LWJGL Forum

Hi there.

I try to put an lwjgl display inside an AWT frame. I followed this example here and changed it up a bit:
http://www.lwjgl.org/wiki/index.php?title=Basic_LWJGL_Applet


I think I have it almost working, however, the canvas is only a solid black rectangle and nothing is drawn on it.

The code is fairly small, I hope its easy to read through / comprehend:
public class TestFrame extends Frame {
private static final long serialVersionUID = -17538123780838670L;

public static void main(String[] args) {
new TestFrame();
}

private Canvas canvas;
private Thread gameThread;
private boolean running;

public TestFrame() {
addWindowListener(new TestWindowListener());
setTitle("Some AWT Frame");
setResizable(true);
setSize(640, 480);
setVisible(true);
setLayout(new BorderLayout());

add(new Label("Center", Label.CENTER), BorderLayout.CENTER);
add(new Label("West", Label.CENTER), BorderLayout.WEST);
add(new Label("North", Label.CENTER), BorderLayout.NORTH);
add(new Label("South", Label.CENTER), BorderLayout.SOUTH);

createCanvas();
}

private void createCanvas() {
canvas = new Canvas() {
private static final long serialVersionUID = -1069002023468669595L;
public void removeNotify() {
stopOpenGL();
}
};
canvas.setFocusable(true);
canvas.requestFocus();
canvas.setIgnoreRepaint(true);
canvas.setSize(320, 240);
canvas.setLocation(64, 64);
canvas.setVisible(true);

add(canvas, BorderLayout.EAST);

System.out.println("Is displayable? "+canvas.isDisplayable());

startOpenGL();
}

private void startOpenGL() {
System.out.println("StartOpenGL");

gameThread = new Thread() {
public void run() {
try {
Display.create();
Display.setParent(canvas);

running = true;
} catch (LWJGLException e) {
e.printStackTrace();
}
while (running) {
updateGL();
}
if (Display.isCreated()) {
Display.destroy();
}
}
};
gameThread.start();
}

private void updateGL() {
GL11.glClear(GL11.GL_COLOR_BUFFER_BIT);

render();

Display.update();
Display.sync(60);

int error = GL11.glGetError();
if (error != GL11.GL_NO_ERROR) {
String msg = "Unknown Error";
switch (error) {
case GL11.GL_INVALID_OPERATION:
msg = "Invalid Operation"; break;
case GL11.GL_INVALID_VALUE:
msg = "Invalid Value"; break;
case GL11.GL_INVALID_ENUM:
msg = "Invalid Enum"; break;
case GL11.GL_STACK_OVERFLOW:
msg = "Stack Overflow"; break;
case GL11.GL_STACK_UNDERFLOW:
msg = "Stack Underflow"; break;
case GL11.GL_OUT_OF_MEMORY:
msg = "Out of memory"; break;
}
throw new RuntimeException(msg);
}
}

private void render() {
GL11.glBegin(GL11.GL_QUADS);

GL11.glColor4f(1, 0, 0, 1);
GL11.glVertex3f(0, 0, 0);

GL11.glColor4f(1, 0, 0, 1);
GL11.glVertex3f(0.1f, 0.5f, 0);

GL11.glColor4f(1, 0, 0, 1);
GL11.glVertex3f(0.8f, 0.7f, 0);

GL11.glColor4f(1, 0, 0, 1);
GL11.glVertex3f(0.65f, 0.1f, 0);

GL11.glEnd();
}

private void stopOpenGL() {
System.out.println("StopOpenGL");

running = false;
try {
gameThread.join();
} catch (InterruptedException e) {
e.printStackTrace();
}
}

private void terminate() {
dispose();
System.exit(0);
}

class TestWindowListener extends WindowAdapter {
public void windowClosing(WindowEvent e) {
terminate();
}
}

}

I dont get any errors / exceptions and the debug messages are printed.

Thank you all for the help.

It doesn't look like you are specifying the view matrix at all. LWJGL defaults to a 2D view with the width and height of the display. This means that you are probably creating a polygon that is less then 1 pixel big so it is not showing up. Try making a much bigger polygon.

As it seems glViewport is not set correctly when using a canvas. After setting glViewport I got it working.
The Projection matrix was not needed as the default was from [-1, 1] on all axes.