IRC log of svg on 2013-08-15
Timestamps are in UTC.
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- logging to http://www.w3.org/2013/08/15-svg-irc
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- RRSAgent, make logs public
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- Zakim, this will be GA_SVGWG
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- ok, trackbot, I see GA_SVGWG(SVG1)4:30PM already started
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- Meeting: SVG Working Group Teleconference
- 20:28:30 [trackbot]
- Date: 15 August 2013
- 20:28:31 [Zakim]
- +krit
- 20:28:31 [Zakim]
- -krit
- 20:28:32 [Zakim]
- +krit
- 20:28:57 [Zakim]
- +[IPcaller]
- 20:29:04 [heycam]
- Zakim, [ is me
- 20:29:04 [Zakim]
- +heycam; got it
- 20:29:30 [Zakim]
- +cabanier
- 20:30:29 [heycam]
- Chair: Cameron
- 20:30:33 [heycam]
- Agenda: http://lists.w3.org/Archives/Public/public-svg-wg/2013JulSep/0054.html
- 20:30:35 [heycam]
- Regrets: Rich
- 20:32:17 [TabAtkins]
- Dear SVG: Please kill your namespaces faster. Love, Tab.
- 20:35:57 [Zakim]
- +nikos
- 20:37:04 [krit1]
- TabAtkins: we would need to add the SVG elements to the HTML parser
- 20:37:04 [nikos]
- scribenick: nikos
- 20:37:16 [TabAtkins]
- krit1++
- 20:37:28 [TabAtkins]
- But really it's the xlink that's killing me today.
- 20:37:36 [TabAtkins]
- Which requires only local changes to the language.
- 20:37:36 [nikos]
- Topic: Publishing and renaming CSSMatrix
- 20:37:41 [heycam]
- Removing xlink is something we can do without a lot of the other stuff.
- 20:37:59 [cabanier]
- I thought we already agree to killing that off
- 20:38:03 [krit]
- https://dvcs.w3.org/hg/FXTF/raw-file/tip/matrix/index.html
- 20:38:06 [TabAtkins]
- Yeah, but it's not edited in yet. ^_^
- 20:38:23 [krit]
- http://dev.w3.org/fxtf/matrix/
- 20:38:43 [nikos]
- heycam: we haven't published this yet?
- 20:38:46 [nikos]
- krit: correct
- 20:38:48 [nikos]
- krit: 2 issues
- 20:38:55 [nikos]
- krit: first is name. CSS WG doesn't want CSS prefix
- 20:39:11 [nikos]
- heycam: dictionary ones don't matter since they're not exposed in script
- 20:39:21 [nikos]
- ... interfaces intended to be used outside probably shouldn't have css in the name
- 20:39:35 [nikos]
- krit: suggestion was either TransformationMatrix or TransformMatrix
- 20:39:38 [nikos]
- ... I don't have others
- 20:39:58 [nikos]
- heycam: if we named it Matrix, there might be a risk of conflicting with scripts that define Matrix already
- 20:40:06 [nikos]
- krit: we also have conflict with other working groups
- 20:40:19 [nikos]
- ... was discussed on fxtf mailing list
- 20:40:31 [nikos]
- ... was suggested to name it Deprecated Matrix
- 20:40:34 [nikos]
- heycam: ugly name!
- 20:40:41 [nikos]
- cabanier: web gl want to have something more primitive
- 20:40:56 [nikos]
- ... not useful for authors. The reason we are doing this is to make operations easier for them
- 20:41:15 [nikos]
- heycam: I'm not convinced by argument that we shouldn't have it becaues JS authors can write something that can run faster
- 20:41:29 [nikos]
- ... browsers can implement with native js behind the scenes and avoid the overhead
- 20:42:02 [TabAtkins]
- I'm down with TransformMatrix.
- 20:42:29 [nikos]
- krit: because Matrix is so generic, I don't think it's a bad idea to have a prefix
- 20:43:12 [nikos]
- heycam: you said CSS WG has already resolved to publish? what was their final view on name? have an issue in the spec?
