Un-screwing screwed coordinates

Hello everybody!

I am currently developing a 2D OpenGL application using Java and an AWTGLCanvas from LWJGL embedded in a window. Everything seems to work perfectly except from the coordinates. While OpenGL coordinates normally look like this:

The x axis seems to be mirrored, i.e.

Now my question obviously is: Why?

The relevant code so far looks like this:


// Note: initGL is called by LWJGL when the canvas is created.
@Override
protected void initGL() {
    GL11.glViewport(0, 0, getWidth(), getHeight());
    GL11.glMatrixMode(GL11.GL_PROJECTION);
    GL11.glLoadIdentity();
    GLU.gluOrtho2D(0, getWidth(), getHeight(), 0);
    GL11.glMatrixMode(GL11.GL_MODELVIEW);
    GL11.glLoadIdentity();
}

@Override
protected void paintGL() {
    if (renewViewport) {
        initGL();
        renewViewport = false;
    }

    GL11.glLoadIdentity();

    GL11.glClear(GL11.GL_COLOR_BUFFER_BIT | GL11.GL_DEPTH_BUFFER_BIT);
    GL11.glPolygonMode(GL11.GL_FRONT_AND_BACK, GL11.GL_LINE);

    // Note zoomAmount is within [1, 100] at all times, so negative scaling can't be the cause.
    GL11.glScalef(zoomAmount, zoomAmount, 1);
    GL11.glTranslatef(cameraPosition.x, cameraPosition.y, 0);

    drawThis();
    drawThat();

    super.paintGL();
}

Thanks in advance.