Optimise effectiveOpacity and make it inlineable.

This cut's off some cycles in discardUpdateRequest()
which is called from most places when something in
the items changes.

3 files changed, 28 insertions, 18 deletions

diff --git a/src/gui/graphicsview/qgraphicsitem.cpp b/src/gui/graphicsview/qgraphicsitem.cpp
index ca39713..b913d89 100644
--- a/src/gui/graphicsview/qgraphicsitem.cpp
+++ b/src/gui/graphicsview/qgraphicsitem.cpp
@@ -2028,21 +2028,7 @@ qreal QGraphicsItem::opacity() const
 */
 qreal QGraphicsItem::effectiveOpacity() const
 {
-    if (!d_ptr->parent)
-        return d_ptr->opacity;
-
-    int myFlags = d_ptr->flags;
-    int parentFlags = d_ptr->parent ? d_ptr->parent->d_ptr->flags : 0;
-
-    // If I have a parent, and I don't ignore my parent's opacity, and my
-    // parent propagates to me, then combine my local opacity with my parent's
-    // effective opacity into my effective opacity.
-    if (!(myFlags & QGraphicsItem::ItemIgnoresParentOpacity)
-        && !(parentFlags & QGraphicsItem::ItemDoesntPropagateOpacityToChildren)) {
-        return d_ptr->opacity * d_ptr->parent->effectiveOpacity();
-    }
-
-    return d_ptr->opacity;
+    return d_ptr->effectiveOpacity();
 }
 
 /*!
diff --git a/src/gui/graphicsview/qgraphicsitem_p.h b/src/gui/graphicsview/qgraphicsitem_p.h
index 61f6496..d92d76e 100644
--- a/src/gui/graphicsview/qgraphicsitem_p.h
+++ b/src/gui/graphicsview/qgraphicsitem_p.h
@@ -277,7 +277,31 @@ public:
     void updateCachedClipPathFromSetPosHelper(const QPointF &newPos);
 
     inline bool isFullyTransparent() const
-    { return q_func()->effectiveOpacity() < .001; }
+    { return effectiveOpacity() < .001; }
+
+    inline qreal effectiveOpacity() const {
+        if (!parent)
+            return opacity;
+
+        qreal o = opacity;
+        QGraphicsItem *p = parent;
+        int myFlags = flags;
+        while (p) {
+            int parentFlags = p->d_ptr->flags;
+
+            // If I have a parent, and I don't ignore my parent's opacity, and my
+            // parent propagates to me, then combine my local opacity with my parent's
+            // effective opacity into my effective opacity.
+            if ((myFlags & QGraphicsItem::ItemIgnoresParentOpacity)
+                || (parentFlags & QGraphicsItem::ItemDoesntPropagateOpacityToChildren))
+                break;
+
+            o *= parent->d_ptr->opacity;
+            p = p->d_ptr->parent;
+            myFlags = parentFlags;
+        }
+        return o;
+    }
 
     inline bool childrenCombineOpacity() const
     {
diff --git a/src/gui/graphicsview/qgraphicsscene.cpp b/src/gui/graphicsview/qgraphicsscene.cpp
index 73d6a93..25ac279 100644
--- a/src/gui/graphicsview/qgraphicsscene.cpp
+++ b/src/gui/graphicsview/qgraphicsscene.cpp
@@ -419,7 +419,7 @@ QList<QGraphicsItem *> QGraphicsScenePrivate::estimateItemsInRect(const QRectF &
         if (QGraphicsItem *item = unindexedItems.at(i)) {
             if (item->d_ptr->ancestorFlags & QGraphicsItemPrivate::AncestorClipsChildren)
                 continue;
-            if (item->d_ptr->visible && item->effectiveOpacity() > qreal(0.0))
+            if (item->d_ptr->visible && !item->d_ptr->isFullyTransparent())
                 itemsInRect << item;
         }
     }
@@ -427,7 +427,7 @@ QList<QGraphicsItem *> QGraphicsScenePrivate::estimateItemsInRect(const QRectF &
         if (QGraphicsItem *item = indexedItems.at(i)) {
             if (item->d_ptr->ancestorFlags & QGraphicsItemPrivate::AncestorClipsChildren)
                 continue;
-            if (item->d_ptr->visible && item->effectiveOpacity() > qreal(0.0))
+            if (item->d_ptr->visible && item->d_ptr->isFullyTransparent())
                 itemsInRect << item;
         }
     }