Changeset 31389

Timestamp:

2008-03-28 01:53:57 (8 months ago)

Author:

hyatt@apple.com

Message:

2008-03-28 David Hyatt <hyatt@apple.com>

Fix a bug where background-position truncates instead of rounding when it evaluates to fractional
pixel values. This matches other browsers.

Reviewed by maciej

Added fast/backgrounds/background-position-rounding.html

• rendering/Length.h: (WebCore::Length::calcValue): (WebCore::Length::calcMinValue):
• rendering/RenderBox.cpp: (WebCore::RenderBox::calculateBackgroundImageGeometry):

Location:

trunk/WebCore

Files:

• ChangeLog (modified) (1 diff)
• rendering/Length.h (modified) (4 diffs)
• rendering/RenderBox.cpp (modified) (2 diffs)

trunk/WebCore/ChangeLog

@@ +1 @@
+2008-03-28  David Hyatt  <hyatt@apple.com>
+
+        Fix a bug where background-position truncates instead of rounding when it evaluates to fractional
+        pixel values.  This matches other browsers.
+
+        Reviewed by maciej
+
+        Added fast/backgrounds/background-position-rounding.html
+
+        * rendering/Length.h:
+        (WebCore::Length::calcValue):
+        (WebCore::Length::calcMinValue):
+        * rendering/RenderBox.cpp:
+        (WebCore::RenderBox::calculateBackgroundImageGeometry):
+
 2008-03-27  Kevin Ollivier  <kevino@theolliviers.com>
 

trunk/WebCore/rendering/Length.h

@@ -104 +104 @@
 
         // note: works only for certain types, returns undefinedLength otherwise
-        int calcValue(int maxValue) const
+        int calcValue(int maxValue, bool roundPercentages = false) const
         {
             switch (type()) {
@@ -110 +110 @@
                     return value();
                 case Percent:
+                    if (roundPercentages)
+                        return static_cast<int>(round(maxValue * percent()));
                     return maxValue * rawValue() / (100 * percentScaleFactor);
                 case Auto:
@@ -118 +120 @@
         }
 
-        int calcMinValue(int maxValue) const
+        int calcMinValue(int maxValue, bool roundPercentages = false) const
         {
             switch (type()) {
@@ -124 +126 @@
                     return value();
                 case Percent:
+                    if (roundPercentages)
+                        return static_cast<int>(round(maxValue * percent()));
                     return maxValue * rawValue() / (100 * percentScaleFactor);
                 case Auto:

trunk/WebCore/rendering/RenderBox.cpp

@@ -578 +578 @@
     EBackgroundRepeat backgroundRepeat = bgLayer->backgroundRepeat();
     
-    int xPosition = bgLayer->backgroundXPosition().calcMinValue(pw - scaledImageWidth);
+    int xPosition = bgLayer->backgroundXPosition().calcMinValue(pw - scaledImageWidth, true);
     if (backgroundRepeat == REPEAT || backgroundRepeat == REPEAT_X) {
         cw = pw + left + right;
@@ -588 +588 @@
     }
 
-    int yPosition = bgLayer->backgroundYPosition().calcMinValue(ph - scaledImageHeight);
+    int yPosition = bgLayer->backgroundYPosition().calcMinValue(ph - scaledImageHeight, true);
     if (backgroundRepeat == REPEAT || backgroundRepeat == REPEAT_Y) {
         ch = ph + top + bottom;