[etoys-dev] Re: repeat-tile

[K. K. Subramaniam]

On Thursday 08 April 2010 10:32:18 pm Bert Freudenberg wrote:
> On 08.04.2010, at 18:52, K. K. Subramaniam wrote:
> > 
> >
> > On Thursday 08 April 2010 02:47:13 pm Bert Freudenberg wrote:
> >> In fact, turtle graphics might be the one intrinsically useful
> >> application of the repeat tile. If that is so, how about moving it to
> >> the pen category?
> > 
> > Repeat is convenient outside of pen drawing.
> 
> Do you have an example?
A couple of them.

I have seen kids drag turnBy:5 tiles multiple times into a script, then try to 
use the repeat tile before they stumble on the fact that repeat 5 turnBy: 5 is 
same as turnBy: 25. Understanding angular magnitudes seems to take more 
'cooking' time than that for linear magnitudes. Is it because one has to run 
one's eye over 'empty space' to gage angles? I don't know.

When placing elements along a circle, it is easier to use repeat tile than to 
dup individual tiles.

    self heading: 0.
    12 timesRepeat: [ self dosomething. self turnBy: 30 ].
or
   self heading:  0.
   60 timesRepeat: [ self dosomething. self turnBy: 6 ].

(Sorry for delayed response. It is summer vacation time for my kids).

Subbu