Added caching of graphics effect source pixmaps to speed up effects.

If an effect is applied repeatedly on the same source, just with
varying parameters, we can save a lot by caching the source pixmaps.

Reviewed-by: Bjørn Erik Nilsen

9 files changed, 102 insertions, 13 deletions

diff --git a/src/gui/effects/qgraphicseffect.cpp b/src/gui/effects/qgraphicseffect.cpp
index 91641b0..96d35b0 100644
--- a/src/gui/effects/qgraphicseffect.cpp
+++ b/src/gui/effects/qgraphicseffect.cpp
@@ -253,7 +253,24 @@ bool QGraphicsEffectSource::isPixmap() const
 */
 QPixmap QGraphicsEffectSource::pixmap(Qt::CoordinateSystem system, QPoint *offset) const
 {
-    return d_func()->pixmap(system, offset);
+    Q_D(const QGraphicsEffectSource);
+
+    QPixmap pm;
+    if (d->m_cachedSystem == system)
+        QPixmapCache::find(d->m_cacheKey, &pm);
+
+    if (pm.isNull()) {
+        pm = d->pixmap(system, &d->m_cachedOffset);
+        d->m_cachedSystem = system;
+
+        d->invalidateCache();
+        d->m_cacheKey = QPixmapCache::insert(pm);
+    }
+
+    if (offset)
+        *offset = d->m_cachedOffset;
+
+    return pm;
 }
 
 /*!
diff --git a/src/gui/effects/qgraphicseffect.h b/src/gui/effects/qgraphicseffect.h
index c5d3ede..c89851e 100644
--- a/src/gui/effects/qgraphicseffect.h
+++ b/src/gui/effects/qgraphicseffect.h
@@ -87,6 +87,7 @@ private:
     friend class QGraphicsEffectPrivate;
     friend class QGraphicsScenePrivate;
     friend class QGraphicsItem;
+    friend class QGraphicsItemPrivate;
     friend class QWidget;
     friend class QWidgetPrivate;
 };
diff --git a/src/gui/effects/qgraphicseffect_p.h b/src/gui/effects/qgraphicseffect_p.h
index ff2fb85..8fb55d8 100644
--- a/src/gui/effects/qgraphicseffect_p.h
+++ b/src/gui/effects/qgraphicseffect_p.h
@@ -55,6 +55,8 @@
 
 #include "qgraphicseffect.h"
 
+#include <QPixmapCache>
+
 #include <private/qobject_p.h>
 #include <private/qpixmapfilter_p.h>
 
@@ -65,7 +67,7 @@ class QGraphicsEffectSourcePrivate : public QObjectPrivate
     Q_DECLARE_PUBLIC(QGraphicsEffectSource)
 public:
     QGraphicsEffectSourcePrivate() : QObjectPrivate() {}
-    virtual ~QGraphicsEffectSourcePrivate() {}
+    virtual ~QGraphicsEffectSourcePrivate() { invalidateCache(); }
     virtual void detach() = 0;
     virtual QRectF boundingRect(Qt::CoordinateSystem system) const = 0;
     virtual QRect deviceRect() const = 0;
@@ -77,9 +79,16 @@ public:
     virtual bool isPixmap() const = 0;
     virtual QPixmap pixmap(Qt::CoordinateSystem system, QPoint *offset = 0) const = 0;
     virtual void effectBoundingRectChanged() = 0;
+    void invalidateCache() const { QPixmapCache::remove(m_cacheKey); }
+
     friend class QGraphicsScenePrivate;
     friend class QGraphicsItem;
     friend class QGraphicsItemPrivate;
+
+private:
+    mutable Qt::CoordinateSystem m_cachedSystem;
+    mutable QPoint m_cachedOffset;
+    mutable QPixmapCache::Key m_cacheKey;
 };
 
 class Q_GUI_EXPORT QGraphicsEffectPrivate : public QObjectPrivate
@@ -94,6 +103,7 @@ public:
         if (source) {
             flags |= QGraphicsEffect::SourceDetached;
             source->d_func()->detach();
+            source->d_func()->invalidateCache();
             delete source;
         }
         source = newSource;
diff --git a/src/gui/graphicsview/qgraphicsitem.cpp b/src/gui/graphicsview/qgraphicsitem.cpp
index 45627f6..5153783 100644
--- a/src/gui/graphicsview/qgraphicsitem.cpp
+++ b/src/gui/graphicsview/qgraphicsitem.cpp
@@ -2482,12 +2482,14 @@ void QGraphicsItem::setOpacity(qreal opacity)
     itemChange(ItemOpacityHasChanged, newOpacityVariant);
 
