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minutes, Pyrmonth, Sydney SVG F2F Day 2 (04/02/2013)

From: Cameron McCormack <cam@mcc.id.au>
Date: Tue, 05 Feb 2013 17:27:49 +1100
Message-ID: <5110A665.8030500@mcc.id.au>
To: "www-svg@w3.org" <www-svg@w3.org>
Minutes here:


which seem to include some of yesterday's minutes.  Text version below:


       [1] http://www.w3.org/

                                - DRAFT -

                     SVG Working Group Teleconference

04 Feb 2013

    See also: [2]IRC log

       [2] http://www.w3.org/2013/02/04-svg-irc


           Mighty Cameron

           Cyril, Various, heycam


      * [3]Topics
          5. [8]Relation between enable-background and isolation
          6. [9]iframe proposal
          7. [10]HTML in SVG
          8. [11]HTML5 video element in SVG
          9. [12]media attribute on iframe
         10. [13]streaming of SVG
         11. [14]Glyph selection and positioning; associating text
             with graphics
         12. [15]global coordinate system
      * [16]Summary of Action Items

    <trackbot> Date: 04 February 2013

    <heycam> Meeting: SVG WG F2F Sydney 2013 Day 2

    <ed> chair: erik

    <heycam> ScribeNick: heycam

Relation between enable-background and isolation property

    krit: we have the enable-background property and the isolation

    … two properties with different name but with the same context,
    they're supposed to do the same thing

    cabanier: except that isolation has different default values:
    auto | isolate, enable-background default value is always

    <cabanier> spec for isolation:




    krit: the idea is that you can get the background of an element
    that you want to filter

    … and have filter operations based on the background

    … this is useful in blending and compositing

    … with feBlend and feComposite

    … the problem is that the relation between enable-background in
    the past is the same as isolation; that's why we wanted a

    … enable-background preserves the background up to the previous
    enable-background:new regardless of what graphics are in

    … this is the default behaviour

    … similar to z-index, making a new stacking context

    … isolation in the past did the same thing but with different

    … the default behaviour now has changed, though

    cabanier: but you can say enable-background works on filters
    but isolation works on graphics

    krit: you could but we shouldn't
    ... do we still want to preserve both properties with different
    ... does it make sense to have two different stackings, one for
    filters and one for compositing?

    nikos: they are for different purposes

    … the reason behind enable-background was an optimisation, if
    you don't have "new" anywhere then background image isn't

    … by setting it to new, you're making a certain region of the
    document available in the background

    krit: that's just like in compositing

    nikos: but they're for different reasons -- for
    enable-background it's an optimisation, for compositing it's
    for the effect you want

    krit: from the implementation pov, there's some cost to
    implement both

    … sometimes it's even not possible

    … if you have overlapping background regions from both

    cabanier: has anyone implemented enable-background for html?

    krit: no

    cabanier: we could say that isolation:auto defaults to
    providing background in svg elements and not in html elements

    nikos: I think they should be kept separate, but when you apply
    a filter to a group the group is isolated

    alex: you have to do it that way anyway

    nikos: that's what illustrator does

    cabanier: sometimes...

    heycam: what is the proposed change?

    cabanier: we can make enable-background "auto" ...

    krit: but it would still mean that you'd have two different

    cabanier: we can just make enable-background and isolation mean
    the same thing

    krit: the main thing is that the situation has changed last
    year… the behaviour of Compositing has changed

    nikos: they can't influence each other; if you apply a filter
    to a group makes it isolated

    krit: if you have enable-background:accumulate
    isolation:isolate what happens?

    nikos: [draws]

    krit: we should have shared text between Filters and
    Compositing saying you isolate up until the ...

    Cyril: you can say isolate has two purposes; one is for
    compositing and one is that it affects filters as if it were
    ... would need to define what happens if you put
    isolation:isolate;enable-background:accumulate on an element

    nikos: if you have
    enable-background:accumulate;isolation:isolate that's not going
    to make a difference

    Cyril: cabanier says isolation takes precedence
    ... what "auto" in isolation? is that different from "isolate"?

    cabanier: it's mostly not isolated, unless you have opacity or
    something that creates a stacking context

    ed: where should this go?

    krit: I'd like to share the wording, and reference Compositing
    from Filters

    cabanier: if you really wanted enable-background to only to
    apply to filters and not influence compositing, you couldn't

    krit: SVG needs to say what stacking is

    ed: jwatt wrote up a z-index proposal, what stacking contexts
    means -- that might be enough

    krit: then define how Filters and Compositing/Blending interact
    with stacking contexts in SVG

    Cyril: will there be any difference between SVG and HTML?

    krit: no

    cabanier: you might want to blend something with opacity with
    the background in SVG… which isn't possible in HTML/CSS

    ml (jwatt's z-index proposal)

      [49] http://lists.w3.org/Archives/Public/www-svg/2009Oct/0042.html

    krit: why doesn't isolation have a new value to mean never

    Cyril: when you use CSS Transforms on SVG elements it makes a
    stacking context, but if you use the attribute it doesn't?

    heycam: that seems bad

    krit: that's not how it's implemented
    ... if you have a transform you should isolate this?

    alex: this doesn't make sense in HTML

    krit: I think transforms shouldn't affect blending/compositing
    in SVG
    ... we first need to know if Compositing and background are
    affected by stacking contexts

    ed: we could use a new term and maybe make it equivalent to
    stacking contexts later

    nikos: "isolated group"

    cabanier: I think doing that for CSS will be a nightmare

    krit: transforms being affected by stacking contexts is stupid

    cabanier: maybe CSS Transforms should be updated?

