[MWForum]re: HELP on rotating turtles and shapes

[mwforum@lists.mathcats.com]

FRI AUG 30th

Hi Wendy, Many, many thanks for your suggestions - I'm looking forward to
incorporating them into my work with my students ( there goes the weekend as
I practise the ideas!!)- 
 Graham Williams
-----Original Message-----
From: Wendy Petti [mailto:wpetti@mathcats.com]
Sent: Friday, 30 August 2002 8:24
To: mwforum@lists.mathcats.com
Subject: [MWForum]re: HELP on rotating turtles and shapes


Turtles can rotate; the shapes they are wearing cannot.  A shape will always
be in a fixed orientation.  MWPro has no advantage over MW 2.0_ in this
regard.  (We can save the MWPro vs MW 2.0_ discussion for another message.)
However, you can create the illusion of rotating shapes.  Do you really need
degree-by-degree rotation? You've already received some helpful advice but
here is how I handled it when I created a project in which one can rotate
pattern blocks by clicking on them (a very similar situation to the one you
describe):

1) As Harvey suggested, I created a set of shapes for each piece.  However,
I did not use the MWPro shapes editor; I was using MW 2.0_ at the time.
Instead, I instructed the turtle to turn and redraw the original shape at
each needed angle, then colored and copied and pasted each of these rotated
shapes into the shapes center, closely cropping each shape.
	One pattern block shape, the trapezoid, required 12 shapes to be
able to fit properly with all other shapes; I rotated the turtle 30 degrees
between drawing each shape.  The diamond and crystal required 6 shapes
(drawn after rotating 60 degrees).  The triangle required 4 shapes (drawn
after rotating 90 degrees).  The hexagon required 2 shapes (drawn after
rotating 30 degrees).  The square required 3 shapes (drawn after rotating 30
degrees).  (Note:  the square of course does not need to be rotated in order
to tessellate with just itself but it needs different angles in order to
nestle up against any side of the other pattern block pieces.)

2) I've created different solutions for getting each turtle to change to the
next rotation of its shape with each mouse click.  The less elegant
solution, but which is easier for newbies to understand, is to write a
procedure for each turtle/puzzle-piece, then set the turtle's instruction to
that procedure name.  As an example, here is my procedure for turning the
"crystal" turtle by having it put on, one click at a time, shapes 13 - 18:

to turn.crystal
if shape > 17 [ht setsh 12]
setsh shape + 1 st
end

(I temporarily hid the turtle because otherwise in changing from shape 18 to
shape 13 it momentarily flashed shape 12, the last trapezoid shape.)

The more elegant solution involves using "turtlesown," but that's another
message!

You can see this pattern blocks project in action here:

http://www.mathcats.com/microworlds/patternblocks.html

Of course, using the project offline is more satisfying because then you can
select and copy a stamped cluster of shapes and paste it over and over
again.  It is possible in this way to fill a page with a tessellating
pattern in a minute or two.

After visiting the page, the pattern blocks project will be cached in your
Temporary Internet Files, if you want to move it into another folder and
look at the shapes and full set of procedures.

Wendy Petti
Math Cats
http://www.mathcats.com
MicroWorlds in Action
http://mia.openworldlearning.org


> In order to tessellate the  plane [ the Mw page
> > ]the students should, ideally, be able to rotate each tile 
> by clicking on it
> > [ ie.e., by clicking on the turtle-wearing-the-tile ] so 
> that they can
> > rotate it degree by degree if necessary in order to make 
> the tessellation
> > work. However, this is where I'm 'stuck' - I don't know how 
> to make the
> > turtle-as-a-tile rotate by clicking on it ! This of course 
> is not an issue
> > if the turtle is 'wearing' say a  square tessellation-tile 
> because it does
> > not have to be rotated in order to tessellate. [IS THIS 
> MAKING SENSE ??]
> Can anyone help please?
> > 
> >   We are currently using Microworlds v 2.03 and I'm 
> wondering if the issue I
> > mention above would be non-issue if we were using 
> Microworlds Pro.  That is
> > to say, would I be able to programme the turtle/tiles to 
> rotate without any
> > problems if we were working in the MwPro environment. Is 
> this the case?
> > 
> >   In several weeks our school will be moving from Win 98  
> to Win XP and I'm
> > also wondering if we should at the same time move on'up to 
> MW Pro? Does anyone have any thoughts on this? 
> > 
> > Graham Williams
> > 
> 
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