Drawing Lab 4 - Animation

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Create a new Java Class called AnimationBasics.  Add the code below to make a standard JPanel drawing example.

import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.RenderingHints;

import javax.swing.JFrame;
import javax.swing.JPanel;

@SuppressWarnings("serial")
public class AnimationBasics extends JPanel {

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

   }

   public static void main(String[] args) throws InterruptedException {
      JFrame frame = new JFrame("Mini Tennis");
      AnimationBasics game = new AnimationBasics();
      frame.add(game);
      frame.setSize(400, 400);
      frame.setVisible(true);
      frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

   }

}

Next add the code below to create an animated ball.

import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.RenderingHints;

import javax.swing.JFrame;
import javax.swing.JPanel;

@SuppressWarnings("serial")
public class AnimationBasics extends JPanel {
   int x = 0; // X position of ball
   int y = 0; // Y position of ball
   int xa = 1; // X direction/acceleration of ball
   int ya = 1; // Y direction/acceleration of ball

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

      //Draw Ball at X and Y
      g2d.fillOval(x, y, 30, 30);
   }

   public void moveBall() {
      //Move Ball based on xa and ya
      x += xa;
      y += ya;
      
      // Check to see if ball is on edge of screen
      // and change xa or ya accordingly
      if (x > 400 - 45)
         xa = -1;
      if (y > 400 - 65)
         ya = -1;
      if (x < 0)
         xa = 1;
      if (y < 0)
         ya = 1;

   }

   public static void main(String[] args) throws InterruptedException {
      JFrame frame = new JFrame("Mini Tennis");
      AnimationBasics game = new AnimationBasics();
      frame.add(game);
      frame.setSize(400, 400);
      frame.setVisible(true);
      frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

      // Main Game Loop
      while (true) {
         // Call the moveBall method
         game.moveBall();

         // Repaint the screen
         game.repaint();

         // Wait 10ms
         Thread.sleep(10);
      }
   }

}

To Do

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Your assignment is to create a Red Ball and a Blue Ball in this project. 

Each ball will need it's own variables (x,y,xa,ya) [variables will need to be named different EX: blueX, blueY, blueXA, blueYA] and its own moveBall method.

Blue Ball should start at (100,100) with xa = 1 and ya = -1

Red Ball should start at (300,300) with xa = -1 and ya = -1

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