[Qgis-developer] rendering current line in Grass digitizer is very slow

[Stephan Holl]

Hello,

On Mon, 10 Jul 2006 11:00:09 +0200 "Radim Blazek"
<radim.blazek at gmail.com> wrote:

> GRASS edit in 0.8 is using QgsRubberBand (XOR rendering
> does not work anymore IIRC) and it is probably slow because
> it is not designed for complex graphics.
> I dont know if it can be improved.

Is there any chance to make this working as it was in 0.7.4 also with
qt4, probably before 0.8 will be stable?

I am with Macieks opinion that this should work well in 0.8.

Best
	Stephan

> 
> Radim
> 
> 
> On 7/7/06, Maciek Sieczka <werchowyna at epf.pl> wrote:
> > Hi,
> >
> > Lines in Grass digitizer are being drawn really slowly on pretty
> > fast computers [1]. The more vertices the line has, the slower the
> > rendering. The bug affects only the line being currently digitized,
> > ie. if you just try to modify an existing one by moving or adding
> > single vertices rendering is fast. But when you digitize a long
> > line, with each vertex added the rendering speed decreases.
> >
> > To reproduce:
> >
> > 1. Open a Grass vector in Grass digitizer.
> > 2. Start a new line (or boundary) by putting the first vertex. See
> > how smoothly the line is drawn as you move the cursor with mouse.
> > 3. Now digitize 10, 100, 300 etc. vertices. See how much slower the
> > rendering gets with each vertex put. Note the slow-down does not
> > depend on the zoom level or the amount of features being displayed.
> > The only "reason" for the slow-down is the amount of vertices you
> > have put in the line being currently digitized.
> >
> > Is this a known issue? Is my description clear? Could it be fixed?
> >
> > Using SVN 0.8 of yesterday, Ubuntu Breezy and Dapper.
> >
> > Maciek
> >
> > [1]
> > PM 1,86 GHz, ATI X700 128MB, propriearty drivers, direct rendering
> > on AMD 3200, NVIDIA GX400 64MB, propriearty drivers, direct
> > rendering on
> >
> > --------------------
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> >
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> >
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