SVG Working Group Teleconference -- 26 Feb 2009

<trackbot> Date: 26 February 2009

<scribe> scribe: chris

<scribe> scribenick: chrisl

Referencing ISO-32000-1 for blending [Compositing module]

cl: is this a normative or informative reference, and will the equations be in our spec of just referenced?

cmc: costs money?

cl: of course

ds: prefer to have the equations in our spec, can reference the ISO as well
... and better to be in a RF spec

cl: normative or informative?

ds: informative. Useful to know the connection between them

cl: agree

cmc: if its nortmative then you still should buy it in case

ed: good to have all the equations in our spec

resolved: equations for compositing will be in the svg spec, with an informative reference to ISO 3200-1

<scribe> ACTION: anthony to check equations for blending and add informative ref to ISO 32000-1 [recorded in http://www.w3.org/2009/02/26-svg-minutes.html#action01]

<trackbot> Created ACTION-2480 - Check equations for blending and add informative ref to ISO 32000-1 [on Anthony Grasso - due 2009-03-05].

ag: will do, not checked the equations yet
... will check the equations again, needs some testing to verify

transforms review

<anthony> http://www.w3.org/Graphics/SVG/WG/wiki/CSS-Transforms-Review

http://dev.w3.org/cvsweb/~checkout~/csswg/css3-2d-transforms/Overview.html?rev=1.3&content-type=text/html:%20charset=iso-8859-1

cl: (explains stacking context)

ds: liked your email comments, chris... they seem more likely to be fruitful

before "Currently, Firefox and Safari throw away" say "Since backward compatibility is important we tested current browwsers and currently ...."

should probably motivate why openvg is important

existing implementations get acceleration from openvg, etc

cl: the overasll review document is good, I just had some specific comments

ds: its important that we support css in this useful work

ed: sounds good

ag: been editing live, these are ready to go

cmc: i have a few detailed comments in email
... want clarification on matrix sizes and math

ag: need to commit the new draft of svg transforms

cl: the css spec needs some references to explain transforms and matrices for those unaware

ed: we have a minuted resolution to publish

ds: plh said recently that tight integration and strong coordination is important

ag: did we respond to dean's email?

cmc: send a reply to dean thanking him, and point to this review?

<scribe> ACTION: doug to reply to Dean on 3d transforms [recorded in http://www.w3.org/2009/02/26-svg-minutes.html#action02]

<trackbot> Created ACTION-2481 - Reply to Dean on 3d transforms [on Doug Schepers - due 2009-03-05].

referencing http://www.w3.org/Graphics/SVG/WG/wiki/CSS-Transforms-Review

cmc: i still have some comments yet to make

ds: ok lets talks offline and I will send it over the weekend

cl: css wg will likely be discussing these documents next week in japan

Transitions and Animations

cmc: so we are going to send outr individual non-svgf related stuff directly, and coordinate on a wg response for the svg specific aspects

ds: think individual responses is more timely and allows more discussion
... send responses to www-style with cc to www-svg

ed: i have a bunch of feedback on that, will send it next week

z-index use cases and requirements

issue-2226?

<trackbot> ISSUE-2226 -- Investigate the use cases and requirements for z-index -- RAISED

<trackbot> http://www.w3.org/Graphics/SVG/WG/track/issues/2226

ed: good to have an action on this.
... does our spec deal with z-index?

ag: we have discussed it, in Sydney

http://www.w3.org/2009/02/15-svg-minutes.html#item05

pointer to stacking context http://www.w3.org/TR/CSS21/zindex.html

ed: we could define z-index the same way so that it also applies to svg as well as being compatible with html

'z-index'

Value: auto | <integer> | inherit

Initial: auto

Applies to: positioned elements

Inherited: no

Percentages: N/A

Media: visual

Computed value: as specified

ag: instead of z-index, could also use the transform-style property, to switch on z-ordering for a group of objects

cl: interesting option

ag: yes as it could apply only to container elements
... similar to layered groups
... as soon as document order is lost, impact on streaming and rendering speed so being able to isolate the effects is beneficial

ds: would that need a whole shadow tree?
... if we have layered groups, it could be implemented by making a shadow tree that replaces the docuent order subtree. but that could be expensive on memory

cl: impact on filter effects / render background, and on event bubbling .....

cmc: would complicate document updates as well

ds: maybe contact andrew and ask about layeredg

ed: think you just need a different tree traversal order, not a whole copy of the subtree

ds: impact of that on keyboard navigation / docuent order?
... would this affect hierarchy eg with a use element that points outside the z-ordered group
... example of two circles bing twiddled on z-order, then two use elements that point to them

ag: i would say no, it gets really complex. import the transform not the layered group it could get really hairy

ds: right, using them outside the layering context gets document order not this new rendering order

ag: trying to ease implementor burden while keepin git simple and powerful for authors

ag: a reference to that ISO spec (for full title, for the references) http://www.iso.org/iso/iso_catalogue/catalogue_tc/catalogue_detail.htm?csnumber=51502

ds: need to name this carefully, eg inkscape already has laters that are really more like groups

costs CHF 380,00

ed: so its good to gather use cases and requirements for z-index

ag: does this impact the transforms UC&R?

ed: should still examine the use case for it

cl: good in the transforms UC&R to discuss how this is similar to, and different from, css 2.1 z-index

<scribe> ACTION: anthony draft use cases and requirements for z-index and compare and contrast with transforms and critically discuss with reference to a neo-marxist dialictic [recorded in http://www.w3.org/2009/02/26-svg-minutes.html#action03]

<trackbot> Created ACTION-2482 - Draft use cases and requirements for z-index and compare and contrast with transforms and critically discuss with reference to a neo-marxist dialictic [on Anthony Grasso - due 2009-03-05].

tpac 2009

<ed___> http://lists.w3.org/Archives/Public/public-svg-wg/2009JanMar/0174.html

cl: (explains tpac question - group attendance, timing, cost and location)

ds: an advantage of the proposed location is silicon valley so more particiation from browser vendors like mozilla, applle etc

http://lists.w3.org/Archives/Member/chairs/2009JanMar/0059

ds: its one month after svg open in the same area

cl: prefer the cost-effective location

ds: perhaps shift svg open?

cl: not clear that the tpac will happen. depends on how many groups confirm
... plh suggested a mini-tpac for browser-based technologies like html, css, svg, webapps and so forth

ed: mini-tech plenary sounds good

ds: downside is that we miss being able to meet with other groups

http://www.w3.org/2002/09/wbs/34786/TPAC2009/results

ds: 3d Transforms have an impact on level of detail

ag: we need near and far clipping really
... this is 3d transforms applied toa 2d object then flattened to give a 2d result

back to transforms

oops, should have changed topic sorrry

odf and svg

ds: it would be a win if odf were to use svg natively. currently they don't. its being discussed in svg ig
... who is interested?

ed: yes, sure

- DRAFT -

SVG Working Group Teleconference

26 Feb 2009

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