Changeset 157045 in webkit

Timestamp:

Oct 7, 2013 9:48:09 AM (11 years ago)

Author:

timothy_horton@apple.com

Message:

-webkit-cross-fade paints SVGs at full opacity during cross-fade
​https://bugs.webkit.org/show_bug.cgi?id=122441
<rdar://problem/13973162>

Reviewed by Simon Fraser.

Test: css3/images/cross-fade-svg-with-opacity.html

• platform/graphics/CrossfadeGeneratedImage.cpp:

(WebCore::drawCrossfadeSubimage):
(WebCore::CrossfadeGeneratedImage::drawCrossfade):
Factor the image painting out into a function.
Conditionally use a transparency layer around painting if the image
we're drawing is an SVG (SVGImage is the only Image subclass that will
not respect the context's opacity).

Add a test that ensures that -cross-fade with SVG images draws correctly.

• css3/images/cross-fade-svg-with-opacity-expected.html: Added.
• css3/images/cross-fade-svg-with-opacity.html: Added.

Location:

trunk

Files:

• LayoutTests/ChangeLog (modified) (1 diff)
• LayoutTests/css3/images/cross-fade-svg-with-opacity-expected.html (added)
• LayoutTests/css3/images/cross-fade-svg-with-opacity.html (added)
• Source/WebCore/ChangeLog (modified) (1 diff)
• Source/WebCore/platform/graphics/CrossfadeGeneratedImage.cpp (modified) (2 diffs)

trunk/LayoutTests/ChangeLog

@@ +1 @@
+2013-10-07  Tim Horton  <timothy_horton@apple.com>
+
+        -webkit-cross-fade paints SVGs at full opacity during cross-fade
+        https://bugs.webkit.org/show_bug.cgi?id=122441
+        <rdar://problem/13973162>
+
+        Reviewed by Simon Fraser.
+
+        Add a test that ensures that -cross-fade with SVG images draws correctly.
+
+        * css3/images/cross-fade-svg-with-opacity-expected.html: Added.
+        * css3/images/cross-fade-svg-with-opacity.html: Added.
+
 2013-10-07  Filip Pizlo  <fpizlo@apple.com>
 

trunk/Source/WebCore/ChangeLog

@@ +1 @@
+2013-10-07  Tim Horton  <timothy_horton@apple.com>
+
+        -webkit-cross-fade paints SVGs at full opacity during cross-fade
+        https://bugs.webkit.org/show_bug.cgi?id=122441
+        <rdar://problem/13973162>
+
+        Reviewed by Simon Fraser.
+
+        Test: css3/images/cross-fade-svg-with-opacity.html
+
+        * platform/graphics/CrossfadeGeneratedImage.cpp:
+        (WebCore::drawCrossfadeSubimage):
+        (WebCore::CrossfadeGeneratedImage::drawCrossfade):
+        Factor the image painting out into a function.
+        Conditionally use a transparency layer around painting if the image
+        we're drawing is an SVG (SVGImage is the only Image subclass that will
+        not respect the context's opacity).
+
 2013-10-06  Anders Carlsson  <andersca@apple.com>
 

trunk/Source/WebCore/platform/graphics/CrossfadeGeneratedImage.cpp

@@ -44 +44 @@
 }
 
+static void drawCrossfadeSubimage(GraphicsContext* context, Image* image, CompositeOperator operation, float opacity, IntSize targetSize)
+{
+    IntSize imageSize = image->size();
+
+    // SVGImage resets the opacity when painting, so we have to use transparency layers to accurately paint one at a given opacity.
+    bool useTransparencyLayer = image->isSVGImage();
+
+    GraphicsContextStateSaver stateSaver(*context);
+
+    context->setCompositeOperation(operation);
+
+    if (useTransparencyLayer)
+        context->beginTransparencyLayer(opacity);
+    else
+        context->setAlpha(opacity);
+
+    if (targetSize != imageSize)
+        context->scale(FloatSize(static_cast<float>(targetSize.width()) / imageSize.width(),
+            static_cast<float>(targetSize.height()) / imageSize.height()));
+    context->drawImage(image, ColorSpaceDeviceRGB, IntPoint());
+
+    if (useTransparencyLayer)
+        context->endTransparencyLayer();
+}
+
 void CrossfadeGeneratedImage::drawCrossfade(GraphicsContext* context)
 {
-    float inversePercentage = 1 - m_percentage;
-
-    IntSize fromImageSize = m_fromImage->size();
-    IntSize toImageSize = m_toImage->size();
-
     // Draw nothing if either of the images hasn't loaded yet.
     if (m_fromImage == Image::nullImage() || m_toImage == Image::nullImage())
@@ -59 +79 @@
     context->clip(IntRect(IntPoint(), m_crossfadeSize));
     context->beginTransparencyLayer(1);
-    
-    // Draw the image we're fading away from.
-    context->save();
-    if (m_crossfadeSize != fromImageSize)
-        context->scale(FloatSize(static_cast<float>(m_crossfadeSize.width()) / fromImageSize.width(),
-                                 static_cast<float>(m_crossfadeSize.height()) / fromImageSize.height()));
-    context->setAlpha(inversePercentage);
-    context->drawImage(m_fromImage, ColorSpaceDeviceRGB, IntPoint());
-    context->restore();
 
-    // Draw the image we're fading towards.
-    context->save();
-    if (m_crossfadeSize != toImageSize)
-        context->scale(FloatSize(static_cast<float>(m_crossfadeSize.width()) / toImageSize.width(),
-                                 static_cast<float>(m_crossfadeSize.height()) / toImageSize.height()));
-    context->setAlpha(m_percentage);
-    context->drawImage(m_toImage, ColorSpaceDeviceRGB, IntPoint(), CompositePlusLighter);
-    context->restore();
+    drawCrossfadeSubimage(context, m_fromImage, CompositeSourceOver, 1 - m_percentage, m_crossfadeSize);
+    drawCrossfadeSubimage(context, m_toImage, CompositePlusLighter, m_percentage, m_crossfadeSize);
 
     context->endTransparencyLayer();