Re: Rendering of marker-start at the beginning of a subpath

Hi all,

as you pointed to svg2, I have seen the note
"Note that ‘marker-start’ and ‘marker-end’ refer to the first and last 
vertex of the entire path, not each subpath."
in section 11.7.3 in https://svgwg.org/svg2-draft/
That is really helpful, and good to see, that it is in next version of 
svg spec.

Thanks for helping me here.

Dr. Olaf Hoffmann schrieb:
> Paul LeBeau:
>> That's the sentence I was referring to in my post.  That is later seemingly
>> contradicted (or clarified?) by the paragraph I posted.  It tends to
>> suggest that it may have been intended that start and end markers applied
>> to all subpaths.
>
> Do you mean sentences in the same paragraph:
> "Note that for a 'path' element which ends with a closed sub-path, the last
> vertex is the same as the initial vertex on the given sub-path. In this case,
> if 'marker-end' does not equal none, then it is possible that two markers
> will be rendered on the given vertex."
>
> I cannot see a contradiction (nevertheless, the usage of 'sub-path' can
> be a little bit confusing, but logically it does not cause a problem together
> with the initial definition), it only notes, that it is possible, that this
> happens.  This does not implicate a specific behaviour for sub-paths.
> I clarifies basically, that closed paths have an initial and final point as
> other paths and not just one for both.
> The Z-command implicates, that the initial point of the sub-path
> is the same as the final (and implicates something for some
> stroke-properties as well, but obviously not for markers - but
> currently one cannot have different linecaps at the begin or end of
> the path anyway and if closed the linejoin applies instead).
> Now there can be four different cases (assuming different markers
> for begin, end and mid):
> a) The initial point of the sub-path is the initial point of
> the complete path and the final point of the sub-path is
> the final point of the complete path - in this case, the markers for begin
> and end are drawn at the same vertex.
> b) The initial point of the sub-path is not the initial point of
> the complete path and the final point of the sub-path is
> the final point of the complete path - in this cae, a marker for mid and
> end are drawn at the same vertex.
> c) The initial point of the sub-path is the initial point of
> the complete path and the final point of the sub-path is
> not the final point of the complete path - in this case, a marker for
> begin and mid are drawn at the same vertex.
> d) The initial point of the sub-path is not the initial point of
> the complete path and the final point of the sub-path is
> not the final point of the complete path - in this case,
> two mid markers have a coincidence - because they are
> of the same type, nothing interesting will result from
> this.

It would be helpful, to have those cases in an example. Not only the 
different kind of markers are of interest, but their orientation too. 
The example 67 in section 11.7.3 in https://svgwg.org/svg2-draft/ does 
not contain sub-paths at all. The only example with sub-paths and 
marker-start, marker-mid, and marker-end I have found is
painting-marker-03-f.svg in W3C_SVG_11_TestSuite. But unfortunately it 
uses the same marker reference for all three kind.

Kind regards
Regina

Received on Friday, 27 September 2013 18:40:39 UTC