diff options
Diffstat (limited to 'src/gui')
| -rw-r--r-- | src/gui/graphicsview/qgraphicsscene.cpp | 76 |
1 files changed, 58 insertions, 18 deletions
diff --git a/src/gui/graphicsview/qgraphicsscene.cpp b/src/gui/graphicsview/qgraphicsscene.cpp index e58b93c..a0015dc 100644 --- a/src/gui/graphicsview/qgraphicsscene.cpp +++ b/src/gui/graphicsview/qgraphicsscene.cpp @@ -4362,6 +4362,50 @@ static void _q_paintIntoCache(QPixmap *pix, QGraphicsItem *item, const QRegion & } } +// Copied from qpaintengine_vg.cpp +// Returns true for 90, 180, and 270 degree rotations. +static inline bool transformIsSimple(const QTransform& transform) +{ + QTransform::TransformationType type = transform.type(); + if (type == QTransform::TxNone || type == QTransform::TxTranslate) { + return true; + } else if (type == QTransform::TxScale) { + // Check for 0 and 180 degree rotations. + // (0 might happen after 4 rotations of 90 degrees). + qreal m11 = transform.m11(); + qreal m12 = transform.m12(); + qreal m21 = transform.m21(); + qreal m22 = transform.m22(); + if (m12 == 0.0f && m21 == 0.0f) { + if (m11 == 1.0f && m22 == 1.0f) + return true; // 0 degrees + else if (m11 == -1.0f && m22 == -1.0f) + return true; // 180 degrees. + if(m11 == 1.0f && m22 == -1.0f) + return true; // 0 degrees inverted y. + else if(m11 == -1.0f && m22 == 1.0f) + return true; // 180 degrees inverted y. + } + } else if (type == QTransform::TxRotate) { + // Check for 90, and 270 degree rotations. + qreal m11 = transform.m11(); + qreal m12 = transform.m12(); + qreal m21 = transform.m21(); + qreal m22 = transform.m22(); + if (m11 == 0.0f && m22 == 0.0f) { + if (m12 == 1.0f && m21 == -1.0f) + return true; // 90 degrees. + else if (m12 == -1.0f && m21 == 1.0f) + return true; // 270 degrees. + else if (m12 == -1.0f && m21 == -1.0f) + return true; // 90 degrees inverted y. + else if (m12 == 1.0f && m21 == 1.0f) + return true; // 270 degrees inverted y. + } + } + return false; +} + /*! \internal @@ -4530,32 +4574,28 @@ void QGraphicsScenePrivate::drawItemHelper(QGraphicsItem *item, QPainter *painte if (invertable) diff *= painter->worldTransform(); deviceData->lastTransform = painter->worldTransform(); - if (!invertable - || diff.type() > QTransform::TxTranslate - || painter->worldTransform().type() > QTransform::TxScale) { + bool allowPartialCacheExposure = false; + bool simpleTransform = invertable && diff.type() <= QTransform::TxTranslate + && transformIsSimple(painter->worldTransform()); + if (!simpleTransform) { pixModified = true; itemCache->allExposed = true; itemCache->exposed.clear(); + deviceData->cacheIndent = QPoint(); pix = QPixmap(); + } else { + allowPartialCacheExposure = deviceData->cacheIndent != QPoint(); } - // ### This is a pretty bad way to determine when to start partial - // exposure for DeviceCoordinateCache but it's the least intrusive - // approach for now. -#if 0 - // Only if the device rect isn't fully contained. - bool allowPartialCacheExposure = !viewRect.contains(deviceRect); -#else - // Only if deviceRect is 20% taller or wider than the desktop. - bool allowPartialCacheExposure = false; - if (widget) { - QRect desktopRect = QApplication::desktop()->availableGeometry(widget); - allowPartialCacheExposure = (desktopRect.width() * 1.2 < deviceRect.width() - || desktopRect.height() * 1.2 < deviceRect.height()); + // Allow partial cache exposure if the device rect isn't fully contained and + // deviceRect is 20% taller or wider than the viewRect. + if (!allowPartialCacheExposure && !viewRect.contains(deviceRect)) { + allowPartialCacheExposure = (viewRect.width() * 1.2 < deviceRect.width()) + || (viewRect.height() * 1.2 < deviceRect.height()); } -#endif + QRegion scrollExposure; - if (deviceData->cacheIndent != QPoint() || allowPartialCacheExposure) { + if (allowPartialCacheExposure) { // Part of pixmap is drawn. Either device contains viewrect (big // item covers whole screen) or parts of device are outside the // viewport. In either case the device rect must be the intersect |