Merge commit 'qt-graphics-team/pixmapfilters-redux' into kinetic-graphicseffect

Conflicts:
	src/opengl/gl2paintengineex/qglengineshadermanager.cpp
	src/opengl/gl2paintengineex/qglengineshadermanager_p.h
	src/opengl/gl2paintengineex/qpaintengineex_opengl2.cpp
	src/opengl/gl2paintengineex/qpaintengineex_opengl2_p.h

Merge custom shader / GL blur pixmap filter implementation from graphics
team repo with implementation from kinetic graphics-team repo.

13 files changed, 698 insertions, 337 deletions

diff --git a/src/gui/graphicsview/qgraphicseffect.cpp b/src/gui/graphicsview/qgraphicseffect.cpp
index 8d2c416..31a437a 100644
--- a/src/gui/graphicsview/qgraphicseffect.cpp
+++ b/src/gui/graphicsview/qgraphicseffect.cpp
@@ -373,13 +373,13 @@ static QImage blurred(const QImage& image, const QRect& rect, int radius)
 int QGraphicsBlurEffect::blurRadius() const
 {
     Q_D(const QGraphicsBlurEffect);
-    return int(d->filter->blurRadius());
+    return int(d->filter->radius());
 }
 
 void QGraphicsBlurEffect::setBlurRadius(int radius)
 {
     Q_D(QGraphicsBlurEffect);
-    d->filter->setBlurRadius(radius);
+    d->filter->setRadius(radius);
 }
 
 QRectF QGraphicsBlurEffect::boundingRect() const
diff --git a/src/gui/image/qpixmapfilter.cpp b/src/gui/image/qpixmapfilter.cpp
index 2b275a3..b7b3733 100644
--- a/src/gui/image/qpixmapfilter.cpp
+++ b/src/gui/image/qpixmapfilter.cpp
@@ -478,6 +478,225 @@ void QPixmapConvolutionFilter::draw(QPainter *painter, const QPointF &p, const Q
     }
 }
 
+/*!
+    \class QPixmapBlurFilter
+    \since 4.6
+    \ingroup multimedia
+
+    \brief The QPixmapBlurFilter class provides blur filtering
+    for pixmaps.
+
+    QPixmapBlurFilter implements a blur pixmap filter,
+    which is applied when \l{QPixmapFilter::}{draw()} is called.
+
+    The filter lets you specialize the radius of the blur as well
+    as the quality.
+
+    By default, the blur effect is produced by applying an exponential
+    filter generated from the specified blurRadius().  Paint engines
+    may override this with a custom blur that is faster on the
+    underlying hardware.
+
+    \sa {Pixmap Filters Example}, QPixmapConvolutionFilter, QPixmapDropShadowFilter
+
+    \internal
+*/
+
+class QPixmapBlurFilterPrivate : public QPixmapFilterPrivate
+{
+public:
+    QPixmapBlurFilterPrivate() : radius(5), quality(Qt::FastTransformation) {}
+
+    int radius;
+    Qt::TransformationMode quality;
+};
+
+
+/*!
+    Constructs a pixmap blur filter.
+
+    \internal
+*/
+QPixmapBlurFilter::QPixmapBlurFilter(QObject *parent)
+    : QPixmapFilter(*new QPixmapBlurFilterPrivate, BlurFilter, parent)
+{
+}
+
+/*!
+    Destructor of pixmap blur filter.
+
+    \internal
+*/
+QPixmapBlurFilter::~QPixmapBlurFilter()
+{
+}
+
+/*!
+    Sets the radius of the blur filter. Higher radius produces increased blurriness.
+
+    \internal
+*/
+void QPixmapBlurFilter::setRadius(int radius)
+{
+    Q_D(QPixmapBlurFilter);
+    d->radius = radius;
+}
+
+/*!
+    Gets the radius of the blur filter.
+
+    \internal
+*/
+int QPixmapBlurFilter::radius() const
+{
+    Q_D(const QPixmapBlurFilter);
+    return d->radius;
+}
+
+/*!
+    Setting the quality to FastTransformation causes the implementation
+    to trade off visual quality to blur the image faster.  Setting the
+    quality to SmoothTransformation causes the implementation to improve
+    visual quality at the expense of speed.  The implementation is free
+    to ignore this value if it only has a single blur algorithm.
+
+    \internal
+*/
+void QPixmapBlurFilter::setQuality(Qt::TransformationMode quality)
+{
+    Q_D(QPixmapBlurFilter);
+    d->quality = quality;
+}
+
+/*!
+    Gets the quality of the blur filter.
+
+    \internal
+*/
+Qt::TransformationMode QPixmapBlurFilter::quality() const
+{
+    Q_D(const QPixmapBlurFilter);
+    return d->quality;
+}
+
+/*!
+    \reimp
+
+    \internal
+*/
+QRectF QPixmapBlurFilter::boundingRectFor(const QRectF &rect) const
+{
+    return rect;
+}
+
+// Blur the image according to the blur radius
+// Based on exponential blur algorithm by Jani Huhtanen
+// (maximum radius is set to 16)
+static QImage blurred(const QImage& image, const QRect& rect, int radius)
+{
+    int tab[] = { 14, 10, 8, 6, 5, 5, 4, 3, 3, 3, 3, 2, 2, 2, 2, 2, 2 };
+    int alpha = (radius < 1)  ? 16 : (radius > 17) ? 1 : tab[radius-1];
+
+    QImage result = image.convertToFormat(QImage::Format_ARGB32_Premultiplied);
+    int r1 = rect.top();
+    int r2 = rect.bottom();
+    int c1 = rect.left();
+    int c2 = rect.right();
+
+    int bpl = result.bytesPerLine();
+    int rgba[4];
+    unsigned char* p;
+
+    for (int col = c1; col <= c2; col++) {
+        p = result.scanLine(r1) + col * 4;
+        for (int i = 0; i < 4; i++)
+            rgba[i] = p[i] << 4;
+
+        p += bpl;
+        for (int j = r1; j < r2; j++, p += bpl)
+            for (int i = 0; i < 4; i++)
+                p[i] = (rgba[i] += ((p[i] << 4) - rgba[i]) * alpha / 16) >> 4;
+    }
+
+    for (int row = r1; row <= r2; row++) {
+        p = result.scanLine(row) + c1 * 4;
+        for (int i = 0; i < 4; i++)
+            rgba[i] = p[i] << 4;
+
+        p += 4;
+        for (int j = c1; j < c2; j++, p += 4)
+            for (int i = 0; i < 4; i++)
+                p[i] = (rgba[i] += ((p[i] << 4) - rgba[i]) * alpha / 16) >> 4;
+    }
+
+    for (int col = c1; col <= c2; col++) {
+        p = result.scanLine(r2) + col * 4;
+        for (int i = 0; i < 4; i++)
+            rgba[i] = p[i] << 4;
+
+        p -= bpl;
+        for (int j = r1; j < r2; j++, p -= bpl)
+            for (int i = 0; i < 4; i++)
+                p[i] = (rgba[i] += ((p[i] << 4) - rgba[i]) * alpha / 16) >> 4;
+    }
+
+    for (int row = r1; row <= r2; row++) {
+        p = result.scanLine(row) + c2 * 4;
+        for (int i = 0; i < 4; i++)
+            rgba[i] = p[i] << 4;
+
+        p -= 4;
+        for (int j = c1; j < c2; j++, p -= 4)
+            for (int i = 0; i < 4; i++)
+                p[i] = (rgba[i] += ((p[i] << 4) - rgba[i]) * alpha / 16) >> 4;
+    }
+
+    return result;
+}
+
+/*!
+    \reimp
+
+    \internal
+*/
+void QPixmapBlurFilter::draw(QPainter *painter, const QPointF &p, const QPixmap &src, const QRectF &srcRect) const
+{
+    Q_D(const QPixmapBlurFilter);
+    if (!painter->isActive())
+        return;
+
+    if (d->radius == 0) {
+        painter->drawPixmap(srcRect.translated(p), src, srcRect);
+        return;
+    }
+
+    QPixmapFilter *filter = painter->paintEngine() && painter->paintEngine()->isExtended() ?
+        static_cast<QPaintEngineEx *>(painter->paintEngine())->createPixmapFilter(type()) : 0;
+    QPixmapBlurFilter *blurFilter = static_cast<QPixmapBlurFilter*>(filter);
+    if (blurFilter) {
+        blurFilter->setRadius(d->radius);
+        blurFilter->setQuality(d->quality);
+        blurFilter->draw(painter, p, src, srcRect);
+        delete blurFilter;
+        return;
+    }
+
+    QImage srcImage;
+    QImage destImage;
+
+    if (srcRect.isNull()) {
+        srcImage = src.toImage();
+        destImage = blurred(srcImage, srcImage.rect(), d->radius);
+    } else {
+        QRect rect = srcRect.toAlignedRect().intersected(src.rect());
+
+        srcImage = src.copy(rect).toImage();
+        destImage = blurred(srcImage, srcImage.rect(), d->radius);
+    }
+
+    painter->drawImage(p, destImage);
+}
+
 // grayscales the image to dest (could be same). If rect isn't defined
 // destination image size is used to determine the dimension of grayscaling
 // process.
@@ -841,235 +1060,4 @@ void QPixmapDropShadowFilter::draw(QPainter *p,
     p->drawPixmap(pos, px, src);
 }
 
