Changeset 70010 in webkit

Timestamp:

Oct 18, 2010 4:53:10 PM (14 years ago)

Author:

vangelis@chromium.org

Message:

2010-10-18 Vangelis Kokkevis <​vangelis@chromium.org>

Reviewed by James Robinson.

[chromium] Prevent the creation of very large textures for layers by switching
to "large layer" mode when a texture is larger than some fixed reasonable size
(set to 2000 pixels for now).
​https://bugs.webkit.org/show_bug.cgi?id=47751

The code also changes the large layer logic to use the current scissor rect used
by the compositor instead of the visible rect to determine how to clip large layers.
This will provide additional texture savings. In addition, the various layer rects
have been converted to use integers instead of floats to preserve uniformity in the code.

Tests: Existing large layer layout tests including huge-layer and huge-layer-img

• platform/graphics/chromium/ContentLayerChromium.cpp: (WebCore::ContentLayerChromium::requiresClippedUpdateRect): (WebCore::ContentLayerChromium::calculateClippedUpdateRect):
• platform/graphics/chromium/LayerChromium.cpp: (WebCore::LayerChromium::getDrawRect):
• platform/graphics/chromium/LayerChromium.h:
• platform/graphics/chromium/LayerRendererChromium.cpp: (WebCore::LayerRendererChromium::drawLayers): (WebCore::LayerRendererChromium::drawLayersRecursive): (WebCore::LayerRendererChromium::scissorToRect):
• platform/graphics/chromium/LayerRendererChromium.h: (WebCore::LayerRendererChromium::currentScissorRect):

Location:

trunk/WebCore

Files:

• ChangeLog (modified) (1 diff)
• platform/graphics/chromium/ContentLayerChromium.cpp (modified) (3 diffs)
• platform/graphics/chromium/LayerChromium.cpp (modified) (1 diff)
• platform/graphics/chromium/LayerChromium.h (modified) (1 diff)
• platform/graphics/chromium/LayerRendererChromium.cpp (modified) (9 diffs)
• platform/graphics/chromium/LayerRendererChromium.h (modified) (4 diffs)

trunk/WebCore/ChangeLog

@@ +1 @@
+2010-10-18  Vangelis Kokkevis  <vangelis@chromium.org>
+
+        Reviewed by James Robinson.
+
+        [chromium] Prevent the creation of very large textures for layers by switching
+        to "large layer" mode when a texture is larger than some fixed reasonable size
+        (set to 2000 pixels for now).
+        https://bugs.webkit.org/show_bug.cgi?id=47751
+
+        The code also changes the large layer logic to use the current scissor rect used
+        by the compositor instead of the visible rect to determine how to clip large layers.
+        This will provide additional texture savings. In addition, the various layer rects
+        have been converted to use integers instead of floats to preserve uniformity in the code.
+        
+        Tests: Existing large layer layout tests including huge-layer and huge-layer-img
+
+        * platform/graphics/chromium/ContentLayerChromium.cpp:
+        (WebCore::ContentLayerChromium::requiresClippedUpdateRect):
+        (WebCore::ContentLayerChromium::calculateClippedUpdateRect):
+        * platform/graphics/chromium/LayerChromium.cpp:
+        (WebCore::LayerChromium::getDrawRect):
+        * platform/graphics/chromium/LayerChromium.h:
+        * platform/graphics/chromium/LayerRendererChromium.cpp:
+        (WebCore::LayerRendererChromium::drawLayers):
+        (WebCore::LayerRendererChromium::drawLayersRecursive):
+        (WebCore::LayerRendererChromium::scissorToRect):
+        * platform/graphics/chromium/LayerRendererChromium.h:
+        (WebCore::LayerRendererChromium::currentScissorRect):
+
 2010-10-18  Jia Pu  <jpu@apple.com>
 

trunk/WebCore/platform/graphics/chromium/ContentLayerChromium.cpp

@@ -144 +144 @@
 bool ContentLayerChromium::requiresClippedUpdateRect() const
 {
-    return !layerRenderer()->checkTextureSize(m_bounds);
+    // To avoid allocating excessively large textures, switch into "large layer mode" if
+    // one of the layer's dimensions is larger than 2000 pixels or the current size
+    // of the visible rect. This is a temporary measure until layer tiling is implemented.
+    static const int maxLayerSize = 2000;
+    return (m_bounds.width() > max(maxLayerSize, layerRenderer()->rootLayerContentRect().width())
+            || m_bounds.height() > max(maxLayerSize, layerRenderer()->rootLayerContentRect().height())
+            || !layerRenderer()->checkTextureSize(m_bounds));
 }
 
@@ -153 +159 @@
     // 2) The content rect-relative rectangle to draw this texture in, returned in drawRect.
 
-    const IntRect contentRect = layerRenderer()->rootLayerContentRect();
+    const IntRect clipRect = layerRenderer()->currentScissorRect();
     const TransformationMatrix& transform = drawTransform();
     // The layer's draw transform points to the center of the layer, relative to
@@ -161 +167 @@
                             m_bounds.height() / 2 - transform.m42());
     // Transform the contentRect into the space of the layer.
-    IntRect contentRectInLayerSpace(layerPos, contentRect.size());
+    IntRect contentRectInLayerSpace(layerPos, clipRect.size());
 
