Changeset 143541 in webkit

Timestamp:

Feb 20, 2013 5:19:25 PM (11 years ago)

Author:

pdr@google.com

Message:

Account for transform in SVG background images
​https://bugs.webkit.org/show_bug.cgi?id=110295

Reviewed by Dirk Schulze.

Source/WebCore:

Tiled SVG background images are rendererd by drawing the SVG content into a temporary
image buffer, then stamping out a tiled pattern using this buffer. Previously the
image buffer did not account for CSS transforms which could result in pixelated backgrounds.

This patch takes advantage of the context's transform when sizing the temporary tiling
image buffer. Because the context's transform also includes scale, this patch simplifies
the SVG image code to no longer track scale.

Test: svg/as-background-image/svg-transformed-background.html

• loader/cache/CachedImage.cpp:

(WebCore):
(WebCore::CachedImage::imageForRenderer):

CachedImage::lookupOrCreateImageForRenderer no longer creates images so it has been
refactored into just "imageForRenderer". Previously there were two versions of
lookupOrCreateImageForRenderer; these have been folded into imageForRenderer.

• loader/cache/CachedImage.h:
• svg/graphics/SVGImage.cpp:

(WebCore::SVGImage::drawPatternForContainer):

To create the temporary tiling image buffer, the final size in screen coordinates is
needed. This is now computed using the current context's CTM. Because the CTM
already includes the page scale, all page scale tracking can be removed.

The adjustments to srcRect and the pattern transform are the same as before, just
refactored to use imageBufferScale which has x and y components.

• svg/graphics/SVGImage.h:
• svg/graphics/SVGImageCache.cpp:

(WebCore::SVGImageCache::setContainerSizeForRenderer):

Because the page scale needed to be cached between calls to
setContainerSizeForRenderer, this function was written to modify an existing cache
entry. Because the page scale no longer needs to be tracked, this code has been
simplified to re-write any existing cache entry.

(WebCore::SVGImageCache::imageSizeForRenderer):

This function has been simplified by calling SVGImageForContainer::size() instead
of computing this value manually. The value returned remains the same, containing
the container size multiplied by zoom.

(WebCore::SVGImageCache::imageForRenderer):

Previously we set the page scale on every call to imageForRenderer. Because page scale
no longer needs to be tracked, this function has been simplified to simply return
the cached SVGImageForContainer.

• svg/graphics/SVGImageForContainer.cpp:

(WebCore::SVGImageForContainer::drawPattern):

• svg/graphics/SVGImageForContainer.h:

(WebCore::SVGImageForContainer::create):
(WebCore::SVGImageForContainer::SVGImageForContainer):
(SVGImageForContainer):

LayoutTests:

• svg/as-background-image/svg-transformed-background-expected.html: Added.
• svg/as-background-image/svg-transformed-background.html: Added.

Location:

trunk

Files:

• LayoutTests/ChangeLog (modified) (1 diff)
• LayoutTests/svg/as-background-image/svg-transformed-background-expected.html (added)
• LayoutTests/svg/as-background-image/svg-transformed-background.html (added)
• Source/WebCore/ChangeLog (modified) (1 diff)
• Source/WebCore/loader/cache/CachedImage.cpp (modified) (2 diffs)
• Source/WebCore/loader/cache/CachedImage.h (modified) (1 diff)
• Source/WebCore/svg/graphics/SVGImage.cpp (modified) (1 diff)
• Source/WebCore/svg/graphics/SVGImage.h (modified) (1 diff)
• Source/WebCore/svg/graphics/SVGImageCache.cpp (modified) (4 diffs)
• Source/WebCore/svg/graphics/SVGImageForContainer.cpp (modified) (1 diff)
• Source/WebCore/svg/graphics/SVGImageForContainer.h (modified) (3 diffs)

trunk/LayoutTests/ChangeLog

@@ +1 @@
+2013-02-20  Philip Rogers  <pdr@google.com>
+
+        Account for transform in SVG background images
+        https://bugs.webkit.org/show_bug.cgi?id=110295
+
+        Reviewed by Dirk Schulze.
+
+        * svg/as-background-image/svg-transformed-background-expected.html: Added.
+        * svg/as-background-image/svg-transformed-background.html: Added.
+
 2013-02-20  Ojan Vafai  <ojan@chromium.org>
 