-/*!
-    \class QPixmapBlurFilter
-    \since 4.6
-    \ingroup multimedia
-
-    \brief The QPixmapBlurFilter class is a convenience class
-    for drawing pixmaps with blur effects.
-
-    By default, the blur effect is produced by applying an exponential
-    filter generated from the specified blurRadius().  Paint engines
-    may override this with a custom blur that is faster on the
-    underlying hardware.
-
-    \sa QPixmapConvolutionFilter
-
-    \internal
- */
-
-class QPixmapBlurFilterPrivate : public QPixmapFilterPrivate
-{
-public:
-    QPixmapBlurFilterPrivate()
-        : quality(QPixmapBlurFilter::High), radius(1) {}
-
-    QPixmapBlurFilter::BlurQuality quality;
-    qreal radius;
-};
-
-/*!
-    Constructs blur filter and attaches it to \a parent.
-
-    \internal
-*/
-QPixmapBlurFilter::QPixmapBlurFilter(QObject *parent)
-    : QPixmapFilter(*new QPixmapBlurFilterPrivate, BlurFilter, parent)
-{
-    Q_D(QPixmapBlurFilter);
-    setBlurRadius(4);
-}
-
-/*!
-    Destroys blur filter.
-
-    \internal
-*/
-QPixmapBlurFilter::~QPixmapBlurFilter()
-{
-}
-
-/*!
-    \enum QPixmapFilter::BlurQuality
-    \since 4.6
-    \ingroup multimedia
-    This enum describes the quality of blur to apply to pixmaps.
-
-    \value Fast Blur faster, potentially losing some quality.
-    \value High Produce the best high-quality blur possible, even if slower.
-
-    \internal
-*/
-
-/*!
-    Returns the quality of the blur.  The default value is High.
-
-    \sa blurRadius()
-    \internal
-*/
-QPixmapBlurFilter::BlurQuality QPixmapBlurFilter::blurQuality() const
-{
-    Q_D(const QPixmapBlurFilter);
-    return d->quality;
-}
-
-/*!
-    Sets the quality of the blur to the \a blurQuality specified.
-
-    Setting the quality to Faster causes the implementation to trade
-    off visual quality to blur the image faster.  Setting the quality
-    to High causes the implementation to improve visual quality
-    at the expense of speed.  The implementation is free to ignore
-    this value if it only has a single blur algorithm.
-
-    \sa setBlurRadius()
-    \internal
-*/
-void QPixmapBlurFilter::setBlurQuality(BlurQuality blurQuality)
-{
-    Q_D(QPixmapBlurFilter);
-    d->quality = blurQuality;
-}
-
-/*!
-    Returns the radius in pixels of the blur.  The default value is 4.
-
-    A smaller radius results in a sharper image.
-
-    \sa blurQuality()
-    \internal
-*/
-qreal QPixmapBlurFilter::blurRadius() const
-{
-    Q_D(const QPixmapBlurFilter);
-    return d->radius;
-}
-
-/*!
-    Sets the radius in pixels of the blur to the \a radius specified.
-
-    Using a smaller radius results in a sharper image.
-
-    \sa setBlurQuality()
-    \internal
-*/
-void QPixmapBlurFilter::setBlurRadius(qreal blurRadius)
-{
-    Q_D(QPixmapBlurFilter);
-    d->radius = blurRadius;
-}
-
-/*!
-    \internal
- */
-QRectF QPixmapBlurFilter::boundingRectFor(const QRectF &rect) const
-{
-    Q_D(const QPixmapBlurFilter);
-    qreal delta = d->radius * 3;
-    QRectF blurRect(rect);
-    blurRect.adjust(-delta, -delta, delta, delta);
-    return blurRect;
-}
-
-// Blur the image according to the blur radius
-// Based on exponential blur algorithm by Jani Huhtanen
-// (maximum radius is set to 16)
-static QImage blurred(const QImage& image, const QRect& rect, int radius)
-{
-    int tab[] = { 14, 10, 8, 6, 5, 5, 4, 3, 3, 3, 3, 2, 2, 2, 2, 2, 2 };
-    int alpha = (radius < 1)  ? 16 : (radius > 17) ? 1 : tab[radius-1];
-
-    QImage result = image.convertToFormat(QImage::Format_ARGB32_Premultiplied);
-    int r1 = rect.top();
-    int r2 = rect.bottom();
-    int c1 = rect.left();
-    int c2 = rect.right();
-
-    int bpl = result.bytesPerLine();
-    int rgba[4];
-    unsigned char* p;
-
-    for (int col = c1; col <= c2; col++) {
-        p = result.scanLine(r1) + col * 4;
-        for (int i = 0; i < 4; i++)
-            rgba[i] = p[i] << 4;
-
-        p += bpl;
-        for (int j = r1; j < r2; j++, p += bpl)
-            for (int i = 0; i < 4; i++)
-                p[i] = (rgba[i] += ((p[i] << 4) - rgba[i]) * alpha / 16) >> 4;
-    }
-
-    for (int row = r1; row <= r2; row++) {
-        p = result.scanLine(row) + c1 * 4;
-        for (int i = 0; i < 4; i++)
-            rgba[i] = p[i] << 4;
-
-        p += 4;
-        for (int j = c1; j < c2; j++, p += 4)
-            for (int i = 0; i < 4; i++)
-                p[i] = (rgba[i] += ((p[i] << 4) - rgba[i]) * alpha / 16) >> 4;
-    }
-
-    for (int col = c1; col <= c2; col++) {
-        p = result.scanLine(r2) + col * 4;
-        for (int i = 0; i < 4; i++)
-            rgba[i] = p[i] << 4;
-
-        p -= bpl;
-        for (int j = r1; j < r2; j++, p -= bpl)
-            for (int i = 0; i < 4; i++)
-                p[i] = (rgba[i] += ((p[i] << 4) - rgba[i]) * alpha / 16) >> 4;
-    }
-
-    for (int row = r1; row <= r2; row++) {
-        p = result.scanLine(row) + c2 * 4;
-        for (int i = 0; i < 4; i++)
-            rgba[i] = p[i] << 4;
-
-        p -= 4;
-        for (int j = c1; j < c2; j++, p -= 4)
-            for (int i = 0; i < 4; i++)
-                p[i] = (rgba[i] += ((p[i] << 4) - rgba[i]) * alpha / 16) >> 4;
-    }
-
-    return result;
-}
-
-/*!
-    \internal
- */
-void QPixmapBlurFilter::draw(QPainter *painter, const QPointF &dest, const QPixmap &src, const QRectF &srcRect) const
-{
-    Q_D(const QPixmapBlurFilter);
-
-    QPixmapFilter *filter = painter->paintEngine() && painter->paintEngine()->isExtended() ?
-        static_cast<QPaintEngineEx *>(painter->paintEngine())->createPixmapFilter(type()) : 0;
-    QPixmapBlurFilter *blurFilter = static_cast<QPixmapBlurFilter*>(filter);
-    if (blurFilter) {
-        blurFilter->setBlurQuality(d->quality);
-        blurFilter->setBlurRadius(d->radius);
-        blurFilter->draw(painter, dest, src, srcRect);
-        delete blurFilter;
-        return;
-    }
-
-    QImage srcImage;
-    QImage destImage;
-
-    if (srcRect.isNull()) {
-        srcImage = src.toImage();
-        destImage = blurred(srcImage, srcImage.rect(), int(d->radius + 0.5));
-    } else {
-        QRect rect = srcRect.toAlignedRect().intersected(src.rect());
-
-        srcImage = src.copy(rect).toImage();
-        destImage = blurred(srcImage, srcImage.rect(), int(d->radius + 0.5));
-    }
-
-    qreal delta = d->radius * 3;
-    painter->drawImage(dest - QPointF(delta, delta), destImage);
-}
-
 QT_END_NAMESPACE
diff --git a/src/gui/image/qpixmapfilter_p.h b/src/gui/image/qpixmapfilter_p.h
index ca27cbf..ac393a1 100644
--- a/src/gui/image/qpixmapfilter_p.h
+++ b/src/gui/image/qpixmapfilter_p.h
@@ -118,6 +118,30 @@ private:
     int columns() const;
 };
 
