Support composition mode source for drawing in dfb

Qt's/DirectFB's composition modes are not compatible for drawing
operations. We only support SourceOver and handle whether or not to
blend colors using DSDRAW_BLEND based on the alpha/opacity value.
If drawing with Source and an opaque color we can still handle the
operation using DirectFB. This has major impact since WebKit fills the
background of web pages using Source.

Reviewed-by: Donald Carr <donald.carr@nokia.com>

1 files changed, 52 insertions, 19 deletions

diff --git a/src/plugins/gfxdrivers/directfb/qdirectfbpaintengine.cpp b/src/plugins/gfxdrivers/directfb/qdirectfbpaintengine.cpp
index 690b387..c86af73 100644
--- a/src/plugins/gfxdrivers/directfb/qdirectfbpaintengine.cpp
+++ b/src/plugins/gfxdrivers/directfb/qdirectfbpaintengine.cpp
@@ -71,6 +71,7 @@ public:
         PorterDuff_None = 0x00,
         PorterDuff_SupportedBlits = 0x01,
         PorterDuff_SupportedPrimitives = 0x02,
+        PorterDuff_SupportedOpaquePrimitives = 0x04,
         PorterDuff_Dirty = 0x10
     };
 
@@ -96,6 +97,7 @@ public:
     inline void unlock();
     static inline void unlock(QDirectFBPaintDevice *device);
 
+    inline bool testCompositionMode(const QPen *pen, const QBrush *brush, const QColor *color = 0) const;
     inline bool isSimpleBrush(const QBrush &brush) const;
 
     void drawTiledPixmap(const QRectF &dest, const QPixmap &pixmap, const QPointF &pos);
@@ -405,11 +407,11 @@ void QDirectFBPaintEngine::drawRects(const QRect *rects, int rectCount)
     if (brush.style() == Qt::NoBrush && pen.style() == Qt::NoPen)
         return;
 
-    if (!(d->compositionModeStatus & QDirectFBPaintEnginePrivate::PorterDuff_SupportedPrimitives)
-        || (d->transformationType & QDirectFBPaintEnginePrivate::Matrix_RectsUnsupported)
+    if ((d->transformationType & QDirectFBPaintEnginePrivate::Matrix_RectsUnsupported)
         || !d->simplePen
         || d->clipType == QDirectFBPaintEnginePrivate::ComplexClip
-        || !d->isSimpleBrush(brush)) {
+        || !d->isSimpleBrush(brush)
+        || !d->testCompositionMode(&pen, &brush)) {
         RASTERFALLBACK(DRAW_RECTS, rectCount, VOID_ARG(), VOID_ARG());
         d->lock();
         QRasterPaintEngine::drawRects(rects, rectCount);
@@ -435,11 +437,11 @@ void QDirectFBPaintEngine::drawRects(const QRectF *rects, int rectCount)
     if (brush.style() == Qt::NoBrush && pen.style() == Qt::NoPen)
         return;
 
-    if (!(d->compositionModeStatus & QDirectFBPaintEnginePrivate::PorterDuff_SupportedPrimitives)
-        || (d->transformationType & QDirectFBPaintEnginePrivate::Matrix_RectsUnsupported)
+    if ((d->transformationType & QDirectFBPaintEnginePrivate::Matrix_RectsUnsupported)
         || !d->simplePen
         || d->clipType == QDirectFBPaintEnginePrivate::ComplexClip
-        || !d->isSimpleBrush(brush)) {
+        || !d->isSimpleBrush(brush)
+        || !d->testCompositionMode(&pen, &brush)) {
         RASTERFALLBACK(DRAW_RECTS, rectCount, VOID_ARG(), VOID_ARG());
         d->lock();
         QRasterPaintEngine::drawRects(rects, rectCount);
@@ -461,16 +463,16 @@ void QDirectFBPaintEngine::drawLines(const QLine *lines, int lineCount)
 {
     Q_D(QDirectFBPaintEngine);
 
-    if (!(d->compositionModeStatus & QDirectFBPaintEnginePrivate::PorterDuff_SupportedPrimitives)
-        || !d->simplePen
-        || d->clipType == QDirectFBPaintEnginePrivate::ComplexClip) {
+    const QPen &pen = state()->pen;
+    if (!d->simplePen
+        || d->clipType == QDirectFBPaintEnginePrivate::ComplexClip
+        || !d->testCompositionMode(&pen, 0)) {
         RASTERFALLBACK(DRAW_LINES, lineCount, VOID_ARG(), VOID_ARG());
         d->lock();
         QRasterPaintEngine::drawLines(lines, lineCount);
         return;
     }
 
-    const QPen &pen = state()->pen;
     if (pen.style() != Qt::NoPen) {
         d->setDFBColor(pen.color());
         CLIPPED_PAINT(QT_PREPEND_NAMESPACE(drawLines<QLine>)(lines, lineCount, state()->matrix, d->surface));
@@ -481,16 +483,16 @@ void QDirectFBPaintEngine::drawLines(const QLineF *lines, int lineCount)
 {
     Q_D(QDirectFBPaintEngine);
 
