ImageBuffer-less SVG masking and clipping.

Source/core/rendering/svg/SVGRenderingContext.cpp

 /*
  * Copyright (C) 2007, 2008 Rob Buis <buis@kde.org>
  * Copyright (C) 2007 Nikolas Zimmermann <zimmermann@kde.org>
  * Copyright (C) 2007 Eric Seidel <eric@webkit.org>
  * Copyright (C) 2009 Google, Inc.  All rights reserved.
  * Copyright (C) 2009 Dirk Schulze <krit@webkit.org>
  * Copyright (C) Research In Motion Limited 2009-2010. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
@@ skipping 38 matching lines @@
 }
 
 SVGRenderingContext::~SVGRenderingContext()
 {
     // Fast path if we don't need to restore anything.
     if (!(m_renderingFlags & ActionsNeeded))
         return;
 
     ASSERT(m_object && m_paintInfo);
 
-    if (m_renderingFlags & EndFilterLayer) {
-        ASSERT(m_filter);
-        m_filter->postApplyResource(m_object, m_paintInfo->context, ApplyToDefaultMode, 0, 0);
-        m_paintInfo->context = m_savedContext;
-        m_paintInfo->setRect(m_savedPaintRect);
+    if (m_renderingFlags & PostApplyResources) {
+        ASSERT(m_masker || m_clipper || m_filter);
+        ASSERT(SVGResourcesCache::cachedResourcesForRenderObject(m_object));
+
+        if (m_filter) {
+            ASSERT(SVGResourcesCache::cachedResourcesForRenderObject(m_object)->filter() == m_filter);
+            m_filter->postApplyResource(m_object, m_paintInfo->context, ApplyToDefaultMode, 0, 0);
+            m_paintInfo->context = m_savedContext;
+            m_paintInfo->setRect(m_savedPaintRect);
+        }
+
+        if (m_clipper) {
+            ASSERT(SVGResourcesCache::cachedResourcesForRenderObject(m_object)->clipper() == m_clipper);
+            m_clipper->postApplyResource(m_object, m_paintInfo->context, ApplyToDefaultMode, 0, 0);
+        }
+
+        if (m_masker) {
+            ASSERT(SVGResourcesCache::cachedResourcesForRenderObject(m_object)->masker() == m_masker);
+            m_masker->postApplyResource(m_object, m_paintInfo->context, ApplyToDefaultMode, 0, 0);
+        }
     }
 
     if (m_renderingFlags & EndOpacityLayer)
-        m_paintInfo->context->endTransparencyLayer();
+        m_paintInfo->context->endLayer();
 
     if (m_renderingFlags & RestoreGraphicsContext)
         m_paintInfo->context->restore();
 }
 
 void SVGRenderingContext::prepareToRenderSVGContent(RenderObject* object, PaintInfo& paintInfo, NeedsGraphicsContextSave needsGraphicsContextSave)
 {
     ASSERT(object);
 
 #ifndef NDEBUG
@@ skipping 51 matching lines @@
             return;
 
         m_renderingFlags |= RenderingPrepared;
         return;
     }
 
     if (!isRenderingMask) {
         if (RenderSVGResourceMasker* masker = resources->masker()) {
             if (!masker->applyResource(m_object, style, m_paintInfo->context, ApplyToDefaultMode))
                 return;
+            m_masker = masker;
+            m_renderingFlags |= PostApplyResources;
         }
     }
 
     RenderSVGResourceClipper* clipper = resources->clipper();
     if (!clipPathOperation && clipper) {
         if (!clipper->applyResource(m_object, style, m_paintInfo->context, ApplyToDefaultMode))
             return;
+        m_clipper = clipper;
+        m_renderingFlags |= PostApplyResources;
     }
 
     if (!isRenderingMask) {
         m_filter = resources->filter();
         if (m_filter) {
             m_savedContext = m_paintInfo->context;
             m_savedPaintRect = m_paintInfo->rect();
             // Return with false here may mean that we don't need to draw the content
             // (because it was either drawn before or empty) but we still need to apply the filter.
-            m_renderingFlags |= EndFilterLayer;
+            m_renderingFlags |= PostApplyResources;
             if (!m_filter->applyResource(m_object, style, m_paintInfo->context, ApplyToDefaultMode))
                 return;
 
