2D графика в Java

/**
 * Represents image canvas
 */
public interface Canvas {
 
    /**
     * Width of the canvas. In other words the number of horizontal pixels.
     * @return width of the canvas
     */
    public int getWidth();
 
    /**
     * Height of the canvas. In other words the number of vertical pixels.
     * @return height of the canvas
     */
    public int getHeight();
 
    /**
     * Sets given color at given coordinates in canvas. The coordinates are
     * in range x in [0; {@link Canvas#getWidth()} - 1] and y in [0; {@link Canvas#getHeight()} - 1].
     * This is similar to the indexing of 2D array.
     * @param x coordinate
     * @param y coordinate
     * @param color desired color of the pixel
     */
    public void setColorAt(int x, int y, Color color);
 
    /**
     * Sets ink for final color transformation of the canvas
     * @param ink to be set
     */
    public void setInk(Ink ink);
 
}

public interface Shape {
 
    /**
     * Prints shape into given canvas using {@link cz.cvut.k36.pr2.hw.hw02.Canvas#setColorAt(int, int, Color)} method.
     * @param canvas to be printed to.
     */
    public void printToCanvas(Canvas canvas);
 
}

class Point {
    final public double x;
    final public double y;
 
    public Point(Point point) {
        x = point.x;
        y = point.y;
    }
 
    public Point(double x, double y) {
        this.x = x;
        this.y = y;
    }
 
}

public class Line implements  Shape{
    Color color;
    private final Point begin;
    private final Point end;
    
    public Line(){
        begin = new Point(0.0, 0.0);
        end = new Point(0.0, 0.0);
    }
 
    public Line(Color color, double startX, double startY, double endX, double endY) {
        this.color = color;
        begin = new Point(startX, startY);
        end = new Point(endX, endY);
    }
 
    public Line(Point begin, Point end) {
        this.begin = begin;
        this.end = end;
    }
    public double getLength() {
        return Math.sqrt(getVectorLength(begin.x, end.x) + getVectorLength(begin.y, end.y));
    }
    private double getVectorLength(double begin, double end) {
        return Math.sqrt((begin - end) * (begin - end));
    }
 
    @Override
    public void printToCanvas(Canvas canvas) {
        
    }
    
}