[ka-Map-users] Re: Canvas memory usage?
justin.george at gmail.com
Tue Jun 27 11:29:24 EDT 2006
I found the problem, actually. I was calling it before the map had
fully initialized, and so it was trying to render a very, very large
canvas (~12000 by 6000 pixels)
I believe this is a known problem, eg, if you are zoomed in, and you
look at a large polygon, the overlays use substantial memory.
Hopefully in the future I'll be able to pass a convex hull of the
intersection of the geometry with the extents on the screen, which
will fix this. Of course, that's all on the spatial database side of
On 6/27/06, Pg <pg.navone at gmail.com> wrote:
> I did a quick check using Firefox 1.5 on Windows 2k, and the memory
> usage seems to be stable when I display canvas objects.
> I'll do some tests on Linux, but in the development and debug I've
> never noted a so big memory jump.
> 2006/6/27, Justin George <justin.george at gmail.com>:
> > I'm having a problem isolating why canvas is using so much memory.
> > Currently, on firefox 1.5, when a canvas is created using the line
> > (in kaXmlOverlay.js, line 1053, kaXmlPolygon.prototype.draw_canvas)
> > var ctx = _BrowserIdent_getCanvasContext(this.canvas);
> > memory usage jumps by around 200mb. This is not important for
> > development, but, as most of our target users have far less memory
> > than this, it is becoming important as we move towards deployment.
> > You're the resident canvas expert, PG, so perhaps you could shed some
> > light on the behavior of canvas?
> > Thanks
> > J
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