JAVA - Physics Falling Ball

 

File : PhysicsSimulation.java

package physicssimulation;

import javax.swing.*;

import java.awt.*;

import java.awt.event.ActionEvent;

import java.awt.event.ActionListener;

import java.util.ArrayList;

import java.util.List;

public class PhysicsSimulation extends JFrame {

    private final SimulationPanel simulationPanel;

    private final Timer timer;

    public PhysicsSimulation() {

        setTitle("2D Physics Simulation");

        setSize(800, 600);

        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        setLocationRelativeTo(null);

        simulationPanel = new SimulationPanel();

        add(simulationPanel);

        timer = new Timer(16, new ActionListener() { // ~60 FPS

            @Override

            public void actionPerformed(ActionEvent e) {

                simulationPanel.updatePhysics();

                simulationPanel.repaint();

            }

        });

        timer.start();

    }

    public static void main(String[] args) {

        SwingUtilities.invokeLater(() -> new PhysicsSimulation().setVisible(true));

    }

}

class SimulationPanel extends JPanel {

    private final List<SimulatedObject> objects;

    private final double gravity = 0.5; // Example gravity

    public SimulationPanel() {

        objects = new ArrayList<>();

        // Add some initial objects

        objects.add(new SimulatedObject(100, 100, 20, 0, 0));

        objects.add(new SimulatedObject(300, 50, 30, 0, 0));

    }

    public void updatePhysics() {

        for (SimulatedObject obj : objects) {

            // Apply gravity

            obj.velocityY += gravity;

            // Update position

            obj.x += obj.velocityX;

            obj.y += obj.velocityY;

            // Simple boundary collision (bounce)

            if (obj.y + obj.size > getHeight()) {

                obj.y = getHeight() - obj.size;

                obj.velocityY *= -0.8; // Reduce velocity on bounce

            }

            if (obj.x + obj.size > getWidth() || obj.x < 0) {

                obj.velocityX *= -1;

            }

        }

    }

    @Override

    protected void paintComponent(Graphics g) {

        super.paintComponent(g);

        Graphics2D g2d = (Graphics2D) g;

        g2d.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);

        // Draw objects

        for (SimulatedObject obj : objects) {

            g2d.fillOval((int) obj.x, (int) obj.y, (int) obj.size, (int) obj.size);

        }

    }

}

======================================================

File : SimulatedObject.java

package physicssimulation;

class SimulatedObject {

    double x, y;

    double size;

    double velocityX, velocityY;

    public SimulatedObject(double x, double y, double size, double velocityX, double velocityY) {

        this.x = x;

        this.y = y;

        this.size = size;

        this.velocityX = velocityX;

        this.velocityY = velocityY;

    }

}