

Create a new plane through 3 points p, q, r.

Parameters:

p, - q, r three double[3] points.

VJPlane

public VJPlane(VJPlane p)

Create a new plane from another plane.

Parameters:

p - a VJPlane.

VJPlane

public VJPlane(VJPlane p,
               float[] q)

Create a new plane parallel to a plane p through a point q. Only D in the plane equation is different for parallel planes.

Parameters:

p - a VJPlane to which this plane is to be parallel.

q - a point through which this new plane should also go.

VJPlane

public VJPlane(float[] p,
               float[] q,
               float[] r,
               VJMatrix m)

Create a new plane through 3 homogenuous coordinates p, q, r defined in a coordinate system, but define the plane in a transformation of that coordinate system defined by m.

Parameters:

p, - q, r three double[4] points.

Method Detail

intersectRay

public float intersectRay(float x0,
                          float y0)

Optimization for finding intersection of this plane with a ray running through x0, y0, 0 with derivative 0,0,1. For this line, dx and dy = 0, z0 = 0, dz = 1. Return the intersection in homogoneous coordinates.

Parameters:

x0, - y0 defines the origin of the ray.

Returns:

the z coordinate of the intersection (others are x0, y0).

check

public static float check(float x,
                          float y,
                          float z,
                          float a,
                          float b,
                          float c,
                          float d)

Return the result of a plane equation with a,b,c,d with a point x,y,z filled in. Should be 0.0 if x,y,z, is within the plane.

Parameters:

x,y,z - the point you want to check.

a,b,c,d - the A,B,C,D of a plane equation.

getGradient

public VJGradient getGradient()

Return the gradient of a plane (the normal vector) as a VJGradient.

Returns:

a VJGradient that contains the normal vector of the plane.

getA

public float getA()

Get the A for the plane equation Ax+By+C+D=0 of this plane

Returns:

double the value of A

getB

public float getB()

Get the B for the plane equation Ax+By+C+D=0 of this plane

Returns:

double the value of B

getC

public float getC()

Get the D for the plane equation Ax+By+C+D=0 of this plane

Returns:

double the value of D

getD

public float getD()

Get the D for the plane equation Ax+By+C+D=0 of this plane

Returns:

double the value of D

setD

public void setD(float d)

Set the D for the plane equation Ax+By+C+D=0 of this plane

Parameters:

d - double the value of D

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object