Array subscript out of range error! I'm confused why!

Hexzeus · **Posted:** Wed Jun 14, 2017 8:09 pm

What is it you are trying to achieve?
Remove data from a specific index in an array by overwriting all the indexes that come after in the array including the starting index, then resizing the array down 1 when an arrow hits the player. So basically i'm trying to take a specific index, "deleting" it, then shifting down the rest of the array to fill in the gap.

What is the problem you are having?
I always get an error saying that the array subscript is out of range in either my "arrowReset" process or my "arrowHit" process. I understand what the error means but i dont know how it was created.

Please specify what version of Turing you are using
4.1.1

Hexzeus · **Posted:** Wed Jun 14, 2017 8:10 pm

oops, i didnt mean to add the .rar twice...

Insectoid · **Posted:** Wed Jun 14, 2017 8:23 pm

Can you copy & paste your code here? I generally post from my phone, which makes opening rar files a bit of a pain.

Hexzeus · **Posted:** Thu Jun 15, 2017 6:26 am

Insectoid @ Wed Jun 14, 2017 8:23 pm wrote:

Can you copy & paste your code here? I generally post from my phone, which makes opening rar files a bit of a pain.

I could but there is like 200 lines.

Insectoid · **Posted:** Thu Jun 15, 2017 9:57 am

That is fine.

Hexzeus · **Posted:** Thu Jun 15, 2017 3:38 pm

Insectoid @ Thu Jun 15, 2017 9:57 am wrote:

That is fine.

Turing:

setscreen ("graphics:900;550")

%--------------------------------------------------

const SPEED : int := 5 %player speed

var playerRight : int := Pic.FileNew ("assets/Hero.gif")
var playerLeft : int := Pic.FileNew ("assets/HeroFlip.gif")
var player : int := playerRight %player's either left or right, default:right
var levelOne : int := Pic.FileNew ("assets/grassland.gif")
var coin : int := Pic.FileNew ("assets/coin.gif")
var arrowDown : int := Pic.FileNew ("assets/arrowDown.gif")
var arrowUp : int := Pic.FileNew ("assets/arrowUp.gif")
var arrowLeft : int := Pic.FileNew ("assets/arrowLeft.gif")
var arrowRight : int := Pic.FileNew ("assets/arrowRight.gif")
var x : int := maxx div 2 - 32 %default x and y pos pf player
var y : int := maxy div 2 - 32
var coinX : int := Rand.Int (100, maxx - 100) %sets random x and y pos of fitst coin
var coinY : int := Rand.Int (100, maxy - 100)
var score : int := 0 %score starts at zero
var numArrows : int := 1
var randArrowDirection : int

var chars : array char of boolean %Input.KeyDown information

var arrowX : flexible array 1 .. numArrows of int
var arrowY : flexible array 1 .. numArrows of int
var arrowSpeed : flexible array 1 .. numArrows of int
var arrowDirection : flexible array 1 .. numArrows of string
var arrowImg : flexible array 1 .. numArrows of int
arrowX (1) := Rand.Int (107, maxx - 107) %sets first arrow's direction, x, y, and speed
arrowY (1) := maxy
arrowSpeed (1) := 3
arrowDirection (1) := "south"
arrowImg (1) := arrowDown
for i : 2 .. 5
numArrows := numArrows + 1 %add 1 to max amount of arrows in array
new arrowDirection, numArrows %resizes arrays
new arrowX, numArrows
new arrowY, numArrows
new arrowSpeed, numArrows
new arrowImg, numArrows
randArrowDirection := Rand.Int (1, 4) %sets new arrow to a random direction, x, y, and speed
if randArrowDirection = 1 then
arrowDirection (i) := "north"
arrowImg (i) := arrowUp
arrowX (i) := Rand.Int (107, maxx - 107)
arrowY (i) := -16
arrowSpeed (i) := Rand.Int (3, 5)
elsif randArrowDirection = 2 then
arrowDirection (i) := "east"
arrowImg (i) := arrowRight
arrowX (i) := -16
arrowY (i) := Rand.Int (107, maxy - 107)
arrowSpeed (i) := Rand.Int (3, 5)
elsif randArrowDirection = 3 then
arrowDirection (i) := "south"
arrowImg (i) := arrowDown
arrowX (i) := Rand.Int (107, maxx - 107)
arrowY (i) := maxy
arrowSpeed (i) := Rand.Int (3, 5)
elsif randArrowDirection = 4 then
arrowDirection (i) := "west"
arrowImg (i) := arrowLeft
arrowX (i) := maxx
arrowY (i) := Rand.Int (107, maxy - 107)
arrowSpeed (i) := Rand.Int (3, 5)
end if
end for

%--------------------------------------------------

process displayScore %used for testing score
loop
Input.KeyDown (chars)
if chars (' ') then
put score
delay (10)
end if
end loop
end displayScore

process displayArrow %used for testing arrow count
loop
Input.KeyDown (chars)
if chars ('p') then
put numArrows
delay (10)
end if
end loop
end displayArrow

process arrowHit
loop
for m : 1 .. numArrows
if Math.Distance (x + 32, y + 32, arrowX (m) + 8, arrowY (m) + 8) <= 30 then
for n : m .. numArrows - 1
arrowDirection (n) := arrowDirection (n + 1)
arrowImg (n) := arrowImg (n + 1)
arrowX (n) := arrowX (n + 1)
arrowY (n) := arrowY (n + 1)
arrowSpeed (n) := arrowSpeed (n + 1)
end for
numArrows := numArrows - 1
new arrowDirection, numArrows %resizes arrays
new arrowX, numArrows
new arrowY, numArrows
new arrowSpeed, numArrows
new arrowImg, numArrows
end if
end for
end loop
end arrowHit

