[SVG] DisplayList-based patterns.

Source/platform/graphics/Pattern.cpp

 /*
  * Copyright (C) 2006, 2007, 2008 Apple Computer, Inc.  All rights reserved.
  * Copyright (C) 2008 Eric Seidel <eric@webkit.org>
  * Copyright (C) 2013 Google, Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
@@ skipping 11 matching lines @@
  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
  * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
 #include "config.h"
 #include "platform/graphics/Pattern.h"
 
 #include "platform/graphics/BitmapPattern.h"
+#include "platform/graphics/DisplayList.h"
+#include "platform/graphics/DisplayListPattern.h"
 #include "platform/graphics/StaticBitmapPattern.h"
 #include "third_party/skia/include/core/SkImage.h"
 #include "third_party/skia/include/core/SkShader.h"
 #include <v8.h>
 
 namespace blink {
 
 PassRefPtr<Pattern> Pattern::createBitmapPattern(PassRefPtr<Image> tileImage, RepeatMode repeatMode)
 {
     if (tileImage->skImage())
         return StaticBitmapPattern::create(tileImage, repeatMode);
 
     return BitmapPattern::create(tileImage, repeatMode);
 }
 
+PassRefPtr<Pattern> Pattern::createDisplayListPattern(PassRefPtr<DisplayList> displayList,
+    RepeatMode repeatMode)
+{
+    return DisplayListPattern::create(displayList, repeatMode);
+}
+
 Pattern::Pattern(RepeatMode repeatMode, int64_t externalMemoryAllocated)
     : m_repeatMode(repeatMode)
     , m_externalMemoryAllocated(0)
 {
     adjustExternalMemoryAllocated(externalMemoryAllocated);
 }
 
 Pattern::~Pattern()
 {
     adjustExternalMemoryAllocated(-m_externalMemoryAllocated);
 }
 
 SkShader* Pattern::shader()
 {
     if (!m_pattern) {
         m_pattern = createShader();

[Stephen White, 2014/10/22 15:11:26]

Tangentially, it looks like the only reason we need to lazy-create the SkShader
is to support a mutable patternSpaceTransform. If we could change the call sites
to not require that (and create a new Pattern when the transform changes), we
could make Pattern a thin wrapper around SkShader, and we wouldn't need the
Pattern subclasses at all (createDisplayListPattern()/createBitmapPattern()
would construct the appropriate SkShader, and pass it to the Pattern). That
would move us closer to the Skia model, too.

[fs, 2014/10/22 15:29:03]

I think this should feasible at least for SVG (I don't really expect the
transform to be used elsewhere though...). It's mostly a matter of cargoing
around that (fairly large - 48 bytes) AffineTransform. Assuming you meant
something like:

class WrappedShader {
   AffineTransform shaderTransform;
   RefPtr<SkShader> shader;
};

I'll add it to my pile if no one gets to it first.

[f(malita), 2014/10/22 16:23:47]

Acknowledged.

     }
 
     return m_pattern.get();
 }
 
 void Pattern::setPatternSpaceTransform(const AffineTransform& patternSpaceTransformation)
 {
     if (patternSpaceTransformation == m_patternSpaceTransformation)
         return;
 
     m_patternSpaceTransformation = patternSpaceTransformation;
     m_pattern.clear();
 }
 
 void Pattern::adjustExternalMemoryAllocated(int64_t delta)
 {
     delta = std::max(-m_externalMemoryAllocated, delta);
 
     v8::Isolate::GetCurrent()->AdjustAmountOfExternalAllocatedMemory(delta);
 
     m_externalMemoryAllocated += delta;
 }
 
 } // namespace blink