Fwd: SVG Tiny 1.2 clarification request

Forwarded by permission of the author, who had first contacted me 
personally.

The question is about non-scaling stroke, so applies also to SVG2.

-------- Forwarded Message --------
Subject:  SVG Tiny 1.2 clarification request
Date:  Thu, 2 May 2019 16:44:46 +0200
From:  Rainer Gutsche <rain@scholtz.de>
Organization:  Scholtz Software GmbH, Peiting, http://www.scholtz.de
To:  Chris Lilley (W3C) <chris@w3.org>



Bonjour Chris,

I'm writing you because I have found you in the list of editors of the 
SVG Tiny 1.2 specification. If you are not the person who can answer my 
question please forward it to one of your colleagues.

My software generates some svg files. One of the users reported that the 
drawn result is not what he has expected to see. I opened a bug report 
for the rendering software and was told that this is the way other big 
players render it also. Some quick tests confirmed this (firefox, gimp), 
others (Corel Draw) not. I have a degree in computer science, I have 
read the specification and I think I have understood it. But in the end 
it's only you from the W3C who can definitely say yes or no. Here is my 
short explanation of the problem:

Have a look at the three different svg files (A, B, C) and the two drawn 
results (A and C). The problem is B. As I understand, B has to be drawn 
in the same manner as A, because the initial coordinates are transformed 
and the style (the stroke-width) is applied afterwards. Furthermore, as 
I understand, the vector-effect property (non-scaling-stroke) applies 
only to already drawn content as shown in your non-scaling-stroke 
example. But when I put B into firefox it looks like C.

I am not a lawyer and I will never use your answer to go to court. ;-) I 
simply want to know what is right and what is wrong, so please give me 
an answer.

Best regards,

Rainer

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Dr.-Ing. Rainer Gutsche, Scholtz Software GmbH, rain@scholtz.de
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