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

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:]
Sent: Friday, November 19, 
2004 10:22 AM
To: 
''
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 
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