kwin/plugins/platforms/wayland/wayland_backend.h
Vlad Zahorodnii b8a70e62d5 Introduce RenderLoop
At the moment, our frame scheduling infrastructure is still heavily
based on Xinerama-style rendering. Specifically, we assume that painting
is driven by a single timer, etc.

This change introduces a new type - RenderLoop. Its main purpose is to
drive compositing on a specific output, or in case of X11, on the
overlay window.

With RenderLoop, compositing is synchronized to vblank events. It
exposes the last and the next estimated presentation timestamp. The
expected presentation timestamp can be used by effects to ensure that
animations are synchronized with the upcoming vblank event.

On Wayland, every outputs has its own render loop. On X11, per screen
rendering is not possible, therefore the platform exposes the render
loop for the overlay window. Ideally, the Scene has to expose the
RenderLoop, but as the first step towards better compositing scheduling
it's good as is for the time being.

The RenderLoop tries to minimize the latency by delaying compositing as
close as possible to the next vblank event. One tricky thing about it is
that if compositing is too close to the next vblank event, animations
may become a little bit choppy. However, increasing the latency reduces
the choppiness.

Given that, there is no any "silver bullet" solution for the choppiness
issue, a new option has been added in the Compositing KCM to specify the
amount of latency. By default, it's "Medium," but if a user is not
satisfied with the upstream default, they can tweak it.
2021-01-06 16:59:29 +00:00

