RE: FLASH: Trouble centering a scaled movie clip

[Matthijs Koevoets]

hi there kevin,


had the same problem some time ago

my solution doesn't require heavy maths but is rather course i suppose

here we go

first i set some variables, they are hard coded boundaries

if the draggable object (the map in your example) has not been scaled then

these are the boundaries within which it is allowed to move.


in my example the map and mask are centered on stage

the width and height of the map would be: 420 (positioned at: top -140,

left -140)

the width and height of the mask: 140

the width and height of the movie: 140


which leaves me with these boundaries:


Set Variable: "maxRight" = "210"

Set Variable: "maxLeft" = "-70"

Set Variable: "maxBottom" = "210"

Set Variable: "maxTop" = "-70"

Set Variable: "startW" = "420"


now i start a loop:

this to get the current width of the map:

	Set Variable: "w" = getProperty("../theMap",_width)

next i want to see what the difference is between the original width of the

map and the current width

and divide that by two to get a number that holds the change in position

	Set Variable: "shift" = (w - startW) / 2

let me explain

suppose the current width is 430

we know the original width was 420

that leaves us with a difference of 10

which means (since the map is scaling from the center) that 5 pixels have

been added to the left and right

the map will have moved 5 pixels to the left and top

these pixels will need to be added to(/subtracted from) the boundaries: the

map is allowed to move five pixels further than before


next i set two variables to hold the current x and y positions of the map:

	Set Variable: "X" = getProperty("../theMap",_x)

	Set Variable: "Y" = getProperty("../theMap",_y)

and here finally i start comparing the x and y positions to the updated

boundaries

if the map crosses a boundary it is returned to that boundary:

	If (X < maxLeft - shift)

      	Set Property ("../theMap", X Position) = maxLeft - shift

	End If

	If (X > maxRight + shift)

	      Set Property ("../theMap", X Position) = maxRight + shift

	End If

	If (Y> maxBottom + shift)

	      Set Property ("../theMap", Y Position) = maxBottom + shift

	End If

	If (Y < maxTop - shift)

	      Set Property ("../theMap", Y Position) = maxTop - shift

	End If

that's it, keep this looping and you're OK

hope it's all clear. if not, don't hesitate to ask

good luck and happy new year to you and the other flashers


matt



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