----- Original Message ----- > From: Mathieu Bouchard <ma...@artengine.ca> > To: Jonathan Wilkes <jancs...@yahoo.com> > Cc: katja <katjavet...@gmail.com>; "pd-list@iem.at" <pd-list@iem.at> > Sent: Friday, November 4, 2011 1:18 PM > Subject: Re: [PD] how to capture window-related mouse-events when toxy is > discontinued? > > Le 2011-11-04 à 07:37:00, Jonathan Wilkes a écrit : > >> Functionally there is no difference between altering a polygon's shape > and the way I am moving it. > > In Tk, to change the coordinates of a canvas-item, you don't have to delete > it and recreate it. There's always a canvas-method named « coords » that > takes the same number of position arguments that the item-constructor did. So > for a rectangle-item, you give two points (four numbers) and for a N-gon > (N-sided polygon), you give N points (2*N points). > > It might not be much faster, though. I expect it to be only a tiny bit > faster. > Just a bit less time parsing, about one less malloc and one less free > (perhaps > several, because you have to remove a tag and add back the exact same). It > doesn't actually redraw anything between the delete and the create.
It seems like it does redraw stuff between the delete and create for a scalar with enough canvas items associated with it. For example, if you make a ds array where each element is a little 10x10 rectangle and plot it with an array size greater than 100, you start to get a kind of strobing effect over the entire array when moving one element with the mouse. > > Now that I think of it, the bbox computation (necessary for scheduling the > redraw) is done twice using create/delete, only once using coords, but that > should be a small amount of time compared to parsing the command. > > BTW, extremely long strings of commands might be parsed repeatedly by the > client > side in pd 43, because it's using [info complete] (just like desiredata). > But in practice, I didn't see it be a problem in profiling desiredata's > client's cpu usage, and I think pd 43 does it just the same. > I didn't profile in all situations, though, so, the technique might hit > problems with big arrays, big DS, big moves or abuse of [print] or of other > post()/error(). > > ______________________________________________________________________ > | Mathieu BOUCHARD ----- téléphone : +1.514.383.3801 ----- Montréal, QC > _______________________________________________ Pd-list@iem.at mailing list UNSUBSCRIBE and account-management -> http://lists.puredata.info/listinfo/pd-list
