Reduce overhead of paint engine-specific pixmap filters

Engine-specific pixmap filters were being created, used, and destroyed
every time draw() was called on QPixmapColorizeFilter, QPixmapBlurFilter,
and so on.  This had a heavy performance penalty and made it difficult
for the GL paint engine to cache shaders from one request to the next.

A generic filter can request an engine-specific filter that matches its
parameters.  The engine can either create a new one or return a previously
allocated filter object.

Ownership of engine-specific pixmap filter objects is moved to the
paint engine itself.

Reviewed-by: Andrew den Exter
Reviewed-by: Michael Brasser
Reviewed-by: Michael Goddard
Reviewed-by: Sarah Smith

4 files changed, 19 insertions, 19 deletions

diff --git a/src/opengl/gl2paintengineex/qpaintengineex_opengl2.cpp b/src/opengl/gl2paintengineex/qpaintengineex_opengl2.cpp
index e41d0b4..2ee92c3 100644
--- a/src/opengl/gl2paintengineex/qpaintengineex_opengl2.cpp
+++ b/src/opengl/gl2paintengineex/qpaintengineex_opengl2.cpp
@@ -1769,14 +1769,6 @@ 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 34f4eb8..a44be90 100644
--- a/src/opengl/gl2paintengineex/qpaintengineex_opengl2_p.h
+++ b/src/opengl/gl2paintengineex/qpaintengineex_opengl2_p.h
@@ -59,6 +59,7 @@
 #include <private/qglengineshadermanager_p.h>
 #include <private/qgl2pexvertexarray_p.h>
 #include <private/qglpaintdevice_p.h>
+#include <private/qglpixmapfilter_p.h>
 
 enum EngineMode {
     ImageDrawingMode,
@@ -140,7 +141,7 @@ public:
 
     const QGLContext* context();
 
-    QPixmapFilter *createPixmapFilter(int type) const;
+    QPixmapFilter *pixmapFilter(int type, const QPixmapFilter *prototype);
 
     void setRenderTextActive(bool);
 
@@ -264,6 +265,10 @@ public:
     bool inRenderText;
 
     float textureInvertedY;
+
+    QScopedPointer<QPixmapFilter> convolutionFilter;
+    QScopedPointer<QPixmapFilter> colorizeFilter;
+    QScopedPointer<QPixmapFilter> blurFilter;
 };
 
 QT_END_NAMESPACE
diff --git a/src/opengl/qgl_p.h b/src/opengl/qgl_p.h
index 2b74e69..7269195 100644
--- a/src/opengl/qgl_p.h
+++ b/src/opengl/qgl_p.h
@@ -352,8 +352,6 @@ public:
 #endif
 
     static void setCurrentContext(QGLContext *context);
-
-    QPixmapFilter *createPixmapFilter(int type) const;
 };
 
 // ### make QGLContext a QObject in 5.0 and remove the proxy stuff
diff --git a/src/opengl/qglpixmapfilter.cpp b/src/opengl/qglpixmapfilter.cpp
index 43f1990..b48c497 100644
--- a/src/opengl/qglpixmapfilter.cpp
+++ b/src/opengl/qglpixmapfilter.cpp
@@ -123,23 +123,28 @@ private:
 
 extern QGLWidget *qt_gl_share_widget();
 
-QPixmapFilter *QGLContextPrivate::createPixmapFilter(int type) const
+QPixmapFilter *QGL2PaintEngineEx::pixmapFilter(int type, const QPixmapFilter *prototype)
 {
+    Q_D(QGL2PaintEngineEx);
     switch (type) {
     case QPixmapFilter::ColorizeFilter:
-        return new QGLPixmapColorizeFilter;
+        if (!d->colorizeFilter)
+            d->colorizeFilter.reset(new QGLPixmapColorizeFilter);
+        return d->colorizeFilter.data();
 
     case QPixmapFilter::BlurFilter:
-        return new QGLPixmapBlurFilter;
+        if (!d->blurFilter)
+            d->blurFilter.reset(new QGLPixmapBlurFilter);
+        return d->blurFilter.data();
 
     case QPixmapFilter::ConvolutionFilter:
-        return new QGLPixmapConvolutionFilter;
+        if (!d->convolutionFilter)
+            d->convolutionFilter.reset(new QGLPixmapConvolutionFilter);
+        return d->convolutionFilter.data();
 
-    default:
-        return 0;
-        break;
+    default: break;
     }
-    return 0;
+    return QPaintEngineEx::pixmapFilter(type, prototype);
 }
 
 extern void qt_add_rect_to_array(const QRectF &r, q_vertexType *array);