This is accurate...not sure about the speed but can't optimise it more as
I'm in the pub at the moment...
put the stuff below in a movie script and call getNearest with your point
list and mouseLoc
Make sure to check that the return value (pNearest) is not 0 (zero)
Like:
nearestPoint = getNearest(pointList,the mouseLoc)
Code below
--------------------------------------------------------------------
-- pList is the list of all points
-- pCenter is the reference center (e.g. mouseLoc)
on getNearest pList,pCenter
pCount = pList.count
if pCount > 0 then -- check it's not an empty list
pNearest = 0
repeat with y = 1 to pCount
pDistance = pythagora2Points(pList[y],pCenter)
if pDistance > pNearest then
pNearest = y
end if
end repeat
return pNearest -- the position in the list..i.e. your pixel position in
the list
end if
end
-- does the Pythagora's avoiding zero values
on pythagora2Points point1,point2
x=point1[1]
y=point1[2]
a=point2[1]
b=point2[2]
if point1=point2 then
return 0
end if
if a=x and b>y then
return (b-y)
end if
if a=x and b<y then
return (y-b)
end if
if b=y and a>x then
return (a-x)
end if
if b=y and a<x then
return (x-a)
end if
if a<>x and b<>y then
c = sqrt(power((a-x),2) + power((b-y),2))
return c
end if
end
--------------------------------------
Good luck
-----Original Message-----
From: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED] On Behalf Of Tim Welford
Sent: 11 April 2006 19:26
To: Lingo programming discussion list
Subject: <lingo-l> Finding the closest point from a list of points in lingo
Hi Guys,
I'm hoping someone can help me out with a quick pointer, I've got a tight
deadline and my minds gone a bit blank.
I have a list of points....
[point(112,456), point(12,485), ...] list goes to about 50
These are actually co-ordinates of certain pixels on my stage.
I need to find the closest one (radius) to any given point - i.e. the
mouseLoc - it needs to be fairly efficient as I will need to do it every
frame \ couple of frames.
Can someone point me in the right direction please.
Many thanks
Tim
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