From 1f9074b743c727165f21149a09fd08e32157faaf Mon Sep 17 00:00:00 2001 From: Andreas Aardal Hanssen Date: Wed, 1 Apr 2009 17:04:50 +0200 Subject: Fix slowdown regression in QGraphicsItem::ItemCoordinateCache Right before Qt 4.5.0 was released, Alexis and I submitted change 7e9b000ee418ef2d9c8fadb2c6b8870e0335bd5e, which accidentally introduced a rounding error causing items whose bounding rect contains fractional numbers (e.g., QRectF(-0.5, -0.5, 11, 11)), to always be drawn with a one-pixel strech even if otherwise untransformed. This caused a significant slowdown for pixmap items and any shape item that uses almost any pen width != 0, if they enable ItemCoordinateCache. The fix is to consistently use the aligned rectangle both when generating the cache pixmap and when drawing it. Reviewed-by: Alexis --- src/gui/graphicsview/qgraphicsscene.cpp | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-) diff --git a/src/gui/graphicsview/qgraphicsscene.cpp b/src/gui/graphicsview/qgraphicsscene.cpp index 1f78a18..ff46e2e 100644 --- a/src/gui/graphicsview/qgraphicsscene.cpp +++ b/src/gui/graphicsview/qgraphicsscene.cpp @@ -4595,16 +4595,17 @@ void QGraphicsScenePrivate::drawItemHelper(QGraphicsItem *item, QPainter *painte if (cacheMode == QGraphicsItem::ItemCoordinateCache) { QSize pixmapSize; bool fixedCacheSize = false; + QRectF brectAligned = brect.toAlignedRect(); if ((fixedCacheSize = itemCache->fixedSize.isValid())) { pixmapSize = itemCache->fixedSize; } else { - pixmapSize = brect.toAlignedRect().size(); + pixmapSize = brectAligned.size().toSize(); } // Create or recreate the pixmap. int adjust = itemCache->fixedSize.isValid() ? 0 : 2; QSize adjustSize(adjust*2, adjust*2); - QRectF br = brect.adjusted(-adjust, -adjust, adjust, adjust); + QRectF br = brectAligned.adjusted(-adjust, -adjust, adjust, adjust); if (pix.isNull() || (!fixedCacheSize && (pixmapSize + adjustSize) != pix.size())) { pix = QPixmap(pixmapSize + adjustSize); itemCache->exposed.clear(); @@ -4614,9 +4615,11 @@ void QGraphicsScenePrivate::drawItemHelper(QGraphicsItem *item, QPainter *painte // Redraw any newly exposed areas. if (itemCache->allExposed || !itemCache->exposed.isEmpty()) { // Fit the item's bounding rect into the pixmap's coordinates. - const QPointF scale(pixmapSize.width() / brect.width(), pixmapSize.height() / brect.height()); QTransform itemToPixmap; - itemToPixmap.scale(scale.x(), scale.y()); + if (fixedCacheSize) { + const QPointF scale(pixmapSize.width() / brect.width(), pixmapSize.height() / brect.height()); + itemToPixmap.scale(scale.x(), scale.y()); + } itemToPixmap.translate(-br.x(), -br.y()); // Generate the item's exposedRect and map its list of expose -- cgit v0.12