Changeset 170646 in webkit

Timestamp:

Jul 1, 2014, 10:25:10 AM (12 years ago)

Author:

Alan Bujtas

Message:

Subpixel rendering: Pixel crack in breadcrumbs at devforums.apple.com.
​https://bugs.webkit.org/show_bug.cgi?id=134491

Reviewed by Simon Fraser.

Do not early round geometry values, while computing background image position. It changes the final
subpixel values and that could lead to wrong snap positions.
pixelSnapBackgroundImageGeometryForPainting() takes care of geometry snapping.

Source/WebCore:
Test: fast/backgrounds/background-image-size-double-rounding.html

• rendering/RenderBoxModelObject.cpp:

(WebCore::RenderBoxModelObject::calculateBackgroundImageGeometry):

LayoutTests:

• fast/backgrounds/background-image-size-double-rounding-expected.html: Added.
• fast/backgrounds/background-image-size-double-rounding.html: Added.

Location:

trunk

Files:

• LayoutTests/ChangeLog (modified) (1 diff)
• LayoutTests/fast/backgrounds/background-image-size-double-rounding-expected.html (added)
• LayoutTests/fast/backgrounds/background-image-size-double-rounding.html (added)
• Source/WebCore/ChangeLog (modified) (1 diff)
• Source/WebCore/rendering/RenderBoxModelObject.cpp (modified) (4 diffs)

trunk/LayoutTests/ChangeLog

@@ +1 @@
+2014-07-01  Zalan Bujtas  <zalan@apple.com>
+
+        Subpixel rendering: Pixel crack in breadcrumbs at devforums.apple.com.
+        https://bugs.webkit.org/show_bug.cgi?id=134491
+
+        Reviewed by Simon Fraser.
+
+        Do not early round geometry values, while computing background image position. It changes the final
+        subpixel values and that could lead to wrong snap positions.
+        pixelSnapBackgroundImageGeometryForPainting() takes care of geometry snapping.
+
+        * fast/backgrounds/background-image-size-double-rounding-expected.html: Added.
+        * fast/backgrounds/background-image-size-double-rounding.html: Added.
+
 2014-06-30  Myles C. Maxfield  <mmaxfield@apple.com>
 

trunk/Source/WebCore/ChangeLog

@@ +1 @@
+2014-07-01  Zalan Bujtas  <zalan@apple.com>
+
+        Subpixel rendering: Pixel crack in breadcrumbs at devforums.apple.com.
+        https://bugs.webkit.org/show_bug.cgi?id=134491
+
+        Reviewed by Simon Fraser.
+
+        Do not early round geometry values, while computing background image position. It changes the final
+        subpixel values and that could lead to wrong snap positions.
+        pixelSnapBackgroundImageGeometryForPainting() takes care of geometry snapping.
+
+        Test: fast/backgrounds/background-image-size-double-rounding.html
+
+        * rendering/RenderBoxModelObject.cpp:
+        (WebCore::RenderBoxModelObject::calculateBackgroundImageGeometry):
+
 2014-07-01  Pratik Solanki  <psolanki@apple.com>
 

trunk/Source/WebCore/rendering/RenderBoxModelObject.cpp

@@ -1150 +1150 @@
     LayoutUnit availableHeight = positioningAreaSize.height() - geometry.tileSize().height();
 
-    LayoutUnit computedXPosition = minimumValueForLength(fillLayer->xPosition(), availableWidth, true);
+    LayoutUnit computedXPosition = minimumValueForLength(fillLayer->xPosition(), availableWidth, false);
     if (backgroundRepeatX == RoundFill && positioningAreaSize.width() > 0 && fillTileSize.width() > 0) {
         int numTiles = std::max(1, roundToInt(positioningAreaSize.width() / fillTileSize.width()));
@@ -1162 +1162 @@
     }
 
-    LayoutUnit computedYPosition = minimumValueForLength(fillLayer->yPosition(), availableHeight, true);
+    LayoutUnit computedYPosition = minimumValueForLength(fillLayer->yPosition(), availableHeight, false);
     if (backgroundRepeatY == RoundFill && positioningAreaSize.height() > 0 && fillTileSize.height() > 0) {
         int numTiles = std::max(1, roundToInt(positioningAreaSize.height() / fillTileSize.height()));
@@ -1182 +1182 @@
 
         if (space >= 0) {
-            computedXPosition = minimumValueForLength(Length(), availableWidth, true);
+            computedXPosition = minimumValueForLength(Length(), availableWidth, false);
             geometry.setSpaceSize(LayoutSize(space, 0));
             geometry.setPhaseX(actualWidth ? actualWidth - fmodf((computedXPosition + left), actualWidth) : 0);
@@ -1202 +1202 @@
 
         if (space >= 0) {
-            computedYPosition = minimumValueForLength(Length(), availableHeight, true);
+            computedYPosition = minimumValueForLength(Length(), availableHeight, false);
             geometry.setSpaceSize(LayoutSize(geometry.spaceSize().width(), space));
             geometry.setPhaseY(actualHeight ? actualHeight - fmodf((computedYPosition + top), actualHeight) : 0);