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Feedback on the bbox changes

From: Erik Dahlström <ed@opera.com>
Date: Thu, 06 Feb 2014 10:56:09 +0100
To: "public-svg-wg@w3.org" <public-svg-wg@w3.org>, "Cameron McCormack" <cam@mcc.id.au>
Message-ID: <op.xautvvkodhsuf5@gnorps>
On Tue, 04 Feb 2014 06:48:35 +0100, Cameron McCormack <cam@mcc.id.au>  
wrote:

...
> Here are the sections in the spec that are currently "ready for WG  
> review" and for which any objections to marking them as "ready for wider  
> review" should be made known before the end of this Friday, 7 February.
>
> * the "Bounding boxes" section of coords.html
>    https://svgwg.org/svg2-draft/coords.html#BoundingBoxes

Please update this to align with  
http://www.w3.org/TR/SVGTiny12/coords.html#BoundingBox (which uses the  
tightest fitting bbox for paths). It's possible to compute these tight  
bboxes in the "fast" way (aka the convex hull of the control points) in  
most cases, and to employ a slightly more expensive algorithm only when  
necessary. We never found this to be a bottleneck in Presto.

Also, the term "bounding box" should be linked to the new algorithm,  
https://svgwg.org/svg2-draft/intro.html#TermBoundingBox.  
http://www.w3.org/TR/SVGTiny12/intro.html#TermBoundingBox could probably  
just be copied across with a few minor changes to the links.

Please add a term 'glyph cell' and state for bbox whether this is a tight  
cell around the glyph geometry or not. Previously this has been assumed to  
be a "full glyph cell", see e.g  
http://www.w3.org/TR/SVGTiny12/coords.html#BoundingBox.

For the bbox algorithm for container elements and 'use', the same values  
for space, fill, stroke, markers are propagated to the (shadow) children  
of that element. But I'm wondering, is there ever a chance you'd want to  
apply some values only to the parent, and not to the children?

For the embedded elements and foreignObject, have we ruled out using css  
for the size/position instead/in addition to plain attributes? Especially  
because most of these elements have not been in svg before (at least not  
in this form), we don't yet have to worry about legacy content that would  
break. In html it is possible to set the size using css, so why not in svg?


-- 
Erik Dahlstrom, Web Technology Developer, Opera Software
Co-Chair, W3C SVG Working Group
Received on Thursday, 6 February 2014 09:56:44 UTC

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