- 20:43:23 [nikos]
- krit: we need the name for the url though so it's problematic to do that
- 20:43:40 [nikos]
- heycam: I think it would be fine, even if we call it CSSMatrix or TranformMatrix to have the matrix as just url
- 20:43:51 [nikos]
- s/matrix as just url/url as just matrix
- 20:44:04 [nikos]
- heycam: I'm fine with publishing and including an issue
- 20:44:17 [nikos]
- krit: CSS WG suggested SVG WG takes care of publication
- 20:44:28 [nikos]
- heycam: couple of other issues open in the spec
- 20:44:40 [nikos]
- ... 1. w part of the point
- 20:44:46 [nikos]
- krit: the main is whether we use float or doubles
- 20:45:28 [nikos]
- krit: Mozilla wants floats. Apple wants double
- 20:45:44 [nikos]
- krit: difference is 10 times on mobile
- 20:46:03 [nikos]
- krit: javascript just uses double
- 20:46:11 [nikos]
- ... so it's just the internal calculation results
- 20:46:22 [nikos]
- ... currently I am using doubles in the spec
- 20:46:30 [nikos]
- heycam: I don't think we need to resolve that before publishing
- 20:46:54 [nikos]
- heycam: what is the plan for replacing SVGMatrix with CSSMatrix?
- 20:47:11 [nikos]
- krit: The whole point of this is to replace SVGMatrix
- 20:47:35 [nikos]
- heycam: so we'll just use CSSMatrix. Won't have any inheritance.
- 20:47:55 [nikos]
- krit: It's backwards compatible, except the new matrix won't throw exceptions as SVGMatrix did
- 20:48:36 [nikos]
- heycam: I also remember roc was concerned about the matrix object being used for 3d and 2d
- 20:48:45 [nikos]
- ... meaning you need the extra components
- 20:48:56 [nikos]
- krit: I think he's ok with it now
- 20:49:10 [nikos]
- heycam: I'll check with him
- 20:50:54 [nikos]
- resolution: Publish first public working draft of new matrix specification
- 20:51:23 [nikos]
- action: Cameron to organise FPWD publication of new matrix specification
- 20:51:24 [trackbot]
- Created ACTION-3517 - Organise fpwd publication of new matrix specification [on Cameron McCormack - due 2013-08-22].
- 20:52:01 [nikos]
- Topic: Progress on subregions hinting in SVG Filters
- 20:52:13 [krit]
- http://www.w3.org/Graphics/fx/wiki/Filter_effects
- 20:52:43 [nikos]
- krit: Erik put together an implementation matrix
- 20:53:12 [nikos]
- krit: We need to specify exactly how subregions are calculated
- 20:53:27 [nikos]
- ... I would like feedback on the table
- 20:53:34 [nikos]
- ... especially where we have question marks
- 20:53:48 [nikos]
- ... we're not clear on how to calculate subregions for some filters at the moment
- 20:54:28 [nikos]
- krit: it's important that the filter region doesn't clip things you don't want clipped
- 20:54:36 [nikos]
- ... a lot of people don't understand the 10% margin
- 20:54:45 [nikos]
- heycam: I never liked it. It's not usually what you want
- 20:54:57 [nikos]
- ... are you suggesting to remove filter region primitive attribute?
- 20:55:08 [nikos]
- krit: no
- 20:55:20 [nikos]
- ... if they are not present then the user agent should calculate automatically
- 20:55:28 [nikos]
- heycam: so changing the default
- 20:55:34 [nikos]
- krit: in a way that fixes content
- 20:55:38 [nikos]
- heycam: I'd be in favour of that
- 20:55:54 [nikos]
- krit: so we need to specify what unbound? is for each in the table
- 20:56:41 [nikos]
- heycam: for filters like feFlood or feTurbulence that conceptually have infinite output, what would we define apart from 'implementation needs to work out how much of the final rendered element to keep'
- 20:56:59 [nikos]
- krit: we could specify 120%. it's not nice though
- 20:57:13 [nikos]
- heycam: can't we just state it needs to be large enough so that it doesn't affect filter output?
- 20:57:50 [nikos]
- krit: If you use feFlood and it will fill the whole SVG file.
- 20:58:02 [nikos]
- ... could use the viewPort
- 20:58:07 [nikos]
- heycam: feFlood is a special case though
- 20:58:42 [nikos]
- ... why can't we say something like 'minimal area based on how that filter primitive is used in the filter chain'
- 20:59:07 [nikos]
- krit: Need to specify that content looks equal on all implementations
- 20:59:22 [nikos]
- heycam: I think that can be achieved by saying the filter primitive is big enough so that it doesn't look different
- 21:00:17 [nikos]
- ... when the element is rendered, there will be some clipping at some point
- 21:00:31 [nikos]
- ... then you can determine the smallest rectangle based on how it is used in the filter chain
- 21:00:52 [nikos]
- ... we can require UAs to generate the filter primitive at the required siz
- 21:00:57 [nikos]
- s/siz/size
- 21:01:03 [nikos]
- krit: I agree. feFlood is still the problem though
- 21:01:33 [nikos]
- heycam: If you didn't have any other clipping, then feFlood would fill the viewport
- 21:02:15 [nikos]
- krit: Would have to check about breaking content
- 21:02:37 [nikos]
- heycam: do you feel we need to specify how to calculate the area for that primitive?