    <scribe> ACTION: krit to ask CSS/FX how blending is supposed to
    work with transforms [recorded in

    <trackbot> Error finding 'krit'. You can review and register
    nicknames at

      [51] http://www.w3.org/Graphics/SVG/WG/track/users%3E.

    <scribe> ACTION: Dirk to ask CSS/FX how blending is supposed to
    work with transforms, opacity, all properties that create
    stacking contexts [recorded in

    <trackbot> Created ACTION-3431 - Ask CSS/FX how blending is
    supposed to work with transforms, opacity, all properties that
    create stacking contexts [on Dirk Schulze - due 2013-02-11].

iframe proposal

    stakagi: we have a document



    birtles: let me summarise

    … in the Abstract there are three main parts

    … one is the iframe element; takagi-san has written out spec
    text to allow iframe in SVG

    … it's similar to HTML's iframe element

    … one addition is the second point, the levels-of-detail, and
    it uses a media query to determine when to show the iframe's

    … it's an attribute on the iframe itself

    … the third part is the global coordinate system, and there's
    some discussion about what that is useful for in the issues

    Cyril: except for the coordinate system, it looks similar to
    the <picture> element or srcset

    … the responsive images, where they want to load one resource
    or another based on media queries

    birtles: wrt the media attribute?

    Cyril: what's the difference between <img> and <iframe> in this

    heycam: it's meant to be just like an HTML <iframe> here

    krit: I thought some WebKit engineers were unhappy with

    … and maybe they would not like it in SVG

    birtles: I've heard the opposite feedback, that <iframe> is the
    way forward, and people shouldn't use <object> and <embed>

    … for example we have seamless and sandbox on iframe now

    krit: for security concerns

    birtles: yes to make it better

    … so this proposal would allow those attributes on <iframe> in
    SVG too

    nikos: this doesn't talk about the difference between seamless
    or not

    birtles: it's not in this document, but we have discussed it

    … I'm not sure how much we need to say

    … the behaviour would be the same as in HTML, in how you
    inherit styles

    … that's all common

    … one area of difference is do you have a border

    … that does need to be defined

    Cyril: what's the difference between <iframe> and <img>?

    ed: iframe has interactive, img is static

    birtles: there used to be a difference where <image> in SVG was
    static as in not animated, but that's changed to allow
    animation now

    alex: so iframe is like the old <animation> element

    ed: this is basically how we implemented Tiny's <animation>
    element -- as an <iframe>
    ... the first thing then is do we want to have an iframe
    element and in SVG 2?

    heycam: we should write down somewhere how foreignObject
    requires HTML to be rendered etc.

    krit: so this proposal has an addition?

    birtles: yes that's the next part of it

    krit: does it make sense to allow that on original <iframe>?

    birtles: first question is whether we should allow <iframe>
    directly in SVG

    … second is whether to have media="" just on SVG's <iframe> or
    on HTML's too

    Cyril: I think the <animation> element had good points, but
    maybe too many in the same element, e.g. control of timeline

    … and the linking to SVG content

    … maybe it's a good idea to split these

    birtles: this isn't about controlling the timeline

    Cyril: that's why I'm saying it's a good idea to split these
    ... we should have a common solution across responsive images

    krit: should we use <iframe> in SVG directly instead of
    inventing it again?

    birtles: yes it would be kind of like a shortcut in SVG without

    … it would be in the SVG namespace, just for convencience

    … it's not reinventing iframe, but importing it and smoothing
    over the gaps

    Cyril: now in respimg they are talking about srcset in <img> or
    a new <picture> element

    … which are both only for static things

    … if you have a map that's interactive you couldn't use

    <stakagi> First of all for with responsive images
    compatibility, I introduced media attribute.

    heycam: maybe srcset or whatever could apply to <iframe>

    birtles: srcset is more about selecting from alternatives, here
    <iframe media> is about when to turn the element on or off



    heycam: could you use scoped style sheets instead media=""?

    birtles: media queries will fetch all of the matched things,
    but in this case we don't want to load everything at once

    Cyril: same thing for respimg

    <stakagi> Especially, i think 'close-viewport' is unique

    birtles: within that media="" attribute, there's a proposal for
    some additional media queries

    … there are two

    … zoom and close-viewport

    … they're additional tests to define when the resources are
    loaded; one is the zoom factor, and the other is how close the
    tile is to the viewport

    Cyril: close as in nearby

    birtles: you give a radius around the tile, once the viewport
    overlaps with this region load this resource

    nikos: why would you let the author set that?

    birtles: one view is to let the UA choose that to optimise

    alex: if you pan the map you'll want to prefetch the tiles
    you're about to see

    birtles: even if we were to use srcset, these additional media
    queries could still be useful in that context

    Cyril: this is touching a lot of areas, CSS, HTML...

    … I am not sure how we can proceed in the SVG WG, coordinate
    with the other groups?

    birtles: there are different routes

    … pointer-events was something that was in SVG initially and
    then later was adopted more widely

    … we could say this media="" stuff only applies in SVG

    … and I think it has more relevance in SVG

    Cyril: we shouldn't give the impression that we're modifying
    <iframe> unilaterally

    birtles: the thing to decide today is do we want to pursue a
    native <iframe> in SVG, and what direction would we like to do
    with media=""

    krit: this is somehow in conflict with the discussion of how to
    allow all HTML elements directly in SVG

    <ed> -- 15 min break --

    <krit> scribeNick: krit


    <heycam> ScribeNick: heycam

    krit: the problem is that HTML uses the CSS box model

    … all HTML elements have this CSS layout

    … one problem is that SVG has coordinate based drawing,
    CSS/HTML has layout based

    … I suggested on whatwg to use something other than

    … we could create a shortcut for this, it just takes a
    width/height and position and everything inside is HTML

    … inside that you have the CSS box model

    … that would be one way to do it

    Cyril: I taught SVG this winter to a group of students, they
    were mixing SVG/HTML with foreignObject, body, etc.

