geometry-challenged

[Thomas Bähler]

Hi Richard


> I can draw a line object from the loc of one object to the loc of 
> another.
> But if I want to draw only in the space _between_ objects rather than
> intersect them, how do I get the points for the location where a line 
> object
> would meet the edge of the other objects if drawn all the way to their
> centers, as indicated by the "X"s below:

There might be a more ellegant solution to your problem but the one 
below works.
It calculates a list of the rounded locations of every pixel of the 
connecting line,
and checks then the first points of each end that are not within the 
buttons.

Cheers
Thomas


on mouseUp
   put the loc of button "Button 1" into LStart
   put the loc of button "Button 2" into LStop
   put (item 1 of LStop) - (item 1 of LStart) into DistX
   put (item 2 of LStop) - (item 2 of LStart) into DistY
   put round((DistX^2+DistY^2)^0.5) into LLength
   put DistX/LLength into XStep
   put DistY/LLength into YStep

   put 0 into i
   put empty into PList -- calculated pixel of the whole line
   repeat LLength times
     put i + 1 into i
     put (item 1 of LStart) + round(XStep*i) & comma & (item 2 of 
LStart) + round(YStep*i) & return after PList
   end repeat
   delete last char of PList

   --search the first Border-Point
   repeat with i = 1 to the number of lines of PList
     if within(button "Button 1",line i of PList) then
       next repeat
     else
       put line i of PList into LStart
       exit repeat
     end if
   end repeat

   --search the second Border-Point
   repeat with i = (the number of lines of PList) down to 1
     if within(button "Button 2",line i of PList) then
       next repeat
     else
       put line i of PList into LStop
       exit repeat
     end if
   end repeat

   put LStart & comma & LStop into Punkte
   set the points of graphic "ConnectingLine" to Punkte
end mouseUp