SVG Working Group Teleconference -- 26 Apr 2012

<trackbot> Date: 26 April 2012

<scribe> Scribe: Cameron

<scribe> ScribeNick: heycam

progress update for SVG2

<ed> http://www.w3.org/Graphics/SVG/WG/wiki/SVG2_Requirements_Commitments

ED: there have been a couple of placeholders added

… I was wondering about how to deal with proposals

… everything in the table that needs a proposal, is it fine to put something in the spec, or should we go through the mailing list first?

CM: could just add it to the spec

… bring it up on the list before, if you think it will be controversial

DS: I couldn't find the canvas topic on the list of requirements

<krit> Tav: http://www.w3.org/Graphics/SVG/WG/wiki/SVG2_Requirements_Commitments

TB: I've taken where people have made committments, where it's easy to do so, I've added a note/annotation in the spec

… I've listed the requirement, resolution, when the resolution was made, why, and who is committed to doing it

… there are some things I don't know where they're supposed to go

ED: the next step is just to start editing those sections

canvas in SVG

<ed> http://lists.w3.org/Archives/Public/www-svg/2011Jul/0081.html

DS: I think it's necessary that we support this

… this will be an SVG canvas element and not an HTML one

TB: would it work just like any other image?

DS: I don't think there's anything special to handle

… in HTML, it has width/height attributes and properties

… referencing the HTML spec might be a tricky part

CM: alex's mail suggests other features for canvas that aren't in the HTML one, automatically calling a function to repaint for example

DS: I am happy to take on that requirement if nobody else wants to

<ChrisL> +1

RESOLUTION: SVG2 will have a canvas element, the exact details TBD.

<ChrisL> good to resolve this, thought we already did but I don't have a link

<scribe> ACTION: Dirk to add an entry to the requirements and commitments page for canvas in SVG [recorded in http://www.w3.org/2012/04/26-svg-minutes.html#action01]

<trackbot> Created ACTION-3263 - Add an entry to the requirements and commitments page for canvas in SVG [on Dirk Schulze - due 2012-05-03].

replacing SVGException with new Web IDL exceptions

CL: no objections, sounds like a good thing to do

ED: I think that's fine

CM: I think it's unlikely people are relying on the exact details of SVGException

RESOLUTION: SVG2 will use Web IDL style exceptions in place of SVGException

<scribe> ACTION: Cameron to make SVG2 use Web IDL exceptions instead of SVGException [recorded in http://www.w3.org/2012/04/26-svg-minutes.html#action02]

<trackbot> Created ACTION-3264 - Make SVG2 use Web IDL exceptions instead of SVGException [on Cameron McCormack - due 2012-05-03].

<scribe> ACTION: Cameron to rewrite SVG2's IDL to use Web IDL [recorded in http://www.w3.org/2012/04/26-svg-minutes.html#action03]

<trackbot> Created ACTION-3265 - Rewrite SVG2's IDL to use Web IDL [on Cameron McCormack - due 2012-05-03].

Hamburg F2F agenda

<ed> http://www.w3.org/Graphics/SVG/WG/wiki/F2F/Hamburg_2012/agenda_proposals

ED: a reminder to put agenda proposals on the page

CL: we decided to meet in zurich already I think

CM: yes

masks and filters being children of what they apply to

http://lists.w3.org/Archives/Public/public-svg-wg/2012AprJun/0020.html

ED: Brian is asking to add this to the requirements list

CM: is the idea to have <mask>, <filter>, etc. to apply to their parents?

CL: it's not clear

… in existing SVG, how would you tell the difference between a mask masking its parent, a <g> or an <svg>, and this new way?

CM: I think automatically having them apply to their parent would break content

CL: we would need a switch to turn that behaviour on

… does mask point to something?

ED: the mask property points to the mask element

… I don't think the mask element points to anything

CL: can we use the absence of this url() value to indicate this new behaviour?

NA: I think the pointer is around the way

ED: one way is to introduce a keyword the mask property, mask="child" for example

… we already have url() or none

<ChrisL> ok so the filter property value is FuncIRI | none | parent

DS: we should take into account that an FX spec will want to specify the mask property

CL: all properties can be expressed as presentation attributes

… are you worried about the webkit mask property?

DS: yes

CL: there, they want to point to an image

… they can still use url() to point to a raster image, we'd just need to relax the wording of the property definition to say it can point to images as well as a mask element

[discussion of whether to allow "child" as a value for the property, vs just the presentation attribute, vs on the mask element itself]

CM: so you would rather an attribute on the <mask> element that says "apply to parent"

<ChrisL> yes

ED: it might be more intuitive that way

<ChrisL> like animation elements do

CL: current implementations would ignore any new <mask applytoparent> elements

ED: one advantage of having it on the property, the element that uses the mask you know directly there that it is going to be masked

… otherwise you need to traverse the subtree and find the mask element

CM: same for animation though

DS: clip path, gradient, patterns

… would the pattern apply to fill or stroke?

CL: same question for gradients

DS: what about two mask elements?

<ChrisL> mask and clip are unambiguous when applying to the parent. gradient and pattern could apply to the stroke or the fill ...