    … they knew how to do it easily

    krit: it's a lot of code that you waste

    … you have to specify <foreignObject>, html namespace, body

    heycam: I thought we wanted to try to avoid having a wrapper

    Cyril: are you switching parser in the middle? if you have XML
    on the outside and you get to this new element, would you
    switch to HTML parsing?

    heycam: no

    … that couldn't work

    cabanier: in HTML don't you switch to SVG parsing when you get

    heycam: it's switching mode within the HTML parser, not
    switching parser

    Cyril: when you have a <foreignObject> with HTML inside, does
    it have to be XML-compliant HTML?

    heycam: yes

    Cyril: can you have a <video> self closed tag?

    heycam: in XML? yes

    cabanier: if you have an HTML file with inline SVG, and inside
    that you have <foreignObject> how is that parsed?

    heycam: that's still HTML

    Cyril: <foreignObject> needs an HTML namespace?

    heycam: on the children of <foreignObject>, say the <body>

    Cyril: you just want to replace <foreignObject> with <html>?

    krit: in addition, not replace

    heycam: I don't think you can make HTML elements inside
    <svg:html> automatically get parsed into the HTML namespace if
    we're being parsed as XML

    ed: that wouldn't allow us to have <iframe> directly as a child
    of other SVG elements

    … <iframe> is a bit special in that it defines a rectangular
    region, just like <foreignObject>

    krit: you cannot just put an HTML element in SVG context

    heycam: we could make it so that the namespace URI, whether it
    is SVG or HTML, doesn't matter

    … thus you could have <g><div></div></g>, and <div> would be in
    the SVG namespace, but that wouldn't matter -- it would behave
    the same as an HTML namespaced <div>

    heycam: Tab also suggested at one point having no namespace, so
    <svg> as the root, no xmlns

    … and then all the SVG- and HTML-named elements could be in no

    … but you would still get SVGCircleElement, HTMLDivElement
    objects created for them

    heycam: one problem with <iframe> as a direct child of <g> is
    how to specify the position of the iframe

    … you could use style="top: …; left: …" or style="transform:

    … SVG has a bunch of global attributes like transform="",
    presentation attributes, etc.

    … should these be allowed on the <iframe>-as-a-child-of-<g>?

    … I feel like we should have <iframe> functionality in SVG

    … without having to have intervening HTML

    birtles: <iframe> has some features which would be useful in
    SVG as well, like seamless for applying styles across nested
    browser contexts

    … and sandbox as well

    heycam: I am a bit worried about these extra attributes on
    SVG's <iframe>

    … if later we want to unify it and HTML's

    … if we allow x="" and y="" and transform="" and display="" on
    our <iframe>, and later we have a plan to allow all HTML
    elements as direct children of SVG elements, it would be bad if
    they stopped working if the element was in the HTML namespace

    … I'd like much the same behaviour across both namespaces

    … (x and y might be ok to have not work in HTML namespace,
    since you want to rely on CSS for layout)

    Cyril: what about for HTML <video>?

    birtles: that raises the same issues
    ... with x and y, I wonder if you could define those to only
    make sense/apply in SVG contexdt

    … and reuse that for both iframe and video

    … x and y would mean "the SVG offset", and by definition
    wouldn't work in HTML

    … the next step, when we try to expand integration further, we
    could decide if we wanted those on <div> and <p>, but that's a
    separate question

    [some talk about the difference between width/height properties
    and attributes on canvas/video/img]

    ed: to me it seems all of these HTML elements that have
    width/height, it's a separate problem from all the other HTML
    elements like p/div

    … I think those that have width/height already would be easier
    to take in as they are, more or less

    … the qn is whether to do that first, or consider the whole set
    of elements

    [discussion of which spec iframe would go in to, SVG 2 or
    another; takagi-san prefers SVG 2, but whatever is quicker]

    ed: I think it makes sense to do all of video, canvas, iframe
    at once

    … I wouldn't mind it being in SVG 2

    heycam: what to do with all the presentation/global attributes
    that would otherwise be on SVG elements?

    ed: just allow x/y to begin with?

    heycam: I think that is safest

    RESOLUTION: SVG 2 will have iframe, canvas, video in the SVG
    namespace and with the same behaviour as HTML's, but allowing
    global SVG attributes on them
    ... iframe, canvas, video will also have x="" and y=""
    attributes in SVG, which eventually will be presentation
    attributes for the new 'x' and 'y' properties

    <scribe> ACTION: stakagi to edit SVG 2 to add the iframe,
    canvas, video elements [recorded in

    <trackbot> Created ACTION-3432 - Edit SVG 2 to add the iframe,
    canvas, video elements [on Satoru Takagi - due 2013-02-12].

    birtles: the next thing is the media="" attribute

    heycam: I think the specs should say whether media="" means
    fetch up front or only once it starts matching

    … I'd like it not to be different from media="" on style, link,
    but I can see that preventing resource fetching is important
    for tiles/maps

    birtles: in the proposal media="" acts like a conditional
    processing attribute

    … so it should prevent processing of elements altogether

    … maybe it needs a different name

    … the reason for choosing media="" was to match the <picture>

    <ed> -- lunchbreak --

    <krit> ScribeNick: krit

HTML5 video element in SVG


      [56] http://www.w3.org/Graphics/SVG/WG/wiki/SVG2Multimedia

    Cyril: Questions related to this topic.
    ... We decided to use HTML5 video element instead of tiny
    video. I implemented it and have quesions
    ... what about bollean attributes without values?
    ... What about self closing tags

    krit: they shoulld be closeable

    heycam: yes, the parser should ignore that and not closing tags
    should be able to have closing tags

