Re: SVG 1.2 Comment: 4 Flowing text and graphics

At 11:08 PM 11/1/2004 +0100, Håkon Wium Lie wrote:

>Also sprach Peter Sorotokin:
>
>  > > > 4 Flowing text and graphics
>  > >
>  > >This section seems to reinvent large parts of HTML and CSS (albeit in
>  > >a semantically poorer manner) in order to achieve a single effect.
>  >
>  > I am puzzled. What exactly does it reinvent in HTML or CSS? Line breaks?
>  > SVG 1.1 already has text layout within a line and text on the path. 
> SVG 1.2
>  > does not add any semantic ("XHTML") features to SVG 1.1, it merely
>  > introduces additional text layout mechanism, mostly built on top of SVG
>  > 1.1. Why is it somehow OK to have single line text flow with all complex
>  > internationalization features (baselines, bidi, vertical text, glyph
>  > orientation) and text-on-the-path and somehow not OK to have (much 
> simpler
>  > to implement!) text in the shape?
>
>The problem lies in how different specs interact. Placing strings of
>text on a line or on a path nicely complements vector graphics and
>naturally belongs in SVG. When you add flowing text you turn SVG from
>a vector graphics format to a generic document format.

That is where I disagree. First of all, it is not really flowing text (it 
always flows even in SVG 1.1), but automatic word wrapping - or line 
breaking. I do not see how text that has automatic line breaking layout 
suddenly needs semantic mark-up. Nor why it makes SVG into generic document 
format. Word wrapping is pure presentation and has nothing to do with 
either semantic or document structure. One already can create multiline SVG 
paragraphs (with tspan and x/y attributes), the only addition in SVG 1.2 is 
automatic breaking of text into lines.

>This may be a simple change in your spec and code, but it has a huge 
>impact on how
>content is authored on the web. HTML has traditionally had this role

And it is going to stay this way. If document is text based than it is 
still much more convenient and natural to author it in HTML (or XHTML). 
However if document is really a sequence of slides or a diagram or a 
collection of links, SVG might make more sense. Right now documents like 
that are authored with a bunch of bitmap images, nested tables and/or 
absolute layout.

>and making a second language duplicate the functionality seems to
>create unnecessary competition between specifications that would be
>better off collaborating. W3C's efforts in Compound Documents is a
>welcome effort to ensure that specs can collaborate in this manner.

Yes, in many cases collaboration is possible. We should have a good 
integration between XHTML and box model and SVG.


>Another way to answer your question would be to turn it around: what
>exactly is wrong with CSS4 introducing polygons, background gradients
>and animation when we already have borders, background images and
>text-decoration: blink?

I think I answered that question in the thread with Ian. There is simply 
nothing inherently CSS-ish in line breaking. Rather, line breaking is 
_inherent_ to text itself, just like character to glyph conversion, 
automatic placement of glyphs one after another, bidi, glyph-orientation or 
baseline alignment. It is just presentation of text.


>  > Also, our implementation feedback
>  > is that you need to add about 10-20% of the code (was 10% in our code) in
>  > the text layout module to get line breaking working even for arbitrary
>  > shapes. All complexity in text layout comes from internationalization, 
> and
>  > incrementability, not line breaking.
>
>This is great, the simpler the better. But your code isn't tied to the
>author using SVG markup, is it?

No, it is not. I have said already that syntax is not so important for text 
engine.


>  > As for your proposal, given our experience on text layout feature
>  > design, it is unlikely that we have enough time to review it before
>  > PR.
>
>I think it's wise to review last call comments before PR.

Sorry, I have already clarified it to Ian that we certainly will review it 
as a comment, but not likely as an SVG 1.2 proposal.

Peter


>Cheers,
>
>-h&kon
>               Håkon Wium Lie                          CTO °þe®ª
>howcome@opera.com                  http://people.opera.com/howcome

Received on Monday, 1 November 2004 22:20:46 UTC