heading = forwardDirection + rotationDegrees (was Re: How can we deal with Message rot?)

Milan Zimmermann milan.zimmermann at sympatico.ca
Tue Jan 2 14:33:04 UTC 2007

On 2006 December 29 01:27, Jerome Peace wrote:
> Many of the deep bugs I run into have the
> TransformationMorph decorator as their root.
> Lots of the gribble leaving problems come from a
> mismatch of assumptions between TfMorph ( which
> believes you can translate the origin into the 3rd
> quadrant) while every body else believes that truncate
> is the same as floor  because all points are in the
> 1st quadrant. Clipping boxes get calculated wrong and
> are often of by one just when you need them not to be.


Could you point out a few concrete examples (class, method) of this behaviour? 
I started work on a (exteremely limited) set of tests for etoys and morphic, 
and perhaps it would make sense to document what you found in a test; 
although documenting something that is (if I understand) considered broken 
may not be as valuable,  it should be easy to convert the test code if/once 
the code under test is refactored.

Thanks Milan

> Results: screen gribbles abound.
> >- inEtoys they are not used directly, but through the
> Player, and this is
> >why your equation does not hold for each individual
> morph. I think
> >you would have to eliminate TransformMorph
> completely, which might
> >complicate other Morphs - until now, that "ugly"
> transformation stuff
> >was factored out.
> As I look at the code I see constant attempts to worry
> about which morph is actually being talked to renderer
> or renderee. The code practically begs to be
> refactored. Its just a big job at the moment.
> I await enlightenment and inspiration. Meanwhile I am
> trying refactorings that lay the ground work for the
> simplification of the Tf mess.
> Yours in service, --Jerome Peace
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