File 0001-fix-slow-scrolling-on-wayland.patch of Package qt6-base
Contains 2 changes:
- wayland: Compress high frequency mouse events (https://bugreports.qt.io/browse/QTBUG-138706)
- wayland: Optimize scroll operation (https://bugreports.qt.io/browse/QTBUG-139231)
diff --git a/src/corelib/global/qnamespace.qdoc b/src/corelib/global/qnamespace.qdoc
index c845cfa7eec..f463d7364ca 100644
--- a/src/corelib/global/qnamespace.qdoc
+++ b/src/corelib/global/qnamespace.qdoc
@@ -227,6 +227,7 @@
application later.
On Windows 8 and above the default value is also true, but it only applies
to touch events. Mouse and window events remain unaffected by this flag.
+ On Wayland the default value is also true, but it only applies to mouse events.
On other platforms, the default is false.
(In the future, the compression feature may be implemented across platforms.)
You can test the attribute to see whether compression is enabled.
diff --git a/src/plugins/platforms/wayland/qwaylandinputdevice.cpp b/src/plugins/platforms/wayland/qwaylandinputdevice.cpp
index 170e80f806c..5f927fca51a 100644
--- a/src/plugins/platforms/wayland/qwaylandinputdevice.cpp
+++ b/src/plugins/platforms/wayland/qwaylandinputdevice.cpp
@@ -63,6 +63,34 @@ Q_LOGGING_CATEGORY(lcQpaWaylandInput, "qt.qpa.wayland.input");
// reasonable number of them. As of 2021 most touchscreen panels support 10 concurrent touchpoints.
static const int MaxTouchPoints = 10;
+QWaylandEventCompressionPrivate::QWaylandEventCompressionPrivate()
+{
+ timeElapsed.start();
+ delayTimer.setSingleShot(true);
+}
+
+bool QWaylandEventCompressionPrivate::compressEvent()
+{
+ using namespace std::chrono_literals;
+
+ if (!QCoreApplication::testAttribute(Qt::AA_CompressHighFrequencyEvents))
+ return false;
+
+ const auto elapsed = timeElapsed.durationElapsed();
+ timeElapsed.start();
+ if (elapsed < 100us || delayTimer.isActive())
+ {
+ // The highest USB HID polling rate is 8 kHz (125 μs). Most mice use lowe polling rate [125 Hz - 1000 Hz].
+ // Reject all events faster than 100 μs, because it definitely means the application main thread is
+ // freezed by long operation and events are delivered one after another from the queue. Since now we rely
+ // on the 0 ms timer to deliver the last pending event when application main thread is no longer freezed.
+ delayTimer.start(0);
+ return true;
+ }
+
+ return false;
+}
+
QWaylandInputDevice::Keyboard::Keyboard(QWaylandInputDevice *p)
: mParent(p)
{
@@ -140,6 +168,8 @@ QWaylandInputDevice::Pointer::Pointer(QWaylandInputDevice *seat)
cursorTimerCallback();
});
#endif
+
+ mEventCompression.delayTimer.callOnTimeout(this, &QWaylandInputDevice::Pointer::flushFrameEvent);
}
QWaylandInputDevice::Pointer::~Pointer()
@@ -914,14 +944,16 @@ void QWaylandInputDevice::Pointer::pointer_axis(uint32_t time, uint32_t axis, in
mParent->mTime = time;
- if (version() < WL_POINTER_FRAME_SINCE_VERSION) {
- qCDebug(lcQpaWaylandInput) << "Flushing new event; no frame event in this version";
- flushFrameEvent();
- }
+ maybePointerFrame();
}
void QWaylandInputDevice::Pointer::pointer_frame()
{
+ if (mEventCompression.compressEvent()) {
+ qCDebug(lcQpaWaylandInput) << "compressed pointer_frame event";
+ return;
+ }
+
flushFrameEvent();
}
@@ -952,11 +984,9 @@ void QWaylandInputDevice::Pointer::pointer_axis_stop(uint32_t time, uint32_t axi
switch (axis) {
case axis_vertical_scroll:
qCDebug(lcQpaWaylandInput) << "Received vertical wl_pointer.axis_stop";
- mFrameData.delta.setY(0); //TODO: what's the point of doing this?
break;
case axis_horizontal_scroll:
qCDebug(lcQpaWaylandInput) << "Received horizontal wl_pointer.axis_stop";
- mFrameData.delta.setX(0);
break;
default:
qCWarning(lcQpaWaylandInput) << "wl_pointer.axis_stop: Unknown axis: " << axis
@@ -964,25 +994,7 @@ void QWaylandInputDevice::Pointer::pointer_axis_stop(uint32_t time, uint32_t axi
return;
}
- // May receive axis_stop for events we haven't sent a ScrollBegin for because
- // most axis_sources do not mandate an axis_stop event to be sent.