    Cyril: ok
    ... checked with tiny waht we miss
    ... tiny has a timeline
    ... they are in webanimations, but will they be in media

    birtles: we discuss it next week and have ideas

    silvia: i like the idea of timelines

    Cyril: timeline is on doc for tiny
    ... pause on element you don't care
    ... how do we have this feature in SVG?

    birtles: talk about it that next week
    ... we didn't get put the mechnaics now

    Cyril: you need to be careful of timelines between groups

    shanestephens_: we should take care of it
    ... if we don't, the media controler should provide it
    ... but we want to make it work

    Cyril: do you wat to control the doc timeline (start timeline
    on load)

    birtles: yes, we define what 0 line is on a documen


    silvia: you could have the media group under the timeline
    ... every media element has a videocontroler
    ... media controlers are objects that can be shared?


    Cyril: animation element whcih has 2 features
    ... link to animation, control the timeline, how in


    birtles: webanimations has timing groups
    ... <par> and <seq>

    Cyril: animations can poiint to a external document

    shanestephens_: I would modify media controler to have a
    timeline. Seems better

    Cyril: image with ref to image… no timeline. video would have
    with resource restrictions
    ... video should point to svg content to control timeline on
    this svg content
    ... image does not have any control
    ... no MediaElements interface
    ... I would not expect a video to run script
    ... cartoons are one example
    ... come back to streaming later

    silvia: should be in HTML first

    birtles: right

    Cyril: yes, commen problem: spec features between html and svg
    ... how can i run and stop video declaritly
    ... in html you need scripts and events

    birtles: ah, needs to be expressed in webanimations

    Cyril: svg document and html document differ and both do not
    have timeline

    birtles: all documents have a timelien

    shanestephens_: embedding does not worry me
    ... when you use css svg then this will introduce a timline
    given by WebAnimation
    ... html will have a timeline

    birtles: so you want 10s after document load?

    Cyril: yes

    birtles: you can do that with svg animation already
    ... but you can not do with nesting animation yet
    ... we need to think about a declaritive way
    ... might be different to pass it through WG.

    shanestephens_: don't think so

    Cyril: css animtions trigger when style attached. This was not
    possible to synchronize
    ... how to fixx that

    birtles: intentionally it will be fixed magically
    ... e.g. time groups are one way
    ... no absolute time in CSS yet, but could be added
    ... helps synchronizing
    ... more work on CSS side needed

    shanestephens_: there is more that we need to discuss with the
    CSS WG
    ... we should work on appro. to sync CSS to the CSS WG

    Cyril: in tiny we had transformable attribute
    ... transforms like scale could be defined that it just had an
    affect on the position

    krit: so CTM gets transformed but just affects the position?

    Cyril: basically
    ... do same restrictions apply? do we still need that?
    ... if so, it should be in CSS Trnasforms?

    AlexD: maybe

    shanestephens_: we should come up with a unified model for

    heycam: like trnasform-behavior: normal and position?

    Cyril: yes, where you transform CTM, or just a point
    ... where is transform on text?
    ... not in CSS transforms,


    AlexD: no, we do that

    Cyril: synchMaster and tolerance
    ... nother point in SVG tiny
    ... what if one point is lacking
    ... then you can define if you do not care if audio and video
    are in synch or not. It was possible to allow a tolerance

    shanestephens_: mediaControler does it, but no master

    birtles: webanimation it is sometimes hard to do simple things

    shanestephens_: spec of tiny is very hard to understand and

    Cyril: but the model is simple

    shanestephens_: is the spec not easy enought ridden or the spec
    not good enough?

    AlexD: former

    <birtles> (we decided in web animations not to address sync
    tolerance initially, but just to have strict synchronisation)

    birtles: we won't allow tolerance in the first version

    Cyril: RTP is not used much, so it might not a valid use case,
    but people use multiplex streams, they won't like
    ... but hybrid cases, different streams from different media,
    sounds interesting

    shanestephens_: yes, there are things that ususally separate
    video and audio stream for example

    silvia: in html it is regarded as quality of browser
    ... html allows implementation to decide about the tolerance
    ... if i am web dev, and have 4 medias. Then I want them come
    in enought speed, so that they can displayed together
    ... let browser decide how to get quality for streamed media

    Cyril: yeah, but sometimes it depends on one master
    ... but ok for now
    ... what baout visibility? start from 10s of video, should it
    display one fray for this 10s?

    heycam: Can you do that?

    silvia: it always does that
    ... either give it a poster, or it will give the first frame.
    not described in html, but the way it works

    Cyril: basic interface of media seems to be the same
    ... did not lost anything to tiny

    birtles: media attribute on iframe

media attribute on iframe

    silvia: is this about media queries?

    all: yes

    Cyril: iframe is one way to get HTML things into SVG

    (see minutes of morning)

    birtles: usecase: map and you want control when resources are
    loaded and displayed
    ... media attribute defines (with media queries), when this
    will happen
    ... media for attribute with two different behvaiors (we meean
    dont load, don't show) but we want don't show but load if you
    ... maybe we rename it to sth. else

    <stakagi> The srcset attribute : An HTML extension for adaptive
    images : [57]http://drafts.htmlwg.org/srcset/w3c-srcset/

      [57] http://drafts.htmlwg.org/srcset/w3c-srcset/

    <stakagi> The picture element : An HTML extension for adaptive
    images : [58]http://picture.responsiveimages.org/

