- From: Cameron McCormack <cam@mcc.id.au>
- Date: Wed, 8 Apr 2009 17:59:19 +1000
- To: public-svg-wg@w3.org
http://www.w3.org/2009/04/08-svg-minutes.html
[1]W3C
[1] http://www.w3.org/
- DRAFT -
SVG Working Group Teleconference
08 Apr 2009
[2]Agenda
[2] http://lists.w3.org/Archives/Public/public-svg-wg/2009AprJun/0016.html
See also: [3]IRC log
[3] http://www.w3.org/2009/04/08-svg-irc
Attendees
Present
[IPcaller], anthony, heycam, Doug_Schepers, ed, ChrisL
Regrets
Chair
Erik
Scribe
Cameron
Contents
* [4]Topics
1. [5]SVG Integration module
2. [6]Progress on 1.1 second edition
3. [7]Color module
4. [8]Transforms module
* [9]Summary of Action Items
_________________________________________________________
<trackbot> Date: 08 April 2009
<scribe> Scribe: Cameron
<scribe> ScribeNick: heycam
SVG Integration module
DS: not much to show yet, thought i'd get something going
<shepazu>
[10]http://dev.w3.org/SVG/modules/integration/SVGIntegration.html
[10] http://dev.w3.org/SVG/modules/integration/SVGIntegration.html
DS: i'm going to start by integrating that embedding document i once
wrote
ED: sounds good
<shepazu> [11]http://www.schepers.cc/svg/blendups/embedding.html
[11] http://www.schepers.cc/svg/blendups/embedding.html
DS: also how to extend svg, starting with what we had in 1.2T
... i'll put in whatever hooks cameron needs for doing the tables of
attributes and elements
CL: did how we do attributes change recently?
CM: still experimenting, once the build scripts are finalised i'll
mail the list with details
<shepazu>
[12]http://www.w3.org/TR/SVGTiny12/conform.html#ConformingSVGEncodin
g
[12] http://www.w3.org/TR/SVGTiny12/conform.html#ConformingSVGEncoding
[doug reads out D.7]
CL: nice that that wording is in there
DS: does the current svg in html proposal violate that?
CL: the intention would be not to violate that, not sure about the
current proposal
DS: i don't think it does violate it
... as to what hooks to put into the spec to generate the tables of
attributes etc., i'll leave it to cameron to work out what's best
... a question about svg in an <img> element
... what if you have svg referenced from html <img>
... <object> has .contentDocument
<ChrisL> script in svg wich is in an image, or script somewhere else
getting at svg in an image through script?
DS: does <img>?
... i'm kind of thinking that we might say no
ED: i don't think that would work, at least in opera 10
DS: should it?
ED: we made a decision not to allow it. it's just whether you put
the interface on that <img> element. but we chose not to.
... since it doesn't allow scripting inside the referenced document,
that's why we chose to leave out the interface
CL: but why prevent accessing the document from outside?
DS: i think from a security and efficient viewpoint, it might be
better not to get at the contents at all
ED: my question is, what would happen if you inserted a <script>
inside the referenced document?
CL: i'm talking about getting to the document at all. whether it's
readonly or read-write is a separate question.
... maybe if it comes from a different host you wouldn't be allowed
to, but that's just a standard cross site restriction, nothing to do
with it being an <img>
DS: if you reference using <object>, <embed>, etc., you already have
that capability
... we're talking about one particular embedding scenario that walls
it off more
CM: perhaps you specifically want to disallow access from the
containing html (and to disallow script running inside the svg),
hence you'd use <img>
DS: the canvas api operates on <canvas> and not <img>, right?
ED: yes
DS: so you wouldn't be able to modify the image referenced by <img>
but not an svg referenced by that element (i.e., there wouldn't be
that inconsistency)
... so with <img> you can't access the DOM from the outside
CL: if you can't access the DOM from inside or the outside, do you
need to build a DOM at all?
DS: text
CL: might be an accessibility concern if an AT can't access the text
as a DOM
CM: perhaps the AT uses privileged methods to get at the DOM, not
just standard script in the web page
DS: in the html wg we're discussing accessibility of canvas
... for the purposes of svg in <img>, there might be an api (mini
dom?) hanging off the <img> that exposes the text information and
nothing else
ED: i would prefer in that case to have specialised access for ATs
... i started to look at this; we still have the DOM for SVGs
referenced by <img>, so in our source code we can access it
... but you're just prevented from accessing it in script
... i don't think it'd be a problem to expose that information to
ATs
... i'd have to check how we integrate with ATs, though, but i don't
think it'd be a problem
... i agree that it'd be useful for such tools to be able to access
that information inside
[discussions about getting AT vendors involved in helping with SVG
accessibility speccing]
<scribe> ACTION: Doug to contact AT vendors about SVG accessibility
[recorded in
[13]http://www.w3.org/2009/04/08-svg-minutes.html#action01]
<trackbot> Created ACTION-2515 - Contact AT vendors about SVG
accessibility [on Doug Schepers - due 2009-04-15].