269 lines
6.6 KiB
C++

/*
KWin - the KDE window manager
This file is part of the KDE project.
SPDX-FileCopyrightText: 2019 Roman Gilg <subdiff@gmail.com>
SPDX-FileCopyrightText: 2013 Martin Gräßlin <mgraesslin@kde.org>
SPDX-License-Identifier: GPL-2.0-or-later
*/
#ifndef KWIN_WAYLAND_BACKEND_H
#define KWIN_WAYLAND_BACKEND_H
// KWin
#include "platform.h"
#include <config-kwin.h>
#include <kwinglobals.h>
// Qt
#include <QHash>
#include <QImage>
#include <QObject>
#include <QPoint>
#include <QSize>
class QTemporaryFile;
struct wl_buffer;
struct wl_display;
struct wl_event_queue;
struct wl_seat;
struct gbm_device;
namespace KWayland
{
namespace Client
{
class Buffer;
class ShmPool;
class Compositor;
class ConnectionThread;
class EventQueue;
class Keyboard;
class Pointer;
class PointerConstraints;
class PointerGestures;
class PointerSwipeGesture;
class PointerPinchGesture;
class Registry;
class RelativePointer;
class RelativePointerManager;
class Seat;
class SubCompositor;
class SubSurface;
class Surface;
class Touch;
class XdgShell;
}
}
namespace KWin
{
namespace Wayland
{
class WaylandBackend;
class WaylandSeat;
class WaylandOutput;
class WaylandCursor : public QObject
{
Q_OBJECT
public:
explicit WaylandCursor(WaylandBackend *backend);
~WaylandCursor() override;
virtual void init();
virtual void move(const QPointF &globalPosition) {
Q_UNUSED(globalPosition)
}
void installImage();
protected:
void resetSurface();
virtual void doInstallImage(wl_buffer *image, const QSize &size, qreal scale);
void drawSurface(wl_buffer *image, const QSize &size, qreal scale);
KWayland::Client::Surface *surface() const {
return m_surface;
}
WaylandBackend *backend() const {
return m_backend;
}
private:
WaylandBackend *m_backend;
KWayland::Client::Pointer *m_pointer;
KWayland::Client::Surface *m_surface = nullptr;
};
class WaylandSubSurfaceCursor : public WaylandCursor
{
Q_OBJECT
public:
explicit WaylandSubSurfaceCursor(WaylandBackend *backend);
~WaylandSubSurfaceCursor() override;
void init() override;
void move(const QPointF &globalPosition) override;
private:
void changeOutput(WaylandOutput *output);
void doInstallImage(wl_buffer *image, const QSize &size, qreal scale) override;
void createSubSurface();
QPointF absoluteToRelativePosition(const QPointF &position);
WaylandOutput *m_output = nullptr;
KWayland::Client::SubSurface *m_subSurface = nullptr;
};
class WaylandSeat : public QObject
{
Q_OBJECT
public:
WaylandSeat(wl_seat *seat, WaylandBackend *backend);
~WaylandSeat() override;
KWayland::Client::Pointer *pointer() const {
return m_pointer;
}
void installGesturesInterface(KWayland::Client::PointerGestures *gesturesInterface) {
m_gesturesInterface = gesturesInterface;
setupPointerGestures();
}
private:
void destroyPointer();
void destroyKeyboard();
void destroyTouch();
void setupPointerGestures();
KWayland::Client::Seat *m_seat;
KWayland::Client::Pointer *m_pointer;
KWayland::Client::Keyboard *m_keyboard;
KWayland::Client::Touch *m_touch;
KWayland::Client::PointerGestures *m_gesturesInterface = nullptr;
KWayland::Client::PointerPinchGesture *m_pinchGesture = nullptr;
KWayland::Client::PointerSwipeGesture *m_swipeGesture = nullptr;
uint32_t m_enteredSerial;
WaylandBackend *m_backend;
};
/**
* @brief Class encapsulating all Wayland data structures needed by the Egl backend.
*
* It creates the connection to the Wayland Compositor, sets up the registry and creates
* the Wayland output surfaces and its shell mappings.
*/
class KWIN_EXPORT WaylandBackend : public Platform
{
Q_OBJECT
Q_INTERFACES(KWin::Platform)
Q_PLUGIN_METADATA(IID "org.kde.kwin.Platform" FILE "wayland.json")
public:
explicit WaylandBackend(QObject *parent = nullptr);
~WaylandBackend() override;
void init() override;
wl_display *display();
KWayland::Client::Compositor *compositor();
KWayland::Client::SubCompositor *subCompositor();
KWayland::Client::ShmPool *shmPool();
OpenGLBackend *createOpenGLBackend() override;
QPainterBackend *createQPainterBackend() override;
DmaBufTexture *createDmaBufTexture(const QSize &size) override;
void flush();
WaylandSeat *seat() const {
return m_seat;
}
KWayland::Client::PointerConstraints *pointerConstraints() const {
return m_pointerConstraints;
}
void pointerMotionRelativeToOutput(const QPointF &position, quint32 time);
bool supportsPointerLock();
void togglePointerLock();
bool pointerIsLocked();
QVector<CompositingType> supportedCompositors() const override;
WaylandOutput* getOutputAt(const QPointF &globalPosition);
Outputs outputs() const override;
Outputs enabledOutputs() const override;
QVector<WaylandOutput*> waylandOutputs() const {
return m_outputs;
}
Q_SIGNALS:
void systemCompositorDied();
void connectionFailed();
void pointerLockSupportedChanged();
void pointerLockChanged(bool locked);
private:
void initConnection();
void createOutputs();
void updateScreenSize(WaylandOutput *output);
void relativeMotionHandler(const QSizeF &delta, const QSizeF &deltaNonAccelerated, quint64 timestamp);
wl_display *m_display;
KWayland::Client::EventQueue *m_eventQueue;
KWayland::Client::Registry *m_registry;
KWayland::Client::Compositor *m_compositor;
KWayland::Client::SubCompositor *m_subCompositor;
KWayland::Client::XdgShell *m_xdgShell = nullptr;
KWayland::Client::ShmPool *m_shm;
KWayland::Client::ConnectionThread *m_connectionThreadObject;
WaylandSeat *m_seat = nullptr;
KWayland::Client::RelativePointer *m_relativePointer = nullptr;
KWayland::Client::RelativePointerManager *m_relativePointerManager = nullptr;
KWayland::Client::PointerConstraints *m_pointerConstraints = nullptr;
QThread *m_connectionThread;
QVector<WaylandOutput*> m_outputs;
WaylandCursor *m_waylandCursor = nullptr;
bool m_pointerLockRequested = false;
#if HAVE_GBM && HAVE_WAYLAND_EGL
int m_drmFileDescriptor = 0;
gbm_device *m_gbmDevice;
#endif
};
inline
wl_display *WaylandBackend::display()
{
return m_display;
}
inline
KWayland::Client::Compositor *WaylandBackend::compositor()
{
return m_compositor;
}
inline
KWayland::Client::SubCompositor *WaylandBackend::subCompositor()
{
return m_subCompositor;
}
inline
KWayland::Client::ShmPool* WaylandBackend::shmPool()
{
return m_shm;
}
} // namespace Wayland
} // namespace KWin
#endif // KWIN_WAYLAND_BACKEND_H