- if (!mScrollBeginSent) {
- // TODO: For now, we just ignore these events, but we could perhaps take this as an
- // indication that this compositor will in fact send axis_stop events for these sources
- // and send a ScrollBegin the next time an axis_source event with this type is encountered.
- return;
- }
-
- QWaylandWindow *target = QWaylandWindow::mouseGrab();
- if (!target)
- target = focusWindow();
- Qt::KeyboardModifiers mods = mParent->modifiers();
- const bool inverted = mFrameData.verticalAxisInverted || mFrameData.horizontalAxisInverted;
- WheelEvent wheelEvent(focusWindow(), Qt::ScrollEnd, mParent->mTime, mSurfacePos, mGlobalPos,
- QPoint(), QPoint(), Qt::MouseEventNotSynthesized, mods, inverted);
- target->handleMouse(mParent, wheelEvent);
- mScrollBeginSent = false;
- mScrollDeltaRemainder = QPointF();
+ mScrollEnd = true;
}
void QWaylandInputDevice::Pointer::pointer_axis_discrete(uint32_t axis, int32_t value)
@@ -1043,6 +1055,14 @@ void QWaylandInputDevice::Pointer::pointer_axis_relative_direction(uint32_t axis
}
}
+inline void QWaylandInputDevice::Pointer::maybePointerFrame()
+{
+ if (version() < WL_POINTER_FRAME_SINCE_VERSION) {
+ qCDebug(lcQpaWaylandInput) << "Flushing new event; no frame event in this version";
+ pointer_frame();
+ }
+}
+
void QWaylandInputDevice::Pointer::setFrameEvent(QWaylandPointerEvent *event)
{
qCDebug(lcQpaWaylandInput) << "Setting frame event " << event->type;
@@ -1051,12 +1071,9 @@ void QWaylandInputDevice::Pointer::setFrameEvent(QWaylandPointerEvent *event)
flushFrameEvent();
}
- mFrameData.event = event;
+ mFrameData.event.reset(event);
- if (version() < WL_POINTER_FRAME_SINCE_VERSION) {
- qCDebug(lcQpaWaylandInput) << "Flushing new event; no frame event in this version";
- flushFrameEvent();
- }
+ maybePointerFrame();
}
void QWaylandInputDevice::Pointer::FrameData::resetScrollData()
@@ -1136,11 +1153,24 @@ void QWaylandInputDevice::Pointer::flushScrollEvent()
{
QPoint angleDelta = mFrameData.angleDelta();
+ // The wayland protocol has separate horizontal and vertical axes, Qt has just the one inverted flag
+ // Pragmatically it should't come up
+ const bool inverted = mFrameData.verticalAxisInverted || mFrameData.horizontalAxisInverted;
+
// Angle delta is required for Qt wheel events, so don't try to send events if it's zero
if (!angleDelta.isNull()) {
- QWaylandWindow *target = QWaylandWindow::mouseGrab();
- if (!target)
- target = focusWindow();
+ QWaylandWindow *target = mScrollTarget;
+ if (!mScrollBeginSent) {
+ if (!target)
+ target = QWaylandWindow::mouseGrab();
+ if (!target)
+ target = focusWindow();
+ }
+ if (!target) {
+ qCDebug(lcQpaWaylandInput) << "Flushing scroll event aborted - no scroll target";
+ mFrameData.resetScrollData();
+ return;
+ }
if (isDefinitelyTerminated(mFrameData.axisSource) && !mScrollBeginSent) {
qCDebug(lcQpaWaylandInput) << "Flushing scroll event sending ScrollBegin";
@@ -1150,27 +1180,46 @@ void QWaylandInputDevice::Pointer::flushScrollEvent()
mParent->modifiers(), false));
mScrollBeginSent = true;
mScrollDeltaRemainder = QPointF();
+ mScrollTarget = target;
