- From: Charles Pritchard <chuck@jumis.com>
- Date: Tue, 25 May 2010 14:52:26 -0700
- To: Jatinder Mann <jmann@microsoft.com>
- CC: "public-canvas-api@w3.org" <public-canvas-api@w3.org>
- Message-ID: <4BFC469A.40601@jumis.com>
This was revised last year, and will be adjusted appropriately in a future version of Firefox, per Robert O'Callahan. I believe this is the end of the thread which addressed the issue: http://lists.whatwg.org/htdig.cgi/whatwg-whatwg.org/2009-October/023706.html It's quite subtle, but it's standardized in the drawing-model section. -Charles On 5/25/2010 11:56 AM, Jatinder Mann wrote: > > As we were reviewing the globalCompositeOperation property [1] of the > Canvas 2D Context, we have noticed that there is a large inconsistency > with the way web browsers implement this property. > > Firefox 3.6.3 and Opera 10.5 have a similar behaviour that matches the > current version of the Canvas 2D Context spec. Chrome 4.1 and Safari > 4.0.5 behave similarly to each other, albeit differently from the > spec. Today, web developers cannot reliably use this property in > designing their webpages due to this interoperability issue. > > We consider that the Safari implementation of the Drawing Model makes > more sense from a web developer point of view. Most of the Canvas APIs > are applied to the next primitive being drawn. However, the clipping > behavior, as defined in the current Drawing Model [2], affects the > current contents of the Canvas outside of the current primitive being > drawn. The Safari Drawing Model calls for the clipping region to only > affect the current primitive being drawn. > > We recommend updating the spec to match the Safari Drawing Model. We > would like to discuss this area in more detail. > > Thank you, > > Jatinder > > [1] http://dev.w3.org/html5/2dcontext/#compositing > > [2] http://dev.w3.org/html5/2dcontext/#drawing-model > > Jatinder Mann | Microsoft Program Manager | jmann@microsoft.com > <mailto:jmann@microsoft.com> >
Received on Tuesday, 25 May 2010 21:53:13 UTC