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.
This further decouples scene items from scene windows. The SurfaceItem
still needs to access the underlying window, I would like to re-iterate
over that later.
With this change, it will be possible to introduce WindowItem factory
function in the Toplevel class.
If window quads need to be generated after the wl_surface is destroyed,
the SurfaceItemWayland::mapToBuffer() function will return wrong values.
In order to fix that, we need to store the last surface-to-buffer matrix
in SurfaceItem.
Window quads need to be in some coordinate space. Since we want items to
be used not only for rendering windows, window-local coordinates do not
suffice.
This change makes scene items generate quads in the item-local coordinate
space.
The model matrix is used to map the quads to the global screen coordinate
system from the item coordinate space.
Since the quads are in the item local coordinate space, the mvp matrix
needs to be updated on every draw call. Given the render data, tracking
the last mvp matrix won't result in less glUniform calls. If this indeed
becomes a serious performance bottleneck, we can explore the possibility
of dumping mvp matrices in a UBO, which have been introduced in OpenGL
3.1.
The scene items depend on the scene windows for caching window quads.
The goal of this change is to move window quads management to item.
Merging window quads in one list and then splitting them is inefficient,
it will be highly desirable if window quads are removed from the public
api so we can optimize window quad management.
With this change, the window quad type becomes irrelevant to render
backends for the most part. Note that the Xrender backend is a bit
nitpicky about window quads, so the shadow item doesn't create generic
"WindowQuadShadow" quads anymore.
They are used only by X11Client, so make X11Client call relevants
methods on the surface item directly instead. In hindsight, it will be a
really good idea to make SurfaceItemX11 and SurfaceItemXwayland(?)
automatically manage the window pixmap. However, it can be done once
an item freezing api is added and we fix the cross-fade animation.
One of the scene redesign goals is to make wayland surface items
re-usable. So we have the same rendering path for drag-and-drop icons,
software cursors, and window surfaces.
The biggest issue at the moment is that window pixmaps are tightly
coupled with scene windows.
This change de-couples window pixmaps from scene windows. In order to
achieve that, some architecture changes were made.
The WindowPixmap class was replaced with the SurfacePixmap class. A
surface pixmap is created by a surface item.
Under the hood, a SurfacePixmap will create a PlatformSurfaceTexture
object, which contains all the information necessary for the renderer.
The SceneOpenGLTexture class was removed. However, the GLX and the EGL
on X11 backends still mess with GLTexture's internals.
Currently, dealing with sub-surfaces is very difficult due to the scene
design being heavily influenced by X11 requirements.
The goal of this change is to re-work scene abstractions to make improving
the wayland support easier.
The Item class is based on the QQuickItem class. My hope is that one day
we will be able to transition to QtQuick for painting scene, but in
meanwhile it makes more sense to have a minimalistic internal item class.
The WindowItem class represents a window. The SurfaceItem class represents
the contents of either an X11, or a Wayland, or an internal surface. The
DecorationItem and the ShadowItem class represent the server-side deco and
drop-shadow, respectively.
At the moment, the SurfaceItem is bound to the scene window, but the long
term plan is to break that connection so we could re-use the SurfaceItem
for things such as software cursors and drag-and-drop additional icons.
One of the responsibilities of the Item is to schedule repaints as needed.
Ideally, there shouldn't be any addRepaint() calls in the core code. The
Item class schedules repaints on geometry updates. In the future, it also
has to request an update if its opacity or visibility changes.
