RE: [cgmo-webcgm] Reading the CGM standard: LINE AND EDGE TYPE DEFINITION

["Dieter Weidenbrueck" <dieter@itedo.com>]

Title: Reading the CGM standard: LINE AND EDGE TYPE DEFINITION

Hi Franck,

 

this is how we read the Spec:

 

The Dash Cycle Repeat Length is the actual length of an entire pattern.

The unit of this value is determined by the LINE WIDTH SPECIFICATION MODE.

The sum of all 'dash elements' corresponds to this value.

Thus you can calculate a factor to determine the length of lines or gaps:

 

F = DASH CYCLE REPEAT LENGTH / sum of Dash Elements

Here:

F = 608 / 15000.

Hence the first line piece has the length: 10000 * 608/ 15000,

the first gap is 2000 * 608/15000

etc.

 

Hope this helps,

Dieter

-----Original Message-----
From: DULUC Franck [mailto:franck.duluc@airbus.com]
Sent: Friday, November 19, 2004 10:22 AM
To: 'cgmo-webcgm@lists.oasis-open.org'
Subject: [cgmo-webcgm] Reading the CGM standard: LINE AND EDGE TYPE DEFINITION

Dear all,

Here is a technical question on CGM coming from Philippe Buffet which is working for me, here in Airbus.

Thanks in advance for your support.

Franck

------------------------------------------------------------------------------------------------

Hi all,

I have a question about Line and Edge Type Definition.
I have made the following definition:

  26:LINE AND EDGE TYPE DEFINITION    Offset:314         Length:12
    P1 : Line Type                  Value: -4
    P2 : Dash Cycle Repeat Length   Value: 608
    P3 : number of elements         Value: 4
    P4 : element                    Value: 10000
    P5 : element                    Value: 2000
    P6 : element                    Value: 1000
    P7 : element                    Value: 2000

However, in the ISO CGM functional specification, I found the following paragraph:

"The dash cycle repeat length defines the length of one complete cycle of the dash pattern. The lengths of
the dash elements are normalized so that the sum of the specifiers in the list of dash elements equals the
dash cycle repeat length."

Does that mean that I should have used 15000 as "Dash Cycle Repeat Length" value instead of 608 or does I just misunderstand the ISO specification ? I am a bit confused as metachek accepts the above Line and Edge type definition.

Every help or comments will be appreciated.

Thanks in Advance.

CS
Philippe Buffet
on behalf of AIRBUS France
for Technical Data and Services
Data Definition & Research - SDND

Phone: +33 (0)5 61 18 26 89
Fax:+33 (0)5 61 93 59 44
<Mailto:philippe.buffet@airbus.com>