Class point2D

Object
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   +--Vector
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         +--point2D

class point2D

extends Vector

The point2D class defines a point in 2-dimensional Euclidean space via homogeneous coordinates (i.e. as a 3-vector (x,y,1)). This allows affine transformations to be applied to 2-D points via matrix multiplication.
Defined in point2D.js

Requires:

- Vector
- Matrix

Field Detail

components

Array components

The components of the 2D point. This allows multiplication by affine transformation matrices and other useful Vector operations.

n

<final> Integer n

The "dimension" of the point; ALWAYS 2. Important that this.n != 3; gives "illusion" of 2-D vector while allowing multiplication by matrices with 3 columns for transformations

See Also:

Constant Field Values

x

Number x

The x value of the 2D point.

y

Number y

The y value of the 2D point.

zero

<static> Object zero

point2D

point2D(<Number> x, <Number> y)

Constructor function. Makes a new 2D point (x,y,1).

Parameters:
x - the x component; if x is a point2D object, will create a duplicate of the point
y - the y component

Requires:
- Vector
- Matrix

make3D

point3D make3D()

Converts a 2D point to a 3D point with a 0 z-component.

Returns:
the 3D point

map

point2D map(func)

Maps this point to a new 2D point according to a given function. Overwrites the map function of the Vector class. Used internally for things like addition, multiplication, dot products, etc.

Parameters:
func - {Object} the mapping function

Returns:
the new, mapped point

rotate

point2D rotate(<Number> theta)

Rotates a point through a degree theta and returns a new point.

Parameters:
theta - the degree (in radians) by which to rotate the point

Returns:
a new point that is the old rotated through an angle theta

toString

String toString()

Produces a string representation of the point. Overwrites the toString function of the Vector class.

Returns:
the string (x,y)

toVector

Vector toVector()

Converts point2D object back to a Vector. Will no longer be homogeneous coordinates.

Returns:
the vector [x,y,z]

translate

point2D translate(<Number> dx, <Number> dy)

Translates a point (x,y,1) to (x+dx, y+dy, 1).

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

Returns:
a new point that is the old one translated