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

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

recording on email list

-----Original Message-----
From: Forrest Carpenter [mailto:forrest@sdicgm.com]
Sent: Friday, June 10, 2005 2:08 PM
To: Cruikshank, David W
Subject: RE: [cgmo-webcgm] POLL ISSUE: zero-valued LINE WIDTH, stroke
weight


Dave,

My vote for 1) is A
My vote for 2) is B, but A would be ok, I am very much against C

Forrest

-----Original Message-----
From: Cruikshank, David W [mailto:david.w.cruikshank@boeing.com] 
Sent: Friday, June 10, 2005 3:18 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