DMXGetScreenCount - Man Page

#include <X11/extensions/dmxext.h>

Bool DMXGetScreenCount(Display *dpy,
                       int *screen_count);

DMXGetScreenCount() returns the number of back-end screens that a Xdmx(1) server controls.  Since a DMX screen usually fills all of the available area on a back-end server, there is usually a one-to-one correspondence between DMX screens and backend servers.  However, it is also possible for a DMX screen to cover only part of the available area on a back-end server, and for more than one DMX screens to occupy different parts of the visible area on the same back-end server.

A DMX screen may be managed as a regular X screen in the Xdmx(1) server or may be joined with other DMX screens using Xinerama.

DMXGetScreenCount() sets screen_count and returns True unless there is a protocol error.

If Xinerama is active, only one logical screen will be available to clients of the Xdmx(1) server.  However, this call will accurately reflect the number of composite back-end screens that the Xdmx(1) server is using.

DMXGetScreenAttributes(3), DMXChangeScreensAttributes(3), DMX(3), Xdmx(1)

DMX(3), DMXChangeScreensAttributes(3), DMXGetScreenAttributes(3), DMXGetWindowAttributes(3).