}
Qt::ScrollPhase phase = mScrollBeginSent ? Qt::ScrollUpdate : Qt::NoScrollPhase;
QPoint pixelDelta = mFrameData.pixelDeltaAndError(&mScrollDeltaRemainder);
- Qt::MouseEventSource source = mFrameData.wheelEventSource();
-
-
- // The wayland protocol has separate horizontal and vertical axes, Qt has just the one inverted flag
- // Pragmatically it should't come up
- const bool inverted = mFrameData.verticalAxisInverted || mFrameData.horizontalAxisInverted;
qCDebug(lcQpaWaylandInput) << "Flushing scroll event" << phase << pixelDelta << angleDelta;
target->handleMouse(mParent, WheelEvent(focusWindow(), phase, mParent->mTime, mSurfacePos, mGlobalPos,
- pixelDelta, angleDelta, source, mParent->modifiers(), inverted));
+ pixelDelta, angleDelta, mFrameData.wheelEventSource(), mParent->modifiers(), inverted));
+ }
+
+ if (mScrollEnd) {
+ if (mScrollBeginSent) {
+ if (auto target = mScrollTarget.get()) {
+ qCDebug(lcQpaWaylandInput) << "Flushing scroll end event";
+ target->handleMouse(mParent, WheelEvent(focusWindow(), Qt::ScrollEnd, mParent->mTime, mSurfacePos, mGlobalPos,
+ QPoint(), QPoint(), mFrameData.wheelEventSource(), mParent->modifiers(), inverted));
+ }
+ mScrollBeginSent = false;
+ mScrollDeltaRemainder = QPointF();
+ } else {
+ // May receive axis_stop for events we haven't sent a ScrollBegin for because
+ // most axis_sources do not mandate an axis_stop event to be sent.
+
+ // TODO: For now, we just ignore these events, but we could perhaps take this as an
+ // indication that this compositor will in fact send axis_stop events for these sources
+ // and send a ScrollBegin the next time an axis_source event with this type is encountered.
+ }
+ mScrollEnd = false;
+ mScrollTarget.clear();
}
+
mFrameData.resetScrollData();
}
void QWaylandInputDevice::Pointer::flushFrameEvent()
{
- if (auto *event = mFrameData.event) {
+ mEventCompression.delayTimer.stop();
+
+ if (auto *event = mFrameData.event.get()) {
if (auto window = event->surface) {
window->handleMouse(mParent, *event);
} else if (mFrameData.event->type == QEvent::MouseButtonRelease) {
@@ -1183,8 +1232,7 @@ void QWaylandInputDevice::Pointer::flushFrameEvent()
event->modifiers); // , Qt::MouseEventSource source =
// Qt::MouseEventNotSynthesized);
}
- delete mFrameData.event;
- mFrameData.event = nullptr;
+ mFrameData.event.reset();
}
//TODO: do modifiers get passed correctly here?
diff --git a/src/plugins/platforms/wayland/qwaylandinputdevice_p.h b/src/plugins/platforms/wayland/qwaylandinputdevice_p.h
index bcaf025840d..b9582daf32c 100644
--- a/src/plugins/platforms/wayland/qwaylandinputdevice_p.h
+++ b/src/plugins/platforms/wayland/qwaylandinputdevice_p.h
@@ -75,6 +75,16 @@ class CursorSurface;
Q_DECLARE_LOGGING_CATEGORY(lcQpaWaylandInput);
+struct QWaylandEventCompressionPrivate
+{
+ QWaylandEventCompressionPrivate();
+
+ bool compressEvent();
+
+ QElapsedTimer timeElapsed;
+ QTimer delayTimer;
+};
+
class Q_WAYLANDCLIENT_EXPORT QWaylandInputDevice
: public QObject
, public QtWayland::wl_seat
@@ -362,7 +372,7 @@ public:
Qt::MouseButton mLastButton = Qt::NoButton;
struct FrameData {
