W3C home > Mailing lists > Public > www-svg@w3.org > January 2003

Re: High-Quality Dynamic SVG Viewer

From: Thomas E Deweese <thomas.deweese@kodak.com>
Date: Tue, 28 Jan 2003 07:43:33 -0500
Message-ID: <15926.31477.991817.872749@frog.rl.kodak.com>
To: Dean Jackson <dean@w3.org>
Cc: Thomas E Deweese <thomas.deweese@kodak.com>, Chris Lilley <chris@w3.org>, www-svg@w3.org

>>>>> "DJ" == Dean Jackson <dean@w3.org> writes:

DJ> On Mon, 27 Jan 2003, Thomas E Deweese wrote:

>>  I would actually tend toward limiting the types of tags that the
>> 'auto-close' trick happens for.  Generally what we want is for this
>> to happen for the grouping elements:
>> 
>> svg, g, defs, switch, symbol...
>> 
>> I would say that if there are any open elements other than these
>> (and symbol is a little questionable) then progressive rendering
>> should be inhibited.

DJ> I would add path and polyline in here.  Imagine downloading a huge
DJ> path that is the outline of Russia or Norway. It would be nice to
DJ> render something if possible.

    See, I really don't like this.  What you don't want is to have
'ugly' content drawn during the progressive rendering - this is
exactly the sort of thing that will make designers shut it off in most
cases.  So if you were just stroking the outline you might be all
right drawing it as it comes in, but what if you also filled it? You
would keep closing the path and getting these ugly polygons with a
straight line cutting across the page.  Worse, what if the fill and
stroke properties (i.e. fill="none" stroke="red") were after the path
data, you would end up using the default fill/stroke and fill a shape
you weren't supposed to :/.

>> Thus you can never have 1/2 a gradient definition (which BTW would
>> theoretically work in lots of cases since we have rules to fill out
>> the gradient space - but I just don't think it's a good idea).

DJ> Thinking about it a little more, I feel that it should be left up
DJ> to the implementation in most cases. The SVG spec can just say how
DJ> we expect things to happen, but not place any requirements on the
DJ> techniques.

    If you are going to do progressive rendering I think it's pretty
important that the rendering look like the final thing with some stuff
missing, having radical changes in the appearance of elements in the
rendering is IMHO very bad.
Received on Tuesday, 28 January 2003 07:43:59 GMT

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