qpa: add non-opaque fill support

Add non-opaque fill support for qpa through new QBlittable flag
"AlphaFillRectCapability" and add related implementation in DirectFB
qpa platform.

Change-Id: I863a270e24c96c432489099a34dc1f3a2be52280
Reviewed-by: Qt Doc Bot <qt_docbot@qt-project.org>
Reviewed-by: Jørgen Lind <jorgen.lind@nokia.com>

2 files changed, 62 insertions, 11 deletions

diff --git a/src/gui/painting/qblittable_p.h b/src/gui/painting/qblittable_p.h
index c36de8fa08..654a0a0533 100644
--- a/src/gui/painting/qblittable_p.h
+++ b/src/gui/painting/qblittable_p.h
@@ -62,6 +62,7 @@ public:
         SourcePixmapCapability          = 0x0002,
         SourceOverPixmapCapability      = 0x0004,
         SourceOverScaledPixmapCapability = 0x0008,
+        AlphaFillRectCapability         = 0x0010,
 
         // Internal ones
         OutlineCapability               = 0x0001000
@@ -76,6 +77,12 @@ public:
 
     virtual void fillRect(const QRectF &rect, const QColor &color) = 0;
     virtual void drawPixmap(const QRectF &rect, const QPixmap &pixmap, const QRectF &subrect) = 0;
+    virtual void alphaFillRect(const QRectF &rect, const QColor &color, QPainter::CompositionMode cmode) {
+        Q_UNUSED(rect);
+        Q_UNUSED(color);
+        Q_UNUSED(cmode);
+        qWarning("Please implement alphaFillRect function in your platform or remove AlphaFillRectCapability from it");
+    }
 
     QImage *lock();
     void unlock();
diff --git a/src/gui/painting/qpaintengine_blitter.cpp b/src/gui/painting/qpaintengine_blitter.cpp
index d4e0a5967b..20dd98b9bf 100644
--- a/src/gui/painting/qpaintengine_blitter.cpp
+++ b/src/gui/painting/qpaintengine_blitter.cpp
@@ -73,6 +73,7 @@ public:
         , fillRectMask(0)
         , drawRectMask(0)
         , drawPixmapMask(0)
+        , alphaFillRectMask(0)
         , capabillitiesState(0)
     {
         if (capabilities & QBlittable::SolidRectCapability)
@@ -83,6 +84,8 @@ public:
            setSourceOverPixmapMask();
         if (capabilities & QBlittable::SourceOverScaledPixmapCapability)
             setSourceOverScaledPixmapMask();
+        if (capabilities & QBlittable::AlphaFillRectCapability)
+            setAlphaFillRectMask();
     }
 
     inline bool canBlitterFillRect() const
@@ -90,6 +93,11 @@ public:
         return checkStateAgainstMask(capabillitiesState, fillRectMask);
     }
 
+    inline bool canBlitterAlphaFillRect() const
+    {
+        return checkStateAgainstMask(capabillitiesState, alphaFillRectMask);
+    }
+
     inline bool canBlitterDrawRectMask() const
     {
         return checkStateAgainstMask(capabillitiesState, drawRectMask);
@@ -147,6 +155,24 @@ private:
         updateStateBits(&fillRectMask, STATE_CLIP_COMPLEX, false);
     }
 
+    void setAlphaFillRectMask() {
+        updateStateBits(&alphaFillRectMask, STATE_XFORM_SCALE, false);
+        updateStateBits(&alphaFillRectMask, STATE_XFORM_COMPLEX, false);
+
+        updateStateBits(&alphaFillRectMask, STATE_BRUSH_PATTERN, false);
+        updateStateBits(&alphaFillRectMask, STATE_BRUSH_ALPHA, true);
+
+        updateStateBits(&alphaFillRectMask, STATE_PEN_ENABLED, true);
+
+        //Sub-pixel aliasing should not be sent to the blitter
+        updateStateBits(&alphaFillRectMask, STATE_ANTIALIASING, true);
+        updateStateBits(&alphaFillRectMask, STATE_ALPHA, false);
+        updateStateBits(&alphaFillRectMask, STATE_BLENDING_COMPLEX, false);
+
+        updateStateBits(&alphaFillRectMask, STATE_CLIPSYS_COMPLEX, false);
+        updateStateBits(&alphaFillRectMask, STATE_CLIP_COMPLEX, false);
+    }
+
     void setSourcePixmapMask() {
         updateStateBits(&drawPixmapMask, STATE_XFORM_SCALE, true);
         updateStateBits(&drawPixmapMask, STATE_XFORM_COMPLEX, false);
@@ -177,6 +203,7 @@ private:
     uint fillRectMask;
     uint drawRectMask;
     uint drawPixmapMask;
+    uint alphaFillRectMask;
     uint capabillitiesState;
 };
 
@@ -194,7 +221,7 @@ public:
 
     void lock();
     void unlock();
-    void fillRect(const QRectF &rect, const QColor &color);
+    void fillRect(const QRectF &rect, const QColor &color, bool alpha);
     void clipAndDrawPixmap(const QRectF &clip, const QRectF &target, const QPixmap &pm, const QRectF &sr);
 