- QWaylandPointerEvent *event = nullptr;
+ QScopedPointer<QWaylandPointerEvent> event;
QPointF delta;
QPoint delta120;
@@ -379,7 +389,13 @@ public:
} mFrameData;
bool mScrollBeginSent = false;
+ bool mScrollEnd = false;
QPointF mScrollDeltaRemainder;
+ QPointer<QWaylandWindow> mScrollTarget;
+
+ QWaylandEventCompressionPrivate mEventCompression;
+
+ void maybePointerFrame();
void setFrameEvent(QWaylandPointerEvent *event);
void flushScrollEvent();
diff --git a/src/plugins/platforms/wayland/qwaylandintegration.cpp b/src/plugins/platforms/wayland/qwaylandintegration.cpp
index 669d47ee3b8..fc869de669f 100644
--- a/src/plugins/platforms/wayland/qwaylandintegration.cpp
+++ b/src/plugins/platforms/wayland/qwaylandintegration.cpp
@@ -87,6 +87,8 @@ QWaylandIntegration::QWaylandIntegration(const QString &platformName)
: mPlatformName(platformName), mFontDb(new QGenericUnixFontDatabase())
#endif
{
+ QCoreApplication::setAttribute(Qt::AA_CompressHighFrequencyEvents);
+
mDisplay.reset(new QWaylandDisplay(this));
mPlatformServices.reset(new QWaylandPlatformServices(mDisplay.data()));
diff --git a/src/plugins/platforms/wayland/qwaylandshmbackingstore.cpp b/src/plugins/platforms/wayland/qwaylandshmbackingstore.cpp
index d8fc7b18ca3..591e5064ebd 100644
--- a/src/plugins/platforms/wayland/qwaylandshmbackingstore.cpp
+++ b/src/plugins/platforms/wayland/qwaylandshmbackingstore.cpp
@@ -159,6 +159,8 @@ QWaylandShmBackingStore::QWaylandShmBackingStore(QWindow *window, QWaylandDispla
// recreateBackBufferIfNeeded always resets mBackBuffer
if (mRequestedSize.isValid() && waylandWindow())
recreateBackBufferIfNeeded();
+ else
+ mBackBuffer = nullptr;
qDeleteAll(copy);
wl_event_queue_destroy(oldEventQueue);
});
@@ -183,11 +185,15 @@ QPaintDevice *QWaylandShmBackingStore::paintDevice()
void QWaylandShmBackingStore::updateDirtyStates(const QRegion ®ion)
{
- // Update dirty state of buffers based on what was painted. The back buffer will
- // not be dirty since we already painted on it, while other buffers will become dirty.
+ // Update dirty state of buffers based on what was painted. The back buffer will be
+ // less dirty, since we painted to it, while other buffers will become more dirty.
+ // This allows us to minimize copies between front and back buffers on swap in the
+ // cases where the painted region overlaps with the previous frame (front buffer).
for (QWaylandShmBuffer *b : std::as_const(mBuffers)) {
if (b != mBackBuffer)
b->dirtyRegion() += region;
+ else
+ b->dirtyRegion() -= region;
}
}
@@ -198,7 +204,7 @@ void QWaylandShmBackingStore::beginPaint(const QRegion ®ion)
const QMargins margins = windowDecorationMargins();
const QRegion regionTranslated = region.translated(margins.left(), margins.top());
- const bool bufferWasRecreated = recreateBackBufferIfNeeded(regionTranslated);
+ const bool bufferWasRecreated = recreateBackBufferIfNeeded();
updateDirtyStates(regionTranslated);
// Although undocumented, QBackingStore::beginPaint expects the painted region
@@ -223,7 +229,7 @@ void QWaylandShmBackingStore::endPaint()
// Inspired by QCALayerBackingStore.
