[Newbies] The bouncing sound
madevu at pacbell.net
Thu Feb 21 07:53:07 UTC 2008
What you're hearing is not a sound associated with the "bounce" but
rather a sound associated with an object hitting the "fence".
The "fence" is a feature that makes a "forward" command which would
take an object beyond the edge of its container result in the the
object's jiggling back into the field of view, accompanied by a
special "fence" sound. The intent is to reduce the incidence of
"runaways" when beginners write scripts using "forward" which rapidly
take an object beyond an edge of its container, thus making it
When using "bounce", it's advisable to *disable* the "fence", because
the interactions between the logic of the two features can produce
Use the world's "playfield options" menu to disable the fence.
However, without the fence, in your student's example, there seem to
be situations in which the the paddle overshoots the boundary and
disappears. I think you could eliminate these situations by slightly
reducing the factor used in the paddle's script1.
In the olpc/etoys image, there's an added preference that suppresses
the fence *sound*, thus allowing the fence feature to be used to keep
an object within its container's bounds but without the annoyance of
hearing the "fence" sound. But this is not in 3.9.
These two features -- a container's "fence" feature and the ability
for a moving object to request "bounce" -- have always, unhappily,
been somewhat in conflict. For the "next" system we expect to have a
much more harmonious and consistent and understandable way of offering
BTW, unless you have a compelling reason to be using 3.9, and
particularly if tile-scripting is the main focus of your class I
suggest that you have your students use a Squeakland image rather than
a 3.9 or 3.10, simply because extensive enhancements, fixes, and
documentation for tile-scripting ("etoys") are available in the
Squeakland images. But if you do decide to switch, it's probably best
to wait a short while until the "new Squeakland image" gets released.
This will be based on the OLPC-etoys image, which is the system in
which all the advances in etoys have been made over the past 18 months
-- hundreds of bug-fixes, feature-enhancements, performance
improvement, example projects, tutorials, and other documentation,
plus a large user community.
On Feb 20, 2008, at 8:29 PM, polishookm wrote:
> Here's a project file that demonstrates the problem. I'm working in
> the most recent ver. of Squeak from www.squeak.org (just downloaded
> a few days ago) .... 3.9-final-7067
> When I activate the script with the object controlled by a joystick,
> the first few times it hits the top of the world and it's silent -
> all is well. But at some point, after 3 or 4 or 5 collisions, it's
> no longer silent.
> All help much appreciated and thanks very much in advance for
> looking at the project (made by a student in the class I'm teaching).
> Scott Wallace wrote:
>> Hi, polishookm,
>> I cannot reproduce the phenomenon you describe in any image I have
>> close to hand -- not in Squeak 3.9, not in Squeakland3.8-05, and
>> not in the OLPC etoys image. (Can anyone else?)
>> What version of Squeak are you using? If it's 3.10, I'll leave it
>> for other 3.10 users to track this down, since I don't have a copy
>> of 3.10 handy.
>> Otherwise, perhaps you could email me a copy of a project of yours
>> which exhibits this symptom...
>> -- Scott
>> On Feb 20, 2008, at 6:38 PM, polishookm wrote:
>>> I"m finding that with
>>> [Rectangle forward by 5]
>>> [Rectangle bounce silence]
>>> the rectangle eventually collides with the top of the world and
>>> bounces off in the opposite direction - with no sound ... the
>>> bounce is silent.
>>> However, this script
>>> [Rectangle forward by JoyStick's upDown * 8]
>>> [Rectangle bounce silence]
>>> doesn't allow the Rectangle bounce silently off the edge of the
>>> world. In this case, when the rectangle reaches the top of the
>>> world, it makes a bouncing sound. The exact sound can be selected
>>> in the [Rectangle bounce silence] tile. But selecting 'silence' as
>>> the sound doesn't seem to work.
>>> Am I missing something obvious? Shouldn't it be possible to
>>> silence the bounce?
>>> Beginners mailing list
>>> Beginners at lists.squeakfoundation.org
> Mark Polishook, D.M.A.
> Technology Coordinator
> Morehead Hall, Rm 132
> Center for Academic Advising and Adult Learning
> Montclair State University
> Montclair, NJ 07043
> polishookm at mail.montclair.edu
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