0

I have a problem that puzzles me. I have this small application that creates a JFrame that should update the graphics at the desired fps. But when I start the application, it runs at 120 fps instead of 60 fps. If I set fps = 30, it runs at 60fps, if fps =60, it runs at 120fps, and so on (to measure the fps I use FRAPS).

Here's the SSCCE:

import java.awt.*;
import javax.swing.*;

public class Controller
{
    public static TheFrame window;
    public static long time = 0;
    public static boolean funciona = true;
    public static int fps = 60;
    public static int x;

    public static void main(String [] args)
    {
        window = new TheFrame();
        while(funciona) {
            time = System.nanoTime();
            window.Redraw();
            time = System.nanoTime() - time;
            try {Thread.sleep( (1000/fps) - (time/1000000) );} catch (Exception e){}
        }
    }
}

class TheFrame
{
    public JFrame theFrame;
    public CanvasScreen canvas;

    public TheFrame()
    {
        canvas = new CanvasScreen();
        theFrame = new JFrame();
        theFrame.setSize(1280, 720);
        theFrame.setContentPane(canvas);
        theFrame.setUndecorated(true);
        theFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        theFrame.setVisible(true);
    }

    public void Redraw()
    {
        theFrame.repaint();
    }
}

class CanvasScreen extends JComponent
{
    public void paintComponent(Graphics g)
    {
    }
}

The Timer sets the program at 60fps as desired, but it actually draws 30 fps, repeating each frame twice. The paintComponent() is painting twice each time repaint() is called. How can I change it to just paint once? Thanks in advance.

user1319734
  • 427
  • 1
  • 4
  • 7
  • 2
    1) For better help sooner, post an [SSCCE](http://sscce.org/). (And draw/display the frame rate for each second) 2) Use a `Timer` to trigger `repaint()` in Swing animations, instead of calling `Thread.sleep(n)` 3) Don't name your custom component after a class of the AWT. – Andrew Thompson May 06 '12 at 20:36
  • 1
    This [`AnimationTest`](http://stackoverflow.com/a/3256941/230513) is an example that shows an average over the last few frames. – trashgod May 06 '12 at 20:50
  • This is not really an SSCCE. Where's the code that initializes and runs this? It may be trivial, but it's still important to witness the triviality of it. – Marko Topolnik May 06 '12 at 21:05

0 Answers0