- 21:02:41 [nikos]
- krit: I think that's a good idea
- 21:02:51 [nikos]
- ... to ensure consistency between implementations
- 21:03:12 [nikos]
- heycam: I'd be fine if we had something like that written down. Do you want to do that?
- 21:03:13 [nikos]
- krit: yes
- 21:03:46 [nikos]
- action: Dirk to specify how to calculate automatic filter region for unbounded primitives
- 21:03:47 [trackbot]
- Created ACTION-3518 - Specify how to calculate automatic filter region for unbounded primitives [on Dirk Schulze - due 2013-08-22].
- 21:04:01 [nikos]
- Topic: Collapsing CSS Filter functions and the problem of color clamping on
- 21:04:01 [nikos]
- intermediate results
- 21:04:24 [nikos]
- krit: a lot of filter effects short hands can be represented with a colour matrix
- 21:04:45 [nikos]
- ... ideally you can collapse the filter chain to a single operation on the matrix
- 21:04:57 [nikos]
- ... but we currently define that values should be clamped at each stage
- 21:05:23 [nikos]
- ... do we want to keep current behaviour or can we relax the specification to allow optimisation in this case?
- 21:05:48 [Zakim]
- +Doug_Schepers
- 21:05:51 [nikos]
- ... it's a balance between performance and ease of authoring
- 21:06:19 [nikos]
- heycam: is there a benefit to clamping at each filter? is that something authors would need or want?
- 21:07:10 [nikos]
- heycam: there are similar thinks in CSS with colour values
- 21:07:32 [nikos]
- ... I can't remember where exactly but it talks about allowing values to go out of range and clamp in the final step
- 21:07:37 [nikos]
- ... so there might be precedence
- 21:08:27 [nikos]
- nikos: I think it would be confusing for authors to get different results depending on whether a shorthand is used or not
- 21:08:53 [krit]
- s/colour/color/g
- 21:08:54 [nikos]
- heycam: my feeling is that we should allow intermediate results to go out of range and clamp at the end
- 21:08:55 [krit]
- :D
- 21:10:04 [nikos]
- krit: initially I was for clamping at the end. Now i'm not sure. There are cases where you can guarantee that you don't need to clamp
- 21:10:12 [nikos]
- ... so I support clamping at each step now
- 21:10:24 [nikos]
- heycam: I can't see an author use for clamping each stage
- 21:10:35 [nikos]
- ... if there was one I think it would be better to have explicit control to opt in to that
- 21:10:54 [nikos]
- krit: there is another case. contrast 200% then another filter primitive with contrast 50% and they wonder why they don't get the same result
- 21:11:12 [nikos]
- ...it's a corner case though. I don't think it's actually useful to do that.
- 21:11:57 [nikos]
- heycam: I can imagine cases where an image has colour values that are almost fully bright and you apply a brightness filter and you want to clamp
- 21:12:51 [nikos]
- heycam: I'm not sure which I prefer
- 21:12:55 [nikos]
- krit: I think we should keep the clamping for now
- 21:13:50 [nikos]
- shepazu: I've seen some pretty crazy stuff come out of authoring tools
- 21:14:15 [nikos]
- heycam: I'm not sure how much performance benefit there is from collapsing down to a single operation on a colour matrix
- 21:14:47 [nikos]
- ... I think implementations often slow down with filters because they are creating lots of off-screen surfaces
- 21:15:03 [nikos]
- ... here that shouldn't matter as you can work on the same surface
- 21:16:28 [nikos]
- resolution: maintain clamping colour matrices for filter effects at each step in the filter chain
- 21:16:43 [nikos]
- Topic: Geometry API and Accessible SVG Community Groups
- 21:16:59 [nikos]
- shepazu: there are 2 community groups you guys might be interested in
- 21:17:04 [nikos]
- 1. SVG accessibility
- 21:17:23 [shepazu]
- http://www.w3.org/community/svga11y/
- 21:17:25 [shepazu]
- http://www.w3.org/community/svga11y/2013/08/15/roadmap/
- 21:17:42 [nikos]
- 2. geometry API
- 21:18:18 [shepazu]
- http://www.w3.org/community/geometryapi/wiki/Use_Cases_and_Requirements
- 21:18:18 [shepazu]
- http://www.w3.org/community/geometryapi/
- 21:18:19 [nikos]
- use cases and requirements doc (in progress)
- 21:18:53 [nikos]
- SVG accessibility is unclear. There's few normative requirements, a lot comes from the doc that Charles wrote about mapping and authoring guidelines
- 21:19:06 [nikos]
- shepazu: very old. refers to SVG 1.0
- 21:19:31 [nikos]
- ... After talking to accessibility experts. The state of SVG is ok, but there's a lot of tests that need to be run
- 21:19:45 [nikos]
- ... so the whole point of this group is to write tests and write requirements
- 21:19:57 [nikos]
- ... we're going to have a workshop/hackathon
- 21:20:12 [nikos]
- heycam: sounds good. for me I don't feel I have the knowledge to know what we need to change in SVG
- 21:20:20 [nikos]
- krit: who would attend the workshop?
