Clone window?

I've been working on a screensaver for the past couple weeks using AgateLib and a game engine built on top of it I've been working on for a while now.

I've created fake fullscreen, removing the window border, resizing it to the main monitor size and moving it to 0,0. Now I need to duplicate the screensaver onto all screens, is there any way to do it?

AgateLib doesn't have any

AgateLib doesn't have any sort of facility for that sort of thing. Hardware accelerated graphics across multiple screens is a tricky thing, because one has to keep track of whether different screens are powered by different video cards, and copying/moving textures between the video memory on each video card.