[Bf-python] memo + new MetaBall

[guignot]

hi !

This short memo concerns the homogeneity of the interface.


The python API gives user access to most of  the internals of Blender.

To access a data, the user will have two functions :
objid->getData()
objid->setData( value)

For instance, in the module Camera, we access the ClipStart value with 
the functions :

cam_id->getClipStart()
and cam_id->setClipStart(value)



The function get data returns an error if the identifier does not 
correspond to a valid C object (typically an instance of a class) or if 
the syntax of the call is not correct.
If everything is allright, it will of course return the data (maybe a 
list containing the data for vectors or coordinates )
The function setdata returns an error for the same reasons and the data 
in case of success (NOT PyNone, returning the data allows the user to 
perform a security check)
(for vectors or coordinates, we can use (Python point of view) set(list) 
or set(val1,val2,val3). Or both. I choosed the latter but it can be 
easily changed.



Access to compound data :

So far, so good...
Many classes have lists of hmmm... things...
To access these data, two possibilities :

we can use  : obid->getTypeObjectData1nameData2name(position)

or : obid->getTypeObjectData1name(Data2name,position)

A little example with the MetaBall module.
The MetaBall class contains a list of Metaelem, which are the balls of 
the metaball.

These Metaelems contain 17 fields, for instance the fields 
'rad',rad2','x','y','z'

The access to the field 'x' of the third metaelem of the metaball mb can 
be granted with
mb->getMetaElemx(2)   (2 because begins at 0)
or by mb->getMetaElem('x',2)

Same thing for set.

The new MetaBall implements both possibilities.

What's your opinion :
a) implement both
b) implement first only
c) implement second only ?
d) implement another one ?



If you feel concerned by these issues, please answer asap, the longer we 
wait, the more code will have to be modified to follow the guidelines...


jms : what do you mean by "implement Alt-C "? convert MBall to Mesh ? 
Why not, if you think it's useful.



-->Willian : tried to follow nan cod. guidelines! but 80cols is WAY TOO 
SHORT!!!!!!!!!!!!!!!!!!
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