frink.graphics

Class LineSegment3DFloat

java.lang.Object

frink.graphics.LineSegment3DFloat

public class LineSegment3DFloat
extends java.lang.Object

This represents a line segment in 3-D space. It contains methods to determine the distance from the line segment (or an infinite line) to a point. This is useful in, say, drawing cylinders.

Author:

Alan Eliasen, eliasen@mindspring.com

Field Summary

Fields

Modifier and Type	Field and Description
BoundingBox3DFloat	bbox The bounding box of this line.
Point3DFloat	p1 The endpoints of the line.
Point3DFloat	p2 The endpoints of the line.

Constructor Summary

Constructors

Constructor and Description
LineSegment3DFloat(float x1, float y1, float z1, float x2, float y2, float z2) Construct a line segment with the 2 specified endpoints.
LineSegment3DFloat(Point3DFloat p1, Point3DFloat p2) Construct a line segment with the 2 specified endpoints.

Method Summary

Modifier and Type	Method and Description
float	distance(float px, float py, float pz) Calculate the distance from this finite line segment to the specified point in 3D.
float	distance(Point3DFloat p) Calculate the distance from this finite line segment to the specified point in 3D.
float	distanceToLine(Point3DFloat p) Calculate the distance from an infinite line (not a line segment!) to the specified point in 3D.
BoundingBox3DFloat	getBoundingBox() Gets the bounding box of this line segment.
boolean	inCylinder(float px, float py, float pz, float radius) Returns true if the point is within an uncapped finite cylinder surrounding the line segment with the specified radius.
boolean	inTaperedCappedCylinder(float px, float py, float pz, float radius1, float radius2) Returns true if the specified point is within a tapered cylinder with spherical endcaps.
boolean	inTaperedCylinder(float px, float py, float pz, float radius1, float radius2) Returns true if the point (px, py, pz) is within an uncapped finite tapered cylinder surrounding the line segment with the specified radii at the endpoints.
static LineSegment3DFloat	pointAndNormal(float x, float y, float z, float nx, float ny, float nz) Construct a line segment from a point and a normal vector (this function will normalize the normal.) The line segment will be of length 1.
static LineSegment3DFloat	pointAndNormal(float x, float y, float z, float nx, float ny, float nz, float d0, float d1) Construct a line segment from a point and a normal vector (this function will normalize the normal.) The line segment will extend along the normal with the specified start and end distances d0 and d1 from the starting point.
static LineSegment3DFloat	towardPoint(float x1, float y1, float z1, float x2, float y2, float z2, float d0, float d1) Makes a line segment from point 1 toward point 2.

Methods inherited from class java.lang.Object

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

Field Detail

p1

public Point3DFloat p1

The endpoints of the line.

p2

public Point3DFloat p2

The endpoints of the line.

bbox

public BoundingBox3DFloat bbox

The bounding box of this line.

Constructor Detail

LineSegment3DFloat

public LineSegment3DFloat(Point3DFloat p1,
                          Point3DFloat p2)

Construct a line segment with the 2 specified endpoints.

LineSegment3DFloat

public LineSegment3DFloat(float x1,
                          float y1,
                          float z1,
                          float x2,
                          float y2,
                          float z2)

Construct a line segment with the 2 specified endpoints.

Method Detail

pointAndNormal

public static LineSegment3DFloat pointAndNormal(float x,
                                                float y,
                                                float z,
                                                float nx,
                                                float ny,
                                                float nz)

Construct a line segment from a point and a normal vector (this function will normalize the normal.) The line segment will be of length 1. This is probably what you want to use when working with an infinite line.

pointAndNormal

public static LineSegment3DFloat pointAndNormal(float x,
                                                float y,
                                                float z,
                                                float nx,
                                                float ny,
                                                float nz,
                                                float d0,
                                                float d1)

Construct a line segment from a point and a normal vector (this function will normalize the normal.) The line segment will extend along the normal with the specified start and end distances d0 and d1 from the starting point. For example, if d0=0, the line will start at (x,y,z) and have a length of d1. This can project along the line forwards and backwards.

towardPoint

public static LineSegment3DFloat towardPoint(float x1,
                                             float y1,
                                             float z1,
                                             float x2,
                                             float y2,
                                             float z2,
                                             float d0,
                                             float d1)

Makes a line segment from point 1 toward point 2. The line segment will extend along the normal with the specified start and end distances d0 and d1 from the starting point. For example, if d0=0, the line will start at point 1 and have a length of d1. This can project along the line forward and backwards.

distance

public float distance(Point3DFloat p)

Calculate the distance from this finite line segment to the specified point in 3D. Rendering the points within a certain distance gives a cylinder with spherical endcaps, which is highly useful for constructive solid geometry. See https://stackoverflow.com/questions/849211/shortest-distance-between-a-point-and-a-line-segment

distance

public float distance(float px,
                      float py,
                      float pz)

Calculate the distance from this finite line segment to the specified point in 3D. Rendering the points within a certain distance gives a cylinder with spherical endcaps, which is highly useful for constructive solid geometry. See https://stackoverflow.com/questions/849211/shortest-distance-between-a-point-and-a-line-segment

distanceToLine

public float distanceToLine(Point3DFloat p)

Calculate the distance from an infinite line (not a line segment!) to the specified point in 3D. See: https://mathworld.wolfram.com/Point-LineDistance3-Dimensional.html

inCylinder

public boolean inCylinder(float px,
                          float py,
                          float pz,
                          float radius)

Returns true if the point is within an uncapped finite cylinder surrounding the line segment with the specified radius.

inTaperedCylinder

public boolean inTaperedCylinder(float px,
                                 float py,
                                 float pz,
                                 float radius1,
                                 float radius2)

Returns true if the point (px, py, pz) is within an uncapped finite tapered cylinder surrounding the line segment with the specified radii at the endpoints.

inTaperedCappedCylinder

public boolean inTaperedCappedCylinder(float px,
                                       float py,
                                       float pz,
                                       float radius1,
                                       float radius2)

Returns true if the specified point is within a tapered cylinder with spherical endcaps. The radii are at point1 and point2.

getBoundingBox

public BoundingBox3DFloat getBoundingBox()

Gets the bounding box of this line segment.