DS: i wonder if much of the challenge for them is in drilling in to
embedded DOMs (e.g., via <object>)
[discussions of appropriate title/desc]
DS: this'd be for the svg semantics spec (which would deal with
aria, too)
ED: another thing for the integration spec would be css fonts and
web fonts, whether or not scripts should run in referenced svg fonts
CL: if an svg has an @font-face, which points back to the same
document; if that document has script, should it run?
... how about if they're in different documents?
... not sure where the line lies
DS: some of these trickier decisions fall out from higher level
decisions
No telcons next week.
Progress on 1.1 second edition
ED: what's the status on the scripts?
[14]http://mcc.id.au/temp/struct.html
[14] http://mcc.id.au/temp/struct.html
CM: changes since last update are the interfaces at the bottom of
that
[15]http://dev.w3.org/SVG/profiles/1.1F2/master/svg.idl
[15] http://dev.w3.org/SVG/profiles/1.1F2/master/svg.idl
CM: the idl file is using javadoc-style comments now
[people are happy with javadoc-style comments in the idl]
<ChrisL> (discussion about svg)
CL: what are we doing about rng?
CM: should we still include the dtd in the appendix?
CL: i guess we should; we should add some wording about problems
with dtds, non-namespace-aware, etc.
... we should fix the non-deterministic problems and other things
that were identified
... add wording to say that if you want to validate including rdf
etc., then suggest using rng
CM: we might want to rewrite some of the text in extend.html
CL: where's the rng coming from?
... i think it would be better to start with the 1.2T rng and
add/remove things
ED: There's an rng for 1.2 full, not sure how correct it is
CL: i don't think it's quite correct
... the other option is to take the dtd and convert it to rng
... so i think it would be best to start from 1.2T and add the 1.1
features
<ChrisL> a trang conversion is probably not going to be very
readable
<scribe> ACTION: Chris to make RNG for 1.1 based on the 1.2T one
[recorded in
[16]http://www.w3.org/2009/04/08-svg-minutes.html#action02]
<trackbot> Created ACTION-2516 - Make RNG for 1.1 based on the 1.2T
one [on Chris Lilley - due 2009-04-15].
CM: there are still a few outstanding 1.1 errata that need working
on
ED: it would be useful if people could finish those off, and talk
about them after next week
Color module
CL: there has been a question asked of me about why we support
rendering-intent
... my answer was because the ICC spec has rendering intent
... people have pushed back and said that it's probably going away
from the next ICC spec
... and many profiles have only a single table
... we have to say what happens if the user requests a rendering
intent and there isn't a table for it
... i will be discussing with the openicc people at libre graphics
some of the options for that, but that's a new issue
... at minimum it needs to go into the spec as an issue
... hopefully i can add some text to describe fallback
AG: i can also talk to some people here to see what fallback to use
... i got a group of people together within cisra to discuss the
color module, and from that review we felt that it wasn't targetting
anything specific
... i went back and talked to some other cisra people, and we
figured that with the current features that are in the color module,
it's best targetted towards office printing
... not sure if that's the original intent of the spec
CL: it should cover that, but i don't think it should be specific to
it
AG: it does cover everything from regular web authoring up to office
printing
... it's probably not sufficient for high end printing
... we should specify what areas we are intending to target
CL: it would be helpful if you could let us know what is missing for
high end printing
... not necessarily to put it into the spec, but just to know
AG: in terms of the current spec being useful for office printing,
one feature we think is missing is "preserve black"
... where you'd be able to say that RGB black (or CMYK black) would
be preserved as black at the printer
CL: is that different from black point compensation?
... if i have rgb(0.0001, 0, 0) is that also black?
... black point preservation says what really is black, given the
surroundings
AG: this is basically for text. if you specify some text as black,
you'd want to preserve that so that at the end when printing, it
doesn't use CMY to make up the colour. but uses the black ink
CL: so you're using black as a spot colour, and saying not to
separate it
AG: yes
... the other area where this is useful is for fonts
... because if you pull out a font that's a bitmap, you could say
preserve black on the bitmap so that they don't get colour converted
... otherwise you still might get a browny colour out at the end for
your text
CL: but you still want it to be optional?
... e.g. if you're matching up with other black parts of the image
AG: haven't thought that far ahead
... if you have line art between the text, you might want to use
preserve black on the line art too
... some of these guys would be happy to join a call to discuss
things that are missing
... we're still doing some more review on it, we'll get comments in
in a week or two
CL: i started looking at a global default for icc profiles
... it's fairly easy to do, not sure it gains you much
AG: the other thing is that icc profiles are referenced by name. is
it possible to reference them by id?
