Array of Type

Blitz3D Forums/Blitz3D Programming/Array of Type

Banshee

(Posted 2005) [#1]

This is a confusing subject for me, and i'm sure it has already been asnwered somewhere but here goes...

I have written a pathfinding routine for my Paradise Island game which creates a path in the following datatype

type AIpath
field x,z
end Type

This works fine except I want to have multiple units in the game all recording their own path, so I dimensioned a pointer for the datatype

dim path(unitQty).AIpath

The problem is that path().AIpath stores a pointer to the entire AIpath stack, rather than creating individual stacks for each unit.

Is there a way to dimension the data type itself? ie:

type AIpath(unitQty)
field x,z
end type

Rhyolite

(Posted 2005) [#2]

Dim Path(num).AIpath

Path(1) = New AIpath
Path(1)\X = 12

You should then always be able to refernece unit (1) by using

X = Path(1)\X

Does that help?

Rhy :)

Stevie G

(Posted 2005) [#3]

The above should be .. Dim Path.AIpath( num )

Stevie

Banshee

(Posted 2005) [#4]

When I try that Stevie G I need to find the syntax that works for commands like this:

path.aiPath(id)=Last aiPath(id)

If I do

path.aiPath(id)=last aiPath

then surely i'm getting the last aiPath in memory arn't I? Which probably isn't the last path entry for the specific unit i'm seeking.

big10p

(Posted 2005) [#5]

Blitz doesn't natively let you create separate lists of the same type - I believe BMax does, though. However, this is easily solved by implementing your own separate linked lists of types.

Given your example, you would first need to expand the aiPath type:

Type aiPath
  Field x,y
  Field link.aiPath
End Type

Now create an array to hold the pointers to each individual linked list:

Dim path.aiPath(unitQty)

Now, create a new instance and add it to 'player1' linked list:

point.aiPath = New aiPath
point\x = blah
point\y = blah
point\link = path(player1)
path(player1) = point

To iterate through player1's entire path:

point.aiPath = path(player1)
While point <> Null
  ; Do stuff with this point here.

  ; Get next point in linked list.
  point = point\link
Wend

Well, that's the basic idea, anyway. :)

Also, have a look at my post in this thread for a similar method except it implements the working of an actual stack:
http://www.blitzbasic.com/Community/posts.php?topic=48442#539401

Banshee

(Posted 2005) [#6]

Thank you, it's as I feared :(

My implementation may allow me to use coded breaks which should be a bit faster in runtime but before I try to get that working i'm going to have a look at the pathfinding algorythm, if I can make it store less waypoints for each path I may just set up a small array for each unit.