[compiz] Patch to wobbly snap for outputs

[David Reveman]

On Mon, 2006-12-18 at 11:03 -0700, Mike Cook wrote:
> On Mon, Dec 18, 2006 at  9:50 AM, David Reveman wrote: 
> > -            if (y1 < pBox- >y2 && y2 > pBox- >y1)
> > +           /* consider strut if start/end overlaps box, size ends in box,
> > +              and edge is outside box or both edge & size in same output
> > +              (in order to handle struts across multiple outputs) */
> > +           if (y1 < pBox- >y2 && y2 > pBox- >y1 && x2 < pBox- >x2 &&
> > +               (x1 < pBox- >x1 ||
> > +                   outputDeviceForPoint(w- >screen, x1, y1) ==
> > +                   outputDeviceForPoint(w- >screen, x2- 1, y2- 1)))
> > 
> > The "x2 < pBox- >x2"  check makes a lost of sense. However I fail to see
> > why this:
> > 
> > +               (x1 < pBox- >x1 ||
> > +                   outputDeviceForPoint(w- >screen, x1, y1) ==
> > +                   outputDeviceForPoint(w- >screen, x2- 1, y2- 1))
> > 
> > check is necessary. We already know that "x2 < pBox- >x2" so the only
> > struts that are rejected from this check is those that are partially
> > outside the box vertically and why we would want to reject those?
> 
> Since we know the strut ends within the box, that secondary check is
> meant to handle the two basic cases of a smaller box (such as for an
> output workarea) to allow a strut which starts outside it, and for a larger
> box (such as for the screen workarea) to ignore any internal struts which
> cross over multiple outputs.

Sorry, I still don't get it. What struts are a vertical kicker panel
setting?

+-----------------+-----------------+
|                _|_                |
|               | | |               |
|               | | |               |
|               |_|_|               |
|                 |                 |
+-----------------+-----------------+

If the screen looks like this and the thing in the middle is a panel
covering both outputs I assume that the struts are set to either

leftX1 = screenW / 2 - panelW / 2;
leftX2 = screenW / 2 + panelW / 2;

or

rightX1 = screenW / 2 - panelW / 2;
rightX2 = screenW / 2 + panelW / 2;

or that both those set are set.

"if (y1 < pBox->y2 && y2 > pBox->y1 && x2 < pBox->x2)"

should set the left edge properly for both outputs in all those cases.

What am I missing?

-David