[skia] Improve performance of GraphicsContext::createCompatibleBuffer by using SkDevice:createCompatibleDevice
https://bugs.webkit.org/show_bug.cgi?id=103896
Reviewed by Stephen White.
Source/WebCore:
Refactored GraphicsContext::createCompatibleBuffer (platform common
code) to use platform-specific implementations provided by ImageBuffer.
There is no change in behavior for non-skia ports. The skia
implementation uses skia'a own createCompatibleDevice implementation,
which offers several performance benefits:
1. For accelerated contexts, the backing store may be allocated from
the scratch texture pool, which minimizes texture allocation and
deallocation overhead.
2. The backing store will not be initially cleared if it is known
in advance that fully opaque contents will be drawn into the buffer.
3. For non-accelerated contexts, if the backing store is flagged as
opaque, faster blitter loop implementations will be used for drawing
the buffer contents into other buffers. (e.g. generated opaque gradient
fills)
No new tests: covered by existing layout tests
* platform/graphics/Generator.h:
(Generator):
Added hasAlpha method so that it can be used by GeneratorGeneratedImage
* platform/graphics/GeneratorGeneratedImage.cpp:
(WebCore::GeneratorGeneratedImage::drawPattern):
Passing m_generator->hasAlpha() to createCompatibleBuffer in order to
take advantage of optimizations that apply to opaque buffers.
* platform/graphics/Gradient.h:
(Gradient):
Made hasAlpha virtual so that it now overrides Generator::hasAlpha
* platform/graphics/GraphicsContext.cpp:
(WebCore::GraphicsContext::createCompatibleBuffer):
Refactored to use platform-specific implementation
* platform/graphics/GraphicsContext.h:
* platform/graphics/ImageBuffer.cpp:
(WebCore::createCompatibleBuffer):
Non-skia implementation. Mimics old
GraphicsContext::createCompatibleBuffer
* platform/graphics/ImageBuffer.h:
(ImageBuffer):
New skia-specific constructor
* platform/graphics/skia/ImageBufferSkia.cpp:
(WebCore::ImageBuffer::createCompatibleBuffer):
(WebCore::ImageBuffer::ImageBuffer):
* platform/graphics/skia/PlatformContextSkia.cpp:
(WebCore::PlatformContextSkia::createCompatibleDevice):
(WebCore):
* platform/graphics/skia/PlatformContextSkia.h:
(PlatformContextSkia):
LayoutTests:
Added image failure expectation for test needing new baselines
* platform/chromium/TestExpectations:
git-svn-id: http://svn.webkit.org/repository/webkit/trunk@136755 268f45cc-cd09-0410-ab3c-d52691b4dbfc
13 files changed
