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

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

I was responding to the statement that zero width lines resulted in no stroke.  This is clearly covered by the guidelines in Annex D.  As is the zero character height:

D.4.6.9   CHARACTER HEIGHT 
The next available value smaller than or equal to the specified value is selected.  If no such value is available, the next larger value is selected.  If a zero height is specified in the metafile, it is recommended that interpreters select the minimum available height for affected primitives. 

O% is a whole other question.

thx...Dave

-----Original Message-----
From: Dieter Weidenbrück [mailto:dieter@itedo.com]
Sent: Wednesday, May 18, 2005 4:00 PM
To: Cruikshank, David W; Benoit Bezaire;
cgmo-webcgm@lists.oasis-open.org
Subject: RE: Re[2]: [cgmo-webcgm] Initial values, % sub-issue [was:
Re[2]: [cgmo-webcgm] Style properties]


Dave,

> -----Original Message-----
> From: Cruikshank, David W [mailto:david.w.cruikshank@boeing.com]
> Sent: Wednesday, May 18, 2005 11:30 PM
> To: Benoit Bezaire; cgmo-webcgm@lists.oasis-open.org
> Subject: RE: Re[2]: [cgmo-webcgm] Initial values, % sub-issue [was:
> Re[2]: [cgmo-webcgm] Style properties]
>
>
> For Line Width and Edge Width, zero width, minimum width, and no
> stroke are different if you follow the guidelines in Annex D of
> the Standard
>
> D.4.6.3   LINE WIDTH
> If a device cannot produce a line of the exact specified width,
> the closest implemented width is chosen.  If a zero width is
> specified in the metafile, it is recommended that interpreters
> select the minimum available width for affected primitives.
>
> D.4.6.18   EDGE WIDTH
> If a device cannot produce a line of the exact specified width,
> the closest implemented width is chosen.  If a zero width is
> specified in the metafile, it is recommended that interpreters
> select the minimum available width for affected primitives.
This is what I referred to when I said "it is impossible" to have 0 width.
A thin line will always be drawn, which is a heritage that I would
rather see being removed.

So 0% of
- any color results in white,
- of text-height results in ...?
- of line-weight results in a thin line

We should agree on a result that is understandable for a user, if possible.
The thin line is difficult to accept unless you know CGM inside out. You
wouldn't
believe how many support cases we have had because of that thin line.


>
> On the Text issue, I remember a proposal the Text Height be
> removed because of the issue with RT boxes, etc.  I see no reason
> why Text Colour should be affected.  Is Text Font in our
> requjirements document?
I can't recall text height or font being removed, and I still think
they are useful.

Cheers,
Dieter

>
> thx...Dave
>
> -----Original Message-----
> From: Benoit Bezaire [mailto:benoit@itedo.com]
> Sent: Wednesday, May 18, 2005 11:55 AM
> To: cgmo-webcgm@lists.oasis-open.org
> Subject: Re[2]: [cgmo-webcgm] Initial values, % sub-issue [was: Re[2]:
> [cgmo-webcgm] Style properties]
>
>
> Wednesday, May 18, 2005, 11:51:29 AM, Lofton wrote:
> LH> At 04:58 PM 5/18/2005 +0200,
> LH> =?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
>
> LH> That creates something of a contradiction:
>
> LH> lw' = sw * lw
> LH> ew' = sw * sw
>
> LH> WebCGM 1.0 T.20.4 says that LINE WIDTH 0.0 is allowed, and
> means "Minimum
> LH> available line width."
> Is there a visual difference between 0.0, "Minimum available line
> width", and no stroke?
>
> LH> I don't think we want to require that implementations keep track
> LH> of whether the lw' 0.0 comes from the WebCGM instance or from
> LH> application of stroke-weight 0.
> I'm not sure what you mean by 'keep track', but an implementation
> already has to keep track of the style state to be able to revert back
> to the original look (i.e., to implement clearStyleAttr() )
>
> --
>  Benoit   mailto:benoit@itedo.com
>
>
> >> > text-font: (gone?)
> >>not gone as far as I am concerned.
>
> LH> Dave should queue this as an issue.  (Dave, do you recall minuting the
> LH> earlier discussion?  I clearly remember discussing it in a meeting or
> LH> telecon, perhaps Munich, and thought we concluded that it should go.)
>
> LH> -Lofton
>
>
>