+class QPixmapBlurFilterPrivate;
+
+class Q_GUI_EXPORT QPixmapBlurFilter : public QPixmapFilter
+{
+    Q_OBJECT
+    Q_DECLARE_PRIVATE(QPixmapBlurFilter)
+
+public:
+    QPixmapBlurFilter(QObject *parent = 0);
+    ~QPixmapBlurFilter();
+
+    void setRadius(int radius);
+    void setQuality(Qt::TransformationMode mode);
+
+    int radius() const;
+    Qt::TransformationMode quality() const;
+
+    QRectF boundingRectFor(const QRectF &rect) const;
+    void draw(QPainter *painter, const QPointF &dest, const QPixmap &src, const QRectF &srcRect = QRectF()) const;
+
+private:
+    friend class QGLPixmapBlurFilter;
+};
+
 class QPixmapColorizeFilterPrivate;
 
 class Q_GUI_EXPORT QPixmapColorizeFilter : public QPixmapFilter
@@ -159,33 +183,6 @@ public:
     inline void setOffset(qreal dx, qreal dy) { setOffset(QPointF(dx, dy)); }
 };
 
-class QPixmapBlurFilterPrivate;
-
-class Q_GUI_EXPORT QPixmapBlurFilter : public QPixmapFilter
-{
-    Q_OBJECT
-    Q_DECLARE_PRIVATE(QPixmapBlurFilter)
-
-public:
-    QPixmapBlurFilter(QObject *parent = 0);
-    ~QPixmapBlurFilter();
-
-    enum BlurQuality
-    {
-        Fast,
-        High
-    };
-
-    BlurQuality blurQuality() const;
-    void setBlurQuality(BlurQuality blurQuality);
-
-    qreal blurRadius() const;
-    void setBlurRadius(qreal blurRadius);
-
-    QRectF boundingRectFor(const QRectF &rect) const;
-    void draw(QPainter *painter, const QPointF &dest, const QPixmap &src, const QRectF &srcRect = QRectF()) const;
-};
-
 QT_END_NAMESPACE
 
