How to Rotate and Scale a 2D Shape Around the X-Axis in Java?

Rotating a Shape Vertically Around the X-Axis with Scaling

Problem:

You have a 2D graph with an x and y axis and want to rotate a shape around an axis while incorporating a scaling function.

Solution:

To achieve this, you can manipulate the shape's points using transformations such as rotation and scaling. Here's an example that first rotates the shape by a fixed angle and then scales it by a varying scale factor:

<code class="java">import java.awt.*;
import java.awt.event.*;
import java.awt.geom.AffineTransform;
import javax.swing.*;

public class ShapeRotationScaling extends JPanel implements ActionListener {

    private static final int ANGLE_INCREMENT = 1; // in degrees
    private static final double SCALE_INCREMENT = 0.1;
    private int[] shapeXPoints = {200, 200, 240, 240, 220, 220, 200};
    private int[] shapeYPoints = {200, 260, 260, 240, 240, 200, 200};
    private AffineTransform transform = new AffineTransform();
    private double rotationAngle = 0;
    private double scaleFactor = 1;
    private Timer timer = new Timer(100, this);

    public ShapeRotationScaling() {
        this.setPreferredSize(new Dimension(700, 700));
        this.setBackground(Color.white);
        timer.start();
    }

    @Override
    public void actionPerformed(ActionEvent event) {
        // Rotate the shape around the x-axis
        transform.rotate(Math.toRadians(rotationAngle), this.getWidth() / 2, 0);

        // Scale the shape
        transform.scale(scaleFactor, scaleFactor);

        // Increment the rotation angle and scale factor
        rotationAngle += ANGLE_INCREMENT;
        scaleFactor += SCALE_INCREMENT;

        repaint();
    }

    @Override
    public void paintComponent(Graphics g) {
        super.paintComponent(g);
        Graphics2D g2d = (Graphics2D) g;
        g2d.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);

        // Draw the x and y axes
        g2d.drawLine(this.getWidth() / 2, 0, this.getWidth() / 2, this.getHeight());
        g2d.drawLine(0, this.getHeight() / 2, this.getWidth(), this.getHeight() / 2);

        // Apply the transformation to the shape and draw it
        Shape rotatedAndScaledShape = transform.createTransformedShape(new Polygon(shapeXPoints, shapeYPoints, shapeXPoints.length));
        g2d.draw(rotatedAndScaledShape);
    }

    public static void main(String[] args) {
        JFrame frame = new JFrame("Shape Rotation and Scaling");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        ShapeRotationScaling sr = new ShapeRotationScaling();
        frame.add(sr);
        frame.pack();
        frame.setVisible(true);
    }
}</code>

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