Hi, Chris:

>I seem to have found a bug in Rectangle.  In the method 
>
>containsPoint: aPoint 
>	       "Answer whether aPoint is within the receiver."
>	       ^origin <= aPoint and: [aPoint < corner]
>                                             ^^^
>
>the second comparison is a "<".  I think it should be a "<=" instead.

I think the definition as it exists is correct (or at least internally 
correct and consistent as used in Squeak).  It's not explicitly stated 
anywhere, but a Rectangle consists of the set of points bounded by its 
origin and its corner, up to but not including the points on the corner's 
edges (right and bottom edges).

This is because rectangles are frequently tiled, and if the exclusion 
didn't exist, there would be certain points that would be members of 
ajoining Rectangles, instead of belonging solely to one or the other.  
However, exclusion is fundamental to things like mouse hit detection, 
view layout, etc.

Think of it this way:  if you are told to paint a rectangle on a tiled 
floor, starting in the corner (corner: 0 at 0) and going for one tile's 
length in both directions (extent: 1 at 1), you would end up with a single 
tile painted, and would respond "no" to the question of whether the tile 
at 1 at 1 was painted.



     -- tim