     // Clip the entire layer against the visible region in the content rect

trunk/WebCore/platform/graphics/chromium/LayerChromium.cpp

@@ -452 +452 @@
 }
 
-const FloatRect LayerChromium::getDrawRect() const
+const IntRect LayerChromium::getDrawRect() const
 {
     // Form the matrix used by the shader to map the corners of the layer's
     // bounds into the view space.
-    TransformationMatrix renderMatrix = drawTransform();
-    renderMatrix.scale3d(bounds().width(), bounds().height(), 1);
-
-    FloatRect layerRect(-0.5, -0.5, 1, 1);
-    FloatRect mappedRect = renderMatrix.mapRect(layerRect);
+    FloatRect layerRect(-0.5 * bounds().width(), -0.5 * bounds().height(), bounds().width(), bounds().height());
+    IntRect mappedRect = enclosingIntRect(drawTransform().mapRect(layerRect));
     return mappedRect;
 }

trunk/WebCore/platform/graphics/chromium/LayerChromium.h

@@ -157 +157 @@
 
     // Returns the rect containtaining this layer in the current view's coordinate system.
-    const FloatRect getDrawRect() const;
+    const IntRect getDrawRect() const;
 
     // These methods typically need to be overwritten by derived classes.

trunk/WebCore/platform/graphics/chromium/LayerRendererChromium.cpp

@@ -322 +322 @@
     // Enable scissoring to avoid rendering composited layers over the scrollbars.
     GLC(m_context, m_context->enable(GraphicsContext3D::SCISSOR_TEST));
-    FloatRect scissorRect(contentRect);
+    IntRect scissorRect(contentRect);
 
     // The scissorRect should not include the scroll offset.
@@ -335 +335 @@
     // Traverse the layer tree one more time to draw the layers.
     for (size_t i = 0; i < sublayers.size(); i++)
-        drawLayersRecursive(sublayers[i].get(), scissorRect);
+        drawLayersRecursive(sublayers[i].get());
 
     GLC(m_context, m_context->disable(GraphicsContext3D::SCISSOR_TEST));
@@ -502 +502 @@
 
 // Recursively walk the layer tree and draw the layers.
-void LayerRendererChromium::drawLayersRecursive(LayerChromium* layer, const FloatRect& scissorRect)
+void LayerRendererChromium::drawLayersRecursive(LayerChromium* layer)
 {
     static bool depthTestEnabledForSubtree = false;
@@ -508 +508 @@
 
     // Check if the layer falls within the visible bounds of the page.
-    FloatRect layerRect = layer->getDrawRect();
-    bool isLayerVisible = scissorRect.intersects(layerRect);
+    IntRect layerRect = layer->getDrawRect();
+    bool isLayerVisible = m_currentScissorRect.intersects(layerRect);
 
     // Enable depth testing for this layer and all its descendants if preserves3D is set.
@@ -528 +528 @@
     // FIXME: We should check here if the layer has descendants that draw content
     // before we setup for clipping.
-    FloatRect currentScissorRect = scissorRect;
+    IntRect previousScissorRect = m_currentScissorRect;
     bool mustResetScissorRect = false;
     bool didStencilDraw = false;
@@ -535 +535 @@
         // to clip using the stencil buffer.
         if (layer->drawTransform().isIdentityOrTranslation()) {
+            IntRect currentScissorRect = previousScissorRect;
             currentScissorRect.intersect(layerRect);
-            if (currentScissorRect != scissorRect) {
+            if (currentScissorRect != previousScissorRect) {
                 scissorToRect(currentScissorRect);
                 mustResetScissorRect = true;
@@ -581 +582 @@
 
         for (i = 0; i < sublayerList.size(); i++)
-            drawLayersRecursive(sublayerList[i], currentScissorRect);
+            drawLayersRecursive(sublayerList[i]);
     } else {
         const Vector<RefPtr<LayerChromium> >& sublayers = layer->getSublayers();
         for (size_t i = 0; i < sublayers.size(); i++)
-            drawLayersRecursive(sublayers[i].get(), currentScissorRect);
+            drawLayersRecursive(sublayers[i].get());
     }
 
@@ -601 +602 @@
 
     if (mustResetScissorRect) {
-        scissorToRect(scissorRect);
+        scissorToRect(previousScissorRect);
     }
 
@@ -637 +638 @@
 // Sets the scissor region to the given rectangle. The coordinate system for the
 // scissorRect has its origin at the top left corner of the current visible rect.
-void LayerRendererChromium::scissorToRect(const FloatRect& scissorRect)
+void LayerRendererChromium::scissorToRect(const IntRect& scissorRect)
 {
     // Compute the lower left corner of the scissor rect.
-    float bottom = std::max((float)m_rootVisibleRect.height() - scissorRect.bottom(), 0.f);
+    int bottom = std::max(m_rootVisibleRect.height() - scissorRect.bottom(), 0);
     GLC(m_context, m_context->scissor(scissorRect.x(), bottom, scissorRect.width(), scissorRect.height()));
+    m_currentScissorRect = scissorRect;
 }
 

trunk/WebCore/platform/graphics/chromium/LayerRendererChromium.h

@@ -93 +93 @@
     void deleteLayerTexture(unsigned);
 
+    IntRect currentScissorRect() const { return m_currentScissorRect; }
+
     static void debugGLCall(GraphicsContext3D*, const char* command, const char* file, int line);
 
@@ -117 +119 @@
     void updateLayersRecursive(LayerChromium* layer, const TransformationMatrix& parentMatrix, float opacity);
 
-    void drawLayersRecursive(LayerChromium*, const FloatRect& scissorRect);
+    void drawLayersRecursive(LayerChromium*);
 
     void drawLayer(LayerChromium*);
@@ -125 +127 @@
     void drawLayerIntoStencilBuffer(LayerChromium*, bool decrement);
 
-    void scissorToRect(const FloatRect&);
+    void scissorToRect(const IntRect&);
 
     bool makeContextCurrent();
@@ -164 +166 @@
     IntRect m_rootVisibleRect;
     IntRect m_rootContentRect;
+    IntRect m_currentScissorRect;
 
     int m_maxTextureSize;