[Etoys] Fw: Re: PolygonMorph

[Jerome Peace]

--- On Sat, 2/28/09, Jerome Peace <peace_the_dreamer at yahoo.com> wrote:

> From: Jerome Peace <peace_the_dreamer at yahoo.com>
> Subject: Re: [Etoys] PolygonMorph
> To: "antonio" <antoniomoreno at edu.juntaextremadura.net>
> Date: Saturday, February 28, 2009, 1:36 AM
> Hi antonio,
> 
> Good recipes. I was easily able to recreate the problem.
> 
> This seems at base an old polygon problem that tends to
> happen
> when there is only one vertex. The handles have to take
> extra care
> at that point not to index a non existent one.
> 
> This was repaired in 3.9. Eventually the easiest thing was
> to factor out
> the computation of midpoint (used for the triangle
> handles). The trick was to check for the single vertex and
> handle that as a special case.
> 
> Yoshiki: if you will look at 3.9 or 3.10 
> PolygonMorph>>updateHandles and
> Polygon>>midpoints you should see a solution. This
> code is independent of the other repairs (i.e. cuvier curve
> fitting) so it should be easily portable to etoys and 3.8.
> It might require some repairs to the arrowhead code IIRC.
>  I remember having to repair that as a cascade of this
> repair.
> 
> Hth.
> 
> Yours in curiosity and service, --Jerome Peace
> 
> 
> 
> 
> 
> --- On Fri, 2/27/09, antonio
> <antoniomoreno at edu.juntaextremadura.net> wrote:
> 
> > From: antonio
> <antoniomoreno at edu.juntaextremadura.net>
> > Subject: [Etoys] PolygonMorph
> > To: etoys at laptop.org
> > Date: Friday, February 27, 2009, 3:47 AM
> > Sorry, I know "sometimes" is very poor...
> > I find some differences now:
> > 
> > 1.- create an instance of Curve (Basic categorie at
> Object
> > Catalog)
> > 2.- Halo > Menu > Show handles with it
> > 3.- open its Viewer and look for "vertices",
> > you'll find:
> > remove all vertices but cursor
> > Run this command once 
> >     then  I get an EvaluationError 
> > 
> > 1.- create an instance of Curve (Basic categorie at
> Object
> > Catalog)
> > 2.- open its Viewer and look for "vertices",
> > you'll find also:
> > remove all vertices but cursor
> > Run this command once 
> > 3.- now that you have a black point, get (complicated
> > without
> > easySelection ON, perhaps easySelection could have a
> > keyboard shortcut)
> > its Halo and clic on  Menu > Show handles
> > 4.- look for: remove all vertices but cursor and run
> this
> > command once 
> >     then  I get an PreDebugWindow 
> > 
> > 1.- create an instance of Curve (Basic categorie at
> Object
> > Catalog)
> > 2.- Halo > Menu > Show handles with it
> > 3.- open its Viewer and look for "vertices",
> > you'll find also:
> > remove all vertices but cursor
> > Run this command once 
> > 4.- now that you have a blue circle and a orange
> triangle,
> > clic on the
> > triangle: OrderedCollection error 
> > or try to move the object from the blue circle:
> > OrderedCollection error 
> > 
> > regards
> > 
> > 
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