trunk/Source/WebCore/ChangeLog

@@ +1 @@
+2013-02-20  Philip Rogers  <pdr@google.com>
+
+        Account for transform in SVG background images
+        https://bugs.webkit.org/show_bug.cgi?id=110295
+
+        Reviewed by Dirk Schulze.
+
+        Tiled SVG background images are rendererd by drawing the SVG content into a temporary
+        image buffer, then stamping out a tiled pattern using this buffer. Previously the
+        image buffer did not account for CSS transforms which could result in pixelated backgrounds.
+
+        This patch takes advantage of the context's transform when sizing the temporary tiling
+        image buffer. Because the context's transform also includes scale, this patch simplifies
+        the SVG image code to no longer track scale.
+
+        Test: svg/as-background-image/svg-transformed-background.html
+
+        * loader/cache/CachedImage.cpp:
+        (WebCore):
+        (WebCore::CachedImage::imageForRenderer):
+
+            CachedImage::lookupOrCreateImageForRenderer no longer creates images so it has been
+            refactored into just "imageForRenderer". Previously there were two versions of
+            lookupOrCreateImageForRenderer; these have been folded into imageForRenderer.
+
+        * loader/cache/CachedImage.h:
+        * svg/graphics/SVGImage.cpp:
+        (WebCore::SVGImage::drawPatternForContainer):
+
+            To create the temporary tiling image buffer, the final size in screen coordinates is
+            needed. This is now computed using the current context's CTM. Because the CTM
+            already includes the page scale, all page scale tracking can be removed.
+
+            The adjustments to srcRect and the pattern transform are the same as before, just
+            refactored to use imageBufferScale which has x and y components.
+
+        * svg/graphics/SVGImage.h:
+        * svg/graphics/SVGImageCache.cpp:
+        (WebCore::SVGImageCache::setContainerSizeForRenderer):
+
+            Because the page scale needed to be cached between calls to
+            setContainerSizeForRenderer, this function was written to modify an existing cache
+            entry. Because the page scale no longer needs to be tracked, this code has been
+            simplified to re-write any existing cache entry.
+
+        (WebCore::SVGImageCache::imageSizeForRenderer):
+
+            This function has been simplified by calling SVGImageForContainer::size() instead
+            of computing this value manually. The value returned remains the same, containing
+            the container size multiplied by zoom.
+
+        (WebCore::SVGImageCache::imageForRenderer):
+
+            Previously we set the page scale on every call to imageForRenderer. Because page scale
+            no longer needs to be tracked, this function has been simplified to simply return
+            the cached SVGImageForContainer.
+
+        * svg/graphics/SVGImageForContainer.cpp:
+        (WebCore::SVGImageForContainer::drawPattern):
+        * svg/graphics/SVGImageForContainer.h:
+        (WebCore::SVGImageForContainer::create):
+        (WebCore::SVGImageForContainer::SVGImageForContainer):
+        (SVGImageForContainer):
+
 2013-02-20  Jer Noble  <jer.noble@apple.com>
 

trunk/Source/WebCore/loader/cache/CachedImage.cpp

@@ -158 +158 @@
 }
 
-#if ENABLE(SVG)
-inline Image* CachedImage::lookupOrCreateImageForRenderer(const RenderObject* renderer)
-{
-    if (!m_image)
-        return 0;
-    if (!m_image->isSVGImage())
-        return m_image.get();
-    Image* useImage = m_svgImageCache->imageForRenderer(renderer);
-    if (useImage == Image::nullImage())
-        return m_image.get();
-    return useImage;
-}
-#else
-inline Image* CachedImage::lookupOrCreateImageForRenderer(const RenderObject*)
-{
-    return m_image.get();
-}
-#endif
-
 Image* CachedImage::image()
 {
@@ -205 +186 @@
     }
 
