See also: IRC log
<trackbot> Date: 11 October 2010
<scribe> scribenick: ChrisL
<ed> http://lists.w3.org/Archives/Public/public-fx/2010OctDec/0000.html
anthony: see http://lists.w3.org/Archives/Public/public-fx/2010OctDec/0000.html
and http://dev.w3.org/Graphics-FX/modules/2D-transforms/spec/2DTransforms.html
anthony: sumary at first url,
spec at second one
... some email from dr Olaf, pointed out some things
<anthony> http://lists.w3.org/Archives/Public/public-fx/2010OctDec/0001.html
anthony: mainly concerns related to changes from SVG
ds: wish there was a summary
anthony: I made one
... changed todo list, added some items
... as follows
<anthony> - Address any issues with transform-origin
<anthony> - IDL
<anthony> - Address if the properties are independent of transform attribute used in SVG (1.1, 1.2)
<anthony> - Address if the transform properties are available as presentation attributes
<anthony> - Investigate and address backwards incompatibilities (rotate, origin on which transform is applied)
<anthony> - Address how to determine the difference between original SVG attribute and new presentation attribute (example)
<anthony> - Address if 'transform-origin' property has any influence on appearence of old SVG transform attribute
<anthony> - Address issue for objects with no bounding box (e.g. line)
smfr: problem with assuming
identity is the same as none
... in CSS identity doews something different, establishes a
stacking context
... these need to be different values. initial value of none,
bt identity as a defined value to start or end from
... transform-origin initial value in SVG?
... 50% 50%?
anthony: odd for it to do differnt things in css and svg
smfr: how so?
... for pointer events we have a different initial value for
svg and html
... could do the same here
shepazu: why have it different?
smfr: fill and stroke dont translate to html
ChrisL: yes that is a perfectly reasonable for pointer-events
shepazu: do we have to have it different?
ChrisL: if svg already has them and css does not but has stacking contexts then the initial value needs to be different
ed: could see how many would
brewak with a 50% 50% transform origin
... probably a lot
shepazu: can we make it so that both behaviors work in svg somehow
anthony: given that
transform-origin is not previously part of svg, its new so
should not be too much of an issue
... but for transform property it may break
ChrisL: if its a property then it always has a value. even in older content that does not specify it explicitly
ed: would auto be ok as an initial value
ChrisL: our initial value is 0 0 in the local coordinate system. that can't be expressed with percent syntax which is relative to the bbox
ed: transform-oriin accepts coordinates?
smfr: well, it accepts
lengths
... percent is percent of the border box
shepazu: how to say 50% of the document?
smfr: you can't
ChrisL: so the initial value for svg is 0 0 which is relative to the local coordinate system
<ed> ED: so if we go for "0 0" as the initial value for svg, you would just have to specify transform-origin:center to get the 50%,50% behaviour, not that much work really
smfr: in svg, bbox is pre-transform?
ChrisL: yes
shepazu: can you have an api to get the bbox?
smfr: yes there is one that gets
the bbox of the transformed element. awkward when it maps to
screen space
... existing apis use bbox
... have also had request for api to map local to global
coordinate system
shepazu; dom3 has a request to hace such an api, jwatt made that request
scribe: anticipate html/css will need that
shepazu (lloks for link)
<shepazu> http://lists.w3.org/Archives/Public/www-dom/2010OctDec/0013.html
smfr: resisted giving the cuulative transform, because with 3d transforms flattening can occur, to put a plane in another 3d space so its hard to describe the whole thing
anthony: yes you would need a
whole transform list
... happy to go with the group. initial value for
transform-origin, would be nice to be the center, and then
somehow ...
ChrisL: that would change behaviour for existing content in new and old implementations. it would break all existing content that uses transforms
ed: resolution?
resolution: initial value of transform-origin is auto, which in svg means 0 0 and in html/css means 50% 50%
smfr; so using css to apply this to svg would have the traditional 0,0 origin point?
