CODEWITHSUNDEEP
javainheritance
user2805708
user2805708

Reputation: 1

Transformation the shape assignment! (Need Help!)

I have transformation the shape assignment and I am pretty much done with my coding. However, I don't know how to code for this method.

    public Point2D apply(Point2D p) {

        }

I talked with professor, he said, "apply() needs to create a copy of the given point and then transform the copy. You've made the copy; now transform the copy before returning it."

Can anyone code for this method for me based on what he said?

Regards,

Upvotes: 0

Views: 128

Answers (2)

Christian Tapia
Christian Tapia

Reputation: 34166

In your code you must use your transform() method:

public Point2D apply(Point2D p) {
    double x = p.getX();
    double y = p.getY();
    Point2D newPoint = (Point2D) p.clone();
    transform(newPoint);
    return newPoint;
}
public void transform(Point2D p) {
    double x = p.getX();
    double y = p.getY();
    double newx = Math.cos(radians) * x - Math.sin(radians) * y;
    double newy = Math.sin(radians) * x + Math.cos(radians) * y;
    p.setLocation(newx, newy);
}

If you want to rotate a point (x, y) around another (center_x, center_y), a certain number of degrees (angle), this may help:

public float[] rotatePoint(float x, float y, float center_x, float center_y,
        double angle) {
    float x1 = x - center_x;
    float y1 = y - center_y;
    double angle2 = Math.toRadians(angle);
    float res_x, res_y;
    res_x = (float) (x1 * Math.cos(angle2) - y1 * Math.sin(angle2));
    res_y = (float) (x1 * Math.sin(angle2) + y1 * Math.cos(angle2));
    x = res_x + center_x;
    y = res_y + center_y;

    float[] res = { x, y };
    return res;
}

Upvotes: 0

James
James

Reputation: 4706

"You've made the copy; now transform the copy before returning it."

Your teacher gave you the answer, literally. Call the transform method, with the copy.

Look, I think I can hardly go any clearer than this...

    Point2D newPoint = new Point2D (x, y);
    transform(newPoint);  // <---- You need to add this line
    return newPoint;

Upvotes: 1

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