public void setWindowXPosition(int pos) {
        putInteger("WindowXPosition", pos);
    }
Sets the window's initial X position on the desktop.

<p>This setting is used only with LWJGL3, has no effect on fullscreen
windows, and is ignored if the Center Window flag is true. Its default
value is 0.

@param pos the desired initial position of the window's left edge
    relative to the left edge of the desktop
@see #setCenterWindow(boolean)
jme3-core/src/main/java/com/jme3/system/AppSettings.java