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[prot_fr...@famenzel.at]

Niels Slot schrieb:
> I think it would be a very good thing for KTurtle if it could be used to
> fulfill any requirements a government might have to a Turtle Graphics
> Language. This would mean that teachers from this country can choose to
> use
> KTurtle, which in turn could result in a growing market share for
> KTurtle,
> KDE and free software in general.
>
> Niels
>
> 2009/8/20 Sly <silvia....@gmail.com>
>
> >
> > Tnx Niels!
> > In my private opinion I think that erasing the line (or it's part) or
> > parts
> > of the canvas is not necessary because we have to try to teach
> > children to
> > think in algorithmic way and to assume how the result would look like.
> > And
> > if something is wrong they should change the code. By the changing of

> > code,
> > the result should be changed the way we want to.
> >
> > On the other hand, Z-value would be nice feature.
> >
> > I don't know if I explained correctly why I need command "penerase".
> > So,
> > I'll try again.
> > According to Croatian Teaching plan children should learn how to erase
> > the
> > line (or part of the canvas) using their favorite Turtle Graphics
> > software.
> > In FMSLogo it is done by the penerase command which is same as using
> > forward
> > (or backward) with the color of canvas.
> >
> > I know that Kturtle has completely different philosophy, but I would
> > really
> > like to cover my Teaching plan with Kturtle.
> >
> > Thank you all for help!
> > Silvia
> >
> >
> > On 20 kol, 14:08, Niels Slot <nielss...@gmail.com> wrote:
> > > Your code example almost works in KTurtle. The problem is that the

> result
> > is
> > > indeterministic. The line can either be 'erased' or not. This is
> because
> > of
> > > the Z value of the lines. In the current KTurtle version they all
> have
> > the
> > > same Z value. This means that no line is above or below another line,
>
> > > they're all at the same height. Because of this, when displaying the
> > lines,
> > > the white line can be above or below the original black line.
> > >
> > > I hacked KTurtle a bit to put all lines at a different Z value. This
> way
> > > your code works, the white line is always visible.
> > >
> > > There are still two obvious problems:
> > >
> > > 1. In my implementation the turtle is always painted below the drawn
> > lines.
> > > With a little more work I think\ I can fix this.
> > >
> > > 2. There is a need to change the pen size when their shouldn't be.

> This
> > > seems to be because we're using QGraphicsView which, as Cies
> mentioned,
> > > works great when printing or zooming. I don't know of an efficient

> way to
> > > fix this.
> > >
> > > I'd like to have Cies opionion on this. Do we want to make a way to
> erase
> > > lines? (I would really like it..) If so, is there a way to implement
> it
> > when
> > > we're using QGraphicsView?
> > >
> > > Niels
> > >
> > > 2009/8/20 Sly <silvia.kola...@gmail.com>
> > >
> > >
> >
> > >
> >
>
> >


--
Mit den besten Grüssen
Peter A. Menzel