DMXAddScreen man page
DMXAddScreen — attach a new back-end screen
Bool DMXAddScreen(Display *dpy, const char *displayName, unsigned int mask, DMXScreenAttributes *attr, int *screen);
DMXAddScreen() attaches a back-end screen to the Xdmx(1) server, in place of the previously detached back-end server specified by screen.
displayName is the name of the new back-end display, mask specifies the field in attr that are active, and screen returns the new Xdmx(1) screen number for the attached screen.
The information stored in mask and attr is identical to that used by the DMXChangeScreensAttributes(3) and DMXGetScreenAttributes(3) functions.
DMXAddScreen() will return True if the screen was successfully attached, and False otherwise. False will be returned if the -addremovescreens command line option was not specified on the Xdmx(1) command line, the input value of screen is out of range, screen is not currently detached, displayName cannot be opened, has unexpected visuals, or has characteristics that do not match the previously detached screen.
DMXAddScreen() can generate BadLength, BadAlloc, and BadValue errors.
Attributes that are not specified will default to 0. This may lead to unintended results.
Unlike other functions in the DMX(3) API, this function uses screen for both input and output.
DMXRemoveScreen(3), DMXChangeScreensAttributes(3), DMXGetScreenAttributes(3), DMX(3), Xdmx(1)