Hi Bert --
That is a very good point! I'd forgotten that embedding makes an object live in the coordinate system of its owner -- and that is what it is supposed to do. However, it's clear from this and other examples that I can think of that this perhaps should be the default, but it might be a good idea to put a flag on a player to "use the coordinate system that its owner uses".
Let me think about this over the weekend ...
Cheers,
Alan
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At 1:40 PM +0200 4/19/03, Bert Freudenberg wrote:
Am Freitag, 18.04.03 um 22:51 Uhr schrieb Alan Kay:
Hi Phil --
At 5:38 PM -0400 4/17/03, Phil Firsenbaum wrote:
Interesting...I actually saw this message on the Squeak archive. i didn't receive it on the mailing list, though.
Anyhow, even if the pen were down and the pendulum simulated reality i think it would draw lines on top of lines unless the area under the pen was scrolling. Do you see what I mean?
Well, here's a little exercise in relativized thinking ...
Embed a round little object like an ellipse to be the bob of the pendulum, call it "bob". Make another little object called "plotter", put its pen down. See what happens when you do:
plotter's y increase by 1 plotter's x <- bob's x
"Relativized thinking" is fine, but the implementation is itself relative, so this does not work.
After embedding, the bob lives in the coordinate system of its parent, the pendulum. Rotating the pendulum does nothing to the bob
- just look at its geometry category, it's static. I then tried
using a PolygonMorph as pendulum because it does not use a TransformMorph, but then, the transform of the embedded bob goes wild (try it).
The latter behavior looks like a bug, while the former is probably supposed to behave like this. We would have to introduce a "global" or "absolute" position to make this work.
-- Bert
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