The maximum travel distance between points on a desktop is substantially reduced if the pointer is allowed to travel off a screen edge and reappear at the opposite edge. taralli is a tiny standalone program for X Windows which, while running, implements this functionality. In other words, it changes the topology of the desktop to be that of a torus.

taralli has been tested on GNU/Linux and is likely portable to other X platforms. I would appreciate any bug reports and patches, which you can submit through GitHub.

For the common case of a rectangular desktop, you can build and run taralli like so:

$ ./build.sh rectangular
$ ./taralli_rectangular

Perhaps you have a non-rectangular desktop, composed of several monitors at different resolutions. Or you might have different preferences for where the mouse pointer goes when it reaches a screen edge. taralli supports a simple form of customization; see map_beef.c for an example. You define a C function

void map(int *x, int *y);

which receives pointers to the current mouse coordinates, and is allowed to modify those coordinates. A macro WRAP(var, from, to) is available; it expands to (roughly)

if (*var == from) {
    *var = to;
    return;
}

Another function

void map_init(Display *dpy);

will run at program start.

You can build and run the customized program with e.g.

$ ./build.sh beef
$ ./taralli_beef

taralli is available under a BSD license. See the LICENSE file.