package break_out.model;

import break_out.Constants;
import break_out.model.Position;

/**
 * This class represent a two dimensional vector.
 *
 * @author I. Schumacher; modified by Gruppe 175 (Moritz Henseleit, Ruben Meyer)
 */
public class Vector2D implements IVector2D {

	/**
	 * The x part of the vector
	 */
	private double dx;

	/**
	 * The y part of the vector
	 */
	private double dy;

	/**
	 * This constructor creates a new vector with the given x and y parts.
	 *
	 * @param dx the delta x part for the new vector
	 * @param dy the delty y part for the new vector
	 */
	public Vector2D(double dx, double dy) {
		this.dx = dx;
		this.dy = dy;
	}

	/**
	 * This constructor creates a new vector based on the given positions start and end.
	 *
	 * @param start first position
	 * @param end second position
	 */
	public Vector2D(Position start, Position end) {
		// vector(AB) = (B.x - A.x, B.y - A.y)
		this.dx = end.getX() - start.getX();
		this.dy = end.getY() - start.getY();
	}

	/**
	 * Getter for the dx-part
	 *
	 * @return dx The dx part of this vector
	 */
	public double getDx() {
		return dx;
	}

	/**
	 * Setter for the dx-part
	 *
	 * @param dx The new dx part of this vector
	 */
	public void setDx(double dx) {
		this.dx = dx;
	}

	/**
	 * Getter for the dy-part
	 *
	 * @return dy The dy part of this vector
	 */
	public double getDy() {
		return dy;
	}

	/**
	 * Setter for the dy-part
	 *
	 * @param dy The new dy part of this vector
	 */
	public void setDy(double dy) {
		this.dy = dy;
	}

	/**
	 * Rescale part
	 */
	public void rescale() {
		// calc unit vector and set it
		double vectorLength = Math.sqrt(Math.pow(getDx(), 2) + Math.pow(getDy(), 2));  //using the square root of x and y

		// rescaling only needed, if value is not zero
		if(getDx() != 0) setDx((1 / vectorLength) * getDx() * Constants.BALL_SPEED);
		if(getDy() != 0) setDy((1 / vectorLength) * getDy() * Constants.BALL_SPEED);
	}
}