      [58] http://picture.responsiveimages.org/

    silvia: there is also reload audio/video and so on
    ... this is related
    ... means load if you can

    birtles: media on iframe don't show this resorese and preload
    can allow to allow or disallow pre loading

    heycam: would it be fine to turn of poss of iframe to laod and
    show of iframe?
    ... or think of media attribute as controlling multiple things

    Cyril: would our iframe prop. interesting as usecase for
    <picture> and srccset discussion?

    silvia: no, differetn
    ... media queries specify range of conditions
    ... in this size use this, this for another screen size?
    ... what is it on iframe?
    ... how do you define the range?
    ... would make a lot more senese
    ... especially for going to the picture element
    ... what is the use case?

    birtles: SVG conditional prpoposing attr.
    ... it is choosing between possibilieties like <switch>
    ... common case you wouldn't

    silvia: don't think that is going to work
    ... rather embed frame with iframes in there and only one is
    chosen according criterias

    birtles: how is that working on tiling in the mapping use case?
    ... you have a lot offrames with same query

    silvia: is it a use case to turn of tiles?

    Cyril: maybe on details
    ... as more you zoom in, as more details

    birtles: you zoom in and get new tiles for this level?
    ... don't you think this is accepted?

    heycam: if you could use <switch> in HTML....

    silvia: you getting SMIL back to live once per peace
    ... do you have an example

    birtles: yes



    Cyril: in this case you just want to conrol loading

    birtles: yeah, ok

    Cyril: smae problem as on resp images
    ... use cases might be different enough. I your case all tiles
    will have the same queries on a given layer

    <Cyril> s/I your/In your/

    birtles: waht about extensions to media queries regarding to

    ed: maybe a topic of FX TF or CSS WG

    <scribe> ACTION: birtles to discuss iframes with media queries
    with CSS WG [recorded in

    <trackbot> Created ACTION-3433 - Discuss iframes with media
    queries with CSS WG [on Brian Birtles - due 2013-02-12].

streaming of SVG

    <Cyril> [61]http://www.w3.org/Graphics/SVG/WG/wiki/SVGStreaming

      [61] http://www.w3.org/Graphics/SVG/WG/wiki/SVGStreaming

    Cyril: In Seattle F2F I made wiki page
    ... had an action a concrete guideline
    ... put it on my web site for now


      [62] http://perso.telecom-paristech.fr/~concolat/SVG/streaming/

    Cyril: some times you want to stream SVG content
    ... discussed few use cases
    ... defined terms
    ... what is SVG stream, what is a part of it, how do you access
    a part of this stream
    ... tries to brdidege a proposal mp4 together with TTML
    ... defines a concept how to map sources
    ... use cases are cartoons
    ... you jump in at any time 24/7
    ... would be good to make broadcasting of cartoons
    ... popcorn js does similar things
    ... things are not meant to be streamed
    ... live stream not easy
    ... use cases are valid in web content
    ... in multi media player as well
    ... I started what we have now (progressive rendeirng without
    control yet).
    ... communication between client and server missing
    ... do not forward referecnes
    ... element of the future not there, so no content, you are
    ... on progressive rendering you want content be synchronized
    in painting
    ... you can add scripting as well
    ... for simple things the guideline help you
    ... but often you want more
    ... correct displaying on jumping
    ... used access units, generiv term
    ... SVG document is cut into parts and defines and start access
    ... on concatenating, the peaces get a valid document
    ... a cartoon would cut into frames
    ... you seek into this stream
    ... you need to look at the points when you jump
    ... I defined svg stream header.
    ... helps on seeking
    ... it helps to simulate playing from the beginning on cut in
    peace stream
    ... to hget a valid state in a stream, you need to care of
    haveing a valid DOM, scoped stylesheets and maybe JS in a
    correct state on every position

    heycam: is this an authoring requirement?

    Cyril: author defines a state that you would like to have

    heycam: so browser must allow you that

    Cyril: yes
    ... seeking in an SVG stream
    ... in the future where you don't have the data
    ... you need to know what you want to fetch
    ... hte SVG stream header indicates this

    heycam: do you have an header

    Cyril: different ways to do that
    ... in a container, separate file
    ... like WebVTT
    ... WebVTT give you the time offsets
    ... I descirbe how you might use this in HTML5

    silvia: when you asked to put SVG as source files for Video, is
    that waht you asked for.

    Cyril: yeah

    silvia: this gives you a bunch of restrictions
    ... it needs a timeline

    Cyril: there is already a timeline

    silvia: 2s into the file must be the same for every person

    Cyril: I think this is the case

    birtles: yes, you can synch this

    Cyril: if you start storing
    ... container will give you duration
    ... author needs to give duration and can be used to loop
    ... mp4 file does not need to be video, can cntain everything

    silvia: <video> can already point to mp4, even with these
    things embeded into mp4

    Cyril: right
    ... waht is SVG in HTML track?
    ... discussed this in the proposal
    ... I'd like to publish and get feedback

    birtles: how much is required of UA, servers and authors


    Cyril: as UA, you feed stream to preprocessor
    ... don't think there is much to change in browser to support
    ... for servers there is nothing to change
    ... they do mp4 already
    ... mime type is different
    ... to clarify that a container has a SVG inside
    ... but is not SVG

    silvia: webM is not a generic container
    ... just for audio and video maybe WebVTT

    Cyril: is it a valid use case for WebM


    silvia: not at the moment
    ... webm doesn't support it and UA's won't support it anyway,
    since they would need to parse it. don't find a browser that
    can handle this

    Cyril: authors need define Cartoon and then access points +

    silvia: has consequences to put markup data into container that
    is used to work on pixel data
    ... things like Canvas assume to get pixel data on video

    birtles: what baout tools?

