Run Rev's within() function--Was: Problem with mask

[James Hurley]

Wilhelm,

I think the following script, placed in the card of a new stack,  
gives the clearest idea of what the problem is. As you mouse around   
the graphic you can see the mouse corrdinates as well as the results  
of the user-defined within function and Run Rev's within() function.

You can easily see precisely how the Run Rev within() function works.  
It definitely excludes the right and bottom edges of a square, but  
includes the top and left edges. Whatever happens when using the  
within() funciton to construct a mask (or for whatever purpose) has  
to be reconciled to these basic results.

Jim Hurley



local myname, X0, Y0

on mouseDown
   if there is not grc "myTest" then
     create grc "myTest"
     set the style of grc "myTest" to rect
     set the opaque of grc "myTest" to true
     set the width of grc "myTest" to 100
     set the height of grc "myTest" to 100
     set the loc of grc "myTest" to 50,50
   end if
   put the name of the target into myName
   put the topleft of myName into tXY
   put item 1 of tXY into X0
   put item 2 of tXY into Y0
end mouseDOwn

on mouseUP
   put "" into myName
end mouseUP

on mouseMove u,v
   if myName is "" or the number of graphics = 0 then exit mouseMove
   put u,v into tPt

   --Get displacement from upper left corner
   put u - x0 into dx
   put v - y0 into dy

--User defined "within" function
   if  dx  > -1 and  dx < 101 and dy > -1  and  dy < 101 then
     put true into myWithin
   else
     put false into myWithin
   end if

--Built-in within() function
   if within(myName, tPt) then
     put true  into runRevWithin
   else
     put false into runRevWithin
   end if

   put u,v & cr & "myWIthin is " & myWithin & cr & "RR within is " &  
runRevWIthin into msg box
end mouseMove