RE: Re[2]: [cgmo-webcgm] Re:

[Lofton Henderson <lofton@rockynet.com>]

At 09:56 PM 7/8/2004 +0200, Dieter Weidenbrueck wrote:
>[...]
> >-----Original Message-----
> >From: Benoit Bezaire [mailto:benoit@itedo.com]
> >Sent: Thursday, July 08, 2004 9:36 PM
> >To: Dieter Weidenbrueck
> >Cc: Lofton Henderson; cgmo-webcgm@lists.oasis-open.org
> >Subject: Re[2]: [cgmo-webcgm] Re:
> >
> >
> >DW> The coordinate system should be described as follows:
> >
> >DW> width = resulting mm width of VDC extent
> >DW> height = resulting mm height of VDC extent
> >Could I please get a pointer to read on how "resulting mm width/height
> >of VDC extent" gets computed?
>
> >From CGM:1999:
>"6.4.1 Scaling mode
>VDC space may be either an abstract space, which may be mapped to an
>arbitrary size on a physical device, or a metric space, which is [...]

Long story short, this is how I read it (which I think agrees with 
Dieter).  From the rules of CGM:1999 and WebCGM 1.0, every picture in a 
valid WebCGM has a VDC Extent with an inherent width in mm (call it W) and 
height in mm (call it H).

When MM cordinates are used in DOM, then they refer to a coordinate space 
in which the VDC Extent rectangle has lower-left corner (0,0) and upper 
right corner (W,H).


> >
> >DW> top left coordinates: width,height (or 100%,100% where applicable)
> >What does "or 100%, 100% where applicable" mean, where would it be
> >applicable?
>
>I thought we had discussed to express coordinates of a hotspot either in
>mm or in %. I am certainly happy with mm only to keep it simple.

I am opposed to eliminating %.

-Lofton.