JCirconferenza

import java.awt.Color;
import java.awt.Graphics;

public class JCirconferenza extends JOxy {

    private double a, b, c;

    public JCirconferenza() {
        setA(0.0);
        setB(0.0);
        setC(-1.0);
    }

    @Override
    public void paintComponent(Graphics g) {
        super.paintComponent(g);
        double xC = -getA()/ 2.0;
        double yC = -getB()/ 2.0;
        double r = Math.sqrt(xC * xC + yC * yC - getC());
        g.setColor(Color.BLUE);
        g.drawOval(xg(xC - r), yg(yC + r), (int) Math.round(2.0 * r * getScalaX()), (int) Math.round(2.0 * r * getScalaY()));
    }

    public double getA() {
        return a;
    }

    public final void setA(double a) {
        this.a = a;
        repaint();
    }

    public double getB() {
        return b;
    }

    public final void setB(double b) {
        this.b = b;
        repaint();
    }

    public double getC() {
        return c;
    }

    public final void setC(double c) {
        this.c = c;
        repaint();
    }
}