Changeset 28714 in webkit

Timestamp:

Dec 14, 2007, 11:37:12 AM (17 years ago)

Author:

mitz@apple.com

Message:

Reviewed by Darin Adler.

• fix <rdar://problem/5643663> text-shadow and box-shadow offsets 1px smaller than specified which is the root cause of: ​http://bugs.webkit.org/show_bug.cgi?id=12943 box-shadow: small values don't affect shadow position ​http://bugs.webkit.org/show_bug.cgi?id=14736 Safari implementation of text-shadow off by 1px

• platform/graphics/cg/GraphicsContextCG.cpp: (WebCore::GraphicsContext::setShadow): Slightly increase the magnitude of the offsets passed to CGContextSetShadow* to ensure that the end result after truncation is the desired integer offsets.

Location:

trunk/WebCore

Files:

• ChangeLog (modified) (1 diff)
• platform/graphics/cg/GraphicsContextCG.cpp (modified) (2 diffs)

trunk/WebCore/ChangeLog

@@ +1 @@
+2007-12-14  Dan Bernstein  <mitz@apple.com>
+
+        Reviewed by Darin Adler.
+
+        - fix <rdar://problem/5643663> text-shadow and box-shadow offsets 1px smaller than specified
+          which is the root cause of:
+          http://bugs.webkit.org/show_bug.cgi?id=12943
+          box-shadow: small values don't affect shadow position
+          http://bugs.webkit.org/show_bug.cgi?id=14736
+          Safari implementation of text-shadow off by 1px
+
+        * platform/graphics/cg/GraphicsContextCG.cpp:
+        (WebCore::GraphicsContext::setShadow): Slightly increase the magnitude
+        of the offsets passed to CGContextSetShadow* to ensure that the end
+        result after truncation is the desired integer offsets.
+
 2007-12-13  Alp Toker  <alp@atoker.com>
 

trunk/WebCore/platform/graphics/cg/GraphicsContextCG.cpp

@@ -31 +31 @@
 
 #include "AffineTransform.h"
+#include "FloatConversion.h"
 #include "GraphicsContextPlatformPrivate.h"
 #include "KURL.h"
@@ -510 +511 @@
     if (paintingDisabled())
         return;
+    CGContextRef context = platformContext();
+
+    CGFloat width = size.width();
+    CGFloat height = size.height();
+
+#if PLATFORM(MAC)
+    // Work around <rdar://problem/5539388> by ensuring that the offsets will get truncated
+    // to the desired integer.
+    // FIXME: This is not needed post-Leopard.
+    static const CGFloat extraShadowOffset = narrowPrecisionToCGFloat(1.0 / 128);
+    if (width > 0)
+        width += extraShadowOffset;
+    else if (width < 0)
+        width -= extraShadowOffset;
+
+    if (height > 0)
+        height += extraShadowOffset;
+    else if (height < 0)
+        height -= extraShadowOffset;
+#endif
+
     // Check for an invalid color, as this means that the color was not set for the shadow
     // and we should therefore just use the default shadow color.
-    CGContextRef context = platformContext();
     if (!color.isValid())
-        CGContextSetShadow(context, CGSizeMake(size.width(), -size.height()), blur); // y is flipped.
+        CGContextSetShadow(context, CGSizeMake(width, -height), blur); // y is flipped.
     else {
         CGColorRef colorCG = cgColor(color);
         CGContextSetShadowWithColor(context,
-                                    CGSizeMake(size.width(), -size.height()), // y is flipped.
+                                    CGSizeMake(width, -height), // y is flipped.
                                     blur, 
                                     colorCG);