Use background positioning origin for repeating backgrounds

Source/core/paint/BoxPainter.cpp

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "config.h"
 #include "core/paint/BoxPainter.h"
 
 #include "core/HTMLNames.h"
 #include "core/frame/Settings.h"
 #include "core/html/HTMLFrameOwnerElement.h"
@@ skipping 693 matching lines @@
         if (fillLayer.size().size.width().isAuto() && backgroundRepeatX != RoundFill) {
             fillTileSize.setWidth(fillTileSize.width() * positioningAreaSize.height() / (nrTiles * fillTileSize.height()));
         }
 
         geometry.setTileSize(fillTileSize);
         geometry.setPhaseY(geometry.tileSize().height() ? geometry.tileSize().height() - roundToInt(computedYPosition + top) % geometry.tileSize().height() : 0);
         geometry.setSpaceSize(IntSize());
     }
 
     if (backgroundRepeatX == RepeatFill) {
-        geometry.setPhaseX(geometry.tileSize().width() ? geometry.tileSize().width() - roundToInt(computedXPosition + left) % geometry.tileSize().width() : 0);
+        int xOffset = fillLayer.backgroundXOrigin() == RightEdge ? availableWidth - computedXPosition : computedXPosition;
+        geometry.setPhaseX(geometry.tileSize().width() ? geometry.tileSize().width() - roundToInt(xOffset + left) % geometry.tileSize().width() : 0);
         geometry.setSpaceSize(IntSize());
     } else if (backgroundRepeatX == SpaceFill && fillTileSize.width() > 0) {
         int space = getSpaceBetweenImageTiles(positioningAreaSize.width(), geometry.tileSize().width());
         int actualWidth = geometry.tileSize().width() + space;
 
         if (space >= 0) {
             computedXPosition = roundedMinimumValueForLength(Length(), availableWidth);

[pdr., 2015/08/18 06:41:08]

I think we need to account for the origin for SpaceFill as well.

In https://drafts.csswg.org/css-backgrounds-3/#the-background-repeat under
'space' it says the background position should be used which would include the
origin.

[davve, 2015/08/18 06:52:15]

Not sure I follow. Spec says for space: "The value of ‘background-position’ for
this direction is ignored, unless there is not enough space for two copies of
the image in this direction .."

the 'unless' part covered by falling back to NoRepeatFill a couple of lines
down.

             geometry.setSpaceSize(IntSize(space, 0));
             geometry.setPhaseX(actualWidth ? actualWidth - roundToInt(computedXPosition + left) % actualWidth : 0);
         } else {
             backgroundRepeatX = NoRepeatFill;
         }
     }
     if (backgroundRepeatX == NoRepeatFill) {
         int xOffset = fillLayer.backgroundXOrigin() == RightEdge ? availableWidth - computedXPosition : computedXPosition;
         geometry.setNoRepeatX(left + xOffset);
         geometry.setSpaceSize(IntSize(0, geometry.spaceSize().height()));
     }
 
     if (backgroundRepeatY == RepeatFill) {
-        geometry.setPhaseY(geometry.tileSize().height() ? geometry.tileSize().height() - roundToInt(computedYPosition + top) % geometry.tileSize().height() : 0);
+        int yOffset = fillLayer.backgroundYOrigin() == BottomEdge ? availableHeight - computedYPosition : computedYPosition;
+        geometry.setPhaseY(geometry.tileSize().height() ? geometry.tileSize().height() - roundToInt(yOffset + top) % geometry.tileSize().height() : 0);
         geometry.setSpaceSize(IntSize(geometry.spaceSize().width(), 0));
     } else if (backgroundRepeatY == SpaceFill && fillTileSize.height() > 0) {
         int space = getSpaceBetweenImageTiles(positioningAreaSize.height(), geometry.tileSize().height());
         int actualHeight = geometry.tileSize().height() + space;
 
         if (space >= 0) {
             computedYPosition = roundedMinimumValueForLength(Length(), availableHeight);
             geometry.setSpaceSize(IntSize(geometry.spaceSize().width(), space));
             geometry.setPhaseY(actualHeight ? actualHeight - roundToInt(computedYPosition + top) % actualHeight : 0);
         } else {
@@ skipping 298 matching lines @@
     }
 }
 
 bool BoxPainter::shouldForceWhiteBackgroundForPrintEconomy(const ComputedStyle& style, const Document& document)
 {
     return document.printing() && style.printColorAdjust() == PrintColorAdjustEconomy
         && (!document.settings() || !document.settings()->shouldPrintBackgrounds());
 }
 
 } // namespace blink