[Bf-committers] Global Undo Problem

[Ton Roosendaal]

Hi,

I can't expect people to read CVS logs all, and still have to make a  
page on this on blender3d.org. So here's an update. :)

Important to know this: it's still a project heavily in development, as  
a proof-of-concept test. I was worried especially about unacceptable  
speed & memory usage for undo 'pushing' (saving), which will frustrate  
workflow. So for now, an undo push only happens on 2 places in the  
source code (after a transform, and at pressing a button), which is far  
insufficient for a real working undo of course.

Once the basic functionality is considered acceptable, we'll put energy  
in integrating it well, which mainly will be adding 100s of undo push  
calls in the code. We also have to review which hotkeys to use for it,  
and for which actions you want it, and how much settings we should  
provide for it (steps, memory, per window, etc).
After that, feedback on proper functioning of the undo itself is  
welcome.

Also an undo or redo itself (a restore) still has some issues. It  
currently has about the same speed as reading a file, which can cause  
delays when for example a lot of display lists have to be calculated  
(3d texture display, subsurf) or for particle systems. Will be looked  
at.

The latest version of the undo code, committed yesterday, now uses a  
full memory based system, with minimum storage requirements and  
delta-compression.
Tests I did - and first feedback - give very positive results. On this  
relative slow Mac (450 Mhz) I get acceptable undo-saving on files of 20  
MB still.

Conclusion; for now only test the delays caused by saving undo (after  
grab, after button press). That should be acceptable, or I don't even  
consider to pursue this method. :)

-Ton-


On Monday, Sep 6, 2004, at 11:23 Europe/Amsterdam, Bart wrote:

>
> Testet last CVS too and got a small problem:
>
> Create a cube, scale it and press U for Undo, The global undo goes  
> back two steps (scaling and creation of the cube).
>
> Shodan wrote this about Global Undo:
>
>> Hi,
>> I've tested the latest CVS, and i have to say you have made a great  
>> job about Undo/redo System, pretty fast.
>> I was very happy about a Global Undo, especially i make some time  
>> wrong manipulation while i'm tweaking UV and thus... i
>> was surprised that UV editor isn't affected by Undo/Redo system.
>> So, just a feedback, Maybe are you already fixating this.
>> a little question: there is a way to flush Undo/Redo's history?
>
> Bart.
> _______________________________________________
> Bf-committers mailing list
> Bf-committers at projects.blender.org
> http://projects.blender.org/mailman/listinfo/bf-committers
>
>
------------------------------------------------------------------------ 
--
Ton Roosendaal  Blender Foundation ton at blender.org  
http://www.blender.org