RE: [cgmo-webcgm] Initial values, % sub-issue [was: Re[2]: [cgmo-webcgm] Style properties]

[Lofton Henderson <lofton@rockynet.com>]

At 04:58 PM 5/18/2005 +0200, =?US-ASCII?Q?Dieter__Weidenbruck?= wrote:
> > stroke-weight: maps to LINE WIDTH & EDGE WIDTH, 100% is ok.
>Do we allow for 0%? This is actually impossible inside the CGM, but no
>problem for implementors.
>Result: no stroke

As I have been editing, I noticed something.  The CD text for the table in 
5.7.5 [1] says:  "(> 0%)" for stroke-weight and character-height.  So 
currently it is well specified for both WebCGM style properties and CGM 
attributes:

-- style properties:  cannot be zero
-- CGM attributes:  can be zero, WebCGM mandates the effect recommended in 
CGM appendix D.5 ("minimum available line width")

Summarizing the previous long thread, there are two sub-issues for us to 
address and decide.

sub-ISSUE 1.) CGM attributes.
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What should WebCGM 2.0 say about zero-valued attributes?

Options:

1a.) No change (allowed, minimum available size)
1b.) Like 1a, but add some practical guidance for "minimum available".
1c.) Like 1b, but further warn against zero values (actual results are not 
likely to match what was expected.)
1d.) Change PPF to prohibit zero-valued
1e.) Change PPF to deprecate zero-valued
1f.) Change PPF to allow, and effect is "no stroke".

Recommendation [LH].  1a or 1c.

sub-ISSUE 2.) WebCGM style properties.
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What should WebCGM 2.0 say about zero-valued attributes?

2a.) No change (it's prohibited in CD text).
2b.) Change to allowed, effect same as zero LINE WIDTH.
2c.) Change to allowed, effect is no stroke.

Recommendation [LH].  2a.

Hope this is helpful,
-Lofton.