Initial PaintInvalidationState support for SVG

Source/core/rendering/PaintInvalidationState.cpp

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "config.h"
 #include "core/rendering/PaintInvalidationState.h"
 
 #include "core/rendering/RenderInline.h"
 #include "core/rendering/RenderLayer.h"
 #include "core/rendering/RenderView.h"
 #include "core/rendering/svg/RenderSVGModelObject.h"
+#include "core/rendering/svg/RenderSVGRoot.h"
 #include "platform/Partitions.h"
 
 namespace blink {
 
 PaintInvalidationState::PaintInvalidationState(const RenderView& renderView)
     : m_clipped(false)
     , m_cachedOffsetsEnabled(true)
     , m_forceCheckForPaintInvalidation(false)
     , m_paintInvalidationContainer(*renderView.containerForPaintInvalidation())
 {
@@ skipping 47 matching lines @@
 
             if (renderer.style()->hasInFlowPosition() && renderer.hasLayer())
                 m_paintOffset += renderer.layer()->offsetForInFlowPosition();
         }
 
         m_clipped = !fixed && next.m_clipped;
         if (m_clipped)
             m_clipRect = next.m_clipRect;
     }
 
+    if (m_cachedOffsetsEnabled && renderer.isSVGRoot()) {
+        const RenderSVGRoot& svgRoot = toRenderSVGRoot(renderer);
+        m_svgTransform = svgRoot.localToBorderBoxTransform();
+        if (svgRoot.shouldApplyViewportClip())
+            addClipRectRelativeToPaintOffset(svgRoot.pixelSnappedSize());
+    }
+
     applyClipIfNeeded(renderer);
 
     // FIXME: <http://bugs.webkit.org/show_bug.cgi?id=13443> Apply control clip if present.
 }
 
+PaintInvalidationState::PaintInvalidationState(const PaintInvalidationState& next, const RenderSVGModelObject& renderer)
+    : m_clipped(next.m_clipped)
+    , m_cachedOffsetsEnabled(next.m_cachedOffsetsEnabled)
+    , m_forceCheckForPaintInvalidation(next.m_forceCheckForPaintInvalidation)
+    , m_clipRect(next.m_clipRect)
+    , m_paintOffset(next.m_paintOffset)
+    , m_paintInvalidationContainer(next.m_paintInvalidationContainer)
+    , m_svgTransform(next.m_svgTransform)
+{
+    ASSERT(renderer != m_paintInvalidationContainer);
+
+    if (m_cachedOffsetsEnabled)
+        m_svgTransform *= renderer.localToParentTransform();
+}
+
+void PaintInvalidationState::addClipRectRelativeToPaintOffset(const LayoutSize& clipSize)
+{
+    LayoutRect clipRect(toPoint(m_paintOffset), clipSize);
+    if (m_clipped) {
+        m_clipRect.intersect(clipRect);
+    } else {
+        m_clipRect = clipRect;
+        m_clipped = true;
+    }
+}
+
 void PaintInvalidationState::applyClipIfNeeded(const RenderObject& renderer)
 {
     if (!renderer.hasOverflowClip())
         return;
 
     const RenderBox& box = toRenderBox(renderer);
 
     // Do not clip scroll layer contents because the compositor expects the whole layer
     // to be always invalidated in-time.
-    if (box.usesCompositedScrolling()) {
+    if (box.usesCompositedScrolling())
         ASSERT(!m_clipped); // The box should establish paint invalidation container, so no m_clipped inherited.
-    } else {
-        LayoutRect clipRect(toPoint(m_paintOffset), box.layer()->size());
-        if (m_clipped) {
-            m_clipRect.intersect(clipRect);
-        } else {
-            m_clipRect = clipRect;
-            m_clipped = true;
-        }
-    }
+    else
+        addClipRectRelativeToPaintOffset(box.layer()->size());
 
     m_paintOffset -= box.scrolledContentOffset();
 }
 
 } // namespace blink