basic sprite AI in director problems

[leearach2004]

Hi there i am new to director programing but understand the basics of lingo. I am creating a simple childs game that has one character that needs to collect objects by moving around a 2d screen that had walls in certain places. This works fine as does the wall hit test.

But i also want another charcter that will move all around the screen that you have to avoid. I put together the following code from some examples for the enemy charcter, it works kinda by changing direction when a wall is hit but it this also means that it does not walk around the whole screen somtimes it does other times just goes in a circle.

global movemalc, malcdir

-- exit frame event handler
on exitFrame me
  -- if left key pressed
  if (movemalc = 1) then
    -- set sprite to left direction member
    sprite(26).member = "malcleft"
    -- set sprite's width and height
    sprite(26).width = 25
    sprite(26).height = 25
    -- set malc direction to l
    malcdir ="l"
    -- set move function
    movem(me,-5,0)
    
    --if right key pressed
  else if (movemalc = 2) then
    -- set sprite to right direction member
    sprite(26).member = "malcright"
    -- set sprite's width and height
    sprite(26).width = 25
    sprite(26).height = 25
    -- set malc direction to r
    malcdir ="r"
    -- set move function
    movem(me,5,0)
    
    -- if down key pressed
  else if (movemalc = 3) then
    -- set sprite to down direction member
    sprite(26).member = "malcdown"
    -- set sprite's width and height
    sprite(26).width = 25
    sprite(26).height = 25
    -- set malc direction to b
    malcdir ="b"
    -- set move function
    movem(me,0,5)
    
    -- if up key pressed
  else if (movemalc = 4) then
    -- set sprite to top direction member
    sprite(26).member = "malctop"
    -- set sprite's width and height
    sprite(26).width = 25
    sprite(26).height = 25
    -- set malc direction to t
    malcdir ="t"
    -- set move function
    movem(me,0,-5)
  end if
  
end

-- move function
on movem me, dx, dy
  
  -- get this sprite rect and add change to it
  oldRect = sprite(me.spriteNum).rect
  newRect = oldRect + rect(dx,dy,dx,dy)
  
  --set hitWall to false
  hitWall = FALSE
  
  -- loop through wall sprites 2 to 22 and detect collisions
  repeat with i = 2 to 21
    -- if sprite returns hitwall = true
    if sendSprite(i,#hitWall,newRect) then
      -- set hitwall to true
      hitWall = TRUE
      moved
      -- exit repet statment
      exit repeat
    end if
    -- end repeat statment
  end repeat
  
  -- if no collision, then move sprite
  if not hitWall then
    -- set sprite location to dx dy co-ordinates
    sprite(me.spriteNum).loc = sprite(me.spriteNum).loc + point(dx,dy)
  end if
end

-- move malc function
on moved
  
  -- check previous direction
  if(malcdir = "l") then
    movemalc =  4
  else if(malcdir = "r") then
    movemalc = 1
  else if(malcdir = "t") then
    movemalc = 2
  else if(malcdir = "b") then
    movemalc = 3
  end if
end

anyone know any simple ai tutrials or can sugest where i am going wrong would be great

thanks in advance to all

lee

 

[kennethkawamoto]

I suppose you'll need to introduce some randomness into your enemy character's movement. Perhaps something like change its course to random direction at random intervals?

Kenneth Kawamoto

http://www.materiaprima.co.uk