I've started to code a small and simple engine with Java (for games). When I repaint my screen it sometimes flickers. I've looked up answers to this question, and an answer suggested to use the swing timer (which is what I'm doing). Here are the relevant pieces of code (I added in some comments):
public class Game extends JPanel implements ActionListener {
private static final long serialVersionUID = 1L;
private static Window window;
private static ObjectUpdater objects;
private static Timer timer;
private static boolean init = false;
public Game(){
timer = new Timer(30,this);
timer.start();
}
public static void main (String[] self){
new Game();
}
private static void initialize(){
//Tests
//Setting up the window
window = new Window();
//Setting up the updater
objects = new ObjectUpdater();
new Picture(Path.images+Path.img_black,10);
// These are just some objects for the game...
Entity r = new Entity(new Picture(Path.images+Path.img_lapras,0));
r.setVelocity(0.5,0);
Entity r2 = new Entity(new Picture(Path.images+Path.img_lapras,1));
Vector i = new Vector(0,0.5);
r2.setVelocity(i.values()[0],i.values()[1]);
}
// This is where repaint(); is called.
public void actionPerformed(ActionEvent e) {
setDoubleBuffered(true);
if (init == false){
initialize();
init = true;
}
objects.update(); // This updates all the game object's information
window.update(); // This updates the window itself, it's literally: repaint();
}
}
Here is the window object's code because this is where stuff is also happening.
public class Window extends JFrame{
private static final long serialVersionUID = 1L;
public static int refresh_rate = 25;
public static Picture[] image_list = new Picture[0]; // All the images I want to render
private static String win_title = "Window"; // The name of the window
private static int[] win_xy = {640,360}; // The size of the window
public Window(){
//initializes window
setTitle(win_title);
//setUndecorated(true);
setDefaultCloseOperation(EXIT_ON_CLOSE);
setSize(win_xy[0],win_xy[1]);
setLocationRelativeTo(null);
setVisible(true);
setResizable(false);
}
public static int[] getWinSize(){
return win_xy;
}
// Here I'm just "painting" everything in the image_list array...
public void paint(Graphics g) {
super.paint(g);
Graphics2D g2d = (Graphics2D) g;
for (Picture i:image_list){
g2d.drawImage(i.getPic(), i.getXY()[0], i.getXY()[1], null);
}
Toolkit.getDefaultToolkit().sync();
g.dispose();
}
public static void addPicture(Picture element){// This adds images to the image_list
Picture[] result = Arrays.copyOf(image_list, image_list.length +1);
result[image_list.length] = element;
image_list = result;
Arrays.sort(image_list);
}
public void update() {
repaint();
}
}
That's it... Thank you!