-    if (!(d->compositionModeStatus & QDirectFBPaintEnginePrivate::PorterDuff_SupportedPrimitives)
-        || !d->simplePen
-        || d->clipType == QDirectFBPaintEnginePrivate::ComplexClip) {
+    const QPen &pen = state()->pen;
+    if (!d->simplePen
+        || d->clipType == QDirectFBPaintEnginePrivate::ComplexClip
+        || !d->testCompositionMode(&pen, 0)) {
         RASTERFALLBACK(DRAW_LINES, lineCount, VOID_ARG(), VOID_ARG());
         d->lock();
         QRasterPaintEngine::drawLines(lines, lineCount);
         return;
     }
 
-    const QPen &pen = state()->pen;
     if (pen.style() != Qt::NoPen) {
         d->setDFBColor(pen.color());
         CLIPPED_PAINT(QT_PREPEND_NAMESPACE(drawLines<QLineF>)(lines, lineCount, state()->matrix, d->surface));
@@ -715,8 +717,8 @@ void QDirectFBPaintEngine::fillRect(const QRectF &rect, const QBrush &brush)
     if (d->clipType != QDirectFBPaintEnginePrivate::ComplexClip) {
         switch (brush.style()) {
         case Qt::SolidPattern: {
-            if (!(d->compositionModeStatus & QDirectFBPaintEnginePrivate::PorterDuff_SupportedPrimitives)
-                || (d->transformationType & QDirectFBPaintEnginePrivate::Matrix_RectsUnsupported)) {
+            if (d->transformationType & QDirectFBPaintEnginePrivate::Matrix_RectsUnsupported
+                || !d->testCompositionMode(0, &brush)) {
                 break;
             }
             const QColor color = brush.color();
@@ -754,9 +756,9 @@ void QDirectFBPaintEngine::fillRect(const QRectF &rect, const QColor &color)
     if (!color.isValid())
         return;
     Q_D(QDirectFBPaintEngine);
-    if (!(d->compositionModeStatus & QDirectFBPaintEnginePrivate::PorterDuff_SupportedPrimitives)
-        || (d->transformationType & QDirectFBPaintEnginePrivate::Matrix_RectsUnsupported)
-        || d->clipType == QDirectFBPaintEnginePrivate::ComplexClip) {
+    if ((d->transformationType & QDirectFBPaintEnginePrivate::Matrix_RectsUnsupported)
+        || d->clipType == QDirectFBPaintEnginePrivate::ComplexClip
+        || !d->testCompositionMode(0, 0, &color)) {
         RASTERFALLBACK(FILL_RECT, rect, color, VOID_ARG());
         d->lock();
         QRasterPaintEngine::fillRect(rect, color);
@@ -816,6 +818,36 @@ bool QDirectFBPaintEnginePrivate::isSimpleBrush(const QBrush &brush) const
     return (brush.style() == Qt::NoBrush) || (brush.style() == Qt::SolidPattern && !antialiased);
 }
 
+bool QDirectFBPaintEnginePrivate::testCompositionMode(const QPen *pen, const QBrush *brush, const QColor *color) const
+{
+    Q_ASSERT(!pen || pen->style() == Qt::NoPen || pen->style() == Qt::SolidLine);
+    Q_ASSERT(!brush || brush->style() == Qt::NoBrush || brush->style() == Qt::SolidPattern);
+    switch (compositionModeStatus & (QDirectFBPaintEnginePrivate::PorterDuff_SupportedOpaquePrimitives
+                                     |QDirectFBPaintEnginePrivate::PorterDuff_SupportedPrimitives)) {
+    case QDirectFBPaintEnginePrivate::PorterDuff_SupportedPrimitives:
+        return true;
+    case QDirectFBPaintEnginePrivate::PorterDuff_SupportedOpaquePrimitives:
+        if (pen && pen->style() == Qt::SolidLine && pen->color().alpha() != 255)
+            return false;
+        if (brush) {
+            if (brush->style() == Qt::SolidPattern && brush->color().alpha() != 255) {
+                return false;
+            }
+        } else if (color && color->alpha() != 255) {
+            return false;
+        }
+        return true;
+    case QDirectFBPaintEnginePrivate::PorterDuff_None:
+        return false;
+    default:
+        // ### PorterDuff_SupportedOpaquePrimitives|PorterDuff_SupportedPrimitives can't be combined
+        break;
+    }
+    Q_ASSERT(0);
+    return false;
+}
+
+
 void QDirectFBPaintEnginePrivate::lock()
 {
     // We will potentially get a new pointer to the buffer after a
@@ -889,6 +921,7 @@ void QDirectFBPaintEnginePrivate::setCompositionMode(QPainter::CompositionMode m
         break;
     case QPainter::CompositionMode_Source:
         surface->SetPorterDuff(surface, DSPD_SRC);
+        compositionModeStatus |= PorterDuff_SupportedOpaquePrimitives;
         break;
     case QPainter::CompositionMode_SourceOver:
         compositionModeStatus |= PorterDuff_SupportedPrimitives;