    Cyril: we have an svg player and a tool to create container

    birtles: isn't there a lot of potential to get it wrong?

    Cyril: Haven't make the tool for reconstructuring
    ... where can I put it?

    silvia: feels like it does tooo much
    ... sounds more like 10 specs

    Cyril: put it into different sections

    silvia: sounds that some parts would be specified by MPEG

    Cyril: yeah, maybe we do it at MPEG or W3C

    RESOLUTION: Cyril will upload this document for further
    discussion in this group

    <ed> -- 15min break --

    <birtles> scribenick: birtles

Glyph selection and positioning; associating text with graphics

    heycam: I want to see if anyone has a proposal for this, or how
    important it is
    ... regarding the glyph positioning in SVG
    ... a way of selecting and positioning *glyphs* as opposed to

    cabanier: isn't this already possible?

    krit: no that's just unicode, not glyph id

    ed: the only way I know of is to use altGlyph with an SVG font

    heycam: altGlyph as a name attribute and you can select glyph
    by name

    ed: I think it's by id
    ... although there might be a name as well

    <ed> [63]http://www.w3.org/TR/SVG11/text.html#AltGlyphElement

      [63] http://www.w3.org/TR/SVG11/text.html#AltGlyphElement

    krit: nowadays a lot of people icon fonts
    ... is that the use case?

    heycam: now, it's more for things like converting PDF to SVG
    ... you want to position glyphs exactly
    ... so you want predictable glyph selection

    AlexD: the solution in XPS is to have both a character string
    plus a list of glyph IDs
    ... and the package includes the font
    ... so you're guaranteed to have the glyphs

    heycam: I also want to be able to have some graphics with a
    text string associated with it

    cabanier: are you trying to emulate PDF CID fonts

    [explanation of what that means... it just has single offset,
    works in one direction, so you don't have to specify x,y every

    scribe: it also includes an n-to-m mapping so you can say this
    set of glyphs represents this set of characters

    heycam: altGlyph also has this

    [some discussion about how altGlyph's addressing works]

    scribe: so are people interested in solving this in the SVG2

    cabanier: how does this work in pdf.js?

    heycam: it renders to canvas and creates hidden spans over the
    text so you can highlight it

    cabanier: so doing it with canvas sounds problematic. it sounds
    like we need to solve this
    ... identity encoded fonts are so easy

    heycam: one thing about altGlyph is that you can use it in the
    middle of other text too
    ... e.g. <text>abc<altGlyph glyphRef="100">de</altGlyph></text>
    ... "abc" will use usual layout and font-fallback
    ... but "de" might, in this case, be represented by a single
    glyph 100
    ... but what if the text direction differs?
    ... what does it mean to have absolute positions in this case
    since the whole thing can be shuffled around?

    cabanier: so you're mixing absolute positioning with default
    ... it would be easier if you switch modes when you have glyph
    ... so maybe you need <idText> or <cidText>

    heycam: <glyphs>?

    cabanier: something like that

    heycam: do you still like the idea of having glyph IDs and
    character data
    ... would a list be better
    ... not one altGlyph per glyph

    AlexD: yeah, a comma-separated list would be better

    cabanier: you might want to define the mapping up-front

    heycam: is that how CID fonts work?

    cabanier: not CID, but PDF

    heycam: so you define a table up-front?

    cabanier: yes

    heycam and ed: but for SVG we want to have the unicode text
    there as well as a fallback

    scribe: not just a series of glyph IDs and a table

    heycam: so CID is either horizontal or vertical and then just

    cabanier: yes, you start with the CTM and then just offsets
    ... and it's always LTR or top-to-bottom
    ... and the default just uses the default width

    heycam: I'd prefer to have something like altGlyph but
    *outside* a <text> element
    ... so you're not mixing text layed out by the browser and
    author-positioned text

    cabanier: but then you'd need the font

    heycam: if you're missing the font or some glyphs aren't there
    use a box or the undefined glyph

    cabanier: there's also entity text
    ... where you want to map some particular characters to
    something else
    ... not sure what the use case is
    ... but it's in InDesign for the Asian market

    heycam: I'm not sure I'm keen on the table idea
    ... it's nice to have all the character data in the DOM itself
    ... for AT tools etc.

    cabanier: it just gets bigger that's all

    heycam: so in PDF, when you select between horizontal and
    vertical is that something you do on the command that draws the
    text or is it when you select the glyph

    cabanier: it's the encoding, it's either horizontal or vertical

    <birtles_> scribenick: birtles_

    cabanier: but writing-mode also does top-to-bottom
    ... can all the font formats that can currently be referenced
    in the web content, do they all identify glyphs by integers?
    ... I believe so

    ed: but not SVG fonts

    heycam: ok, so numbers are probably ok
    ... we just need to come up for a name for the element and the

    cabanier: and if you want an n-to-m mapping table you need
    somewhere to put that

    <birtles> scribenick: birtles

    heycam: I don't think we need that

    cabanier: I just think it's going to get verbose
    ... so what if you have several glyphs

    heycam: it looks like <___ ids="10,1">ab</___>

    cabanier: and then you would have offset="20, 40" ?

    heycam: I'd rather use x,y,dx,dy for that

    cabanier: you shouldn't have to specify *all* the offsets, just
    the ones where you are tweaking them
    ... the default spacing should be fine for most cases

    heycam: so maybe you want <tspans> for that?

    cabanier and ed: no we don't want tspans

    heycam: what if you want differently coloured text in the

    ed: break it up

    heycam: but what about selection and hit-testing
    ... if you have to have separate elements for different
    formatting you'd lose the ability to know that it's the same
    text run