 QT_END_HEADER
diff --git a/src/opengl/gl2paintengineex/qglcustomshaderstage.cpp b/src/opengl/gl2paintengineex/qglcustomshaderstage.cpp
index bcd9f27..a82caa0 100644
--- a/src/opengl/gl2paintengineex/qglcustomshaderstage.cpp
+++ b/src/opengl/gl2paintengineex/qglcustomshaderstage.cpp
@@ -110,9 +110,9 @@ void QGLCustomShaderStage::removeFromPainter(QPainter* p)
     d->m_manager->setCustomStage(0);
 }
 
-const char* QGLCustomShaderStage::source()
+const char* QGLCustomShaderStage::source() const
 {
-    Q_D(QGLCustomShaderStage);
+    Q_D(const QGLCustomShaderStage);
     return d->m_source.constData();
 }
 
diff --git a/src/opengl/gl2paintengineex/qglcustomshaderstage_p.h b/src/opengl/gl2paintengineex/qglcustomshaderstage_p.h
index 659f7ba..70e9ff0 100644
--- a/src/opengl/gl2paintengineex/qglcustomshaderstage_p.h
+++ b/src/opengl/gl2paintengineex/qglcustomshaderstage_p.h
@@ -71,9 +71,10 @@ public:
     virtual void setUniforms(QGLShaderProgram*) = 0;
 
     void setUniformsDirty();
+
     bool setOnPainter(QPainter*);
     void removeFromPainter(QPainter*);
-    const char* source();
+    const char* source() const;
 
 protected:
     void setSource(const QByteArray&);
diff --git a/src/opengl/gl2paintengineex/qglengineshadermanager.cpp b/src/opengl/gl2paintengineex/qglengineshadermanager.cpp
index 848a7f1..dab1257 100644
--- a/src/opengl/gl2paintengineex/qglengineshadermanager.cpp
+++ b/src/opengl/gl2paintengineex/qglengineshadermanager.cpp
@@ -87,7 +87,6 @@ QGLEngineShaderManager::QGLEngineShaderManager(QGLContext* context)
       useTextureCoords(false),
       compositionMode(QPainter::CompositionMode_SourceOver),
       customSrcStage(0),
-      customSrcStagePrev(0),
       blitShaderProg(0),
       simpleShaderProg(0),
       currentShaderProg(0)
@@ -162,7 +161,7 @@ QGLEngineShaderManager::QGLEngineShaderManager(QGLContext* context)
 #if defined(QT_DEBUG)
         // Check that all the elements have been filled:
         for (int i = 0; i < TotalShaderCount; ++i) {
-            if (qglEngineShaderSourceCode[i] == 0) {
+            if (i != CustomImageSrcFragmentShader && qglEngineShaderSourceCode[i] == 0) {
                 int enumIndex = staticMetaObject.indexOfEnumerator("ShaderName");
                 QMetaEnum m = staticMetaObject.enumerator(enumIndex);
 
@@ -314,10 +313,9 @@ void QGLEngineShaderManager::setCompositionMode(QPainter::CompositionMode mode)
 void QGLEngineShaderManager::setCustomStage(QGLCustomShaderStage* stage)
 {
     // If the custom shader has changed, then destroy the previous compilation.
-    if (customSrcStagePrev && stage && customSrcStagePrev != stage)
-        removeCustomStage(customSrcStagePrev);
+    if (customSrcStage && stage && customSrcStage != stage)
+        removeCustomStage(customSrcStage);
 
-    customSrcStagePrev = customSrcStage;
     customSrcStage = stage;
     shaderProgNeedsChanging = true;
 }
@@ -326,7 +324,7 @@ void QGLEngineShaderManager::removeCustomStage(QGLCustomShaderStage* stage)
 {
     Q_UNUSED(stage); // Currently we only support one at a time...
 
-    QGLShader* compiledShader = compiledShaders[CustomImageSrcFragmentShader];
+    QGLShader *compiledShader = compiledShaders[CustomImageSrcFragmentShader];
 
     if (!compiledShader)
         return;
@@ -341,10 +339,8 @@ void QGLEngineShaderManager::removeCustomStage(QGLCustomShaderStage* stage)
         }
     }
 
-    delete compiledShader;
     compiledShaders[CustomImageSrcFragmentShader] = 0;
     customSrcStage = 0;
-    customSrcStagePrev = 0;
     shaderProgNeedsChanging = true;
 }
 
@@ -456,7 +452,6 @@ bool QGLEngineShaderManager::useCorrectShaderProg()
     requiredProgram.positionVertexShader = compiledShaders[positionVertexShaderName];
     requiredProgram.srcPixelFragShader = compiledShaders[srcPixelFragShaderName];
 
-
     const bool hasCompose = compositionMode > QPainter::CompositionMode_Plus;
     const bool hasMask = maskType != QGLEngineShaderManager::NoMask;
 
@@ -545,7 +540,6 @@ bool QGLEngineShaderManager::useCorrectShaderProg()
     else
         requiredProgram.compositionFragShader = 0;
 
-
     // At this point, requiredProgram is fully populated so try to find the program in the cache
     bool foundProgramInCache = false;
     for (int i = 0; i < cachedPrograms.size(); ++i) {
@@ -612,15 +606,24 @@ void QGLEngineShaderManager::compileNamedShader(QGLEngineShaderManager::ShaderNa
     if (compiledShaders[name])
         return;
 
-    QGLShader *newShader = new QGLShader(type, ctx, this);
+    QGLShader *newShader;
 
-    const char* sourceCode;
-    if (name == CustomImageSrcFragmentShader)
-        sourceCode = customSrcStage->source();
-    else
-        sourceCode = qglEngineShaderSourceCode[name];
+    QByteArray source;
+    if (name == CustomImageSrcFragmentShader) {
+        source = customSrcStage->source();
+        source += qglslCustomSrcFragmentShader;
 
-    newShader->compile(sourceCode);
+        newShader = customShaderCache.object(source);
+        if (!newShader) {
+            newShader = new QGLShader(type, ctx, this);
+            newShader->compile(source);
+            customShaderCache.insert(source, newShader);
+        }
+    } else {
+        source = qglEngineShaderSourceCode[name];
+        newShader = new QGLShader(type, ctx, this);
+        newShader->compile(source);
+    }
 
 #if defined(QT_DEBUG)
     // Name the shader for easier debugging
diff --git a/src/opengl/gl2paintengineex/qglengineshadermanager_p.h b/src/opengl/gl2paintengineex/qglengineshadermanager_p.h
index 9d881cc..69574ba 100644
--- a/src/opengl/gl2paintengineex/qglengineshadermanager_p.h
+++ b/src/opengl/gl2paintengineex/qglengineshadermanager_p.h
@@ -199,23 +199,23 @@
         O = Global Opacity
 
 
-    CUSTOM SHADER CODE (idea, depricated)
+    CUSTOM SHADER CODE
     ==================
 
     The use of custom shader code is supported by the engine for drawImage and
     drawPixmap calls. This is implemented via hooks in the fragment pipeline.
+
     The custom shader is passed to the engine as a partial fragment shader
     (QGLCustomShaderStage). The shader will implement a pre-defined method name
     which Qt's fragment pipeline will call:
 
-        lowp vec4 customShader()
-
-    Depending on the custom type, the custom shader has a small API it can use
-    to read pixels. The basic custom type is for image/pixmap drawing and thus
-    can use the following to sample the src texture (non-premultiplied)
+        lowp vec4 customShader(sampler2d src, vec2 srcCoords)
 
-        lowp vec4 QSampleSrcPixel(mediump vec2 coords)
+    The provided src and srcCoords parameters can be used to sample from the
+    source image.
 