 
@@ -287,7 +314,7 @@ void QBlitterPaintEnginePrivate::updateClipState(QPainterState *)
     caps.updateState(STATE_CLIP_COMPLEX, complexClip);
 }
 
-void QBlitterPaintEnginePrivate::fillRect(const QRectF &rect, const QColor &color)
+void QBlitterPaintEnginePrivate::fillRect(const QRectF &rect, const QColor &color, bool alpha)
 {
     Q_Q(QBlitterPaintEngine);
     pmData->unmarkRasterOverlay(rect);
@@ -298,14 +325,20 @@ void QBlitterPaintEnginePrivate::fillRect(const QRectF &rect, const QColor &colo
     if (clipData) {
         if (clipData->hasRectClip) {
             unlock();
-            pmData->blittable()->fillRect(targetRect & clipData->clipRect, color);
+            if (alpha)
+                pmData->blittable()->alphaFillRect(targetRect & clipData->clipRect, color, q->state()->compositionMode());
+            else
+                pmData->blittable()->fillRect(targetRect & clipData->clipRect, color);
         } else if (clipData->hasRegionClip) {
             QVector<QRect> rects = clipData->clipRegion.rects();
             for (int i = 0; i < rects.size(); ++i) {
                 QRect intersectRect = rects.at(i).intersected(targetRect.toRect());
                 if (!intersectRect.isEmpty()) {
                     unlock();
-                    pmData->blittable()->fillRect(intersectRect, color);
+                    if (alpha)
+                        pmData->blittable()->alphaFillRect(intersectRect, color, q->state()->compositionMode());
+                    else
+                        pmData->blittable()->fillRect(intersectRect, color);
                 }
             }
         }
@@ -314,11 +347,17 @@ void QBlitterPaintEnginePrivate::fillRect(const QRectF &rect, const QColor &colo
             && targetRect.width() <= q->paintDevice()->width()
             && targetRect.height() <= q->paintDevice()->height()) {
             unlock();
-            pmData->blittable()->fillRect(targetRect, color);
+            if (alpha)
+                pmData->blittable()->alphaFillRect(targetRect, color, q->state()->compositionMode());
+            else
+                pmData->blittable()->fillRect(targetRect, color);
         } else {
             QRectF deviceRect(0, 0, q->paintDevice()->width(), q->paintDevice()->height());
             unlock();
-            pmData->blittable()->fillRect(deviceRect & targetRect, color);
+            if (alpha)
+                pmData->blittable()->alphaFillRect(deviceRect & targetRect, color, q->state()->compositionMode());
+            else
+                pmData->blittable()->fillRect(deviceRect & targetRect, color);
         }
     }
 }
@@ -460,8 +499,10 @@ void QBlitterPaintEngine::fill(const QVectorPath &path, const QBrush &brush)
 void QBlitterPaintEngine::fillRect(const QRectF &rect, const QColor &color)
 {
     Q_D(QBlitterPaintEngine);
-    if (d->caps.canBlitterFillRect() && color.alpha() == 0xff) {
-        d->fillRect(rect, color);
+    if (d->caps.canBlitterAlphaFillRect()) {
+        d->fillRect(rect, color, true);
+    } else if (d->caps.canBlitterFillRect() && color.alpha() == 0xff) {
+        d->fillRect(rect, color, false);
     } else {
         d->lock();
         d->pmData->markRasterOverlay(rect);
@@ -477,9 +518,12 @@ void QBlitterPaintEngine::fillRect(const QRectF &rect, const QBrush &brush)
     Q_D(QBlitterPaintEngine);
 
     if (qbrush_style(brush) == Qt::SolidPattern
+        && d->caps.canBlitterAlphaFillRect()) {
+        d->fillRect(rect, qbrush_color(brush), true);
+    } else if (qbrush_style(brush) == Qt::SolidPattern
         && qbrush_color(brush).alpha() == 0xff
         && d->caps.canBlitterFillRect()) {
-        d->fillRect(rect, qbrush_color(brush));
+        d->fillRect(rect, qbrush_color(brush), false);
     } else if (brush.style() == Qt::TexturePattern
               && d->caps.canBlitterDrawPixmap(rect, brush.texture(), rect)) {
         bool rectIsFilled = false;
@@ -550,7 +594,7 @@ void QBlitterPaintEngine::drawRects(const QRect *rects, int rectCount)
     Q_D(QBlitterPaintEngine);
     if (d->caps.canBlitterDrawRectMask()) {
         for (int i=0; i<rectCount; ++i)
-            d->fillRect(rects[i], qbrush_color(state()->brush));
+            d->fillRect(rects[i], qbrush_color(state()->brush), false);
     } else {
         d->pmData->markRasterOverlay(rects, rectCount);
         QRasterPaintEngine::drawRects(rects, rectCount);
@@ -562,7 +606,7 @@ void QBlitterPaintEngine::drawRects(const QRectF *rects, int rectCount)
     Q_D(QBlitterPaintEngine);
     if (d->caps.canBlitterDrawRectMask()) {
         for (int i = 0; i < rectCount; ++i)
-            d->fillRect(rects[i], qbrush_color(state()->brush));
+            d->fillRect(rects[i], qbrush_color(state()->brush), false);
     } else {
         d->pmData->markRasterOverlay(rects, rectCount);
         QRasterPaintEngine::drawRects(rects, rectCount);