[css-transforms-1] Some comments on the non-scaling stroke spec text

[smfr]

http://www.w3.org/mid/201205132051.25760.Dr.O.Hoffmann@gmx.de

[smfr]

Also https://lists.w3.org/Archives/Public/public-fx/2012AprJun/0043.html

Need to resolve on impact of non-invertible transforms on non-scaling strokes.

[smfr]

Testing shows that non-scaling stroke only respects transforms inside the <svg> in current implementations.

[smfr]

SVG2 provides control of this: https://www.w3.org/TR/SVG2/coords.html#VectorEffectProperty

[smfr]

Issue is when an animation causes the transformation to pass through non-inverible matrix, there will be a moment when nothing is rendered.

[css-meeting-bot]

The CSS Working Group just discussed Comments on Scaling Stroke, and agreed to the following resolutions:

RESOLUTION: Close both 930 and 929 with no change to transforms spec

The full IRC log of that discussion

<dino> Topic: Comments on Scaling Stroke
<dino> Github Topic: https://github.com/w3c/csswg-drafts/issues/930
<dino> also https://github.com/w3c/csswg-drafts/issues/929
<dino> smfr: two similar issues
<dino> smfr: current implementations draw nothing when the matrix is non-invertible
<dino> smfr: this is just for svg's non-scaling stroke
<dino> smfr: some comments want *something* to be drawn, but that would be a change to SVG
<dino> smfr: suggest keeping the current behaviour of drawing nothing
<dino> TabAtkins: agree
<dino> dbaron: i agree too. we'd need to work out what to draw.
<dino> Rossen: is this a spec change?
<dino> smfr: current spec doesn't say anything about non-scaling stroke
<dino> smfr: not sure where that should be covered
<dino> Rossen: sounds like we don't need to make a change in L1. Any change would have to be in the SVG specification.
<smfr> https://www.w3.org/TR/SVG2/coords.html#VectorEffectProperty
<dino> smfr: SVG 2 has some things to control the behaviour ^^
<Rossen> http://www.w3.org/TR/SVG2/painting.html#non-scaling-stroke
<smfr> https://www.w3.org/TR/SVG2/painting.html#non-scaling-stroke
<dino> Rossen: I can't see anything in the non-scaling stroke text about this.
<dino> Rossen: OK. Seems that the consensus is that the Transforms L1 text doesn't need to mention this. If there is a change to SVG, it will happen elsewhere
<dino> RESOLUTION: Close both 930 and 929 with no change to transforms spec

[smfr]

This was resolved.