Re: [cgmo-webcgm] Review of WebCGM 2.0 Profile

[Lofton Henderson <lofton@rockynet.com>]

At 12:56 AM 10/5/2005 -0700, Cruikshank, David W wrote:
> Here's my review of column 2 of the
> PPF for WebCGM 2.0

Thanks for the review.

I look at all of them.  Most are obviously editorial.  A couple
probably need a quick look, to sort out the best correction:

T.18.4
T.20.24
T.20.27
T.22.2
Section 6.16

Plus I was unclear exactly what you were suggesting on T.25.4 and
T.26.6.

Comments embedded...

> Review
> of WebCGM 2.0 PPF  concentrating on column 2, WebCGM
> requirements
>
> For most of 
> the entries in column 2 that Rob already caught as not matching the
> wording in the model profile column, I defer to Rob’s
> corrections.
>
> T13.2  Number of
> pictures  should be Same as model profile:
> No

Right, WebCGM is a 1-picture profile, as clearly stated in Ch.2 and Ch.3,
and in the details box of the PPF.  So "No" is an
editorial oversight.


> T16.3 
> VDC Type  should be Same as model profile:
> Yes  Rob
> caught this, too.

Clearly it must be "Yes", since the details box is
empty.


> T18.4 
> Transparency  I have a note that indicates there probably should be
> a note under “Other” indicating that this element should be prohibited
> when the colour model has an alpha channel?

Why?  This element says whether (for example) gaps in dashed lines
show what is behind, or show the Auxiliary Colour.  It seems
unrelated to the presence of an alpha channel.


> T18.8 
> Marker Clipping Mode  there is a string “P>” preceding the first
> question

Fixed.


> T18.9 
> Edge Clipping Mode  there is a string “P>” preceding the first
> question

Fixed.


> T20.24 
> Hatch Index  should this be changed to Same as model profile:
> No
> with a reference to 6.19 like we do for Line
> Type?

Unsure.  Unlike Line Type, it is WebCGM Hatch Index is technically
identical to MP.  So that argues for "Yes" (same as
MP).  

Recommendation:  Leave it "Yes" (same as MP), and put an
informative "Note.  See 6.19 for further discussion of hatch
interiors in WebCGM."


> T20.27 
> Edge Type  should this be changed to Same as model profile:
> No
> with a reference to 6.18 like we do for Line
> Type?

Unsure.  Is it supposed to match?  Do the registered types make
sense for edges?  Some obviously don't, like "break"
style, single arrow, double dot.  I suspect that this is
intentional, because some of the registered line type values are nonsense
as edge types.

Recommendation:  Leave it "Yes" (same as MP), and put an
informative "Note.  See 6.18 for further discussion of line and
edge type definitions in WebCGM."


> T20.44 
> Edge Cap  should be Same as model profile -
> No  Rob
> caught this, too.

Right.  Clearly it should be "no", since the details in
the box differ from the MP.


> T22.2 
> Application Data  it’s interesting that the model profile says
> “The use of this element shall not
> be restricted.” and we prohibit
> it?

Yes, interesting.  That statement was not in the MP of CGM:1992
Amd.2 (the original normative PPF, to which WebCGM 1.0 was
written).  It somehow got added when the PPF (and rules for
profiles) were rolled into the CGM:1999 republication.  I don't know
what it means.  And I can't find an erratum which indicates that the
change should have been made (to CGM:1999 PPF).

I suggest we ignore it.  Alternately, we could put a note indicating
the above, or that the specification in the CGM:1999 PPF is suspected to
be an error.


> T25.4 
> Font substitution  font metrics and glyph metrics in WebCGM column
> should probably be aligned with model profile as Rob
> noted.

I don't understand this one.  You mean to change "Annex I"
to "Annex I.2" or "clause I.2"?  (Btw, I believe
"Annex I.2" is the proper ISO style.)


> T26.6 
> Font substitution  Align WebCGM column as noted by Rob for
> references to Font metrics

Ditto.  Do you mean to change "I" to
"I.2"?


> 6.16 
> Symbol Library  should we remove this section entirely since Symbol
> Library is now obsolete?  This would require renumbering and also
> require adjustments to links in Line Type, Hatch Index, and Edge
> Type.

Yes it would.  I don't feel strongly.  Is it better to leave it
and indicate that it is 1.0, removed (obsoleted) in 2.0?

Regards,
-Lofton.