CL: what does the id look like in the spec?
... if there's a big complicated string, we'd only want to use that
once in a document
<anthony>
[17]http://dev.w3.org/SVG/modules/color/master/SVGColor.html
[17] http://dev.w3.org/SVG/modules/color/master/SVGColor.html
<ChrisL> not *that* spec :)
<ChrisL> [18]http://www.color.org/ICC1V42.pdf
[18] http://www.color.org/ICC1V42.pdf
CL: the profile's unique id is an MD5 hash
... using that everywhere in a document wouldn't be nice
<ChrisL> ok so the short readable name instgead of a n MD5
unreadable thing is much nicer
AG: 'local' is optional too
Transforms module
AG: i was reading through the conformance criteria section in 1.2T
<anthony> "If using features defined in SVG Full, an extension must
not redefine the syntax of the syntax of those features."
<anthony> "An extension must not redefine the semantics of any
existing SVG element or attribute."
AG: we'd need to use unique names, we can't redefine semantics of
existing attribute names
<ChrisL> (found the unique name thing - its section 7.2.18 Profile
ID field (Bytes 84 to 99))
<anthony>
[19]http://www.w3.org/TR/2009/WD-SVG-Transforms-20090320/#transform-
list-extensions
[19] http://www.w3.org/TR/2009/WD-SVG-Transforms-20090320/#transform-list-extensions
CM: i assume it's more for 3rd party extensions rather than
restricting how the WG can extend the language
AG: i'd like to start discussing some of the issues that were raised
<anthony> ISSUE-2233?
<trackbot> ISSUE-2233 -- adopt the syntax for CSS Transforms --
RAISED
<trackbot> [20]http://www.w3.org/Graphics/SVG/WG/track/issues/2233
[20] http://www.w3.org/Graphics/SVG/WG/track/issues/2233
AG: here dino asks why we dropped translateX/Y/Z etc.
... there's no real cost in having them in there, is it worth
dropping them or keeping them?
DS: i don't think it makes a big deal either way
... i think i was the one who originally raised the issue about
adding too many transform items, but if there's a plausible story
for them making it easier for authors, i'm all for it
CM: the cognitive cost of having both translate(5) and translateX(5)
doing the same thing probably isn't too great
JW: my concern was about implementation strategies and optimising
memory usage
... rather than having 16 values for some of the transforms you
could cut it down to 1 or 2 quite often
... there's probably enough in there that implementations would have
to deal with that complexity anyway, so perhaps it's not a concern
CM: do implementations keep around only a single value for
transform="scale(4)" at the moment, rather than storing all 6 values
for 2d transforms?
JW: the moz code at the moment stores the full matrices
AG: i'd imagine a lot of transform pipelines would be like that
JW: was thinking of implementing it with an operator overload kind
of thing, with classes for the different types
... but that's probably a bad strategy anyway ;)
AG: if you do have translateX/Y/Z, do we keep the current
translate() transform item as is?
<anthony> translate(<tx> [<ty> [<tz>]])
AG: would we still allow translate() to do a 3d translate?
CM: in the css proposal do they only allow two parameters to
translate()?
AG: yes, and have an additional translate3d()
CM: maybe they did that to avoid trampling on existing svg transform
items
AG: they have no optional components for translate3d(), but keep
translate() the same as svg's
DS: we should have a call with dino to discuss these instead of
guessing at intentions
<scribe> ACTION: Anthony to mail dino CCing public-fx to get him to
join an SVG call to discuss transforms [recorded in
[21]http://www.w3.org/2009/04/08-svg-minutes.html#action03]
<trackbot> Created ACTION-2517 - Mail dino CCing public-fx to get
him to join an SVG call to discuss transforms [on Anthony Grasso -
due 2009-04-15].
<shepazu> public-fx
Summary of Action Items
[NEW] ACTION: Anthony to mail dino CCing public-fx to get him to
join an SVG call to discuss transforms [recorded in
[22]http://www.w3.org/2009/04/08-svg-minutes.html#action03]
[NEW] ACTION: Chris to make RNG for 1.1 based on the 1.2T one
[recorded in
[23]http://www.w3.org/2009/04/08-svg-minutes.html#action02]
[NEW] ACTION: Doug to contact AT vendors about SVG accessibility
[recorded in
[24]http://www.w3.org/2009/04/08-svg-minutes.html#action01]
[End of minutes]
_________________________________________________________
--
Cameron McCormack ≝ http://mcc.id.au/
Received on Wednesday, 8 April 2009 08:00:10 UTC