Simplify DirectFB clipping

Instead of storing whether or not our clip is dirty and updating it in
every paint operation we'll just update it whenever it changes. This is
more intuitive and should be faster for the common case as well.

Also make sure to implement clip(region).

Prevent multiple updateClip() calls for a single clip operation by
introducing a flag to check whether we recursed into the different
clip() calls.

Reviewed-by: Donald <qt-info@nokia.com>

2 files changed, 36 insertions, 25 deletions

diff --git a/src/plugins/gfxdrivers/directfb/qdirectfbpaintengine.cpp b/src/plugins/gfxdrivers/directfb/qdirectfbpaintengine.cpp
index 741c4e4..ba715c3 100644
--- a/src/plugins/gfxdrivers/directfb/qdirectfbpaintengine.cpp
+++ b/src/plugins/gfxdrivers/directfb/qdirectfbpaintengine.cpp
@@ -119,13 +119,14 @@ private:
     IDirectFB *fb;
     quint8 opacity;
 
-    bool dirtyClip;
     ClipType clipType;
     QDirectFBPaintDevice *dfbDevice;
     uint compositionModeStatus;
 
-    QDirectFBPaintEngine *q;
+    bool inClip;
     QRect currentClip;
+
+    QDirectFBPaintEngine *q;
     friend class QDirectFBPaintEngine;
 };
 
@@ -236,7 +237,7 @@ static inline void drawRects(const T *rects, int n, const QTransform &transform,
                 d->surface->SetClip(d->surface, &clipRegion);           \
                 operation;                                              \
             }                                                           \
-            d->dirtyClip = true;                                        \
+            d->updateClip();                                            \
             break; }                                                    \
         case QDirectFBPaintEnginePrivate::ComplexClip:                  \
         case QDirectFBPaintEnginePrivate::ClipUnset:                    \
@@ -297,8 +298,8 @@ bool QDirectFBPaintEngine::end()
 void QDirectFBPaintEngine::clipEnabledChanged()
 {
     Q_D(QDirectFBPaintEngine);
-    d->dirtyClip = true;
     QRasterPaintEngine::clipEnabledChanged();
+    d->updateClip();
 }
 
 void QDirectFBPaintEngine::penChanged()
@@ -341,26 +342,49 @@ void QDirectFBPaintEngine::setState(QPainterState *state)
 {
     Q_D(QDirectFBPaintEngine);
     QRasterPaintEngine::setState(state);
-    d->dirtyClip = true;
     d->setPen(state->pen);
     d->opacity = quint8(state->opacity * 255);
     d->setCompositionMode(state->compositionMode());
     d->setTransform(state->transform());
     d->setRenderHints(state->renderHints);
+    if (d->surface)
+        d->updateClip();
 }
 
 void QDirectFBPaintEngine::clip(const QVectorPath &path, Qt::ClipOperation op)
 {
     Q_D(QDirectFBPaintEngine);
-    d->dirtyClip = true;
+    const bool wasInClip = d->inClip;
+    d->inClip = true;
     QRasterPaintEngine::clip(path, op);
+    if (!wasInClip) {
+        d->inClip = false;
+        d->updateClip();
+    }
+}
+
+void QDirectFBPaintEngine::clip(const QRegion &region, Qt::ClipOperation op)
+{
+    Q_D(QDirectFBPaintEngine);
+    const bool wasInClip = d->inClip;
+    d->inClip = true;
+    QRasterPaintEngine::clip(region, op);
+    if (!wasInClip) {
+        d->inClip = false;
+        d->updateClip();
+    }
 }
 
 void QDirectFBPaintEngine::clip(const QRect &rect, Qt::ClipOperation op)
 {
     Q_D(QDirectFBPaintEngine);
-    d->dirtyClip = true;
+    const bool wasInClip = d->inClip;
+    d->inClip = true;
     QRasterPaintEngine::clip(rect, op);
+    if (!wasInClip) {
+        d->inClip = false;
+        d->updateClip();
+    }
 }
 
 void QDirectFBPaintEngine::drawRects(const QRect *rects, int rectCount)
@@ -371,7 +395,6 @@ void QDirectFBPaintEngine::drawRects(const QRect *rects, int rectCount)
     if (brush == Qt::NoBrush && pen == Qt::NoPen)
         return;
 
-    d->updateClip();
     if (!(d->compositionModeStatus & QDirectFBPaintEnginePrivate::PorterDuff_SupportedPrimitives)
         || (d->transformationType & QDirectFBPaintEnginePrivate::Matrix_RectsUnsupported)
         || !d->simplePen
@@ -401,7 +424,6 @@ void QDirectFBPaintEngine::drawRects(const QRectF *rects, int rectCount)
     if (brush == Qt::NoBrush && pen == Qt::NoPen)
         return;
 
-    d->updateClip();
     if (!(d->compositionModeStatus & QDirectFBPaintEnginePrivate::PorterDuff_SupportedPrimitives)
         || (d->transformationType & QDirectFBPaintEnginePrivate::Matrix_RectsUnsupported)
         || !d->simplePen
@@ -426,7 +448,6 @@ void QDirectFBPaintEngine::drawRects(const QRectF *rects, int rectCount)
 void QDirectFBPaintEngine::drawLines(const QLine *lines, int lineCount)
 {
     Q_D(QDirectFBPaintEngine);
-    d->updateClip();
 
     if (!(d->compositionModeStatus & QDirectFBPaintEnginePrivate::PorterDuff_SupportedPrimitives)
         || !d->simplePen
@@ -448,7 +469,6 @@ void QDirectFBPaintEngine::drawLines(const QLine *lines, int lineCount)
 void QDirectFBPaintEngine::drawLines(const QLineF *lines, int lineCount)
 {
     Q_D(QDirectFBPaintEngine);
-    d->updateClip();
 
     if (!(d->compositionModeStatus & QDirectFBPaintEnginePrivate::PorterDuff_SupportedPrimitives)
         || !d->simplePen
@@ -491,7 +511,6 @@ void QDirectFBPaintEngine::drawImage(const QRectF &r, const QImage &image,
     than the max image cache size we fall back to raster engine.
     */
 