+    Transformations, clipping, opacity, and composition modes set using QPainter
+    will be respected when using the custom shader hook.
 */
 
 #ifndef QGLENGINE_SHADER_MANAGER_H
@@ -233,7 +233,6 @@ QT_BEGIN_NAMESPACE
 
 QT_MODULE(OpenGL)
 
-
 struct QGLEngineShaderProg
 {
     QGLShader*          mainVertexShader;
@@ -276,7 +275,7 @@ struct QGLEngineCachedShaderProg
 static const GLuint QT_VERTEX_COORDS_ATTR  = 0;
 static const GLuint QT_TEXTURE_COORDS_ATTR = 1;
 
-class QGLEngineShaderManager : public QObject
+class Q_OPENGL_EXPORT QGLEngineShaderManager : public QObject
 {
     Q_OBJECT
 public:
@@ -362,6 +361,7 @@ public:
         MainFragmentShader,
 
         ImageSrcFragmentShader,
+        CustomSrcFragmentShader,
         ImageSrcWithPatternFragmentShader,
         NonPremultipliedImageSrcFragmentShader,
         CustomImageSrcFragmentShader,
@@ -408,7 +408,6 @@ public:
     Q_ENUMS(ShaderName)
 #endif
 
-
 private:
     QGLContext*     ctx;
     bool            shaderProgNeedsChanging;
@@ -421,12 +420,13 @@ private:
     bool                        useTextureCoords;
     QPainter::CompositionMode   compositionMode;
     QGLCustomShaderStage*       customSrcStage;
-    QGLCustomShaderStage*       customSrcStagePrev;
 
     QGLShaderProgram*     blitShaderProg;
     QGLShaderProgram*     simpleShaderProg;
     QGLEngineShaderProg*  currentShaderProg;
 
+    QCache<QByteArray, QGLShader> customShaderCache;
+
     // TODO: Possibly convert to a LUT
     QList<QGLEngineShaderProg> cachedPrograms;
 
diff --git a/src/opengl/gl2paintengineex/qglengineshadersource_p.h b/src/opengl/gl2paintengineex/qglengineshadersource_p.h
index 4e32f91..e379aa3 100644
--- a/src/opengl/gl2paintengineex/qglengineshadersource_p.h
+++ b/src/opengl/gl2paintengineex/qglengineshadersource_p.h
@@ -290,6 +290,14 @@ static const char* const qglslImageSrcFragmentShader = "\
         return texture2D(imageTexture, textureCoords); \
     }";
 
+static const char* const qglslCustomSrcFragmentShader = "\
+    varying highp vec2      textureCoords; \
+    uniform       sampler2D imageTexture; \
+    lowp vec4 customShader(sampler2D texture, vec2 coords); \
+    lowp vec4 srcPixel() { \
+        return customShader(imageTexture, textureCoords); \
+    }";
+
 static const char* const qglslImageSrcWithPatternFragmentShader = "\
     varying highp vec2      textureCoords; \
     uniform lowp  vec4      patternColor; \
diff --git a/src/opengl/gl2paintengineex/qpaintengineex_opengl2.cpp b/src/opengl/gl2paintengineex/qpaintengineex_opengl2.cpp
index b04c7e6..db306a5 100644
--- a/src/opengl/gl2paintengineex/qpaintengineex_opengl2.cpp
+++ b/src/opengl/gl2paintengineex/qpaintengineex_opengl2.cpp
@@ -1092,6 +1092,21 @@ void QGL2PaintEngineEx::drawImage(const QRectF& dest, const QImage& image, const
     d->drawTexture(dest, src, image.size(), !image.hasAlphaChannel());
 }
 
+void QGL2PaintEngineEx::drawTexture(const QRectF &dest, GLuint textureId, const QSize &size, const QRectF &src)
+{
+    Q_D(QGL2PaintEngineEx);
+    ensureActive();
+    d->transferMode(ImageDrawingMode);
+
+    QGLContext *ctx = d->ctx;
+    glActiveTexture(GL_TEXTURE0 + QT_IMAGE_TEXTURE_UNIT);
+    glBindTexture(GL_TEXTURE_2D, textureId);
+
+    d->updateTextureFilter(GL_TEXTURE_2D, GL_REPEAT,
+                           state()->renderHints & QPainter::SmoothPixmapTransform, textureId);
+    d->drawTexture(dest, src, size, false);
+}
+
 void QGL2PaintEngineEx::drawTextItem(const QPointF &p, const QTextItem &textItem)
 {
     Q_D(QGL2PaintEngineEx);
@@ -1636,6 +1651,14 @@ QOpenGL2PaintEngineState::~QOpenGL2PaintEngineState()
 {
 }
 
+QPixmapFilter *QGL2PaintEngineEx::createPixmapFilter(int type) const
+{
+    const QGLContext *ctx = QGLContext::currentContext();
+    if (ctx)
+        return ctx->d_func()->createPixmapFilter(type);
+    return 0;
+}
+
 QT_END_NAMESPACE
 
 #include "qpaintengineex_opengl2.moc"
diff --git a/src/opengl/gl2paintengineex/qpaintengineex_opengl2_p.h b/src/opengl/gl2paintengineex/qpaintengineex_opengl2_p.h
index 21c296d..3ff2dca 100644
--- a/src/opengl/gl2paintengineex/qpaintengineex_opengl2_p.h
+++ b/src/opengl/gl2paintengineex/qpaintengineex_opengl2_p.h
@@ -88,8 +88,7 @@ public:
     bool canRestoreClip;
 };
 
