Can anyone recommend an X11 textbook? All I can find is the Xlib Programming Manual by Adrian Nye which is out of print (but available).
I'm using freeGlut as the basis of an OpenGL art work program and I want to control the basic screen saver functions.
Currently I'm using code with crude console calls to xset such as:
 
// turn the display off
system("xset dpms force off");
system("xset s on");
system("xset s activate");
system("xset led \"Scroll Lock\"");
 
// turn the display on
system("xset dpms force on");
system("xset s reset");
system("xset s off);
system("xset -led \"Scroll Lock\"");
 
but I'm not getting the behaviour I want and I can't determine the state of the display using these console calls.
I figure that if I make lower-level direct calls to Xlib functions, things will be cleaner and easier to debug.
 
Advice please.
Clive.