What is the extent of a truncated rectangle? (reply to milan from heading = forwardDir... thread)

Milan Zimmermann milan.zimmermann at sympatico.ca
Fri Jan 5 03:06:17 UTC 2007


Hi Jerome,

Thanks for the details and Mantis links. I just took a look so far, and 
hopefuly spend more time on it  when I get back the week after next.

Milan
On 2007 January 2 22:14, Jerome Peace wrote:
> What is the extent of a truncated rectangle? (from
> heading = forwardDir... thread)
> was
>  heading = forwardDirection + rotationDegrees (was Re:
> How can we deal with Message rot?)
>
> Hi Milan,
>
> Thanks for your interest in this issue.
>
> Look at:
> http://bugs.impara.de/view.php?id=2453
> 0002453: [Bugs] What is the extent of a truncated
> rectangle?
>
> and for a specific example
>
> http://bugs.impara.de/view.php?id=2709
> 0002709: Sample instances have their leftmost row of
> pixels clipped off.
>
> The latter has a fix for the polygon curve morph
> sample instance.
> Which included extending ceiling and floor to the
> Point and Rectangle classes.
>
> I confess I was lazy and snuck these methods into the
> morphic package instead of negotiating with Andreas
> and getting the truncation and roundoff methods
> adopted into the graphic package. That still needs to
> be done.
>
> The current formalities of modularization are easier
> to work around that work with.
>
> I've been coming across varients of this bug since Oct
> 2004. (Mantis #0000360)
>
> There are numerous reports on mantis that touch on
> this.
>
> also search for reports with "render" or
> for reports with "drama" (as in dramatic
> demonstration)
> for reports with "transf" (as in transform)
>
> or reports from "wiz" many of my reports deal with
> these kind of things.
>
> HTH.
>
>
> Yours in service, --Jerome Peace
>
> Previous message:
> >Milan Zimmermann milan.zimmermann at sympatico.ca
> >Tue Jan 2 14:33:04 UTC 2007 wrote:
> >
> >On 2006 December 29 01:27, Jerome Peace wrote:
> ><<snip>>
> >
> >> 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.
>
> >Jerome,
> >
> >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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