I have written the following little framework for a game I was hoping to write for Linux. This works fine with the same version of the JDK on Windows - a black screened window with a frames-per-second readout on the top left, but this fails to work under Fedora 10. I have installed Sun's official JDK and all I get is the Swing window which is the default grey and nothing else.
Little help?
Game.java
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| public class Game {
private static Universe theGame = null;
public static void main(String[] args) {
theGame = new Universe();
}
} |
Universe.java
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| import java.awt.*;
import java.awt.event.*;
import java.awt.image.*;
import java.util.Random;
import javax.swing.JFrame;
public class Universe extends Canvas {
private JFrame theFrame;
private BufferStrategy bufferStrategy;
private BufferedImage bufferedImage;
private GraphicsEnvironment graphicsEnvironment;
private GraphicsDevice graphicsDevice;
private GraphicsConfiguration graphicsConfiguration;
private Graphics graphics;
private Graphics2D graphics2D;
private Color colorBackground;
private Random random;
private static final int SCREEN_WIDTH = 640;
private static final int SCREEN_HEIGHT = 480;
private static final int SCREEN_DEPTH = 32;
private static int fps;
private static int frames;
private static long totalTime;
private static long currentTime;
private static long lastTime;
private boolean isRunning = false;
private Font theFont = new Font("Courier New", Font.PLAIN, 12);
private static boolean isFullScreen = false;
public Universe() {
initUniverse();
}
private void initUniverse() {
theFrame = new JFrame();
theFrame.setIgnoreRepaint(true);
graphicsEnvironment = GraphicsEnvironment.getLocalGraphicsEnvironment();
graphicsDevice = graphicsEnvironment.getDefaultScreenDevice();
graphicsConfiguration = graphicsDevice.getDefaultConfiguration();
bufferedImage = graphicsConfiguration.createCompatibleImage(Universe.SCREEN_WIDTH, Universe.SCREEN_HEIGHT);
if (!isFullScreen) {
theFrame.add(this);
theFrame.pack();
theFrame.setVisible(true); theFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
theFrame.add(this);
theFrame.pack();
theFrame.setVisible(true);
theFrame.setSize(Universe.SCREEN_WIDTH, Universe.SCREEN_HEIGHT);
} else {
theFrame.setUndecorated(true);
theFrame.addKeyListener(new KeyAdapter() {
public void keyPressed(KeyEvent ke) {
if(ke.getKeyCode() == KeyEvent.VK_ESCAPE )
isRunning = false;
}
});
graphicsDevice.setFullScreenWindow(theFrame);
if(graphicsDevice.isDisplayChangeSupported()) {
graphicsDevice.setDisplayMode(new DisplayMode(Universe.SCREEN_WIDTH, Universe.SCREEN_HEIGHT, Universe.SCREEN_DEPTH, DisplayMode.REFRESH_RATE_UNKNOWN));
}
}
theFrame.createBufferStrategy(2);
bufferStrategy = theFrame.getBufferStrategy();
colorBackground = Color.BLACK;
random = new Random();
setupFPS();
gameLoop();
}
private void setupFPS() {
Universe.fps = 0;
Universe.frames = 0;
Universe.totalTime = 0;
Universe.currentTime = 0;
Universe.lastTime = 0;
}
private void gameLoop() {
isRunning = true;
Universe.currentTime = System.currentTimeMillis();
while(isRunning) {
try {
Universe.lastTime = Universe.currentTime;
Universe.currentTime = System.currentTimeMillis();
Universe.totalTime += Universe.currentTime - Universe.lastTime;
if (Universe.totalTime > 1000) {
Universe.totalTime -= 1000;
Universe.fps = Universe.frames;
Universe.frames = 0;
}
++Universe.frames;
clear();
updateInput();
updateLogic();
updateRender();
displayFPS();
flip();
} catch (Exception e) {
System.out.println("ERROR:" + e.getMessage());
} finally {
cleanUp();
}
}
isRunning = false;
shutdownGame();
shutDownProgram();
}
private void shutDownProgram() {
cleanUp();
if (isFullScreen) {
graphicsDevice.setFullScreenWindow(null);
}
System.exit(0);
}
private void shutdownGame() {
}
private void updateInput() {
}
private void updateLogic() {
}
private void updateRender() {
}
private void displayFPS() {
graphics2D.setColor(Color.WHITE);
graphics2D.setFont(theFont);
graphics2D.drawString(String.format("FPS: %s", Universe.fps), 20, 20);
}
private void clear() {
graphics2D = bufferedImage.createGraphics();
graphics2D.setColor(colorBackground);
graphics2D.fillRect(0, 0, Universe.SCREEN_WIDTH, Universe.SCREEN_HEIGHT);
}
private void flip() {
graphics = bufferStrategy.getDrawGraphics();
graphics.drawImage(bufferedImage, 0, 0, null);
if (!bufferStrategy.contentsLost()) {
bufferStrategy.show();
}
Thread.yield();
}
private void cleanUp() {
if (graphics != null) {
graphics.dispose();
graphics = null;
}
if (graphics2D != null) {
graphics2D.dispose();
graphics2D = null;
}
}
public boolean isRunning() {
return isRunning;
}
} |
The official Sun JDK is in the system path (/etc/profile) and I have compiled it using that and also uninstalled the OpenJDK stuff but to no avail. What the hell is going on? Any ideas? As I said, this code works perfectly under Windows with the same version of the JDK. I even ran "javac -version" and "java -version" to make sure no other Fedora-specific JDK was overriding the official one. But nothing helps.
