Re: gEDA-user: weird names in PCB part library

[John Luciani <jcljr58@yahoo.com>]

> Stuart Brorson wrote:

>>Perhaps back in the stone age, when PCB was written
for the 
>>Altair 8800^H^H^H^H^H^H^H^H^H^H Atari [2],
generating symbols on the 
fly
>>from an M4 macro was a good idea in order to save
space memory. 
>>Seems to have totally misunderstood.

>Creating using M4 means that you can generate
footprints in a 
>*parameterized* manner, which is 100 times better
than the WYSIWYG 
>concept. Really.

Creating the footprints in a parameterized manner is
much faster. It is also easier to make updates.

You can create the newlib footprint in a parameterized
manner using a scripting language. I do not use any of
the M4 symbols. I created a Perl library that outputs
the various element commands. From a component data
table (like the tables in IPC SM782A) I generate all 
of the defined packages for a pakage family with about
20 lines of code.

In generating the footprints it has been useful to
have a tool capable of more than just parameterized
substitution. The M4 code was difficult for me to
read. Trying to keep all the positional parameters
straight is cumbersome. 

Having commands that use key-value pairs has been
easier for me to maintain. To add a pin to an element
I would use the command ---

  element_add_pin(x => 100, y => 100, thickness => 80,
                  drill_hole => 40, name => "",
                  pin_number => 1, flags =>
PIN_SQUARE)

>> <> Now,
>> however, it strikes me as a weird relic of the past
which can only
>> frighten users away, encouraging them to continue
hiding under the
>> skirts of commerical layout software vendors.

>If  the purpose of geda was to emulate the commercial
software, that 
>would be a very bad move.

>Free software means that we are free to make thinks
better, without the 
>contstraints that commercial vendors face.

I believe the point was to improve the free software
to have a viable alternative to commercial software.

(* jcl *)




	
		
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