Bug 96015

Summary: 2D canvas strokeRect: negative width or height should affect winding direction
Product: WebKit Reporter: Justin Novosad <junov>
Component: CanvasAssignee: Nobody <webkit-unassigned>
Status: NEW    
Severity: Normal CC: bfulgham, darin, dino, ian, krit, senorblanco, simon.fraser, webkit-bug-importer
Priority: P2 Keywords: InRadar
Version: 528+ (Nightly build)   
Hardware: All   
OS: All   
Attachments:
Description Flags
Example none

Justin Novosad
Reported 2012-09-06 13:19:14 PDT
From whatwg strokeRect spec: "the path has a single subpath are four points, with coordinates (x, y), (x+w, y), (x+w, y+h), and (x, y+h), connected to each other in that order by straight lines" Emphasis on: "in that order" This means that if w is negative xor y is negative, then the vertices should be drawn in counter clockwise order. This has an effect on how line dashes are drawn. This is currently broken because CanvasRenderingContext2D::strokeRect calls validateRectForCanvas, which normalizes the rectangle to make w and h positive. When fixing the, care must be taken not to regress any of the graphics ports. The skia port of GraphicsContext is capable of handling negative w/h, haven't looked at the others yet.
Attachments
Example (379 bytes, text/html)
2014-04-05 08:33 PDT, Dirk Schulze 		no flags
Details
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Dirk Schulze
Comment 1 2014-04-05 08:33:28 PDT
Created attachment 228677 [details] Example Example file.
Brent Fulgham
Comment 2 2022-07-18 14:23:01 PDT
WebKit still doesn't seem to handle this properly.
Radar WebKit Bug Importer
Comment 3 2022-07-18 14:23:12 PDT
<rdar://problem/97219927>
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