[etoys-dev] Etoys: Etoys-kfr.95.mcz

karl ramberg karlramberg at gmail.com
Wed Oct 26 05:03:38 EDT 2011

> On Tue, Oct 25, 2011 at 1:03 PM, Derek O'Connell <doc at doconnel.f9.co.uk> wrote:
>> On 25/10/11 11:26, Bert Freudenberg wrote:
>>>  On 24.10.2011, at 23:00, karl ramberg wrote:
>>> > Yes, these could be in SketchMorph instead.
>>>  That's not the point. I am concerned with the behavior, not where
>>>  it's implemented (although doing it in the morph would be the Right
>>>  Thing).
>>>  When we introduce new behavior we make a promise that if users use
>>>  that behavior, it will continue to work. Older projects should work
>>>  in newer Etoys versions. So we need to get the basic behavior of a
>>>  new tile right from the beginning. (if we wanted to allow experiments
>>>  with your code we could hide the new tiles from normal users - e.g.,
>>>  there already are tile categories you only see by enabling some
>>>  preference)
The Etoys category code is hard to read :-( I'm not really sure how to
extend and enable more categories using the preferences. I have tested
a little but have not found a solution yet.
>>>  The behavior you introduce with these tiles is inferior to the
>>>  Scratch model. It's procedural. It applies e.g. a hue shift but there
>>>  is no way to read back the current hue shift. If you want a blurred,
>>>  hue shifted sketch you would have to have a script that does "restore
>>>  base graphic", "shift hue", "apply blur". If you want to change the
>>>  blur value interactively, this script would have to be ticking all
>>>  the time, which is hugely inefficient.
>>>  With the properties I was proposing, there simply would be some new
>>>  slots in the viewer for hueShift, blurAmount, etc. Changing the blur
>>>  amount in the viewer would immediately update the Sketch. No script
>>>  needed. Setting it back to 0 would reveal the original unblurred
>>>  image (and performance would be back to normal and the property would
>>>  be removed). This would be like playing with the heading - as soon as
>>>  you change the number in the viewer, the object on screen changes.
>>>  This is a bit like rolling Derek's ScratchEffectsMorph directly into
>>>  SketchMorph. But it would be a lot simpler, there would be no new
>>>  instance variables, etc.
>>>  *If* we were going to add a "special effects morph" then it should be
>>>  general. You could drop any morph into it (be it a sketch or
>>>  rectangle or camera) and it would apply some effects. Similarly to
>>>  ScreeningMorph.
In Scratch you have the sprite morph do the drawing so switching out
the form is a little easier and cleaner.
Player is not involved in drawing so it's a little trickier in Etoys.
A ScreeningMorph could work.


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