Bug 81528

Summary:

Applying stroke with globalCompositeOperation set to source-in, source-out, destination-in, destination-atop, copy displays incorrectly

Product:

WebKit

Reporter:

Jim Allanson <jimallanson>

Component:

Canvas

Assignee:

Nobody <webkit-unassigned>

Status:

RESOLVED DUPLICATE

Severity:

Normal

Keywords:

HTML5

Priority:

Version:

528+ (Nightly build)

Hardware:

OS:

Windows 7

URL:

http://jsfiddle.net/dH7KW/

Attachments:

Description	Flags
Expected behaviour, as tested in Firefox 10, IE 10, Opera 11	none
Incorrect Rendering in Webkit	none

Description Jim Allanson 2012-03-19 11:15:50 PDT

Created attachment 132612 [details]
Expected behaviour, as tested in Firefox 10, IE 10, Opera 11

When a stroke is applied to a canvas with the globalCompositeOperation set to:

- source-in
- source-out
- destination-in
- destination-atop
- copy

The composition does not occur as expected, with the destination image still visible where it should not be.

Reference rendering from Mozilla Firefox 10: http://i.imgur.com/zoQsB.png (Identical to IE 10 & Opera 11)
Webkit rendering: http://i.imgur.com/NiNpO.png

jsFiddle testing stroke composition for each globalCompositeOperation: http://jsfiddle.net/dH7KW/

Comment 1 Jim Allanson 2012-03-19 11:16:45 PDT

Created attachment 132613 [details]
Incorrect Rendering in Webkit

Comment 2 Jim Allanson 2012-03-27 01:28:26 PDT

I forgot to mention in the original report, this is fairly easy to work around. Just create a new Canvas element, apply the stroke to it, then draw that canvas to the destination using drawImage() with the desired globalCompositeOperation set.

Comment 3 Jim Allanson 2012-03-27 01:37:02 PDT

Duplicate of bug 66762, missed this the first time I searched.

*** This bug has been marked as a duplicate of bug 66762 ***