I don't know what it is called.. Maybe inkscape already has this feature?
I am currently using the inkscape version provided by Debian Unstable. Inkscape 0.43, I beleive.. and that while I realy like the product and appreaciate it's development I find that it is realy to very slow to be much use at the moment.
I mean it's making it 3 or 4 times more difficult/longer to make fairly simple shapes then it should.. And this is due totally to how slow it is. Otherwise it's the easiest thing I've ever used as far as vector-based drawing tools go.. and I am very serious about that.
What I would like to see is that while editing shapes and such while using the 'edit path nodes or control panels' tool that while your actually working and moving lines around that it doesn't try to render things realtime.. That is while your moving nodes around it will not try to update the image.
Instead I'd like to see a sort of very simple line that represents were that paticular line will go or show how the shape is modified. Something that is simple and quick... Then after you drop the node or unclick it or hold the pointer stationary for a few moments that it will update the scene.
That way the human-interactive part can be very quick and yet you can do the render part very exact and it won't matter so much how fast the scene is able to refresh or whatnot.
Right now I have problems because I need to hold the mouse and wait for the screen to update. Also after I release the button and move the mouse quickly then the item that I am holding onto will sometimes 'follow' the pointer a bit and screw up the changes I just made.. which then I'd have to undo and redo it.
But I figure if you use a quick sort of preview line and leave the heavy rendering stuff to wait until after I release the mouse then that will solve this problem almost completely and make the application much more usable.
This sort of behavior is what I find in other vector-based applications such as XaraLX.
Somebody created Debian packages for it and made mention of it at the XaraLX development list... http://www.xaraxtreme.org/maillists/archive/dev/msg00117.html
So using that you can see what I mean incase my description is to horrible for you to follow. Maybe you can borrow some of the code they use for doing that?
The other thing that I noticed is that while your zoomed it very far simply moving the mouse around will eat up 100% of the cpu. This is not while dragging anything or adjusting any nodes or anything like that, but simply moving it around will cause this.
I noticed this a bit with the Gimp, but the effect is much more pronounced in Inkscape. So maybe it's a GTK issue?
Thank you very much for making this application aviable, btw. Aside from the issues I pointed out it seems very top-notch to me. I don't want to give the impression that I don't like it or anything or I don't appreaciate the work you guys are doing, because I do.