    AlexD: I want a javascript function that just gets the text
    run, I shouldn't have to piece it together

    heycam: I think we can easily add a tspan-like element in the
    ... which would also mean you don't have to do <___ dx="0 0 0 0
    3 0">...</___> to tweak the position of just a few characters
    ... typically when you have a font family do they tend to have
    the same glyph ids?

    cabanier and AlexD: they can be all mixed up

    heycam: well, you have to know the font when you author it


    AlexD: that's right, that's part of the authoring exercise

    heycam: since selections in the document are represented as a
    DOM selection using a range
    ... you couldn't do that if you didn't have the character IDs
    and only had IDs

    AlexD: the problem is that if you have a <____> and you have 10
    ids and 10 characters, you still can't match up ids to
    characters for text selection since we don't have the mapping

    heycam: so you could only select the whole lot at once
    ... we could assume some default
    ... in firefox you can select half a ligature
    ... can we use something like that as a default
    ... and then also provide a mechanism if you want something
    more accurate

    AlexD: I think you'll run into all the same problems that face
    SVG fonts not coping with shaping

    heycam: so we need the table

    AlexD: the mapping table works better, it's a simple lookup
    ... and that gives you delineated glyph boundaries that you can
    use for selection

    heycam: so if you have 3 characters mapping to one glyph
    ... then when you select that glyph you get back those 3

    birtles: how do you do the reverse look-up if you have
    different characters mapping to the same glyph?

    AlexD: that doesn't normally happen, but it can

    heycam: what does PDF do?

    [discussion about the complexities of an n-to-m mapping where
    one glyph/grapheme cluster can be used for multiple characters
    and one character/string of characters can be mapped to
    different glyphs depending on context/author preference]

    krit: what if you have an SVG-in-opentype font you might want
    to select the SVG one or not

    cabanier and heycam: they have the same ID, you can't do that

    heycam: normally in the DOM the character data is the actual
    ... and I think various things expect that to be the case

    cabanier: even if the element name is different?

    heycam: yeah
    ... I'm pretty sure AT tools walk the DOM and find character
    data to read out

    cabanier: so we should try to keep those tools happy?

    heycam: not only that, but also the DOM selection stuff

    cabanier: but if we put it there we cannot do selection

    heycam: we can if we resolve how to look up the mapping

    AlexD: you can have the table separate and then you don't need
    the IDs next to the character data

    cabanier: what do the AT tools use

    heycam: they just walk the DOM as far as I am away
    ... but that was only one concern
    ... if you select some text with the mouse
    ... there's a corresponding DOM range that's indexed by
    ... if there's no character data in the DOM, what are you
    referring to?

    ed: you could construct some kind of shadow tree dom ;)

    heycam: is there a method on the text selection that gets the
    character data?

    krit: what are use cases?

    all: representing PDF in SVG?

    birtles: how far does CSS Fonts' font-feature-settings get us
    with this use case?
    ... when you want to select a particular variant, use a <tspan>
    with the appropriate feature?

    heycam: it's conceivable but there may be issues if some
    browsers don't support all the layout features of the given
    ... I'd like to have think about how we can still have
    character data directly in the DOM but have reliable selection
    of glyphs corresponding to a selection of characters in the DOM
    without having duplicated information in the table as well as
    in the character data of the element

    <scribe> ACTION: Cameron to think about glyph selection and
    positioning [recorded in

    <trackbot> Created ACTION-3434 - Think about glyph selection
    and positioning [on Cameron McCormack - due 2013-02-12].

    <heycam> ScribeNick: heycam

global coordinate system



    birtles: I'm not sure if I can summarise this well

    … you can see that it's about establishing how different tiles
    map to one another's coordinate systems

    … is this useful?

    … there are some alternatives listed there

    … there are different ways you could use a viewBox, and
    different ways you could use the coordinates of the child
    content for the same effect

    … you could say that all child content used in the one document
    is the same coordinate system

    … and in the child content if it wanted to represent the data
    in a different coordinate system it could have its own viewBox

    birtles: three different options on how you could author this

    … they each have advantages/disadvantages

    … for example if you say everything is in a global coordinate
    system, you introduce a coupling between the child tiles and
    the parent

    … the proposal here is that because each of these 3
    alternatives have disadvantages, we should use a
    globalCoordinateSystem element

    … it's also mentioned further on that this would allow
    different kinds of coordinate systems; ones which are useful
    for connection diagrams, or one for building plans

    alex: the only thing is that <globalCorodinateSystem> applies
    to siblings, it's different from SVG usually where it would
    apply such a transform to a group



    <stakagi> formula:


    heycam: why not just have tiles wrap their local coordinate
    space data in a viewBox or transform that transforms it into
    the agreed-upon global coordinate system?
    ... then you don't need a new <globalCoordinateSystem> element
    ... is there a disadvantage to this?

    alex: you need to know in the outer document what the position
    and size of the tile is, so you can avoid loading it unless it
    is in view

