Re: [gtk-list] BIG plots in gnome-canvas

[Federico Mena Quintero <federico nuclecu unam mx>]

>  I am thinking about porting my old Windows program to Gtk(Gtk--) It
>  generates huge plots which easily can have 1000k points. As I was
>  using CView from MFC,which I think is more like a drawing area, my
>  program was responsible for generating screen plots for a given
>  resolution in pixel coordinates.
>  
>  Would it be wise to dump that code, draw whole plot on
>  gnome-canvas(are they going to become gtkcanvas any time soon?) and
>  let them handle zooming?

A million points is a lot :-)

You may want to do some sort of recursive subdivision of the points
using canvas groups; that way the canvas will be able to handle them
efficiently.  Or you can create your own custom item type to handle
zillions of points efficiently.

You may want to take a look at Guppi/Goose (http://www.gnome.org/guppi), 
which does plots and (from the screenshots) seems to handle lots of
data points just fine.  I am not sure if it is using the canvas these
days, but you may want to take a look anyways.

I am very interested in making the canvas more efficient when there
are zillions of objects in the same group; Raph Levien's work on
microtiling may help here.  Please tell me if you have any ideas.

>  PS. Is it a right mailing list to ask questions about gnome-canvas?
>  Should I ask this question on GNOME list instead?

Maybe questions about the canvas are more appropriate for gnome-list :-)

Good luck,

  Federico