-    d->updateClip();
 #if !defined QT_NO_DIRECTFB_PREALLOCATED || defined QT_DIRECTFB_IMAGECACHE
     if (!(d->compositionModeStatus & QDirectFBPaintEnginePrivate::PorterDuff_SupportedBlits)
         || (d->transformationType & QDirectFBPaintEnginePrivate::Matrix_BlitsUnsupported)
@@ -534,7 +553,6 @@ void QDirectFBPaintEngine::drawPixmap(const QRectF &r, const QPixmap &pixmap,
 {
     Q_D(QDirectFBPaintEngine);
 
-    d->updateClip();
     if (pixmap.pixmapData()->classId() != QPixmapData::DirectFBClass) {
         RASTERFALLBACK(DRAW_PIXMAP, r, pixmap.size(), sr);
         d->lock();
@@ -569,7 +587,6 @@ void QDirectFBPaintEngine::drawTiledPixmap(const QRectF &r,
                                            const QPointF &offset)
 {
     Q_D(QDirectFBPaintEngine);
-    d->updateClip();
     if (pixmap.pixmapData()->classId() != QPixmapData::DirectFBClass) {
         RASTERFALLBACK(DRAW_TILED_PIXMAP, r, pixmap.size(), offset);
         d->lock();
@@ -674,7 +691,6 @@ void QDirectFBPaintEngine::fillRect(const QRectF &rect, const QBrush &brush)
     Q_D(QDirectFBPaintEngine);
     if (brush.style() == Qt::NoBrush)
         return;
-    d->updateClip();
     if (d->clipType != QDirectFBPaintEnginePrivate::ComplexClip) {
         switch (brush.style()) {
         case Qt::SolidPattern: {
@@ -718,7 +734,6 @@ void QDirectFBPaintEngine::fillRect(const QRectF &rect, const QColor &color)
     if (!color.isValid())
         return;
     Q_D(QDirectFBPaintEngine);
-    d->updateClip();
     if (!(d->compositionModeStatus & QDirectFBPaintEnginePrivate::PorterDuff_SupportedPrimitives)
         || (d->transformationType & QDirectFBPaintEnginePrivate::Matrix_RectsUnsupported)
         || d->clipType == QDirectFBPaintEnginePrivate::ComplexClip) {
@@ -764,9 +779,9 @@ void QDirectFBPaintEngine::initImageCache(int size)
 
 QDirectFBPaintEnginePrivate::QDirectFBPaintEnginePrivate(QDirectFBPaintEngine *p)
     : surface(0), antialiased(false), simplePen(false),
-      transformationType(0), opacity(255), dirtyClip(true),
+      transformationType(0), opacity(255),
       clipType(ClipUnset), dfbDevice(0),
-      compositionModeStatus(0), q(p)
+      compositionModeStatus(0), inClip(false), q(p)
 {
     fb = QDirectFBScreen::instance()->dfb();
     surfaceCache = new SurfaceCache;
@@ -977,7 +992,6 @@ static inline qreal fixCoord(qreal rect_pos, qreal pixmapSize, qreal offset)
 
 void QDirectFBPaintEnginePrivate::drawTiledPixmap(const QRectF &dest, const QPixmap &pixmap, const QPointF &off)
 {
-    Q_ASSERT(!dirtyClip);
     Q_ASSERT(!(transformationType & Matrix_BlitsUnsupported));
     const QTransform &transform = q->state()->matrix;
     const QRect destinationRect = transform.mapRect(dest).toRect().normalized();
@@ -1070,9 +1084,7 @@ void QDirectFBPaintEnginePrivate::drawTiledPixmap(const QRectF &dest, const QPix
 
 void QDirectFBPaintEnginePrivate::updateClip()
 {
-    if (!dirtyClip)
-        return;
-
+    Q_ASSERT(surface);
     currentClip = QRect();
     const QClipData *clipData = clip();
     if (!clipData || !clipData->enabled) {
@@ -1094,14 +1106,12 @@ void QDirectFBPaintEnginePrivate::updateClip()
     } else {
         clipType = ComplexClip;
     }
-
-    dirtyClip = false;
 }
 
 void QDirectFBPaintEnginePrivate::systemStateChanged()
 {
-    dirtyClip = true;
     QRasterPaintEnginePrivate::systemStateChanged();
+    updateClip();
 }
 
 IDirectFBSurface *SurfaceCache::getSurface(const uint *buf, int size)
diff --git a/src/plugins/gfxdrivers/directfb/qdirectfbpaintengine.h b/src/plugins/gfxdrivers/directfb/qdirectfbpaintengine.h
index b939b68..80108b2 100644
--- a/src/plugins/gfxdrivers/directfb/qdirectfbpaintengine.h
+++ b/src/plugins/gfxdrivers/directfb/qdirectfbpaintengine.h
@@ -101,6 +101,7 @@ public:
     virtual void setState(QPainterState *state);
 
     virtual void clip(const QVectorPath &path, Qt::ClipOperation op);
+    virtual void clip(const QRegion &region, Qt::ClipOperation op);
     virtual void clip(const QRect &rect, Qt::ClipOperation op);
 
     static void initImageCache(int size);