RE: Clarification on non-scaling stroke and markers

Philip,

I agree that your interpretation, that markers should inherit the "non-scaling-ness" of the stroke, is "least astonishing". However, I could see in contexts where the marker is a functional part of the drawing (as opposed to an annotation of the stroke) that it would need to maintain its location and size relative to the rest of the drawing.

Spit-balling a little, because I have a limited understanding of all the various use domains:

It seems that use cases for propagation of non-scaling-ness are:

1)    Maps, where the marker is an annotation of the stroke, not an integral part of the drawing.

2)    Wire traces, schematic diagrams and other technical documents, again annotating the stroke

The argument against non-scaling-ness is:

1)    (ab)use of markers to create drawing elements - logical forms in logic diagrams(??)

I'm sure that there's a few people here with more to add...

~ P

From: Philip Rogers [mailto:pdr@google.com]
Sent: Tuesday, June 05, 2012 8:59 AM
To: www-svg@w3.org<mailto:www-svg@w3.org>
Subject: Clarification on non-scaling stroke and markers

www-svg,

I'm looking for clarification on non-scaling strokes and markers. Does vector-effect=non-scaling-stroke on a path apply to its markers?

It looks like SVG 2 will be the first version of the spec supporting both markers and non-scaling-stroke. I think it's least surprising to include markers as part of the stroke so that they will be affected by non-scaling-stroke. The marker spec hints otherwise: "Properties inherit into the 'marker' element from its ancestors; properties do not inherit from the element referencing the 'marker' element", which seems to say that markers do not inherit the stroke element's non-scaling-property.

Markers: http://www.w3.org/TR/SVG/single-page.html#painting-Markers
Non-scaling-stroke: http://www.w3.org/TR/SVGTiny12/single-page.html#painting-NonScalingStroke

Thank you,
Philip