Re: More on getObjectExtent()

As far as information for a glossary entry, I think what Lofton has
suggested is good.

The answers to Dieter's questions should not be in the glossary, but should
be in the discussion in 5.7.6, where it describes getObjectExtent.

-raster images:  To me this is implied as the extent of the raster
image...is more clarification needed?
-text: already covered in 5.7.6
-visibility/transparency: already addressed in 5.7.6, but possibly not the
right answer - "not affected by ... APS attributes or style properties"
Maybe visibility should affect the result?  Didn't we discuss this already?
transformations: already covered in 5.7.6

thx...Dave


On Sun, Nov 30, 2008 at 9:50 AM, Weidenbrueck, Dieter <dweidenbrueck@ptc.com
> wrote:

>  Lofton,
>
> good start. Do we need to add something about
> - raster images
> - text (should be treated as paths)
> - visibility/transparency (do they have an impact or not)
> - transformations (they do have an impact)
>
> Opinions?
>
> Regards,
> dieter
>
>  ------------------------------
> *From:* public-webcgm-wg-request@w3.org [mailto:
> public-webcgm-wg-request@w3.org] *On Behalf Of *Lofton Henderson
> *Sent:* Sonntag, 30. November 2008 17:26
> *To:* WebCGM WG
>
> *Subject:* Re: More on getObjectExtent()
>
> Since not everyone is satisfied with the simple fix of "s/abstract
> locus/locus/" in 5.7.6, I'll make a proposal to close the "locus" issue:
> delete the word "abstract" and link "locus" to a glossary entry.
>
> Here is a first draft proposal:
>
> [[[
> locus --
> The Oxford dictionary defines locus as:  "Curve formed by all points
> satisfying particular equation of relation between coordinates, or by point,
> line, or surface, moving according to mathematically defined conditions."
> In the WebCGM specification, locus refers to the set of points that comprise
> the path or shape of a Graphical Primitive element, or in the appropriate
> context, the combined shapes or paths collectively of all of the Graphical
> Primitive elements in an Application Structure (APS).  I.e., the locus of an
> APS comprises the combined loci of all of the graphical primitives in the
> APS.  Locus does not include defining data that are not part of the shape or
> path of the graphical primitive, such as control points of Bezier
> primitives, or the center point of a Circular Arc Center primitive.
> ]]]
>
> Question 1:  Are people okay with the solution of adding a definition to
> the Glossary?
>
> Question 2:  Suggestions for improvement of the definition?
>
> -Lofton.
>
>
>
> At 09:45 AM 11/19/2008 -0700, Lofton Henderson wrote:
>
> Dave,
>
> At 08:32 AM 11/19/2008 -0800, David Cruikshank wrote:
>
> I would agree with dropping "abstract".  Locus is a perfectly valid term to
> define the path of the primitive.
>
> Probably ought to capture it somewhere to document the decision.
>
>
> Just to clarify that last sentence -- you mean that you support the issue
> processing proposal to roll it into Issue3 in the DoC (see URI below)?
>
> Thanks,
> -Lofton.
>
>
> On Wed, Nov 19, 2008 at 8:04 AM, Lofton Henderson <lofton@rockynet.com>
> wrote:
>
> At 09:26 AM 11/19/2008 -0500, Bezaire, Benoit wrote:
>
> I think the wording should be revised.
>
>
> Fair enough.
>
>
> Even Google doesn't come up with anything meaning full for "Abstract
> locus".
>
>
> However, it does give lots of hits for a search like "definition of
> mathematical locus".  And we use "locus" repeatedly, in the proper sense, in
> the profile (Ch.6) -- i.e., "locus" is a pretty common term in  and has been
> used in WebCGM, for example, since 1999.  So it is my hastily-invented
> modifier "abstract" that is problematic.
>
> Actually, I think a good solution would be to drop the word "abstract".
> The next sentence after its occurrence fully explains what "abstract" was
> meant to convey.  (And we have agreed to clarify that sentence.)
>
> (See the getObjectExtent definition in 5.7.6:
> http://docs.oasis-open.org/webcgm/v2.1/cs01/WebCGM21-DOM.html#L5095 .)
>
> Okay?
>
> (Shall I just add this to fix to the clarification in DoC #3:
> http://www.w3.org/Graphics/WebCGM/WG/2008/WebCGM21-LC-comments.html#Issue3
> ?)
>
> -Lofton.
>
>
>  ------------------------------
> *From:* Lofton Henderson [mailto:lofton@rockynet.com <lofton@rockynet.com>]
>
> *Sent:* Tuesday, November 18, 2008 6:52 PM
>
> *To:* Bezaire, Benoit; WebCGM WG
> *Subject:* Re: More on getObjectExtent()
>
> At 01:52 PM 11/18/2008 -0500, Bezaire, Benoit wrote:
>
> The wording says "[...] The bounding box calculation is based on the
> abstract locus of the primitives within the APS."
> What does 'abstract locus' mean?
>
>
> The locus is the set of points comprising the drawn primitive (it's a term
> I dredged up from my memory of some old math courses -- I hope I got it
> right).  "Abstract locus" means that things like line width are not
> included, but rather only the point positions as if the item were drawn with
> an abstract, infinitely fine pen.
>
>
> I'd like to know if getObjectExtent() returns a tight bounding box on a
> given APS. i.e., given a polybezier, are control points part of the bounding
> box calculations or not?
>
>
> No.  The control points are part of the defining data, but not part of the
> drawn primitive.
>
> -Lofton.
>
>