bool QWaylandShmBackingStore::scroll(const QRegion ®ion, int dx, int dy)
{
- if (!mBackBuffer)
+ if (Q_UNLIKELY(!mBackBuffer || !mFrontBuffer))
return false;
const qreal devicePixelRatio = waylandWindow()->scale();
@@ -236,19 +242,35 @@ bool QWaylandShmBackingStore::scroll(const QRegion ®ion, int dx, int dy)
recreateBackBufferIfNeeded();
- QImage *backBufferImage = mBackBuffer->image();
-
const QPoint scrollDelta(dx, dy);
const QMargins margins = windowDecorationMargins();
const QRegion adjustedRegion = region.translated(margins.left(), margins.top());
- const QRect boundingRect = adjustedRegion.boundingRect();
- const QPoint devicePixelDelta = scrollDelta * devicePixelRatio;
+ const QRegion inPlaceRegion = adjustedRegion - mBackBuffer->dirtyRegion();
+ const QRegion frontBufferRegion = adjustedRegion - inPlaceRegion;
+
+ if (!inPlaceRegion.isEmpty()) {
+ const QRect inPlaceBoundingRect = inPlaceRegion.boundingRect();
+ const QPoint devicePixelDelta = scrollDelta * devicePixelRatio;
+
+ qt_scrollRectInImage(*mBackBuffer->image(),
+ QRect(inPlaceBoundingRect.topLeft() * devicePixelRatio,
+ inPlaceBoundingRect.size() * devicePixelRatio),
+ devicePixelDelta);
+ }
- qt_scrollRectInImage(*backBufferImage,
- QRect(boundingRect.topLeft() * devicePixelRatio,
- boundingRect.size() * devicePixelRatio),
- devicePixelDelta);
+ if (!frontBufferRegion.isEmpty()) {
+ QPainter painter(mBackBuffer->image());
+ painter.setCompositionMode(QPainter::CompositionMode_Source);
+ painter.scale(qreal(1) / devicePixelRatio, qreal(1) / devicePixelRatio);
+ for (const QRect &rect : frontBufferRegion) {
+ QRect sourceRect(rect.topLeft() * devicePixelRatio,
+ rect.size() * devicePixelRatio);
+ QRect destinationRect((rect.topLeft() + scrollDelta) * devicePixelRatio,
+ rect.size() * devicePixelRatio);
+ painter.drawImage(destinationRect, *mFrontBuffer->image(), sourceRect);
+ }
+ }
// We do not mark the source region as dirty, even though it technically has "moved".
// This matches the behavior of other backingstore implementations using qt_scrollRectInImage.
@@ -289,6 +311,8 @@ void QWaylandShmBackingStore::flush(QWindow *window, const QRegion ®ion, cons
if (windowDecoration() && windowDecoration()->isDirty())
updateDecorations();
+ finalizeBackBuffer();
+
mFrontBuffer = mBackBuffer;
QMargins margins = windowDecorationMargins();
@@ -313,6 +337,8 @@ QWaylandShmBuffer *QWaylandShmBackingStore::getBuffer(const QSize &size, bool &b
mBuffers.removeAt(i);
if (mBackBuffer == buffer)
mBackBuffer = nullptr;
+ if (mFrontBuffer == buffer)
+ mFrontBuffer = nullptr;
delete buffer;
}
}
@@ -341,7 +367,7 @@ QWaylandShmBuffer *QWaylandShmBackingStore::getBuffer(const QSize &size, bool &b
return nullptr;
}
-bool QWaylandShmBackingStore::recreateBackBufferIfNeeded(const QRegion &nonDirtyRegion)
+bool QWaylandShmBackingStore::recreateBackBufferIfNeeded()
{
wl_display_dispatch_queue_pending(mDisplay->wl_display(), mEventQueue);
@@ -375,30 +401,6 @@ bool QWaylandShmBackingStore::recreateBackBufferIfNeeded(const QRegion &nonDirty
qsizetype oldSizeInBytes = mBackBuffer ? mBackBuffer->image()->sizeInBytes() : 0;
qsizetype newSizeInBytes = buffer->image()->sizeInBytes();
- // mBackBuffer may have been deleted here but if so it means its size was different so we wouldn't copy it anyway
- if (mBackBuffer != buffer && oldSizeInBytes == newSizeInBytes) {
- const QRegion clipRegion = buffer->dirtyRegion() - nonDirtyRegion;
- const auto clipRects = clipRegion.rects();
- if (!clipRects.empty()) {
- Q_ASSERT(mBackBuffer);
- const QImage *sourceImage = mBackBuffer->image();
- QImage *targetImage = buffer->image();
-
- QPainter painter(targetImage);
