CODEWITHSUNDEEP
randomsprite
Konvict Boy
Konvict Boy

Reputation: 3

Generating random sprites

I am just a beginner and was doing some time with games and got a problem

package minigames;

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

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

public class fallingball extends JPanel {


   int x = 250;
   int y = 0;

   private void moveBall() {
      y = y + 1;


   }


   public void paint(Graphics g){
      super.paint(g);
      Graphics2D g2d = (Graphics2D) g;
      g2d.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
      g2d.setColor(Color.black);
      g2d.fillOval(x, y, 30, 30);
   }

   public static void main(String[] args) throws InterruptedException{
      JFrame f = new JFrame("Falling Ball");
      fallingball game = new fallingball();
      f.add(game);
      f.setSize(500, 500);
      f.setResizable(false);
      f.setLocationRelativeTo(null);
      f.setVisible(true);
      f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

      while (true) {
         game.moveBall();
         game.repaint();
         Thread.sleep(10);
      }
   }

}

only 1 ball is generated and it gets fallen down. i wanted to generate balls falling randomly and from different x co-ordinate in the frame how can i do that

Upvotes: 0

Views: 68

Answers (1)

jrafferty
jrafferty

Reputation: 108

Well for the random x you want to

import java.util.Random();

and use

Random rnd = new Random();
x = rnd.nextInt(<HIGHEST X VALUE POSSIBLE>)+1;

That will make a random integer from 0 to the max X value and assign it to x. NOTE (it's +1 because rnd.nextInt(n) creates a value from 0 to n-1.
To get more balls to keep falling try this in your loop:

while (true) {
     game.moveBall();
     game.repaint();
     Thread.sleep(10);
     if (y >= <MAX y>) {
      y = 0;
      x = rnd.nextInt(<max x>)+1;
    }
  }

You just need to reset the y when it goes off screen, otherwise it's just falling lower and lower without being visible. This is a fast solution. Ideally you would use objects and create/destroy them when off screen, this will make only 1 keep falling randomly. Adjust it as needed.

Also please read here for a game loop:
http://www.java-gaming.org/index.php?topic=24220.0

while (true)

is a pretty bad gameloop

Upvotes: 0

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