     // Update.
-    if (d_ptr->scene)
+    if (d_ptr->scene) {
+        d_ptr->invalidateGraphicsEffectsRecursively();
         d_ptr->scene->d_func()->markDirty(this, QRectF(),
                                           /*invalidateChildren=*/true,
                                           /*maybeDirtyClipPath=*/false,
                                           /*force=*/false,
                                           /*ignoreOpacity=*/true);
+    }
 
     if (d_ptr->isObject)
         emit static_cast<QGraphicsObject *>(this)->opacityChanged();
@@ -4949,6 +4951,22 @@ int QGraphicsItemPrivate::depth() const
 /*!
     \internal
 */
+void QGraphicsItemPrivate::invalidateGraphicsEffectsRecursively()
+{
+    QGraphicsItemPrivate *itemPrivate = this;
+    do {
+        if (itemPrivate->graphicsEffect) {
+            itemPrivate->notifyInvalidated = 1;
+
+            if (!itemPrivate->updateDueToGraphicsEffect)
+                static_cast<QGraphicsItemEffectSourcePrivate *>(itemPrivate->graphicsEffect->d_func()->source->d_func())->invalidateCache();
+        }
+    } while ((itemPrivate = itemPrivate->parent ? itemPrivate->parent->d_ptr.data() : 0));
+}
+
+/*!
+    \internal
+*/
 void QGraphicsItemPrivate::invalidateDepthRecursively()
 {
     if (itemDepth == -1)
@@ -5280,11 +5298,7 @@ void QGraphicsItem::update(const QRectF &rect)
         return;
 
     // Make sure we notify effects about invalidated source.
-    QGraphicsItem *item = this;
-    do {
-        if (item->d_ptr->graphicsEffect)
-            item->d_ptr->notifyInvalidated = 1;
-    } while ((item = item->d_ptr->parent));
+    d_ptr->invalidateGraphicsEffectsRecursively();
 
     if (CacheMode(d_ptr->cacheMode) != NoCache) {
         // Invalidate cache.
@@ -10721,6 +10735,7 @@ QPixmap QGraphicsItemEffectSourcePrivate::pixmap(Qt::CoordinateSystem system, QP
     }
 
     pixmapPainter.end();
+
     return pixmap;
 }
 
diff --git a/src/gui/graphicsview/qgraphicsitem_p.h b/src/gui/graphicsview/qgraphicsitem_p.h
index 6550362..8fd1a75 100644
--- a/src/gui/graphicsview/qgraphicsitem_p.h
+++ b/src/gui/graphicsview/qgraphicsitem_p.h
@@ -177,6 +177,7 @@ public:
         wantsActive(0),
         holesInSiblingIndex(0),
         sequentialOrdering(1),
+        updateDueToGraphicsEffect(0),
         globalStackingOrder(-1),
         q_ptr(0)
     {
@@ -221,6 +222,7 @@ public:
     bool discardUpdateRequest(bool ignoreClipping = false, bool ignoreVisibleBit = false,
                               bool ignoreDirtyBit = false, bool ignoreOpacity = false) const;
     int depth() const;
+    void invalidateGraphicsEffectsRecursively();
     void invalidateDepthRecursively();
     void resolveDepth();
     void addChild(QGraphicsItem *child);
@@ -502,6 +504,7 @@ public:
     quint32 wantsActive : 1;
     quint32 holesInSiblingIndex : 1;
     quint32 sequentialOrdering : 1;
+    quint32 updateDueToGraphicsEffect : 1;
 
     // Optional stacking order
     int globalStackingOrder;
@@ -589,8 +592,11 @@ public:
     inline const QWidget *widget() const
     { return 0; }
 
-    inline void update()
-    { item->update(); }
+    inline void update() {
+        item->d_ptr->updateDueToGraphicsEffect = true;
+        item->update();
+        item->d_ptr->updateDueToGraphicsEffect = false;
+    }
 
     inline void effectBoundingRectChanged()
     { item->prepareGeometryChange(); }
@@ -619,6 +625,7 @@ public:
 
     QGraphicsItem *item;
     QGraphicsItemPaintInfo *info;
+    QTransform lastEffectTransform;
 };
 
 
diff --git a/src/gui/graphicsview/qgraphicsscene.cpp b/src/gui/graphicsview/qgraphicsscene.cpp
index a624b10..fc8ce8a 100644
--- a/src/gui/graphicsview/qgraphicsscene.cpp
+++ b/src/gui/graphicsview/qgraphicsscene.cpp
@@ -4569,6 +4569,11 @@ void QGraphicsScenePrivate::drawSubtreeRecursive(QGraphicsItem *item, QPainter *
         else
             painter->setWorldTransform(*transformPtr);
         painter->setOpacity(opacity);
+
+        if (sourced->lastEffectTransform != painter->worldTransform()) {
+            sourced->lastEffectTransform = painter->worldTransform();
+            sourced->invalidateCache();
+        }
         item->d_ptr->graphicsEffect->draw(painter, source);
         painter->setWorldTransform(restoreTransform);
         sourced->info = 0;
diff --git a/src/gui/kernel/qwidget.cpp b/src/gui/kernel/qwidget.cpp
index de08312..088197e 100644
--- a/src/gui/kernel/qwidget.cpp
+++ b/src/gui/kernel/qwidget.cpp
@@ -93,6 +93,7 @@
 # include "qx11info_x11.h"
 #endif
 
