RE: [cgmo-webcgm] POLL ISSUE: zero-valued LINE WIDTH, stroke weight

["Cruikshank, David W" <david.w.cruikshank@boeing.com>]

There seems to be some question on whether this question was asked and answered before.  Going through the thread, I couln't find all the responses linked directly to the question and it wasn't clear to me that everyone answered the issues separately.

Sorry, if you think this was a duplicate, but I would like collect the poll results directly to these specific questions.

Please reply all when responding so they get tracked with the thread on the OASIS site.

thx...Dave

-----Original Message-----
From: Cruikshank, David W 
Sent: Friday, June 10, 2005 1:18 PM
To: CGM Open WebCGM TC
Subject: [cgmo-webcgm] POLL ISSUE: zero-valued LINE WIDTH, stroke weight


All,

I've read through the thread on this one and will summarize.

There are two questions here and everyone needs to answer them independently.

1)  What should WebCGM say about the treatment of zero width lines (line width specifier of 0 value on the Line Width attribute element in CGM)?
   a)  Leave it as it is specified in WebCGM?
   b)  Change the meaning of a zero value to mean "no stroke"?
Recommendation a)

2)  What should WebCGM say about the allowable values and treatment of the stroke weight style property of WebCGM set through the DOM?
   a)  Limit value of both NVCC and relative scale to >0?
   b)  Allow zero values for both NVDC and relative scale and adopt CGM conventions?
   c)  Allow zero values for both NVDC and relative scale and define the meaning as "no stroke"?
Recommendation a)

Summaries

1)  The CGM standards allows for parameter values for the line width specifier of the Line Width attribute element to be non-negative.  That means the Line Width can be set to zero in CGM.  In the "informative" guideline for interpreters in Annex D, the CGM standard recommends: "If a zero size is specified in the metafile, it is recommended that interpreters select the minimum available size for affected primitives."  Currently in the WebCGM 2.0 Profile (T20.3), the meaning of a zero value is "Minimum available line width".

2)  Currently the WebCGM 2.0 DOM chapter has a restriction of the allowable values for stroke width.  It limits the relative scale stroke width to >0%, but doesn't address absolute NVDC as far as I can tell.

Personal thoughts