CM: I wonder if it's more useful for clip path, mask, filters than gradients/patterns

<ChrisL> who proposed the requirement?

Brian Birtles

<ChrisL> ACTION: brian to propose in detail how mask and clip work on parents [recorded in http://www.w3.org/2012/04/26-svg-minutes.html#action04]

<trackbot> Created ACTION-3266 - Propose in detail how mask and clip work on parents [on Brian Birtles - due 2012-05-03].

<scribe> ACTION: Cameron to follow up with Brian about ACTION-3266 [recorded in http://www.w3.org/2012/04/26-svg-minutes.html#action05]

<trackbot> Created ACTION-3267 - Follow up with Brian about ACTION-3266 [on Cameron McCormack - due 2012-05-03].

July F2F dates

<ed> http://lists.w3.org/Archives/Public/public-svg-wg/2012AprJun/0023.html

CM: if we could move it to the start of the week, that would be convenient to have at the start of the week

krit, http://www.w3.org/Graphics/SVG/WG/wiki/Meetings

CL: we need to find out if the Seattle site and the Paris site can do it

… I also proposed in the email that the Seattle side start a couple of hours earlier, 7am-3pm say, that would make it 4pm-midnight in France

<krit> Seattle F2F 23 to 25 of July

<ChrisL> Ok so its Mon 23 to Weds 25 July

transforms on svg:svg elements

DS: we already have viewBox on <svg:svg>, when does transform apply?

… I propose, transform then viewBox then preserveAspectRatio then width/height/etc.

CM: so like wrapping the <svg> element with a <g transform>

… I think that makes sense

ED: is this only for nested elements?

DS: also for top level

CL: I think it's important for the behaviour of referencing this top level element, and just rendering it, to be the same

… so it should also apply to the top level

… people who are doing mapping, where you want to zoom in and move around, it's easier to have a transform and modify it on the root

DS: and keep the viewBox

CM: where does the currentTranslate, currentScale fit in?

ED: I think they would come in first

CL: we did define this precisely in TIny 1.2

… we decided to copy that across to SVG2

<ed> http://www.w3.org/TR/SVGTiny12/svgudom.html#svg__SVGSVGElement

DS: would we want to integrate the currentTranslate, currentScale into the transform?

<ChrisL> no, I was thinking more of http://www.w3.org/TR/SVGTiny12/coords.html#transform-userspace

<ed> http://www.w3.org/TR/SVG11/struct.html#__svg__SVGSVGElement__currentScale

ED: the UA translations/scales might be modified by browser chrome, menu items

… I think it makes sense to keep separate

CM: I'm happy to keep them separate

DS: does this also mean we make SVGSVGElement be SVGTransformable?

CL: yes I think we would

<scribe> ACTION: Dirk to investigate currentTranslate etc. and how they fit with <svg:svg transform=""> [recorded in http://www.w3.org/2012/04/26-svg-minutes.html#action06]

<trackbot> Created ACTION-3268 - Investigate currentTranslate etc. and how they fit with <svg:svg transform=""> [on Dirk Schulze - due 2012-05-03].

text decorations and rotated glyphs

http://lists.w3.org/Archives/Public/www-svg/2012Mar/0056.html

CM: do text decorations rotate along with rotated glyphs?

CL: what the content author expects is "it depends"

… if they're rotating a few glyphs 10 degrees left and right, they probably want the underline to be continuous underneath

… if they're doing shifts and things, they probably want the decoration to shift with the glyphs

… that argues to me to have both behaviours, and a way to switch between them

CL: sometimes the underline is just drawn as a stroke, but sometimes it's a feature of the font

… also CSS has some odd rules for colouring of decorations

CM: I hope we can have the same behaviour as CSS for decoration colours

CL: I think we made a good effort to align with CSS

ED: CSS doesn't have paints for fill/stroke

<ChrisL> css color property is effectively text-fill-color

CL: would this be a separate property or a new value for text-decoration?

CM: I think a separate property would be better

<ChrisL> text-decoration-transform : track | ignore

<scribe> ACTION: Cameron to propose a property for making text decorations rotate or not [recorded in http://www.w3.org/2012/04/26-svg-minutes.html#action07]

<trackbot> Created ACTION-3269 - Propose a property for making text decorations rotate or not [on Cameron McCormack - due 2012-05-03].

mail from EXI regarding path syntax

<ed> http://www.w3.org/mid/23204FACB677D84EBD57175AB7B5A71C01176D05F061@FMSAMAIL.fmsa.local

CL: I thought we had decided anyway to have an element syntax for paths

… and an API that works on both syntaxes

… an EXI pre-processor could also use the API to decompose the path out into the verbose notation

<ed> http://www.w3.org/Graphics/SVG/WG/wiki/SVG2_Requirements_Mailing_List_Feedback#Introduce_element-based_path_syntax

<scribe> ACTION: Chris to the mail from EXI WG on the current status of the verbose path notation [recorded in http://www.w3.org/2012/04/26-svg-minutes.html#action08]

<trackbot> Created ACTION-3270 - The mail from EXI WG on the current status of the verbose path notation [on Chris Lilley - due 2012-05-03].

<scribe> Chair: Erik

- DRAFT -

SVG Working Group Teleconference

26 Apr 2012

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