The 3D display window is opened by the callback function
d3_createDisplayWindow, linked to the 
button
in the control panel.
The display window has its own event handler. It reacts to ConfigureNotify and Expose events. When an Expose event occurs, the net is redrawn. Since a series of Expose events is created in some cases, all but the last one are ignored. If the size of the display window is changed, a ConfigureNotify event causes the net to be centered in the new window and redrawn. All Expose events are blocked in this case.
The display window is created by XtCreatePopupShell. It contains
an inner frame (see 
). After the window becomes visible
the Xlib variables d3_display, d3_window and
d3_screen are created as well as the graphic context
d3_gc. Each subsequent reference to the display window is performed by
Xlib functions (see ).