Re: ISSUE: does clipping affect getObjectExtent?

[...in order to close this formally in the WG...]

RECOMMENDATION: clipping does NOT affect getObjectExtent calculation,

This option was unanimous in the limited discussion that occurred on this 
thread,
http://lists.oasis-open.org/archives/cgmo-webcgm/200902/msg00031.html

-Lofton.


At 10:04 AM 2/4/2009 -0700, Lofton Henderson wrote:
>ISSUE:  does clipping affect getObjectExtent?
>
>Reference: 
>http://lists.w3.org/Archives/Public/public-webcgm-wg/2008Dec/0005.html
>
>Discussion:  The specification is imprecise about what things affect gOE 
>[1] and what things do not.  Clipping is one example.  We have previously 
>resolved that APS Attributes and non-text Style Properties do not affect 
>gOE [1].  This would include the 'visibility' APS attr. -- does not 
>affect.  I.e., gOE returns the bounding box (BB) of the loci of the 
>primitives in the object, whether 'visible' or not.  By extension, 
>visibility in any form would not affect the BB calculation -- Alpha 
>transparency (Escape, or "a" of rgba), transparent cell color (TCC), 
>occlusion of the object by an opaque object on top of it, etc.  (Is this 
>another issue?)
>
>It would be consistent to say that clipping does not affect gOE, i.e., gOE 
>should return the bounding box of the loci of the graphical primitives, 
>regardless of whether they are clipped or not.  On the other hand, 
>clipping is different from the 'visibility' APS attr in that the latter is 
>discoverable by getAppStructureAttr().  But it is similar to the other 
>sources of visibility (TCC, etc) that are not discoverable via DOM.
>
>The 2.1 Requirements [2] do not answer the question, but hint at a simple 
>requirement.  Past related issues have supported simplicity and ease of 
>calculation.
>
>[1] 
>http://www.w3.org/TR/2009/WD-webcgm21-20090130/WebCGM21-DOM.html#getObjectExtent
>[2] 
>http://docs.oasis-open.org/webcgm/v2.1/WebCGM_21_Requirements.html#get-extent
>
>Options:
>1.) No, clipping does not affect.
>2.) Yes, clipping does affect.
>3.) add a parameter to gOE to choose behavior.
>
>Recommendation.  Option 1, "No".
>
>### end ###
>
>-Lofton.
>
>p.s. This ultimately has to be resolved by the WG, but I think preliminary 
>discussion in the larger audience of the TC is useful.
>
>
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Received on Monday, 9 February 2009 20:20:00 UTC