-
-class QGL2PaintEngineEx : public QPaintEngineEx
+class Q_OPENGL_EXPORT QGL2PaintEngineEx : public QPaintEngineEx
 {
     Q_DECLARE_PRIVATE(QGL2PaintEngineEx)
 public:
@@ -116,9 +115,10 @@ public:
 
 
     virtual void drawPixmap(const QRectF &r, const QPixmap &pm, const QRectF &sr);
-
     virtual void drawImage(const QRectF &r, const QImage &pm, const QRectF &sr,
                            Qt::ImageConversionFlags flags = Qt::AutoColor);
+    virtual void drawTexture(const QRectF &r, GLuint textureId, const QSize &size, const QRectF &sr);
+
     virtual void drawTextItem(const QPointF &p, const QTextItem &textItem);
 
     Type type() const { return OpenGL2; }
@@ -134,6 +134,9 @@ public:
     virtual void sync();
 
     const QGLContext* context();
+
+    QPixmapFilter *createPixmapFilter(int type) const;
+
 private:
     Q_DISABLE_COPY(QGL2PaintEngineEx)
 };
diff --git a/src/opengl/qglpixmapfilter.cpp b/src/opengl/qglpixmapfilter.cpp
index 5a06763..1e72fd8 100644
--- a/src/opengl/qglpixmapfilter.cpp
+++ b/src/opengl/qglpixmapfilter.cpp
@@ -40,20 +40,24 @@
 ****************************************************************************/
 
 #include "private/qpixmapfilter_p.h"
+#include "private/qpixmapdata_gl_p.h"
+#include "private/qpaintengineex_opengl2_p.h"
+#include "private/qglengineshadermanager_p.h"
 #include "qglpixmapfilter_p.h"
 #include "qgraphicssystem_gl_p.h"
 #include "qpaintengine_opengl_p.h"
+#include "qcache.h"
 
-#include "qglpixelbuffer.h"
+#include "qglframebufferobject.h"
 #include "qglshaderprogram.h"
 #include "qgl_p.h"
 
 #include "private/qapplication_p.h"
+#include "private/qmath_p.h"
 
 
 QT_BEGIN_NAMESPACE
 
-
 void QGLPixmapFilterBase::bindTexture(const QPixmap &src) const
 {
     const_cast<QGLContext *>(QGLContext::currentContext())->d_func()->bindTexture(src, GL_TEXTURE_2D, GL_RGBA, true, false);
@@ -97,6 +101,27 @@ private:
     mutable int m_kernelHeight;
 };
 
+class QGLPixmapBlurFilter : public QGLCustomShaderStage, public QGLPixmapFilter<QPixmapBlurFilter>
+{
+public:
+    QGLPixmapBlurFilter();
+    ~QGLPixmapBlurFilter();
+
+    void setUniforms(QGLShaderProgram *program);
+
+protected:
+    bool processGL(QPainter *painter, const QPointF &pos, const QPixmap &src, const QRectF &srcRect) const;
+
+private:
+    static QByteArray generateBlurShader(int radius, bool gaussianBlur);
+
+    mutable QGLShader *m_shader;
+
+    mutable QSize m_textureSize;
+
+    QGLShaderProgram *m_program;
+};
+
 extern QGLWidget *qt_gl_share_widget();
 
 QPixmapFilter *QGLContextPrivate::createPixmapFilter(int type) const
@@ -105,6 +130,8 @@ QPixmapFilter *QGLContextPrivate::createPixmapFilter(int type) const
     case QPixmapFilter::ColorizeFilter:
         return new QGLPixmapColorizeFilter;
 
+    case QPixmapFilter::BlurFilter:
+        return new QGLPixmapBlurFilter;
 
     case QPixmapFilter::ConvolutionFilter:
         return new QGLPixmapConvolutionFilter;
@@ -281,4 +308,250 @@ bool QGLPixmapConvolutionFilter::processGL(QPainter *, const QPointF &pos, const
     return true;
 }
 
