In X11 when a window is maximised if the client is unable to fufill the
space provided we centre align the window.
With the new floating point geometry behaviour of centreing changes.
Instead of a 1 pixel gap at the top, we get a 0.5 pixel gap either side.
When we get into the codepath to "fix" the window in `closeHeight` we
only move the top, giving us an invalid buffer size.
We don't really want to change the logic here; on xwayland with the
scaling opt-out path it's feasible for a floating sized logical size to
still be representable. This code rounds to the native unit after all
the logic has taken effect.
With fractional scaling integer based logical geometry may not match
device pixels. Once we have a floating point base we can fix that. This
also is
important for our X11 scale override, with a scale of 2 we could
get logical sizes with halves.
We already have all input being floating point, this doubles down on it
for all remaining geometry.
- Outputs remain integer to ensure that any screen on the right remains
aligned.
- Placement also remains integer based for now.
- Repainting is untouched as we always expand outwards
(QRectF::toAdjustedRect().
- Decoration is untouched for now
- Rules are integer in the config, but floating in the adjusting/API
This should also be fine.
At some point we'll add a method to snap to the device pixel
grid. Effectively `round(value * dpr) / dpr` though right now things
mostly work.
This also gets rid of a lot of hacks for QRect right and bottom which
are very
confusing.
Parts to watch out in the port are:
QRectF::contains now includes edges
QRectF::right and bottom are now sane so previous hacks have to be
removed
QRectF(QPoint, QPoint) behaves differently for the same reason
QRectF::center too
In test results some adjusted values which are the result of
QRect.center because using QRectF's center should behave the same to the
user.
Anything in xcb_ structs are always in X local, all member variables
aside from buffers are in kwin local space.
This patch ignores a few paths that are not relevant on wayland.
