At 10:39 06.01.2005 -0600, Daniel Nelson wrote:
But calls to native Director methods (imaging Lingo calls, for instance) are machine compiled code, so those run full-speed.
true, and while I never benchmarked it, I always felt that lists are a particular strength of lingo.
Comparisons like this are interesting, but they don't necessarily mean that much.
(longish example follows)
Some months ago I had a particle simulation of the "n-hundred bouncing balls in a square" type. There were reference implementations of the same thing done in java and VB, which both looked awful but performed reasonably fast. The VB-example (which I had in sources) went the number crunching way:
(lingoid pseudo code)
on animationStep
repeat with ballNo = 1 to ballAmount
moveThisBall(ballNo)
repeat with otherballNo = 1 to ballAmount
if otherBallNo = ballNo then
next repeat
else
testForCollision(ballNo,otherBallNo)
end if
end repeat
end repeat
endMy (lazy) attempts to just translate the VB to lingo effectively failed since lingo was dead slow when ballAmount had more than 2 digits.
Thus I decided to use Lingo's strength (lists). I introduced two _sorted_ property lists which keep the LocH / LocV of all the BallSprites in the form
[ballNo:Loc, ... ]
There are methods to update the LocH / LocV value related to some ballNo in those lists and there is a method to return a number of neighboring entries from each of those sorted lists.
(pseudo code)
on animateThisBallStep me me.moveThisBall()
UpdatePropertyListOfHorizontalPositions( me.ballNo, mySprite.locH ) UpdatePropertyListOfVerticalPositions( me.ballNo, mySprite.locV )
LH = getListOfHorizontalNeighbours( me.ballNo, Resolution ) LV = getListOfVerticalNeighbours( me.ballNo, Resolution ) LBallsCloseToMe = getThoseInBothLists( LH,LV )
repeat with otherBallNo in LBallsCloseToMe
me.testForCollision(ballNo,otherBallNo)
end repeat
endThus, Lingo's sorting does the major part of the collision detection and the repeat loop typically goes over a sinle digit number of entries ( instead of m*10^4 entries).
The difference of performance was dramatic and the customer insisted to introduce a new parameter "temperature" in order to slow down the animation...
daniel
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