W3C home > Mailing lists > Public > www-svg@w3.org > May 2011

Re: agenda+ SVG 2 Features and Approach

From: Dr. Olaf Hoffmann <Dr.O.Hoffmann@gmx.de>
Date: Sun, 8 May 2011 14:24:08 +0100
To: www-svg@w3.org
Message-Id: <201105081524.09204.Dr.O.Hoffmann@gmx.de>

I assume already, that SVG2.0 will be a compatible superset of SVG 1.1 and SVG 
tiny 1.2, therefore only issues beyond SVG tiny 1.2:

- avoid backwards incompatible changes (just because some viewers have bugs or
  because some/many just cannot imagine yet, for what some features could be
  maybe used, if implemented correctly)
- define behaviour of stroke-dasharray, in doubt define more properties
  related to this like stroke-dash-cap, stroke-dash-subpath etc
- to-animateTransform define/clarify how to get a smooth change from current
  to to-value
- allow animateTransform of type matrix
- tooltip element, because title and desc are intended for other purposes and
  something like the SVG tiny 1.2 method
  <metadata about="#ID" role="tooltip" property="aria:tooltip" 
  content="This is the tootip text." />
  is not optimal (even if it would work in viewers), there should be a well
  defined SVG method to avoid that authors abuse other elements for this
  functionality or that they always have to create their own tooltip method,
  for example with declarative animation without specifying relations
- additional generic element to structure content of desc, tooltip and maybe
  metadata, like XHTML:div, to be able to add semantics with role, RDFa...
- allow/define viewBox on image to present only parts of the image
- define a method to reference raster images with its own size without the
  need to set width and height
- add requirement for viewers to provide an interface for audio and video on
  demand  (pause authors timing considerations if this option is used);
  similar to what is described in the HTML5 draft for their video and audio -
  a clever combination of both could finally result in pretty useful elements
- explore the option to get free and then required formats for audio and video
  in SVG  (similar as PNG and JFIF/JPEG is required).
- allow authors to specify the required rounding method to device pixels per
  element with an attribute (to top|bottom and left|right, including or
  excluding rounding off/up integer results. 
  This is typically very important to be able to place partly transparent
  objects directly edge to edge without an overlap (or gap) due to rounding
  artefacts of viewers - currently with SVG and typical viewers it is not
  possible to place such objects edge to edge without having some ugly
  artefacts from viewer rounding to device pixels, rendering is not
  predictable for authors, because it may depend on magnification/scaling and
  specific implementation issues.

- stroke with variable width
- pattern along the stroke more advanced than stroke-dasharray, even if this
  becomes defined
- simple method to structure stroke perpendicular to the path direction (for
  example only fragment on fill or only outside fill, arbitrary fractions
  maybe this is covered by advanced vector-effects?
- declarative method to conserve and reuse current values from animation in
- improve to-animation approach to get something similar to CSS-transitions
  within SVG animation.
- star like element, see proposal http://hoffmann.bplaced.net/svgueb/polar.php
  maybe other elements, which simplifies it for authors to specify popular
  named shapes, which have already a more or less good defined semantic
  meaning, but are not trivial to realise for authors.
- explore, whether path commands in polar coordinates have a chance to be used
  by authors or not - see proposal
- alternative methods for simple notation of smooth paths (simple
  interpolation methods to derive smooth curves from simple point lists
  without the need for the author to calculate the derivatives to get control
  points) - maybe already included in the next point
- include declarative method to generate shapes from raw data (especially
  without scripting) - see proposal http://hoffmann.bplaced.net/rdml/
- advanced gradients, pattern methods
- adopt SMIL time containers (layers) and time manipulation module
- parameters
- z-index
- continue efforts with 3D-transformation (compatible with current SVG
  transformations of course)

One option could be to put together only the simpler, not much graphic related 
new features, clarifications and fixes into an intermediate version 1.2 or 
1.3 (this is roughly the first group above) and to prepare more advanced 
features as modules at the same time and combining this later to SVG 2.0 - 
I think, a version 2.0 without many new exciting new features would be 
disappointing for authors and several simpler issues like the tooltip, the 
stroke-dasharray or the to-animateTransform need a faster approach then 
to wait for such more complex features.

Received on Sunday, 8 May 2011 13:24:40 UTC

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