             // Since we're caching the resulting bitmap and do not invalidate it on repaint rect
             // changes, we need to paint the whole filter region. Otherwise, elements not visible
             // at the time of the initial paint (due to scrolling, window size, etc.) will never
             // be drawn.
             m_paintInfo->setRect(IntRect(m_filter->drawingRegion(m_object)));
         }
     }
@@ skipping 83 matching lines @@
     GraphicsContext* imageContext = image->context();
     ASSERT(imageContext);
 
     // Compensate rounding effects, as the absolute target rect is using floating-point numbers and the image buffer size is integer.
     imageContext->scale(FloatSize(unclampedImageSize.width() / absoluteTargetRect.width(), unclampedImageSize.height() / absoluteTargetRect.height()));
 
     imageBuffer = image.release();
     return true;
 }
 
-void SVGRenderingContext::renderSubtreeToImageBuffer(ImageBuffer* image, RenderObject* item, const AffineTransform& subtreeContentTransformation)
+void SVGRenderingContext::renderSubtree(GraphicsContext* context, RenderObject* item, const AffineTransform& subtreeContentTransformation)
 {
     ASSERT(item);
-    ASSERT(image);
-    ASSERT(image->context());
+    ASSERT(context);
 
-    PaintInfo info(image->context(), PaintInfo::infiniteRect(), PaintPhaseForeground, PaintBehaviorNormal);
+    PaintInfo info(context, PaintInfo::infiniteRect(), PaintPhaseForeground, PaintBehaviorNormal);
 
     AffineTransform& contentTransformation = currentContentTransformation();
     AffineTransform savedContentTransformation = contentTransformation;
     contentTransformation = subtreeContentTransformation * contentTransformation;
 
     ASSERT(!item->needsLayout());
     item->paint(info, IntPoint());
 
     contentTransformation = savedContentTransformation;
 }
 
-void SVGRenderingContext::clipToImageBuffer(GraphicsContext* context, const AffineTransform& absoluteTransform, const FloatRect& targetRect, OwnPtr<ImageBuffer>& imageBuffer, bool safeToClear)
-{
-    ASSERT(context);
-    ASSERT(imageBuffer);
-
-    FloatRect absoluteTargetRect = calculateImageBufferRect(targetRect, absoluteTransform);
-
-    // The mask image has been created in the absolute coordinate space, as the image should not be scaled.
-    // So the actual masking process has to be done in the absolute coordinate space as well.
-    context->concatCTM(absoluteTransform.inverse());
-    context->clipToImageBuffer(imageBuffer.get(), absoluteTargetRect);
-    context->concatCTM(absoluteTransform);
-
-    // When nesting resources, with objectBoundingBox as content unit types, there's no use in caching the
-    // resulting image buffer as the parent resource already caches the result.
-    if (safeToClear && !currentContentTransformation().isIdentity())
-        imageBuffer.clear();
-}
-
 FloatRect SVGRenderingContext::clampedAbsoluteTargetRect(const FloatRect& absoluteTargetRect)
 {
     const FloatSize maxImageBufferSize(kMaxImageBufferSize, kMaxImageBufferSize);
     return FloatRect(absoluteTargetRect.location(), absoluteTargetRect.size().shrunkTo(maxImageBufferSize));
 }
 
 IntSize SVGRenderingContext::clampedAbsoluteSize(const IntSize& absoluteSize)
 {
     const IntSize maxImageBufferSize(kMaxImageBufferSize, kMaxImageBufferSize);
     return absoluteSize.shrunkTo(maxImageBufferSize);
@@ skipping 32 matching lines @@
             toRenderSVGImage(m_object)->paintForeground(bufferedInfo);
         } else
             return false;
     }
 
     m_paintInfo->context->drawImageBuffer(imageBuffer.get(), boundingBox);
     return true;
 }
 
 }