- painter.setCompositionMode(QPainter::CompositionMode_Source);
- const qreal targetDevicePixelRatio = painter.device()->devicePixelRatio();
- for (const QRect &clipRect : clipRects) { // Iterate clip rects, because complicated clip region causes higher CPU usage
- if (clipRects.size() > 1)
- painter.save();
- painter.setClipRect(clipRect);
- painter.scale(qreal(1) / targetDevicePixelRatio, qreal(1) / targetDevicePixelRatio);
- painter.drawImage(QRectF(QPointF(), targetImage->size()), *sourceImage, sourceImage->rect());
- if (clipRects.size() > 1)
- painter.restore();
- }
- }
- }
-
mBackBuffer = buffer;
for (QWaylandShmBuffer *buffer : std::as_const(mBuffers)) {
@@ -412,11 +414,40 @@ bool QWaylandShmBackingStore::recreateBackBufferIfNeeded(const QRegion &nonDirty
if (windowDecoration() && window()->isVisible() && oldSizeInBytes != newSizeInBytes)
windowDecoration()->update();
- buffer->dirtyRegion() = QRegion();
-
return bufferWasRecreated;
}
+void QWaylandShmBackingStore::finalizeBackBuffer()
+{
+ Q_ASSERT(mBackBuffer);
+
+ const QRegion clipRegion = mBackBuffer->dirtyRegion();
+ if (clipRegion.isEmpty())
+ return;
+
+ if (Q_UNLIKELY(!mFrontBuffer || mFrontBuffer == mBackBuffer))
+ return;
+
+ const QImage *sourceImage = mFrontBuffer->image();
+ QImage *targetImage = mBackBuffer->image();
+
+ QPainter painter(targetImage);
+ painter.setCompositionMode(QPainter::CompositionMode_Source);
+ const qreal targetDevicePixelRatio = painter.device()->devicePixelRatio();
+ const auto clipRects = clipRegion.rects();
+ for (const QRect &clipRect : clipRects) { // Iterate clip rects, because complicated clip region causes higher CPU usage
+ if (clipRects.size() > 1)
+ painter.save();
+ painter.setClipRect(clipRect);
+ painter.scale(qreal(1) / targetDevicePixelRatio, qreal(1) / targetDevicePixelRatio);
+ painter.drawImage(QRectF(QPointF(), targetImage->size()), *sourceImage, sourceImage->rect());
+ if (clipRects.size() > 1)
+ painter.restore();
+ }
+
+ mBackBuffer->dirtyRegion() = QRegion();
+}
+
QImage *QWaylandShmBackingStore::entireSurface() const
{
return mBackBuffer->image();
@@ -496,6 +527,8 @@ QImage QWaylandShmBackingStore::toImage() const
// instead of flush() for widgets that have renderToTexture children
// (QOpenGLWidget, QQuickWidget).
+ const_cast<QWaylandShmBackingStore *>(this)->finalizeBackBuffer();
+
return *contentSurface();
}
#endif // opengl
diff --git a/src/plugins/platforms/wayland/qwaylandshmbackingstore_p.h b/src/plugins/platforms/wayland/qwaylandshmbackingstore_p.h
index efd80159e85..cfcafb28326 100644
--- a/src/plugins/platforms/wayland/qwaylandshmbackingstore_p.h
+++ b/src/plugins/platforms/wayland/qwaylandshmbackingstore_p.h
@@ -73,7 +73,8 @@ public:
QMargins windowDecorationMargins() const;
QImage *entireSurface() const;
QImage *contentSurface() const;
- bool recreateBackBufferIfNeeded(const QRegion &nonDirtyRegion = QRegion());
+ bool recreateBackBufferIfNeeded();
+ void finalizeBackBuffer();
QWaylandWindow *waylandWindow() const;
void iterateBuffer();
diff --git a/tests/auto/wayland/client/tst_client.cpp b/tests/auto/wayland/client/tst_client.cpp
index 04400e3f26a..09ac4f7f81d 100644
--- a/tests/auto/wayland/client/tst_client.cpp
+++ b/tests/auto/wayland/client/tst_client.cpp
@@ -276,6 +276,8 @@ void tst_WaylandClient::events()
exec([&] {
pointer()->sendEnter(s, window.frameOffset() + mousePressPos);
pointer()->sendFrame(client());
+ pointer()->sendMotion(client(), window.frameOffset() + mousePressPos / 2);
+ pointer()->sendFrame(client());
pointer()->sendMotion(client(), window.frameOffset() + mousePressPos);
pointer()->sendFrame(client());
pointer()->sendButton(client(), BTN_LEFT, Pointer::button_state_pressed);