-    if (m_image)
-        return lookupOrCreateImageForRenderer(renderer);
-
-    return Image::nullImage();
+    if (!m_image)
+        return Image::nullImage();
+
+#if ENABLE(SVG)
+    if (m_image->isSVGImage()) {
+        Image* image = m_svgImageCache->imageForRenderer(renderer);
+        if (image != Image::nullImage())
+            return image;
+    }
+#else
+    UNUSED_PARAM(renderer);
+#endif
+    return m_image.get();
 }
 

trunk/Source/WebCore/loader/cache/CachedImage.h

@@ -98 +98 @@
 
 private:
-    Image* lookupOrCreateImageForRenderer(const RenderObject*);
-
     void clear();
 

trunk/Source/WebCore/svg/graphics/SVGImage.cpp

@@ -142 +142 @@
 }
 
-void SVGImage::drawPatternForContainer(GraphicsContext* context, const FloatSize containerSize, float pageScale, float zoom, const FloatRect& srcRect,
+void SVGImage::drawPatternForContainer(GraphicsContext* context, const FloatSize containerSize, float zoom, const FloatRect& srcRect,
     const AffineTransform& patternTransform, const FloatPoint& phase, ColorSpace colorSpace, CompositeOperator compositeOp, const FloatRect& dstRect)
 {
-    ASSERT(pageScale);
-
     FloatRect zoomedContainerRect = FloatRect(FloatPoint(), containerSize);
     zoomedContainerRect.scale(zoom);
-    FloatRect zoomedAndScaledContainerRect = zoomedContainerRect;
-    zoomedAndScaledContainerRect.scale(pageScale);
-
-    // FIXME(WK110065): This should take advantage of the ImageBuffer resolution instead of scaling the buffer manually.
-    OwnPtr<ImageBuffer> buffer = ImageBuffer::create(expandedIntSize(zoomedAndScaledContainerRect.size()), 1);
-    drawForContainer(buffer->context(), containerSize, zoom, zoomedAndScaledContainerRect, zoomedContainerRect, ColorSpaceDeviceRGB, CompositeSourceOver, BlendModeNormal);
+
+    // The ImageBuffer size needs to be scaled to match the final resolution.
+    AffineTransform transform = context->getCTM();
+    FloatSize imageBufferScale = FloatSize(transform.xScale(), transform.yScale());
+    ASSERT(imageBufferScale.width());
+    ASSERT(imageBufferScale.height());
+
+    FloatRect imageBufferSize = zoomedContainerRect;
+    imageBufferSize.scale(imageBufferScale.width(), imageBufferScale.height());
+
+    OwnPtr<ImageBuffer> buffer = ImageBuffer::create(expandedIntSize(imageBufferSize.size()), 1);
+    drawForContainer(buffer->context(), containerSize, zoom, imageBufferSize, zoomedContainerRect, ColorSpaceDeviceRGB, CompositeSourceOver, BlendModeNormal);
     RefPtr<Image> image = buffer->copyImage(CopyBackingStore, Unscaled);
 
-    // Adjust the source rect and transform for image buffer scale due to pageScale.
+    // Adjust the source rect and transform due to the image buffer's scaling.
     FloatRect scaledSrcRect = srcRect;
-    scaledSrcRect.scale(pageScale);
+    scaledSrcRect.scale(imageBufferScale.width(), imageBufferScale.height());
     AffineTransform unscaledPatternTransform(patternTransform);
-    unscaledPatternTransform.scale(1 / pageScale);
+    unscaledPatternTransform.scale(1 / imageBufferScale.width(), 1 / imageBufferScale.height());
 
     image->drawPattern(context, scaledSrcRect, unscaledPatternTransform, phase, colorSpace, compositeOp, dstRect);

trunk/Source/WebCore/svg/graphics/SVGImage.h

@@ -90 +90 @@
     virtual void draw(GraphicsContext*, const FloatRect& fromRect, const FloatRect& toRect, ColorSpace styleColorSpace, CompositeOperator, BlendMode);
     void drawForContainer(GraphicsContext*, const FloatSize, float, const FloatRect&, const FloatRect&, ColorSpace, CompositeOperator, BlendMode);
-    void drawPatternForContainer(GraphicsContext*, const FloatSize, float, float, const FloatRect&, const AffineTransform&,
-        const FloatPoint&, ColorSpace, CompositeOperator, const FloatRect&);
+    void drawPatternForContainer(GraphicsContext*, const FloatSize, float, const FloatRect&, const AffineTransform&, const FloatPoint&, ColorSpace,
+        CompositeOperator, const FloatRect&);
 
     OwnPtr<SVGImageChromeClient> m_chromeClient;

trunk/Source/WebCore/svg/graphics/SVGImageCache.cpp

@@ -57 +57 @@
     ASSERT(client);
     ASSERT(!containerSize.isEmpty());
+    ASSERT(containerZoom);
 
     FloatSize containerSizeWithoutZoom(containerSize);
     containerSizeWithoutZoom.scale(1 / containerZoom);
 
