[whatwg] Proposal to remove a paragraph from canvas spec

[Ian Hickson]

On Tue, 5 Jul 2011, Robert O'Callahan wrote:
> On Tue, May 31, 2011 at 9:40 AM, Robert O'Callahan <robert at ocallahan.org>wrote:
> > On Fri, May 13, 2011 at 5:53 PM, Ian Hickson <ian at hixie.ch> wrote:
> >
> >> On Fri, 13 May 2011, Robert O'Callahan wrote:
> >> >
> >> > Can you put a note in the spec that we're thinking of changing this 
> >> > behavior, so developers are less likely to start depending on it, 
> >> > and we've got some cover in case it breaks some esoteric stuff that 
> >> > doesn't matter for compat?
> >>
> >> Done.
> >>
> >
> > Thanks. I made this change on mozilla-central so it should appear in 
> > Firefox 7 about 18 weeks from now --- unless we detect that it breaks 
> > the Web.
> 
> It breaks the Web, so we're backing it out.
> 
> It turns out that a lot of canvas apps set up a shadow color and blur, 
> do some drawing, then disable the shadow by setting the blur to zero. 
> With the proposed change, those apps often render incorrectly, and 
> worse, they often render more slowly.

Should we still make shadows only work in source-over mode, or should we 
leave the spec as is in this area?

-- 
Ian Hickson               U+1047E                )\._.,--....,'``.    fL
http://ln.hixie.ch/       U+263A                /,   _.. \   _\  ;`._ ,.
Things that are impossible just take longer.   `._.-(,_..'--(,_..'`-.;.'