+#include <private/qgraphicseffect_p.h>
 #include <private/qwindowsurface_p.h>
 #include <private/qbackingstore_p.h>
 #ifdef Q_WS_MAC
@@ -1806,12 +1807,29 @@ QRegion QWidgetPrivate::clipRegion() const
     return r;
 }
 
+void QWidgetPrivate::invalidateGraphicsEffectsRecursively()
+{
+    Q_Q(QWidget);
+    QWidget *w = q;
+    do {
+        if (w->graphicsEffect()) {
+            QWidgetEffectSourcePrivate *sourced =
+                static_cast<QWidgetEffectSourcePrivate *>(w->graphicsEffect()->source()->d_func());
+            if (!sourced->updateDueToGraphicsEffect)
+                w->graphicsEffect()->source()->d_func()->invalidateCache();
+        }
+        w = w->parentWidget();
+    } while (w);
+}
+
 void QWidgetPrivate::setDirtyOpaqueRegion()
 {
     Q_Q(QWidget);
 
     dirtyOpaqueChildren = true;
 
+    invalidateGraphicsEffectsRecursively();
+
     if (q->isWindow())
         return;
 
@@ -5215,6 +5233,10 @@ void QWidgetPrivate::drawWidget(QPaintDevice *pdev, const QRegion &rgn, const QP
                 paintEngine->d_func()->systemClip = QRegion();
             } else {
                 context.painter = sharedPainter;
+                if (sharedPainter->worldTransform() != sourced->lastEffectTransform) {
+                    sourced->invalidateCache();
+                    sourced->lastEffectTransform = sharedPainter->worldTransform();
+                }
                 sharedPainter->save();
                 sharedPainter->translate(offset);
                 graphicsEffect->draw(sharedPainter, source);
diff --git a/src/gui/kernel/qwidget_p.h b/src/gui/kernel/qwidget_p.h
index f7c2712..a109f32 100644
--- a/src/gui/kernel/qwidget_p.h
+++ b/src/gui/kernel/qwidget_p.h
@@ -360,6 +360,7 @@ public:
     void setOpaque(bool opaque);
     void updateIsTranslucent();
     bool paintOnScreen() const;
+    void invalidateGraphicsEffectsRecursively();
 
     QRegion getOpaqueRegion() const;
     const QRegion &getOpaqueChildren() const;
@@ -729,7 +730,7 @@ class QWidgetEffectSourcePrivate : public QGraphicsEffectSourcePrivate
 {
 public:
     QWidgetEffectSourcePrivate(QWidget *widget)
-        : QGraphicsEffectSourcePrivate(), m_widget(widget), context(0)
+        : QGraphicsEffectSourcePrivate(), m_widget(widget), context(0), updateDueToGraphicsEffect(false)
     {}
 
     inline void detach()
@@ -742,7 +743,11 @@ public:
     { return m_widget; }
 
     inline void update()
-    { m_widget->update(); }
+    {
+        updateDueToGraphicsEffect = true;
+        m_widget->update();
+        updateDueToGraphicsEffect = false;
+    }
 
     inline bool isPixmap() const
     { return false; }
@@ -754,7 +759,7 @@ public:
         if (QWidget *parent = m_widget->parentWidget())
             parent->update();
         else
-            m_widget->update();
+            update();
     }
 
     inline const QStyleOption *styleOption() const
@@ -769,6 +774,8 @@ public:
 
     QWidget *m_widget;
     QWidgetPaintContext *context;
+    QTransform lastEffectTransform;
+    bool updateDueToGraphicsEffect;
 };
 
 inline QWExtra *QWidgetPrivate::extraData() const
diff --git a/src/gui/painting/qbackingstore.cpp b/src/gui/painting/qbackingstore.cpp
index 7c07df8..3cd1402 100644
--- a/src/gui/painting/qbackingstore.cpp
+++ b/src/gui/painting/qbackingstore.cpp
@@ -56,6 +56,7 @@
 #include <private/qwindowsurface_raster_p.h>
 #include <private/qapplication_p.h>
 #include <private/qpaintengine_raster_p.h>
+#include <private/qgraphicseffect_p.h>
 
 #include "qgraphicssystem_p.h"
 
@@ -540,6 +541,8 @@ void QWidgetBackingStore::markDirty(const QRegion &rgn, QWidget *widget, bool up
     Q_ASSERT(widget->window() == tlw);
     Q_ASSERT(!rgn.isEmpty());
 
+    widget->d_func()->invalidateGraphicsEffectsRecursively();
+
     if (widget->d_func()->paintOnScreen()) {
         if (widget->d_func()->dirty.isEmpty()) {
             widget->d_func()->dirty = rgn;
@@ -615,6 +618,8 @@ void QWidgetBackingStore::markDirty(const QRect &rect, QWidget *widget, bool upd
     Q_ASSERT(widget->window() == tlw);
     Q_ASSERT(!rect.isEmpty());
 
+    widget->d_func()->invalidateGraphicsEffectsRecursively();
+
     if (widget->d_func()->paintOnScreen()) {
         if (widget->d_func()->dirty.isEmpty()) {
             widget->d_func()->dirty = QRegion(rect);