Changeset 59668 in webkit

Timestamp:

May 18, 2010 6:25:04 AM (14 years ago)

Author:

zherczeg@webkit.org

Message:

[Qt] Implementing clipToImageBuffer for Qt port.
​https://bugs.webkit.org/show_bug.cgi?id=24289

Reviewed by Kenneth Rohde Christiansen.

The implementation combines pixmap layers and destinationIn
composition mode.

• platform/graphics/qt/GraphicsContextQt.cpp:

(WebCore::TransparencyLayer::TransparencyLayer):
(WebCore::GraphicsContextPlatformPrivate::GraphicsContextPlatformPrivate):
(WebCore::GraphicsContext::savePlatformState):
(WebCore::GraphicsContext::restorePlatformState):
(WebCore::GraphicsContext::inTransparencyLayer):
(WebCore::GraphicsContext::beginTransparencyLayer):
(WebCore::GraphicsContext::endTransparencyLayer):
(WebCore::GraphicsContext::clipToImageBuffer):

Location:

trunk/WebCore

Files:

• ChangeLog (modified) (1 diff)
• platform/graphics/qt/GraphicsContextQt.cpp (modified) (11 diffs)

trunk/WebCore/ChangeLog

@@ +1 @@
+2010-05-18  Zoltan Herczeg  <zherczeg@webkit.org>
+
+        Reviewed by Kenneth Rohde Christiansen.
+
+        [Qt] Implementing clipToImageBuffer for Qt port.
+        https://bugs.webkit.org/show_bug.cgi?id=24289
+
+        The implementation combines pixmap layers and destinationIn
+        composition mode.
+
+        * platform/graphics/qt/GraphicsContextQt.cpp:
+        (WebCore::TransparencyLayer::TransparencyLayer):
+        (WebCore::GraphicsContextPlatformPrivate::GraphicsContextPlatformPrivate):
+        (WebCore::GraphicsContext::savePlatformState):
+        (WebCore::GraphicsContext::restorePlatformState):
+        (WebCore::GraphicsContext::inTransparencyLayer):
+        (WebCore::GraphicsContext::beginTransparencyLayer):
+        (WebCore::GraphicsContext::endTransparencyLayer):
+        (WebCore::GraphicsContext::clipToImageBuffer):
+
 2010-05-18  Eric Seidel  <eric@webkit.org>
 

trunk/WebCore/platform/graphics/qt/GraphicsContextQt.cpp

@@ -168 +168 @@
 
 struct TransparencyLayer : FastAllocBase {
-    TransparencyLayer(const QPainter* p, const QRect &rect)
+    TransparencyLayer(const QPainter* p, const QRect &rect, qreal opacity, QPixmap& alphaMask)
         : pixmap(rect.width(), rect.height())
+        , opacity(opacity)
+        , alphaMask(alphaMask)
+        , saveCounter(1) // see the comment for saveCounter
     {
         offset = rect.topLeft();
@@ -183 +186 @@
         if (painter.paintEngine()->hasFeature(QPaintEngine::PorterDuff))
             painter.setCompositionMode(p->compositionMode());
-        painter.setClipPath(p->clipPath());
+        // if the path is an empty region, this assignment disables all painting
+        if (!p->clipPath().isEmpty())
+            painter.setClipPath(p->clipPath());
     }
 
@@ -194 +199 @@
     QPainter painter;
     qreal opacity;
+    // for clipToImageBuffer
+    QPixmap alphaMask;
+    // saveCounter is only used in combination with alphaMask
+    // otherwise, its value is unspecified
+    int saveCounter;
 private:
     TransparencyLayer(const TransparencyLayer &) {}
@@ -218 +228 @@
 
     QStack<TransparencyLayer*> layers;
+    // Counting real layers. Required by inTransparencyLayer() calls
+    // For example, layers with valid alphaMask are not real layers
+    int layerCount;
     QPainter* redirect;
 
@@ -236 +249 @@
 {
     painter = p;
+    layerCount = 0;
     redirect = 0;
 
@@ -290 +304 @@
 void GraphicsContext::savePlatformState()
 {
+    if (!m_data->layers.isEmpty() && !m_data->layers.top()->alphaMask.isNull())
+        ++m_data->layers.top()->saveCounter;
     m_data->p()->save();
 }
@@ -295 +311 @@
 void GraphicsContext::restorePlatformState()
 {
+    if (!m_data->layers.isEmpty() && !m_data->layers.top()->alphaMask.isNull())
+        if (!--m_data->layers.top()->saveCounter)
+            endTransparencyLayer();
+
     m_data->p()->restore();
 
@@ -679 +699 @@
 bool GraphicsContext::inTransparencyLayer() const
 {
-    return !m_data->layers.isEmpty();
+    return m_data->layerCount;
 }
 
@@ -838 +858 @@
     h = int(qBound(qreal(0), deviceClip.height(), (qreal)h) + 2);
 
-    TransparencyLayer * layer = new TransparencyLayer(m_data->p(), QRect(x, y, w, h));
-
-    layer->opacity = opacity;
-    m_data->layers.push(layer);
+    QPixmap emptyAlphaMask;
+    m_data->layers.push(new TransparencyLayer(m_data->p(), QRect(x, y, w, h), opacity, emptyAlphaMask));
+    ++m_data->layerCount;
 }
 
@@ -850 +869 @@
 
     TransparencyLayer* layer = m_data->layers.pop();
+    if (!layer->alphaMask.isNull()) {
+        layer->painter.resetTransform();
+        layer->painter.setCompositionMode(QPainter::CompositionMode_DestinationIn);
+        layer->painter.drawPixmap(QPoint(), layer->alphaMask);
+    } else
+        --m_data->layerCount; // see the comment for layerCount
     layer->painter.end();
 
@@ -1087 +1112 @@
 }
 
-void GraphicsContext::clipToImageBuffer(const FloatRect&, const ImageBuffer*)
-{
-    notImplemented();
+void GraphicsContext::clipToImageBuffer(const FloatRect& floatRect, const ImageBuffer* image)
+{
+    if (paintingDisabled())
+        return;
+
+    QPixmap* nativeImage = image->image()->nativeImageForCurrentFrame();
+    if (!nativeImage)
+        return;
+
+    IntRect rect(floatRect);
+    QPixmap alphaMask = *nativeImage;
+    if (alphaMask.width() != rect.width() || alphaMask.height() != rect.height())
+        alphaMask = alphaMask.scaled(rect.width(), rect.height());
+
+    m_data->layers.push(new TransparencyLayer(m_data->p(), rect, 1.0, alphaMask));
 }