variable has no value :(

[Clayton]

hey, im working on a game right now and ive come upon a little "snag", you see whenever my game calls the DrawLine procedure from within the Ball module, the Draw.ThickLine command is highlighted and the error "variable has no value" occurs, anybody have any idea why this might be? (i think it might be the array being passed to the procedure..but i dont see what that has to do with it) any help would be appreciated

Turing:

module Ball     export Initialize, Move     View.Set ("offscreenonly,graphics:max;max")     type line :         record             x, y : int             flag : boolean         end record     proc DrawLine (lineArray : array 1 .. * of line)         for x : 1 .. upper (lineArray)             %error here "variable has no value"             Draw.ThickLine (lineArray (x).x - 25, lineArray (x).y - 25, lineArray (x).x + 25, lineArray (x).y + 25, 3, black)         end for     end DrawLine     const lengtH : int := 25     const radius : int := 10     const thickness : int := 3     var x, y, xx, yy, b : int     var xVel, yVel : int := 1     var LineArray : flexible array 1 .. 1 of line     proc Initialize (xVal, yVal : int)         x := xVal         y := yVal     end Initialize     proc CheckCollision         if View.WhatDotColor (x + radius, y) = black then             xVel *= -1         elsif View.WhatDotColor (x - radius, y) = black then             xVel *= -1         elsif View.WhatDotColor (x, y + radius) = black then             yVel *= -1         elsif View.WhatDotColor (x, y - radius) = black then             yVel *= -1         end if     end CheckCollision     proc CheckMouse         if b = 1 then             LineArray (upper (LineArray)).x := xx             LineArray (upper (LineArray)).y := yy             LineArray (upper (LineArray)).flag := true         end if         DrawLine (LineArray)         View.Update         new LineArray, upper (LineArray) + 1     end CheckMouse     proc Move         loop             Mouse.Where (xx, yy, b)             Draw.Cls             Draw.Box (0, 0, maxx, maxy, black)             Draw.FillOval (x, y, radius, radius, green)             x += xVel             y += yVel             CheckMouse             CheckCollision             exit when hasch         end loop     end Move end Ball import Ball Ball.Initialize (maxx div 2, maxy div 2) loop     Ball.Move end loop

[Delos]

code:

proc CheckMouse         if b = 1 then             LineArray (upper (LineArray)).x := xx             LineArray (upper (LineArray)).y := yy             LineArray (upper (LineArray)).flag := true         end if         DrawLine (LineArray)

What about when b != 1? What happens then? Right now, LineArray will be uninitialized unless the mouse button is held down.

Some other comments (to work on once you have things working):
- you've used types for your lines, use them for the ball as well. Compartmentalization is good.
- your Initialize proc should take more values than that! You have too many hard-coded values.
- I would also suggest changing Init from a proc to a fcn. Much, much cleaner.
- I haven't run this yet, so I don't know if there are any potential hiccups from having those two loops...
- I don't particularly like the idea that the module changes the settings of the window. Nor do I like that it has any extraneous code...you should look into that.

[Clayton]

its only a chunk of code that i took from what i have, its not the whole thing, i just gave you what was needed to run, i dont know why theres a View.Set in there but anyway, ya i kinda forgot about the non initialized values so oh well, i guess ill just give it some obscure value off the screen until i can figure out a cleaner, better way of doing things