-    ImageForContainerMap::iterator imageIt = m_imageForContainerMap.find(client);
-    if (imageIt == m_imageForContainerMap.end()) {
-        RefPtr<SVGImageForContainer> image = SVGImageForContainer::create(m_svgImage, containerSizeWithoutZoom, 1, containerZoom);
-        m_imageForContainerMap.set(client, image);
-    } else {
-        imageIt->value->setSize(containerSizeWithoutZoom);
-        imageIt->value->setZoom(containerZoom);
-    }
+    m_imageForContainerMap.set(client, SVGImageForContainer::create(m_svgImage, containerSizeWithoutZoom, containerZoom));
 }
 
@@ -82 +76 @@
 
     RefPtr<SVGImageForContainer> image = it->value;
-    FloatSize size = image->containerSize();
-    if (!size.isEmpty()) {
-        size.scale(image->zoom());
-        imageSize.setWidth(size.width());
-        imageSize.setHeight(size.height());
-    }
-
-    return imageSize;
+    ASSERT(!image->size().isEmpty());
+    return image->size();
 }
 
@@ -99 +87 @@
         return Image::nullImage();
 
-    // The cache needs to know the size of the renderer before querying an image for it.
     ImageForContainerMap::iterator it = m_imageForContainerMap.find(renderer);
     if (it == m_imageForContainerMap.end())
@@ -105 +92 @@
 
     RefPtr<SVGImageForContainer> image = it->value;
-    ASSERT(!image->containerSize().isEmpty());
-
-    // FIXME: Set the page scale in setContainerSizeForRenderer instead of looking it up here.
-    Page* page = renderer->document()->page();
-    image->setPageScale(page->deviceScaleFactor() * page->pageScaleFactor());
-
+    ASSERT(!image->size().isEmpty());
     return image.get();
 }

trunk/Source/WebCore/svg/graphics/SVGImageForContainer.cpp

@@ -46 +46 @@
     const FloatPoint& phase, ColorSpace colorSpace, CompositeOperator compositeOp, const FloatRect& dstRect, BlendMode)
 {
-    m_image->drawPatternForContainer(context, m_containerSize, m_pageScale, m_zoom, srcRect, patternTransform, phase, colorSpace, compositeOp, dstRect);
+    m_image->drawPatternForContainer(context, m_containerSize, m_zoom, srcRect, patternTransform, phase, colorSpace, compositeOp, dstRect);
 }
 

trunk/Source/WebCore/svg/graphics/SVGImageForContainer.h

@@ -39 +39 @@
 class SVGImageForContainer : public Image {
 public:
-    static PassRefPtr<SVGImageForContainer> create(SVGImage* image, const FloatSize& containerSize, float pageScale, float zoom)
+    static PassRefPtr<SVGImageForContainer> create(SVGImage* image, const FloatSize& containerSize, float zoom)
     {
-        return adoptRef(new SVGImageForContainer(image, containerSize, pageScale, zoom));
+        return adoptRef(new SVGImageForContainer(image, containerSize, zoom));
     }
 
@@ -63 +63 @@
     virtual bool currentFrameKnownToBeOpaque() OVERRIDE { return false; }
 
-    FloatSize containerSize() { return m_containerSize; }
-    float pageScale() { return m_pageScale; }
-    float zoom() { return m_zoom; }
-
-    void setSize(FloatSize& size) { m_containerSize = size; }
-    void setZoom(float zoom) { m_zoom = zoom; }
-    void setPageScale(float pageScale) { m_pageScale = pageScale; }
-
 private:
-    SVGImageForContainer(SVGImage* image, const FloatSize& containerSize, float pageScale, float zoom)
-        : m_image(image), m_containerSize(containerSize), m_pageScale(pageScale), m_zoom(zoom) { }
+    SVGImageForContainer(SVGImage* image, const FloatSize& containerSize, float zoom)
+        : m_image(image)
+        , m_containerSize(containerSize)
+        , m_zoom(zoom)
+    {
+    }
 
     virtual void destroyDecodedData(bool /*destroyAll*/ = true) { }
@@ -79 +75 @@
 
     SVGImage* m_image;
-    FloatSize m_containerSize;
-    float m_pageScale;
-    float m_zoom;
+    const FloatSize m_containerSize;
+    const float m_zoom;
 };
 }