- 21:20:33 [nikos]
- shepazu: there's about 16 people in the group now.
- 21:21:38 [nikos]
- ... we want: 1. Accessibility experts who can help us test. 2. People who use accessibility features. 3. SVG people
- 21:21:57 [nikos]
- ... and at least one 'testing' expert
- 21:23:05 [nikos]
- ... I gave a presentation about accessible data visualisation and people were really interested
- 21:23:10 [nikos]
- ... that's where this came from
- 21:23:41 [nikos]
- ... first step is to make a bunch of tests, run them and create an implementation report
- 21:26:07 [nikos]
- nikos: what's the make up of the group. Who do you need?
- 21:26:31 [nikos]
- shepazu: we have lots of interested accessibility experts.
- 21:26:43 [nikos]
- ... they should be able to find people who use accessibility features
- 21:27:13 [nikos]
- ... there's two or three people who are pretty good with SVG
- 21:27:18 [nikos]
- ... would be good to have Rich in the group
- 21:27:28 [nikos]
- ... looking for someone from Adobe
- 21:27:43 [nikos]
- ... I'm looking at September for the hackathon
- 21:29:18 [nikos]
- ... October at the graphical web would be good. Cyril, Tav, and Nikos will be there
- 21:30:35 [nikos]
- ... so we can chat about that and try to organise a time that is good for everyone
- 21:30:55 [nikos]
- shepazu: The other group is the geometry API community group
- 21:31:06 [nikos]
- ... the goal there is to come up with a geometry api (SURPRISE!)
- 21:31:34 [nikos]
- ... we want to meet use cases for SVG primarily. But if we satisfies use cases for other web tech that's ok.
- 21:31:47 [nikos]
- ... I want to be able to do things like calculate intersection of shapes
- 21:35:57 [nikos]
- cabanier: Dirk and I signed up
- 21:36:26 [nikos]
- shepazu: If we can come out with a simple set of use cases and requirements that we might include in SVG 2
- 21:36:38 [nikos]
- krit: should get some SKIA guys in the group
- 21:38:26 [nikos]
- cabanier: is this part of SVG or is it just something that interfaces with SVG?
- 21:38:51 [nikos]
- shepazu: I guess you could interact with other web tech
- 21:39:08 [nikos]
- krit: it would be great to have a document that everyone could reference
- 21:39:53 [nikos]
- shepazu: it would be good to have more people in the group to define the use cases that are important
- 21:40:18 [nikos]
- ... it would be good to have a matrix library (SKIA has), point and vector maths
- 21:40:23 [nikos]
- ... need to drive requirements on those
- 21:41:04 [nikos]
- ... in conclusion. It would be good to get people into the groups to drive the conversation and keep them going
- 21:41:23 [Zakim]
- -cabanier
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- -heycam
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- -krit
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- -nikos
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- -Doug_Schepers
- 21:43:35 [nikos]
- RRSAgent, make minutes
- 21:43:35 [RRSAgent]
- I have made the request to generate http://www.w3.org/2013/08/15-svg-minutes.html nikos
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- - +1.425.373.aaaa
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- GA_SVGWG(SVG1)4:30PM has ended
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- Attendees were +1.425.373.aaaa, krit, [IPcaller], heycam, cabanier, nikos, Doug_Schepers
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