+QGLPixmapBlurFilter::QGLPixmapBlurFilter()
+{
+}
+
+QGLPixmapBlurFilter::~QGLPixmapBlurFilter()
+{
+}
+
+bool QGLPixmapBlurFilter::processGL(QPainter *painter, const QPointF &pos, const QPixmap &src, const QRectF &) const
+{
+    QGLPixmapBlurFilter *filter = const_cast<QGLPixmapBlurFilter *>(this);
+    filter->setSource(generateBlurShader(radius(), quality() == Qt::SmoothTransformation));
+
+    QGLFramebufferObjectFormat format;
+    format.setInternalFormat(src.hasAlphaChannel() ? GL_RGBA : GL_RGB);
+    QGLFramebufferObject *fbo = qgl_fbo_pool()->acquire(src.size(), format);
+
+    if (!fbo)
+        return false;
+
+    glBindTexture(GL_TEXTURE_2D, fbo->texture());
+
+    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
+    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
+    glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
+    glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
+    glBindTexture(GL_TEXTURE_2D, 0);
+
+    QGL2PaintEngineEx *engine = static_cast<QGL2PaintEngineEx *>(painter->paintEngine());
+
+    engine->syncState();
+    painter->save();
+
+    // ensure GL_LINEAR filtering is used
+    painter->setRenderHint(QPainter::SmoothPixmapTransform);
+
+    // prepare for updateUniforms
+    m_textureSize = src.size();
+
+    // first pass, to fbo
+    fbo->bind();
+    if (src.hasAlphaChannel()) {
+        glClearColor(0, 0, 0, 0);
+        glClear(GL_COLOR_BUFFER_BIT);
+    }
+
+    filter->setOnPainter(painter);
+
+    QTransform transform = engine->state()->matrix;
+    if (!transform.isIdentity()) {
+        engine->state()->matrix = QTransform();
+        engine->transformChanged();
+    }
+
+    engine->drawPixmap(src.rect().translated(0, painter->device()->height() - fbo->height()),
+                       src, src.rect());
+
+    if (!transform.isIdentity()) {
+        engine->state()->matrix = transform;
+        engine->transformChanged();
+    }
+
+    fbo->release();
+
+    // second pass, to widget
+    m_program->setUniformValue("delta", 0.0, 1.0);
+    engine->drawTexture(src.rect().translated(pos.x(), pos.y()), fbo->texture(), fbo->size(), src.rect().translated(0, fbo->height() - src.height()));
+    filter->removeFromPainter(painter);
+
+    painter->restore();
+
+    qgl_fbo_pool()->release(fbo);
+
+    return true;
+}
+
+void QGLPixmapBlurFilter::setUniforms(QGLShaderProgram *program)
+{
+    program->setUniformValue("invTextureSize", 1.0 / m_textureSize.width(), 1.0 / m_textureSize.height());
+    program->setUniformValue("delta", 1.0, 0.0);
+
+    m_program = program;
+}
+
+static inline qreal gaussian(qreal dx, qreal sigma)
+{
+    return exp(-dx * dx / (2 * sigma * sigma)) / (Q_2PI * sigma * sigma);
+}
+
+QByteArray QGLPixmapBlurFilter::generateBlurShader(int radius, bool gaussianBlur)
+{
+    Q_ASSERT(radius >= 1);
+
+    QByteArray source;
+    source.reserve(1000);
+
+    source.append("uniform highp vec2      invTextureSize;\n");
+
+    bool separateXY = true;
+    bool clip = false;
+
+    if (separateXY) {
+        source.append("uniform highp vec2      delta;\n");
+
+        if (clip)
+            source.append("uniform highp vec2      clip;\n");
+    } else if (clip) {
+        source.append("uniform highp vec4      clip;\n");
+    }
+
+    source.append("mediump vec4 customShader(sampler2D src, vec2 srcCoords) {\n");
+
+    QVector<qreal> sampleOffsets;
+    QVector<qreal> weights;
+
+    if (gaussianBlur) {
+        QVector<qreal> gaussianComponents;
+
+        qreal sigma = radius / 1.65;
+
+        qreal sum = 0;
+        for (int i = -radius; i <= radius; ++i) {
+            float value = gaussian(i, sigma);
+            gaussianComponents << value;
+            sum += value;
+        }
+
+        // normalize
+        for (int i = 0; i < gaussianComponents.size(); ++i)
+            gaussianComponents[i] /= sum;
+
+        for (int i = 0; i < gaussianComponents.size() - 1; i += 2) {
+            qreal weight = gaussianComponents.at(i) + gaussianComponents.at(i + 1);
+            qreal offset = i - radius + gaussianComponents.at(i + 1) / weight;
+
+            sampleOffsets << offset;
+            weights << weight;
+        }
+
+        // odd size ?
+        if (gaussianComponents.size() & 1) {
+            sampleOffsets << radius;
+            weights << gaussianComponents.last();
+        }
+    } else {
+        for (int i = 0; i < radius; ++i) {
+            sampleOffsets << 2 * i - radius + 0.5;
+            weights << qreal(1);
+        }
+        sampleOffsets << radius;
+        weights << qreal(0.5);
+    }
+
+    int currentVariable = 1;
+    source.append("    mediump vec4 sample = vec4(0.0);\n");
+    source.append("    mediump vec2 coord;\n");
+
+    qreal weightSum = 0;
+    if (separateXY) {
+        source.append("    mediump float c;\n");
+        for (int i = 0; i < sampleOffsets.size(); ++i) {
+            qreal delta = sampleOffsets.at(i);
+
+            ++currentVariable;
+
+            QByteArray coordinate = "srcCoords";
+            if (delta != qreal(0)) {
+                coordinate.append(" + invTextureSize * delta * float(");
+                coordinate.append(QByteArray::number(delta));
+                coordinate.append(")");
+            }
+
+            source.append("    coord = ");
+            source.append(coordinate);
+            source.append(";\n");
+
+            if (clip) {
+                source.append("    c = dot(coord, delta);\n");
+                source.append("    if (c > clip.x && c < clip.y)\n    ");
+            }
+
+            source.append("    sample += texture2D(src, coord)");
+
+            weightSum += weights.at(i);
+            if (weights.at(i) != qreal(1)) {
+                source.append(" * float(");
+                source.append(QByteArray::number(weights.at(i)));
+                source.append(");\n");
+            } else {
+                source.append(";\n");
+            }
+        }
+    } else {
+        for (int y = 0; y < sampleOffsets.size(); ++y) {
+            for (int x = 0; x < sampleOffsets.size(); ++x) {
+                QByteArray coordinate = "srcCoords";
+
+                qreal dx = sampleOffsets.at(x);
+                qreal dy = sampleOffsets.at(y);
+
+                if (dx != qreal(0) || dy != qreal(0)) {
+                    coordinate.append(" + invTextureSize * vec2(float(");
+                    coordinate.append(QByteArray::number(dx));
+                    coordinate.append("), float(");
+                    coordinate.append(QByteArray::number(dy));
+                    coordinate.append("))");
+                }
+
+                source.append("    coord = ");
+                source.append(coordinate);
+                source.append(";\n");
+
+                if (clip)
+                    source.append("    if (coord.x > clip.x && coord.x < clip.y && coord.y > clip.z && coord.y < clip.w)\n    ");
+
+                source.append("    sample += texture2D(src, coord)");
+
+                ++currentVariable;
+
+                weightSum += weights.at(x) * weights.at(y);
+                if ((weights.at(x) != qreal(1) || weights.at(y) != qreal(1))) {
+                    source.append(" * float(");
+                    source.append(QByteArray::number(weights.at(x) * weights.at(y)));
+                    source.append(");\n");
+                } else {
+                    source.append(";\n");
+                }
+            }
+        }
+    }
+
+    source.append("    return ");
+    if (!gaussianBlur) {
+        source.append("float(");
+        if (separateXY)
+            source.append(QByteArray::number(1 / weightSum));
+        else
+            source.append(QByteArray::number(1 / weightSum));
+        source.append(") * ");
+    }
+    source.append("sample;\n");
+    source.append("}\n");
+
+    return source;
+}
+
 QT_END_NAMESPACE
diff --git a/src/opengl/qpixmapdata_gl.cpp b/src/opengl/qpixmapdata_gl.cpp
index e3ee2b2..c0eed4d 100644
--- a/src/opengl/qpixmapdata_gl.cpp
+++ b/src/opengl/qpixmapdata_gl.cpp
@@ -55,6 +55,85 @@ QT_BEGIN_NAMESPACE
 
 extern QGLWidget* qt_gl_share_widget();
 
