[Bf-committers] Re: Regarding the undo function....

[Charles Wardlaw]

You know, once the new python functionality is finished, and all
internal blender structures are accessible through python, it'd be easy
to add undo functionality using Python itself -- you could tree-walk
the sections of the blender structure that are going to be changed,
save the to a memory block (only what's changed, of course), and then
make the changes in the actual blender structure and update the screen.
 IIRC python has the functionality to get names and values of all
properties of a class and its subclasses/children?

As an interim solution, someone might add Hold/Fetch buffers to Blender
(not unlike what was done in 3D Studio R4 -- anyone but me remember
back that far? ^_^; ).  That way a simple keystroke combo would store
the current scene into a memory buffer, for easy recalling later, and
the undo onus would be on the user.  It worked quite well back in the
3DSR4 days, though I must say the editable modifier stack in 3DSMax was
a nice addition.  Now that I think about it, I don't believe 3DSR4 had
a real undo function, either...  I think that came in Max.

And I'm going to bring something up now, and get shot for it: I know
other opensource projects, like Allegro, have started implementing
whole new design structures for their next iteration (IE, allegro is
moving towards a more event-based model for Allegro 5, which will break
all games using the code).  Has anyone started designing Blender 3 yet?
 I can see it being a completely different part in CVS, like tupohuu,
only the code in it would be rethought from the ground up.

Heh, not that I'm a good enough coder to pull such a thing off.  I'm
just an idea man.

- Charles

--- Ton Roosendaal <ton@blender.org> wrote:
> Hi,
> 
> > .... by the Lackness of a few, simple, easy to implement (...  
> > unreliable statement of a novice-programer :) ...) but "ESSENTIAL" 
> 
> > features.
> 
> Apart from text editors, I have not seen real good undo's yet. A lot
> of  
> programs just undo-redo the last action, which is fairly simple but  
> very unsatisfying. Only occasional accidents can be restored that
> way.  
> Even Photoshop only does 1 undo, and for image editors writing undo
> is  
> 'easy to implement' yes.
> Another method is building a 'construction history', allowing someone
>  
> to start over and redo steps.
> 
> > Despite all that, I hope ton and the other developers will be  
> > mercifull and implement this features very (very) soon (correct me
> if  
> > I am wrong).
> 
> As said before, it is not a lack of interest or willingless, it is  
> because the internal structure of Blender was not designed with
> 'undo'  
> in mind. I think someone could try a hackish way to at least have a  
> 'undo/redo', but I doubt the results of this effort is worth the  
> hassle...
> 
> In discussions on a complete new Blender3 project, having 'undo' and 
> 
> 'construction history' are features nobody really disputes.
> 
> -Ton-
> 
>
------------------------------------------------------------------------
> 
> --
> Ton Roosendaal  Blender Foundation ton@blender.org
> 
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