Cześć!

Mam poniższy kod wykorzystujący poprzednie posty Stackoverflow.

Chcę po prostu obrócić prostokąt pod pewnym kątem i sprawić, by poruszał się w fali grzechu.

Ten kod obraca również całą falę grzechu.

Rozumiem, dlaczego tak się dzieje, ale nie wiem, jak osiągnąć mój zamiar.

proszę pomóż!!!

Wielkie dzięki za poświęcenie czasu.

import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.geom.AffineTransform;
import java.util.Timer;
import java.util.TimerTask;
import javax.swing.JFrame;
import javax.swing.JPanel;

public class Withrotation {

    public static int i = 1;
    public static Ticker t;
    public static Repainter r;
    public static int newx, newy;

    public static void main(String[] args) {
        final JFrame frame = new JFrame("Wavy!");
        final WavyPanel wp = new WavyPanel();
        frame.getContentPane().add(wp, BorderLayout.CENTER);
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        t = new Ticker(wp);
        r = new Repainter(wp);
        frame.pack();
        frame.setVisible(true);
        final Timer tickTimer = new Timer();
        final Timer paintTimer = new Timer();
        paintTimer.schedule(r, 1000, 50);
        tickTimer.schedule(t, 1000, 10);
    }

    private static class WavyPanel extends JPanel {

        private final Dimension size = new Dimension(640, 480);
        private int amplitude = 50;
        private int frequency = 5;
        private double x1 = 0;
        private double y1 = 500;
        private int yBase = 0;

        WavyPanel() {
            super(true);
        }

        @Override
        protected void paintComponent(final Graphics g) {
            final Graphics2D g2 = (Graphics2D) g;
            AffineTransform old = g2.getTransform();
            g2.rotate(Math.toRadians(-30));

            g2.clearRect(0, 0, this.getSize().width, this.getSize().height);
            g2.setColor(Color.BLACK);
            g2.fillRect((int) x1, (int) y1, 20, 80);
            g2.setTransform(old);


        }

        @Override
        public Dimension getPreferredSize() {
            return size;
        }

        @Override
        public Dimension getMinimumSize() {
            return size;
        }

        @Override
        public Dimension getMaximumSize() {
            return size;
        }

        public void tick() {
            x1 = x1 + 1;
            final int waveLength = size.width / frequency;
            yBase = (++yBase) % waveLength;
            final double normalized = (double) yBase / (double) waveLength;
            final double radians = normalized * Math.PI * 2;
            final double sine = Math.sin(radians);
            y1 = (int) (sine * amplitude);




        }
    }

    private static class Ticker extends TimerTask {

        private final WavyPanel panel;

        Ticker(final WavyPanel panel) {

            this.panel = panel;

        }

        @Override
        public void run() {
            panel.tick();
        }
    }

    private static class Repainter extends TimerTask {

        private final WavyPanel panel;

        Repainter(final WavyPanel panel) {

            this.panel = panel;

        }

        @Override
        public void run() {
            panel.repaint();

        }
    }
}