Bug 129246

Summary: -webkit-clip-path wrong offset for clipPath references
Product: WebKit Reporter: Dirk Schulze <krit>
Component: CSSAssignee: Dirk Schulze <krit>
Status: RESOLVED FIXED    
Severity: Normal CC: achicu, commit-queue, dino, simon.fraser, webkit-bug-importer
Priority: P2 Keywords: InRadar
Version: 528+ (Nightly build)   
Hardware: Unspecified   
OS: Unspecified   
Bug Depends on:    
Bug Blocks: 126207    
Attachments:
Description Flags
Example - should be a perfect circle
none
Patch
none
Patch for landing none

Dirk Schulze
Reported 2014-02-24 01:03:50 PST
Created attachment 225035 [details] Example - should be a perfect circle If -webkit-clip-path references a <clipPath> element the offset is from the top left of the viewport, not of the HTML element. This changes once a CSS transform is specified. Then the offset is correct. -webkit-transform: translate(0px, 0px)
Attachments
Example - should be a perfect circle (285 bytes, text/html)
2014-02-24 01:03 PST, Dirk Schulze 		no flags
Details
Patch (9.46 KB, patch)
2018-05-20 14:47 PDT, Dirk Schulze 		no flags
DetailsFormatted DiffDiff
Patch for landing (9.84 KB, patch)
2018-06-27 13:32 PDT, Dirk Schulze 		no flags
DetailsFormatted DiffDiff
Show Obsolete (1) View All Add attachment proposed patch, testcase, etc.
Dirk Schulze
Comment 1 2014-02-25 05:06:45 PST
The example makes use of clipPathUnits="userSpaceOnUse". All units an percentage are resolved in the viewport of the <clip-path> element (wrongly btw). All objects within <clipPath> are sized and positioned in this coordinate space. The these objects are just mapped to the coordinate space of the clipped object. This causes the wrong offset and strange behavior of clipping paths with percentage values.
Dirk Schulze
Comment 2 2018-05-20 11:02:17 PDT
https://codepen.io/krit/pen/xjMRWM
Dirk Schulze
Comment 3 2018-05-20 14:47:19 PDT
Created attachment 340807 [details] Patch
Simon Fraser (smfr)
Comment 4 2018-06-26 14:08:28 PDT
Comment on attachment 340807 [details] Patch View in context: https://bugs.webkit.org/attachment.cgi?id=340807&action=review > Source/WebCore/rendering/RenderLayer.cpp:4179 > + downcast<RenderSVGResourceClipper>(*element->renderer()).applyClippingToContext(renderer(), svgReferenceBox, paintingInfo.paintDirtyRect, context); Does hasTagName(SVGNames::clipPathTag) mean that the renderer is always a RenderSVGResourceClipper? (I know the existing code did this.). I would feel happier with an is<> check, otherwise this code will release-assert.
Dirk Schulze
Comment 5 2018-06-27 13:32:37 PDT
Created attachment 343747 [details] Patch for landing
WebKit Commit Bot
Comment 6 2018-06-27 16:28:26 PDT
Comment on attachment 343747 [details] Patch for landing Clearing flags on attachment: 343747 Committed r233287: <https://trac.webkit.org/changeset/233287>
WebKit Commit Bot
Comment 7 2018-06-27 16:28:28 PDT
All reviewed patches have been landed. Closing bug.
Radar WebKit Bug Importer
Comment 8 2018-06-27 16:29:18 PDT
<rdar://problem/41550953>
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