Class Line

Object
   |
   +--Line

class Line

The Line class defines a new object type for a line. It is in a sense a "point-slope" definition of a line. A Line has a base point and a direction, the direction being a unit vector. This is an effective way of defining a line in a way that does not limit it to any specific segment and allows for Affine Transformations to be applied.
Defined in Line.js

Requires:

- point3D

Field Detail

base

point3D base

The "anchor" point.

direction

point3D direction

The direction of the line; will be a unit vector. Use point3D object for this to allow Affine Transformations.

x

<static> Line x

The x-axis. Base: (0,0,0), Direction: Vector.i

y

<static> Line y

The y-axis. Base: (0,0,0), Direction: Vector.j

z

<static> Line z

The z-axis. Base: (0,0,0), Direction: Vector.k

Line

Line(<Object> base, <Object> direction)

The constructor function for a new Line. If only a Line object is supplied as a parameter, a duplicate of that Line will be created.

Parameters:
base - the base point of the Line; can be a point2D, point3D or Vector (of dimension 2 or 3) object. The actual base point of the Line will be a point3D object. (If base is a Line object, creates a clone)
direction - the direction of the Line; can be a point2D, point3D or Vector. Actual direction will be a normalized point3D object.

Requires:
- point3D

contains

Boolean contains(point)

Tests to see if a point lies on the line.

Parameters:
the - point to test

Returns:
true iff point is on line, false otherwise

distanceFrom

Number distanceFrom(<Object> obj)

Gets the distance between a line and another line, plane, or a point.

Parameters:
obj - either a Line, Plane, point2D or point3D, from which to find the distance to the line

Returns:
the distance between obj and the line; 0 if two lines have same base or one contains the base of the other

equalTo

Boolean equalTo(<Line> line)

Tests two lines for equality. Will return true if line is parallel or antiparallel.

Parameters:
line - the line to compare

Returns:
true if line has same base point and is parallel or antiparallel

intersection

point3D intersection(<Object> obj)

Finds the UNIQUE intersection of a line and another Line or Plane.

Parameters:
obj - the line or plane with which to find the intersection point

Returns:
the intersection point (null if obj does not intersect with line)

intersects

Boolean intersects(<Object> obj)

Tests if this line intersects with a given line or plane.

Parameters:
obj - Line or Plane, to test for intersection with the line

Returns:
true if there is a unique intersection point between the line and the given line or plane, false otherwise

isParallel

Boolean isParallel(<Object> obj)

Tests to see if a line is parallel to another line or plane.

Parameters:
obj - either a Line or a Plane, with which to test parallelity

Returns:
true if parallel or anti-parallel, false otherwise

liesIn

Boolean liesIn(<Plane> plane)

Tests if a Line lies in a given Plane.

Parameters:
plane - the plane which may or may not contain this Line

Returns:
true iff Line lies in plane, false otherwise

pointAt

point3D pointAt(<Number> t)

Returns the point on the line at a given value of t.

Parameters:
t - the time value at which to find the point on the line

Returns:
this.base + t*this.direction

pointClosestTo

point3D pointClosestTo(<Object> obj)

Finds the point on this line closest to a given line or point.

Parameters:
obj - a Line or point (or Vector)

Returns:
the point on the original line closes to obj

reflectionIn

Line reflectionIn(<Object> obj)

Returns the line's reflection in the given point, line, or plane.

Parameters:
obj - Plane, Line, or point2D/3D/Vector about which to reflect the line

Returns:
a new line, the old one reflected in obj

rotate

Line rotate(<Number> deg, line)

Rotates a line through an angle about an arbitrary line. Be careful, rotation axis' direction affects the outcome!

Parameters:
deg - the degrees, in radians, to rotate the line
the - line about which to rotate this line

Returns:
a new line that is the old one rotated

toString

String toString()

Returns a string representation of the Line.

Returns:
the string representation of the line, containing all relevant info

translate

Line translate(<Number> dx, <Number> dy, <Number> dz)

Returns a new Line that is the old one translated by dx, dy, and dz. Note that direction does not change in a translation, only the base point.

Parameters:
dx - the x translation
dy - the y translation
dz - the z translation

Returns:
the translated line