mouse_setxrange, mouse_setyrange − define the boundaries for the mouse cursor
void mouse_setxrange(int x1, int x2);
void mouse_setyrange(int y1, int y2);
These two define the boundaries for mouse cursor. x1, x2, y1, and y2 are the coordinates of the left, right, bottom, and top edges of the screen, respectively.
For 3d pointer devices, there is actually another interface. See mouse_getposition_6d(3).
svgalib(7), vgagl(7), libvga.config(5), eventtest(6), mouse_close(3), mouse_init(3), mouse_getposition_6d(3), mouse_setposition(3), mouse_setscale(3), mouse_setwrap(3), mouse_getx(3), mouse_update(3), mouse_waitforupdate(3), vga_setmousesupport(3), mouse_seteventhandler(3), vga_waitevent(3)
This manual page was edited by Michael Weller <eowmob AT exp-math DOT uni-essen DOT de>. The exact source of the referenced function as well as of the original documentation is unknown.
It is very likely that both are at least to some extent are due to Harm Hanemaayer <H DOT Hanemaayer AT inter DOT nl DOT net>.
Occasionally this might be wrong. I hereby asked to be excused by the original author and will happily accept any additions or corrections to this first version of the svgalib manual.