ChrisL: yes
<scribe> ACTION: anthony to add the new initial value of transform-origin to the spec [recorded in http://www.w3.org/2010/10/11-fx-minutes.html#action01]
<trackbot> Created ACTION-17 - Add the new initial value of transform-origin to the spec [on Anthony Grasso - due 2010-10-18].
http://www.w3.org/mid/B53F84D2-D549-4472-A7AE-CCDE9563E1D3@me.com
http://lists.w3.org/Archives/Public/www-svg/2006Jan/0342.html
http://lists.w3.org/Archives/Public/www-svg/2006Jul/0050.html
ed: css3 seems to want to have premultipied gradients, different from canvas and svg
smfr: otherwise gradient from red to transparent has grey in it
ChrisL; that is because transparent is rgba(0000) which is transparent black
scribe: if you want a fade to red, fade to transparent red not transparent black
ed: people would want the css3 gradient systax with canvas and svg. they will be surprised
smfr: could we add a value to color interpolation to say its premultiplied
ChrisL: also in premultiplied, lower resolution for colors as the transparency goes up
smfr: so options are to pushback on premultiplied, or to add a value to allow controlling the interpolation
ed: not that difficult to add
shepazu: more properties
ed: no, existing property with one new value
ChrisL: concerned about hue shifts with fades of pastel colors
<ed> http://www.w3.org/TR/SVG11/painting.html#ColorInterpolationProperty
smfr: we use premultipiied
already for gradients in safari and firefox, certainly for
transitions we use premultiplied
... underlying lirary on mac does not give us a choice
... chris, please post an example
<scribe> ACTION: chris post examples of reduced resolution with premultiplied colors [recorded in http://www.w3.org/2010/10/11-fx-minutes.html#action02]
<trackbot> Created ACTION-18 - Post examples of reduced resolution with premultiplied colors [on Chris Lilley - due 2010-10-18].
smfr: we use this for color transitions and for css3 gradients. that spec is not finished though
ed: hoped to have elika here for
this one
... http://www.w3.org/Graphics/fx/track/issues/3
http://www.w3.org/mid/4C2B18DD.6020209@w3.org
http://dev.w3.org/csswg/css3-text-layout/test-writing-mode-direction.svg
all implementations do different things with writing-mode. want to alighn with svg but there is inconsistet implementation behaviour
scribe: wanted to see if spec defines correct behaviour
ChrisL: do we have a table of results for different implementations on that test?
ed: no. put this topic off until
elika is here
... batik does 123 on second line in orange, in differnt way to
opera. not well tested code in opera, not much used
... not that well defined in spec either.
ChrisL: good topic for tpac, needs a whiteboard
anthony: hope to be there
ed: will be there too
... good to define transforms more at tpac too
adjourned
<scribe> agenda: http://lists.w3.org/Archives/Public/public-fx/2010OctDec/0008.html
This is scribe.perl Revision: 1.135 of Date: 2009/03/02 03:52:20 Check for newer version at http://dev.w3.org/cvsweb/~checkout~/2002/scribe/ Guessing input format: RRSAgent_Text_Format (score 1.00) Succeeded: s/who/how/ Succeeded: s/valie/value/ Succeeded: s/value/value of transform-origin/ Succeeded: s/does the right thing/would have the traditional 0,0 origin point/ Succeeded: s/soec/spec/ Found ScribeNick: ChrisL Inferring Scribes: ChrisL Default Present: +1.408.636.aaaa, smfr, ed, ChrisL, Shepazu, anthony Present: +1.408.636.aaaa smfr ed ChrisL Shepazu anthony Agenda: http://lists.w3.org/Archives/Public/public-fx/2010OctDec/0008.html Found Date: 11 Oct 2010 Guessing minutes URL: http://www.w3.org/2010/10/11-fx-minutes.html People with action items: anthony chris[End of scribe.perl diagnostic output]
