[PATCH weston 6/6] zoom: Change how we select a zoom location

[Bill Spitzak]

On 01/20/2015 07:44 AM, Derek Foreman wrote:

>> This would have to be changed to only zoom the output containing the
>> center of the current keyboard focus in my proposal, but I kind of feel
>> that would be better anyway.
>
> Why is that better?  I don't really have much of an opinion one way or
> the other.  But this is all subjective.  I'll vote for my way because I
> already wrote it like this, you vote for yours, someone else can break
> the tie? ;)

I figured it was better because it would only zoom one output, which is 
what all the other values do. Also because it allows the "what to zoom" 
to be identified by an xy pair.

>>> -    wl_list_for_each(output, &compositor->output_list, link) {
>>> -        if (pixman_region32_contains_point(&output->region,
>>> -                           wl_fixed_to_double(seat->pointer->x),
>>> -                           wl_fixed_to_double(seat->pointer->y),
>>> -                           NULL)) {
>>
>> So I propose that the above code refer to two local variables instead of
>> using wl_fixed_to_double(seat->pointer->x/y). You set those two
>> variables by calling some function (since it may want to be reused
>> elsewhere) that turns a seat into an x/y location, using the rules you
>> suggested.
>
> I'm not sure I follow.  Are you saying we should have a
> "weston_set_zoom_focus()" function and call that every time we change
> the pointer location (or keyboard focus if there's no pointer)?

I meant a function would be called that would calculate and return the 
xy values. Something like this:

    wl_fixed_t x, y;
    weston_get_interesting_xy_for_seat(seat, &x, &y); // this function
    ... use x,y ...