diff options
Diffstat (limited to 'src/gui/painting/qbackingstore.cpp')
-rw-r--r-- | src/gui/painting/qbackingstore.cpp | 56 |
1 files changed, 44 insertions, 12 deletions
diff --git a/src/gui/painting/qbackingstore.cpp b/src/gui/painting/qbackingstore.cpp index ecc0d1cac2..2304ee2256 100644 --- a/src/gui/painting/qbackingstore.cpp +++ b/src/gui/painting/qbackingstore.cpp @@ -25,11 +25,32 @@ public: { } + // Returns the DPR for the backing store. This is the DPR for the QWindow, + // possibly rounded up to the nearest integer. + qreal backingStoreDevicePixelRatio() const + { + // Note: keep in sync with QWidget::metric()! + qreal windowDpr = window->devicePixelRatio(); + return downscale ? std::ceil(windowDpr) : windowDpr; + } + + // Returns the factor used for converting from device independent to native + // backing store sizes. Normally this is just the gui scale factor, however + // if the backing store rounds the DPR up to the nearest integer then we also + // need to account for the factor introduced by that rounding. + qreal deviceIndependentToNativeFactor() const + { + const qreal roundingFactor = backingStoreDevicePixelRatio() / window->devicePixelRatio(); + const qreal guiFactor = QHighDpiScaling::factor(window); + return roundingFactor * guiFactor; + } + QWindow *window; QPlatformBackingStore *platformBackingStore = nullptr; QScopedPointer<QImage> highDpiBackingstore; QRegion staticContents; QSize size; + bool downscale = qEnvironmentVariableIntValue("QT_WIDGETS_HIGHDPI_DOWNSCALE") > 0; }; /*! @@ -94,12 +115,14 @@ QWindow* QBackingStore::window() const void QBackingStore::beginPaint(const QRegion ®ion) { + const qreal dpr = d_ptr->backingStoreDevicePixelRatio(); + if (d_ptr->highDpiBackingstore && - d_ptr->highDpiBackingstore->devicePixelRatio() != d_ptr->window->devicePixelRatio()) + d_ptr->highDpiBackingstore->devicePixelRatio() != dpr) resize(size()); QPlatformBackingStore *platformBackingStore = handle(); - platformBackingStore->beginPaint(QHighDpi::toNativeLocalRegion(region, d_ptr->window)); + platformBackingStore->beginPaint(QHighDpi::scale(region, d_ptr->deviceIndependentToNativeFactor())); // When QtGui is applying a high-dpi scale factor the backing store // creates a "large" backing store image. This image needs to be @@ -118,8 +141,7 @@ void QBackingStore::beginPaint(const QRegion ®ion) d_ptr->highDpiBackingstore.reset( new QImage(source->bits(), source->width(), source->height(), source->bytesPerLine(), source->format())); - qreal targetDevicePixelRatio = d_ptr->window->devicePixelRatio(); - d_ptr->highDpiBackingstore->setDevicePixelRatio(targetDevicePixelRatio); + d_ptr->highDpiBackingstore->setDevicePixelRatio(dpr); } } } @@ -184,13 +206,15 @@ void QBackingStore::flush(const QRegion ®ion, QWindow *window, const QPoint & Q_ASSERT(window == topLevelWindow || topLevelWindow->isAncestorOf(window, QWindow::ExcludeTransients)); - QRegion nativeRegion = QHighDpi::toNativeLocalRegion(region, window); + const qreal toNativeFactor = d_ptr->deviceIndependentToNativeFactor(); + + QRegion nativeRegion = QHighDpi::scale(region, toNativeFactor); QPoint nativeOffset; if (!offset.isNull()) { - nativeOffset = QHighDpi::toNativeLocalPosition(offset, window); + nativeOffset = QHighDpi::scale(offset, toNativeFactor); // Under fractional DPR, rounding of region and offset may accumulate to an off-by-one QPoint topLeft = region.boundingRect().topLeft() + offset; - QPoint nativeTopLeft = QHighDpi::toNativeLocalPosition(topLeft, window); + QPoint nativeTopLeft = QHighDpi::scale(topLeft, toNativeFactor); QPoint diff = nativeTopLeft - (nativeRegion.boundingRect().topLeft() + nativeOffset); Q_ASSERT(qMax(qAbs(diff.x()), qAbs(diff.y())) <= 1); nativeRegion.translate(diff); @@ -206,7 +230,8 @@ void QBackingStore::flush(const QRegion ®ion, QWindow *window, const QPoint & void QBackingStore::resize(const QSize &size) { d_ptr->size = size; - handle()->resize(QHighDpi::toNativePixels(size, d_ptr->window), d_ptr->staticContents); + const qreal factor = d_ptr->deviceIndependentToNativeFactor(); + handle()->resize(QHighDpi::scale(size, factor), QHighDpi::scale(d_ptr->staticContents, factor)); } /*! @@ -228,13 +253,13 @@ bool QBackingStore::scroll(const QRegion &area, int dx, int dy) // Disable scrolling for non-integer scroll deltas. For this case // the existing rendered pixels can't be re-used, and we return // false to signal that a repaint is needed. - const qreal nativeDx = QHighDpi::toNativePixels(qreal(dx), d_ptr->window); - const qreal nativeDy = QHighDpi::toNativePixels(qreal(dy), d_ptr->window); + const qreal toNativeFactor = d_ptr->deviceIndependentToNativeFactor(); + const qreal nativeDx = QHighDpi::scale(qreal(dx), toNativeFactor); + const qreal nativeDy = QHighDpi::scale(qreal(dy), toNativeFactor); if (qFloor(nativeDx) != nativeDx || qFloor(nativeDy) != nativeDy) return false; - return handle()->scroll(QHighDpi::toNativeLocalRegion(area, d_ptr->window), - nativeDx, nativeDy); + return handle()->scroll(QHighDpi::scale(area, toNativeFactor), nativeDx, nativeDy); } /*! @@ -242,6 +267,13 @@ bool QBackingStore::scroll(const QRegion &area, int dx, int dy) */ void QBackingStore::setStaticContents(const QRegion ®ion) { + [[maybe_unused]] static const bool didCheckPlatformSupport = []{ + const auto *integration = QGuiApplicationPrivate::platformIntegration(); + if (!integration->hasCapability(QPlatformIntegration::BackingStoreStaticContents)) + qWarning("QBackingStore::setStaticContents(): Platform does not support static contents"); + return true; + }(); + d_ptr->staticContents = region; } |