+/*!
+    \class QGLFramebufferObjectPool
+    \since 4.6
+
+    \brief The QGLFramebufferObject class provides a pool of framebuffer
+    objects for offscreen rendering purposes.
+
+    When requesting an FBO of a given size and format, an FBO of the same
+    format and a size at least as big as the requested size will be returned.
+
+    \internal
+*/
+
+static inline int areaDiff(const QSize &size, const QGLFramebufferObject *fbo)
+{
+    return qAbs(size.width() * size.height() - fbo->width() * fbo->height());
+}
+
+QGLFramebufferObject *QGLFramebufferObjectPool::acquire(const QSize &requestSize, const QGLFramebufferObjectFormat &requestFormat)
+{
+    QGLFramebufferObject *chosen = 0;
+    QGLFramebufferObject *candidate = 0;
+    for (int i = 0; !chosen && i < m_fbos.size(); ++i) {
+        QGLFramebufferObject *fbo = m_fbos.at(i);
+
+        QGLFramebufferObjectFormat format = fbo->format();
+        if (format.samples() == requestFormat.samples()
+            && format.attachment() == requestFormat.attachment()
+            && format.textureTarget() == requestFormat.textureTarget()
+            && format.internalFormat() == requestFormat.internalFormat())
+        {
+            // choose the fbo with a matching format and the closest size
+            if (!candidate || areaDiff(requestSize, candidate) > areaDiff(requestSize, fbo))
+                candidate = fbo;
+        }
+
+        if (candidate) {
+            m_fbos.removeOne(candidate);
+
+            const QSize fboSize = candidate->size();
+            QSize sz = fboSize;
+
+            if (sz.width() < requestSize.width())
+                sz.setWidth(qMax(requestSize.width(), qRound(sz.width() * 1.5)));
+            if (sz.height() < requestSize.height())
+                sz.setHeight(qMax(requestSize.height(), qRound(sz.height() * 1.5)));
+
+            // wasting too much space?
+            if (sz.width() * sz.height() > requestSize.width() * requestSize.height() * 2.5)
+                sz = requestSize;
+
+            if (sz != fboSize) {
+                delete candidate;
+                qDebug() << "Resizing fbo in pool:" << sz;
+                candidate = new QGLFramebufferObject(sz, requestFormat);
+            }
+
+            chosen = candidate;
+        }
+    }
+
+    if (!chosen) {
+        qDebug() << "Creating new fbo in pool:" << requestSize;
+        chosen = new QGLFramebufferObject(requestSize, requestFormat);
+    }
+
+    if (!chosen->isValid()) {
+        delete chosen;
+        chosen = 0;
+    }
+
+    return chosen;
+}
+
+void QGLFramebufferObjectPool::release(QGLFramebufferObject *fbo)
+{
+    m_fbos << fbo;
+}
+
 class QGLShareContextScope
 {
 public:
@@ -332,8 +411,11 @@ struct TextureBuffer
     QGL2PaintEngineEx *engine;
 };
 
-static QVector<TextureBuffer> textureBufferStack;
-static int currentTextureBuffer = 0;
+Q_GLOBAL_STATIC(QGLFramebufferObjectPool, _qgl_fbo_pool)
+QGLFramebufferObjectPool* qgl_fbo_pool()
+{
+    return _qgl_fbo_pool();
+}
 
 void QGLPixmapData::copyBackFromRenderFbo(bool keepCurrentFboBound) const
 {
@@ -380,7 +462,8 @@ void QGLPixmapData::swapBuffers()
     copyBackFromRenderFbo(false);
     m_renderFbo->release();
 
-    --currentTextureBuffer;
+    qgl_fbo_pool()->release(m_renderFbo);
+    delete m_engine;
 
     m_renderFbo = 0;
     m_engine = 0;
@@ -398,19 +481,6 @@ void QGLPixmapData::doneCurrent()
         m_renderFbo->release();
 }
 
-static TextureBuffer createTextureBuffer(const QSize &size, QGL2PaintEngineEx *engine = 0)
-{
-    TextureBuffer buffer;
-    QGLFramebufferObjectFormat fmt;
-    fmt.setAttachment(QGLFramebufferObject::CombinedDepthStencil);
-    fmt.setSamples(4);
-
-    buffer.fbo = new QGLFramebufferObject(size, fmt);
-    buffer.engine = engine ? engine : new QGL2PaintEngineEx;
-
-    return buffer;
-}
-
 bool QGLPixmapData::useFramebufferObjects()
 {
     return QGLFramebufferObject::hasOpenGLFramebufferObjects()
@@ -433,33 +503,15 @@ QPaintEngine* QGLPixmapData::paintEngine() const
             qt_gl_share_widget()->makeCurrent();
         QGLShareContextScope ctx(qt_gl_share_widget()->context());
 
-        if (textureBufferStack.size() <= currentTextureBuffer) {
-            textureBufferStack << createTextureBuffer(size());
-        } else {
-            QSize sz = textureBufferStack.at(currentTextureBuffer).fbo->size();
-            if (sz.width() < w || sz.height() < h) {
-                if (sz.width() < w)
-                    sz.setWidth(qMax(w, qRound(sz.width() * 1.5)));
-                if (sz.height() < h)
-                    sz.setHeight(qMax(h, qRound(sz.height() * 1.5)));
-
-                // wasting too much space?
-                if (sz.width() * sz.height() > w * h * 2.5)
-                    sz = QSize(w, h);
-
-                delete textureBufferStack.at(currentTextureBuffer).fbo;
-                textureBufferStack[currentTextureBuffer] =
-                    createTextureBuffer(sz, textureBufferStack.at(currentTextureBuffer).engine);
-                qDebug() << "Creating new pixmap texture buffer:" << sz;
-            }
-        }
-
-        if (textureBufferStack.at(currentTextureBuffer).fbo->isValid()) {
-            m_renderFbo = textureBufferStack.at(currentTextureBuffer).fbo;
-            m_engine = textureBufferStack.at(currentTextureBuffer).engine;
+        QGLFramebufferObjectFormat format;
+        format.setAttachment(QGLFramebufferObject::CombinedDepthStencil);
+        format.setSamples(4);
+        format.setInternalFormat(m_hasAlpha ? GL_RGBA : GL_RGB);
 
-            ++currentTextureBuffer;
+        m_renderFbo = qgl_fbo_pool()->acquire(size(), format);
 
+        if (m_renderFbo) {
+            m_engine = new QGL2PaintEngineEx;
             return m_engine;
         }
 
diff --git a/src/opengl/qpixmapdata_gl_p.h b/src/opengl/qpixmapdata_gl_p.h
index 671f9a7..14fb072 100644
--- a/src/opengl/qpixmapdata_gl_p.h
+++ b/src/opengl/qpixmapdata_gl_p.h
@@ -62,6 +62,19 @@ QT_BEGIN_NAMESPACE
 
 class QPaintEngine;
 class QGLFramebufferObject;
+class QGLFramebufferObjectFormat;
+
+class QGLFramebufferObjectPool
+{
+public:
+    QGLFramebufferObject *acquire(const QSize &size, const QGLFramebufferObjectFormat &format);
+    void release(QGLFramebufferObject *fbo);
+
+private:
+    QList<QGLFramebufferObject *> m_fbos;
+};
+
+QGLFramebufferObjectPool* qgl_fbo_pool();
 
 class QGLPixmapData : public QPixmapData
 {