Scratch

If you want to write a tower defense game where the little bad guys always walk toward the goal following the shortest path, read this:

http://www.policyalmanac.org/games/aStarTutorial.htm

It is just about the simplest tutorial on the A* algorithm I could find.

Last edited by BoltBait (2010-12-01 20:00:49)

Here is an example http://scratch.mit.edu/projects/08jackt/1502037

Last edited by MoreGamesNow (2011-01-02 20:17:52)

If you want to make a tower defence game, to be able to buy towers, you have to have the following script on your buy turrent butten:
<when[ Buy basic turrent ]clicked>
<if> << <( {money}> 99  )> <and> <(  { Basic towers }< 4  )> >
<go back( 1 )layers>
<change{ Basic turrents }by(1)
<change{ money }by(-100)
<broadcast[ Placing #]
  And for your turrent:
#1
<when green flag clicked>
<hide>
<set size to( 30 )%>
#2
<when I receive[ Placing #]
<if><(  { Basic turrents }= 1 )>
<go to front>
<show>
<repeat until> <<  <not>  <touching[ Basic tower 2(or you could do the tower's color)}>>
<if><<  <not> <touching[Basic tower 2(or tower's color)]>
<set[ brightness ]effect to( 0%)
<else>
<set[ brightness ]effect to( -40%)]
<point in direction( 0 )
<forever>
<if><(  { Basic turrents }> 0 )>
<if><( <distance to[ Enemy 1] < 50  )>
<go to front>
<switch to costume[ 2 }
<point towards( Enemy 1)
<change{ Enemy health 1 }by( 10 )
<wait( 1 )second>
<point towards( Enemy 1)
<switch to costume[ 1 ]
<wait( 1 )secsc>
I hope that this helps!
Also, if you want to look at the other scripts in a tower defence game, download Teddy bear tower defence or Teddy bear tower defence #2. The only way you will be able to find it is by searching for ErnieParke and clicking on ErnieParke's stuff.

Sorry about the messed up script.

sebby384 wrote:

How do you get it so that the towers snap into place for example, on ' the biggest tower defense game on scrtch' . How does it work?

<when[ Tower ]clicked>
<repeat until><<  <not> <mouse down?> >>
<go to[ Mouse Pointer ]>
<end>
<set{ X }to( <round( (( <x position> </> <{ width/height of invisible grid }> )) )>
<set{ Y }to( <round( (( <y position> </> <{ width/height of invisible grid }> )) )>
<go to x   (( <{ X }> <*> <{ width/height of invisible grid }> )) )y   (( <{ X }> <*> <{ width/height of invisible grid }> ))

You may have to adjust this with some addition and subtraction