    … this is not possible if you position all of your child
    iframes at 0,0, with the child content all in the same global
    coordinate system

    heycam: we'll continue discussing this later

    <scribe> Chair: Erik

    <scribe> Scribe: Various

    <scribe> Meeting: SVG WG F2F Sydney 2013 Day 2

    <scribe> Scribe: heycam

    <scribe> Chair: Erik

    <scribe> Meeting: SVG WG F2F Sydney 2013 Day 2

    <scribe> ScribeNick: heycam

    <scribe> Chair: Erik

    <scribe> Meeting: SVG WG F2F Sydney 2013 Day 2

Summary of Action Items

    [NEW] ACTION: birtles to discuss iframes with media queries
    with CSS WG [recorded in
    [NEW] ACTION: Brian to spec the setting/getting of an array of
    floats for path handling [recorded in
    [NEW] ACTION: Cameron to add dash control to SVG2 [recorded in
    [NEW] ACTION: Cameron to add length shortcuts to SVG DOM
    [recorded in
    [NEW] ACTION: Cameron to follow-up aligning with global HTML
    attributes in SVG [recorded in
    [NEW] ACTION: Cameron to mail HTML people about moving data to
    Element [recorded in
    [NEW] ACTION: Cameron to relax referencing requirements
    (issue-2295) [recorded in
    [NEW] ACTION: Cameron to spec auto-sized images [recorded in
    [NEW] ACTION: Cameron to think about glyph selection and
    positioning [recorded in
    [NEW] ACTION: Cyril to specify shared-path segments [recorded
    in [77]http://www.w3.org/2013/02/04-svg-minutes.html#action09]
    [NEW] ACTION: Dirk to ask CSS/FX how blending is supposed to
    work with transforms, opacity, all properties that create
    stacking contexts [recorded in
    [NEW] ACTION: Dirk to investigate applying CSS transforms to
    SVG when it is the root element of the document [recorded in
    [NEW] ACTION: Erik to add non-scaling stroke to SVG2 [recorded
    in [80]http://www.w3.org/2013/02/04-svg-minutes.html#action07]
    [NEW] ACTION: heycam to insure that the text chapter talks
    about baseline in terms of CSS features [recorded in
    [NEW] ACTION: heycam to write up examples and text for
    marker-mask [recorded in
    [NEW] ACTION: krit to ask CSS/FX how blending is supposed to
    work with transforms [recorded in
    [NEW] ACTION: Rik to add new procedural methods for catmull-rom
    [recorded in
    [NEW] ACTION: Rik to add the extendPath and addPath methods to
    the SVG 2 [recorded in
    [NEW] ACTION: Rik to edit the SVG 2 spec to add the possibility
    to set the d attribute using a Path object [recorded in
    [NEW] ACTION: Rik to look at how to attach a path or shape
    object to an SVG path element [recorded in
    [NEW] ACTION: Rik to specify the stringifier method for the
    Path object [recorded in
    [NEW] ACTION: stakagi to edit SVG 2 to add the iframe, canvas,
    video elements [recorded in

    [End of minutes]

     Minutes formatted by David Booth's [90]scribe.perl version
     1.137 ([91]CVS log)
     $Date: 2013-02-05 06:24:24 $

      [90] http://dev.w3.org/cvsweb/~checkout~/2002/scribe/scribedoc.htm
      [91] http://dev.w3.org/cvsweb/2002/scribe/

Scribe.perl diagnostic output

    [Delete this section before finalizing the minutes.]
This is scribe.perl Revision: 1.137  of Date: 2012/09/20 20:19:01
Check for newer version at [92]http://dev.w3.org/cvsweb/~checkout~/2002/

      [92] http://dev.w3.org/cvsweb/~checkout~/2002/scribe/

Guessing input format: RRSAgent_Text_Format (score 1.00)

FAILED: s/cabanier: how is the quality of what is produced? If you have
/cabanier: how is the quality of what is produced?/
Succeeded: s/Array v/Array/
Succeeded: s/used to/used too/
Succeeded: s/but the impleme//
Succeeded: s/transformed ref/transform="ref"/
Succeeded: s/in SVG/in HTML/
Succeeded: s/resolution:/RESOLUTION:/g
Succeeded: s/Compositing/SVG/
FAILED: s/shared\?/shared(\?)/
Succeeded: s/birtles/Cyril/
Succeeded: s/birtles/shanestephens_/
Succeeded: s/morening/morning/
FAILED: s/I your/In your/
Succeeded: s/on all tiles/on a given layer/
Succeeded: s/to/too/
Succeeded: s/to/too/
WARNING: Bad s/// command: s/http:\/\/perso.telecom-paristech.fr\/~conco
Found ScribeNick: nikos
Found Scribe: Cyril
Inferring ScribeNick: Cyril
Found ScribeNick: heycam
Found ScribeNick: krit
Found ScribeNick: heycam
Found ScribeNick: krit
Found ScribeNick: birtles
Found ScribeNick: birtles_
Found ScribeNick: birtles
Found ScribeNick: heycam
Found Scribe: Various
Found Scribe: heycam
Inferring ScribeNick: heycam
Found ScribeNick: heycam
Scribes: Cyril, Various, heycam
ScribeNicks: nikos, Cyril, heycam, krit, birtles, birtles_

WARNING: No "Present: ... " found!
Possibly Present: ACTION-3427 ACTION-3428 AlexD Cyril Cyril_ Tav alex al
l birtles birtles_ brian cabanier dino dirk dmitry ed erick erik formula
  glenn heycam https joined jun konno krit krit1 left nikos nikos1 rik sc
ribenick shane shanestephens_ shepazu silvia stakagi stearns stearns_ sv
g trackbot ys-uchida
You can indicate people for the Present list like this:
         <dbooth> Present: dbooth jonathan mary
         <dbooth> Present+ amy

Found Date: 04 Feb 2013
Guessing minutes URL: [93]http://www.w3.org/2013/02/04-svg-minutes.html
People with action items: birtles brian cameron cyril dirk erik heycam k
rit rik stakagi

      [93] http://www.w3.org/2013/02/04-svg-minutes.html

    End of [94]scribe.perl diagnostic output]

      [94] http://dev.w3.org/cvsweb/~checkout~/2002/scribe/scribedoc.htm
Received on Tuesday, 5 February 2013 06:29:46 UTC

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