Changeset 145810 in webkit

Timestamp:

Mar 14, 2013 7:04:32 AM (11 years ago)

Author:

allan.jensen@digia.com

Message:

[Qt] Add support for tiled shadow blur
​https://bugs.webkit.org/show_bug.cgi?id=90082

Reviewed by Noam Rosenthal.

Use the optimized ShadowBlur::drawRectShadow as long as we do not
have a rotating transform. Such a transform would go through the
slow path in ShadowBlur anyway, and would end up using a transformed
TransparencyLayer with an alphaMap which causes scaling artifacts
for us.

Tested by fast/canvas/canvas-scale-fillRect-shadow.html
and fast/canvas/canvas-transforms-fillRect-shadow.html

• platform/graphics/ShadowBlur.cpp:

(WebCore::ShadowBlur::drawInsetShadowWithTiling):

Handle scaling transforms when shadows ignore transforms.

(WebCore::ShadowBlur::drawRectShadowWithTiling):

Ditto.

• platform/graphics/qt/GraphicsContextQt.cpp:

(WebCore::GraphicsContext::fillRect):

Location:

trunk/Source/WebCore

Files:

• ChangeLog (modified) (1 diff)
• platform/graphics/ShadowBlur.cpp (modified) (2 diffs)
• platform/graphics/qt/GraphicsContextQt.cpp (modified) (1 diff)

trunk/Source/WebCore/ChangeLog

@@ +1 @@
+2013-03-14  Allan Sandfeld Jensen  <allan.jensen@digia.com>
+
+        [Qt] Add support for tiled shadow blur
+        https://bugs.webkit.org/show_bug.cgi?id=90082
+
+        Reviewed by Noam Rosenthal.
+
+        Use the optimized ShadowBlur::drawRectShadow as long as we do not
+        have a rotating transform. Such a transform would go through the
+        slow path in ShadowBlur anyway, and would end up using a transformed
+        TransparencyLayer with an alphaMap which causes scaling artifacts
+        for us.
+
+        Tested by fast/canvas/canvas-scale-fillRect-shadow.html
+        and fast/canvas/canvas-transforms-fillRect-shadow.html
+
+        * platform/graphics/ShadowBlur.cpp:
+        (WebCore::ShadowBlur::drawInsetShadowWithTiling):
+            Handle scaling transforms when shadows ignore transforms.
+        (WebCore::ShadowBlur::drawRectShadowWithTiling):
+            Ditto.
+        * platform/graphics/qt/GraphicsContextQt.cpp:
+        (WebCore::GraphicsContext::fillRect):
+
 2013-03-12  Andrey Kosyakov  <caseq@chromium.org>
 

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

@@ -680 +680 @@
         blurAndColorShadowBuffer(templateSize);
     }
+    FloatSize offset = m_offset;
+    if (shadowsIgnoreTransforms()) {
+        AffineTransform transform = graphicsContext->getCTM();
+        offset.scale(1 / transform.xScale(), 1 / transform.yScale());
+    }
 
     FloatRect boundingRect = rect;
-    boundingRect.move(m_offset);
+    boundingRect.move(offset);
 
     FloatRect destHoleRect = holeRect;
-    destHoleRect.move(m_offset);
+    destHoleRect.move(offset);
     FloatRect destHoleBounds = destHoleRect;
     destHoleBounds.inflateX(edgeSize.width());
@@ -737 +742 @@
         blurAndColorShadowBuffer(templateSize);
     }
+    FloatSize offset = m_offset;
+    if (shadowsIgnoreTransforms()) {
+        AffineTransform transform = graphicsContext->getCTM();
+        offset.scale(1 / transform.xScale(), 1 / transform.yScale());
+    }
 
     FloatRect shadowBounds = shadowedRect;
-    shadowBounds.move(m_offset.width(), m_offset.height());
+    shadowBounds.move(offset);
     shadowBounds.inflateX(edgeSize.width());
     shadowBounds.inflateY(edgeSize.height());

trunk/Source/WebCore/platform/graphics/qt/GraphicsContextQt.cpp

@@ -803 +803 @@
         if (hasShadow()) {
             if (shadow->mustUseShadowBlur(this)) {
-                GraphicsContext* shadowContext = shadow->beginShadowLayer(this, normalizedRect);
-                if (shadowContext) {
-                    QPainter* shadowPainter = shadowContext->platformContext();
-                    shadowPainter->fillRect(normalizedRect, p->brush());
-                    shadow->endShadowLayer(this);
-                }
+                // drawRectShadowWithTiling does not work with rotations, and the fallback of
+                // drawing though clipToImageBuffer() produces scaling artifacts for us.
+                if (!getCTM().preservesAxisAlignment()) {
+                    GraphicsContext* shadowContext = shadow->beginShadowLayer(this, normalizedRect);
+                    if (shadowContext) {
+                        QPainter* shadowPainter = shadowContext->platformContext();
+                        shadowPainter->fillRect(normalizedRect, p->brush());
+                        shadow->endShadowLayer(this);
+                    }
+                } else
+                    shadow->drawRectShadow(this, rect, RoundedRect::Radii());
             } else {
                 // Solid rectangle fill with no blur shadow or transformations applied can be done