[Newbies] Re: PolygonMorph intersection

[Jerome Peace]

PolygonMorph intersection


Hi Sudheendra Hangal,

You have actually found a very good bug. 

In investigating I found that the method for Polygon
did not exist in 3.8.

The author of the version in 3.9 is

nk 4/27/2003 16:15 PolygonMorph intersects: {geometry}

nk is Ned Konz who created the connector package.

In building the 3.9 release the release team added
pieces of the the Connectors package.
And while they did as best they could they missed a
piece.

The PolygonMorph>>intersects: methods calls  super
intersects: . None of the classes above PolygonMorph
defines the intersects: method. Thus the error
message.

Simply finding the bug make you a winner in what I
call the Game of Mantis.

see:
http://wiki.squeak.org/squeak/5915
Game of Mantis

The best place for this info would be to start a
Mantis report. 
(You can get a mantis acct freely and easily). 

A good place to start is:

http://bugs.squeak.org/my_view_page.php

Mantis provides a patient persistent way to focus on
an issue.
I use it to accumulate data on a problem until a
solution can be found.
It provides a place to: 

*	alert the community to a problem; 
*	accumulate facts and clues from the analysis; 
*	publish preposed solutions and get feedback; 
*	get solutions harvested and included into the main
stream. 

The above is from:
http://wiki.squeak.org/squeak/5912
Mantis FAQ and Tips

Again thanks for your sharp eyes and easy to follow
recipe for the bug.

Yours in curiosity and service, --Jerome Peace


***
>  
>  
>  
>  [Newbies] Fwd: PolygonMorph intersection
>  Sudheendra Hangal hangal at cs.stanford.edu 
>  Wed May 2 11:06:56 UTC 2007 
>  
>  Hello,
>  I am using Squeak-3.9-final-7067.image on win-xp.
>  
>  I create a polygon using:
>  p := PolygonMorph new.
>  p vertices: {0 at 0. 0 at 200. 200 at 200} color:
Color
>  black borderWidth: 2
>  borderColor: Color green.
>  
>  My original goal is to check if a line segment L is
>  completely contained
>  within this polygon p. Since the System browser
shows
>  that PolygonMorph has
>  an intersects: aRectangle message, I thought I
would
>  create a rectangle with
>  the original and corner as the end points of L and
use
>  it to query
>  intersects.
>  
>  However any attempt to use the intersects:
aRectangle
>  method in
>  PolygonMorph, e.g.
>  
>  r := Rectangle new.
>  r setOrigin: 150 at 0 corner: 175 at 25.
>  p intersects: r
>  returns a message not understood.
>  
>  Am I doing something fundamentally wrong ?
>  
>  I can probably work around, but I would like to
know
>  why a method documented
>  in
>  the system browser does not work as expected.
>  thanks,
>  
>  sgh
***


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