Scale.java

package edu.gatech.cs2340.trydent.math;

/**
 * Represents a scaling of a 2D vector. A scale in general can be (loosely)
 * thought of as a size.
 *
 * @author Garrett Malmquist
 */
public class Scale extends BaseVector<Scale> {

    /**
     * Creates a new scaling with the given scales for the x and y components.
     *
     * @param scaleX
     *            - x scale factor (1.0 is no scaling)
     * @param scaleY
     *            - y scale factor (1.0 is no scaling)
     */
    public Scale(double scaleX, double scaleY) {
        super(2);
        set(scaleX, scaleY);
    }

    /**
     * Creates a new scaling that scales x and y by the same amount.
     *
     * @param scale
     *            - scale factor (1.0 is no scaling)
     */
    public Scale(double scale) {
        this(scale, scale);
    }

    /**
     * Creates a new scale that defaults to <1.0, 1.0>, (ie no scaling).
     */
    public Scale() {
        this(1.0);
    }

    /**
     * Creates a new scaling from the input vector (which can be another
     * scaling).
     *
     * @param other
     *            other vector to copy the x,y components of
     */
    public Scale(BaseVector<?> other) {
        this(other.getX(), other.getY());
    }

    @Override
    public Scale copy() {
        return new Scale(getX(), getY());
    }

    /**
     * Returns a copy of the input vector scaled by this scaling. E.g.:
     *
     * <pre>
     * Position pos = new Position(1, 2);
     * Scale scale = new Scale(0.5);
     * Position scaledPos = scale.applyTo(pos); // scaledPos will now be (0.5, 1.0)
     * </pre>
     *
     * @param <T>
     *            the type of the vector to scale (inferred from the argument)
     * @param vector
     *            vector scale
     * @return a copy of the original vector, scaled by this vector
     */
    @SuppressWarnings("unchecked")
    public <T extends BaseVector<?>> T applyTo(T vector) {
        return (T) vector.copy().scale(this);
    }

}