cse1030.drawing

Class Rotation

java.lang.Object

cse1030.drawing.Transformation

cse1030.drawing.Rotation

public class Rotation
extends Transformation

A class that rotates points about the origin. The amount of rotation is controlled by a scalar parameter called the rotation angle. A positive rotation angle causes points to rotate counterclockwise about the origin.

Author:

CSE1030Z

Constructor Summary

Constructors

Constructor and Description
Rotation(String name, double radians) Construct a rotation transformation given its name and the angle of rotation in radians.

Method Summary

Methods

Modifier and Type	Method and Description
Point2D	apply(Point2D p) Apply the rotation to a point to produce a new point leaving the original point unchanged.
String	toString() Get a string representation of the rotation.
void	transform(Point2D p) Transform a point changing its coordinates.

Methods inherited from class cse1030.drawing.Transformation

getName

Methods inherited from class java.lang.Object

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

Constructor Detail

Rotation

public Rotation(String name,
        double radians)

Construct a rotation transformation given its name and the angle of rotation in radians.

Parameters:

name - the name of the transformation

radians - the rotation angle in radians

Method Detail

transform

public void transform(Point2D p)

Transform a point changing its coordinates. For a rotation of theta radians the x and y coordinates of the point are transformed as follows:

newx = cos(theta) * x - sin(theta) * y
newy = sin(theta) * x + cos(theta) * y

Specified by:

transform in class Transformation

See Also:

Transformation.transform(cse1030.drawing.Point2D)

Parameters:

p - the point to transform

apply

public Point2D apply(Point2D p)

Apply the rotation to a point to produce a new point leaving the original point unchanged.

Specified by:

apply in class Transformation

See Also:

transform(cse1030.drawing.Point2D), Transformation.apply(cse1030.drawing.Point2D)

Parameters:

p - the point to apply the transformation to

Returns:

a new point equal to rotating the input point p

toString

public String toString()

Get a string representation of the rotation. The returned string is the name of the rotation followed by the string " : rotation of " followed by the angle in radians followed by the string " radians". For example, a rotation of 90 degrees named T1 has the following string representation:

"T1 : rotation of 1.5707963267948966 radians"

Overrides:

toString in class Transformation

See Also:

Transformation.toString()

Returns:

the string representation of the rotation