process coinCheck
loop
if Math.Distance (x + 32, y + 32, coinX + 16, coinY + 16) <= 20 then %checks if the distance between the middle of the player and the middle of the coin is less than 20 px
score := score + 1 %if so, add 1 to score
coinX := Rand.Int (100, maxx - 100) %sets new x and y pos of next coin
coinY := Rand.Int (100, maxy - 100)
end if
end loop
end coinCheck

process addArrow
loop
delay (2000) %how often a new arrow gets added
numArrows := numArrows + 1 %add 1 to max amount of arrows in array
new arrowDirection, numArrows %resizes arrays
new arrowX, numArrows
new arrowY, numArrows
new arrowSpeed, numArrows
new arrowImg, numArrows
randArrowDirection := Rand.Int (1, 4) %sets new arrow to a random direction, x, y, and speed
if randArrowDirection = 1 then
arrowDirection (numArrows) := "north"
arrowImg (numArrows) := arrowUp
arrowX (numArrows) := Rand.Int (107, maxx - 107)
arrowY (numArrows) := -16
arrowSpeed (numArrows) := Rand.Int (3, 5)
elsif randArrowDirection = 2 then
arrowDirection (numArrows) := "east"
arrowImg (numArrows) := arrowRight
arrowX (numArrows) := -16
arrowY (numArrows) := Rand.Int (107, maxy - 107)
arrowSpeed (numArrows) := Rand.Int (3, 5)
elsif randArrowDirection = 3 then
arrowDirection (numArrows) := "south"
arrowImg (numArrows) := arrowDown
arrowX (numArrows) := Rand.Int (107, maxx - 107)
arrowY (numArrows) := maxy
arrowSpeed (numArrows) := Rand.Int (3, 5)
elsif randArrowDirection = 4 then
arrowDirection (numArrows) := "west"
arrowImg (numArrows) := arrowLeft
arrowX (numArrows) := maxx
arrowY (numArrows) := Rand.Int (107, maxy - 107)
arrowSpeed (numArrows) := Rand.Int (3, 5)
end if
end loop
end addArrow

process arrowReset
loop
for k : 1 .. numArrows
if (arrowDirection (k) = "north" and arrowY (k) > maxy) or (arrowDirection (k) = "east" and arrowX (k) > maxx) or (arrowDirection (k) = "south" and arrowY (k) < -16)
or (arrowDirection (k) = "west" and arrowX (k) < -16) or (numArrows = 0) then
%if an arrow going in a specif direction reaches the boundaries, set new random direction, x, y, and speed
randArrowDirection := Rand.Int (1, 4)
if randArrowDirection = 1 then
arrowDirection (k) := "north"
arrowImg (k) := arrowUp
arrowX (k) := Rand.Int (107, maxx - 107)
arrowY (k) := -16
arrowSpeed (k) := Rand.Int (3, 5)
elsif randArrowDirection = 2 then
arrowDirection (k) := "east"
arrowImg (k) := arrowRight
arrowX (k) := -16
arrowY (k) := Rand.Int (107, maxy - 107)
arrowSpeed (k) := Rand.Int (3, 5)
elsif randArrowDirection = 3 then
arrowDirection (k) := "south"
arrowImg (k) := arrowDown
arrowX (k) := Rand.Int (107, maxx - 107)
arrowY (k) := maxy
arrowSpeed (k) := Rand.Int (3, 5)
elsif randArrowDirection = 4 then
arrowDirection (k) := "west"
arrowImg (k) := arrowLeft
arrowX (k) := maxx
arrowY (k) := Rand.Int (107, maxy - 107)
arrowSpeed (k) := Rand.Int (3, 5)
end if
end if
end for
end loop
end arrowReset

procedure move %movement, 8 directions
Input.KeyDown (chars)
if chars ('w') then
y := y + SPEED
end if
if chars ('a') then
x := x - SPEED
player := playerLeft
end if
if chars ('s') then
y := y - SPEED
end if
if chars ('d') then
x := x + SPEED
player := playerRight
end if
end move

procedure arrowDraw %draws all arrows
for i : 1 .. numArrows
Pic.Draw (arrowImg (i), arrowX (i), arrowY (i), picMerge)
end for
end arrowDraw

procedure arrowMove %moves all arrows
for j : 1 .. numArrows
if arrowDirection (j) = "north" then
arrowY (j) := arrowY (j) + arrowSpeed (j)
elsif arrowDirection (j) = "east" then
arrowX (j) := arrowX (j) + arrowSpeed (j)
elsif arrowDirection (j) = "south" then
arrowY (j) := arrowY (j) - arrowSpeed (j)
elsif arrowDirection (j) = "west" then
arrowX (j) := arrowX (j) - arrowSpeed (j)
end if
end for
end arrowMove

procedure draw %all draws here to be organized
Pic.Draw (levelOne, 0, 0, picMerge)
Pic.Draw (coin, coinX, coinY, picMerge)
Pic.Draw (player, x, y, picMerge)
arrowDraw
arrowMove
move
View.Update
delay (15)
end draw

%---------------------------
%starts all functions to begin the game
fork displayScore
fork displayArrow
fork coinCheck
fork arrowReset
fork arrowHit
fork addArrow
loop
draw
end loop

%--------------------------

Insectoid · **Posted:** Thu Jun 15, 2017 5:43 pm

Uh, there's a very good chance your issue is caused by your use of processes. Processes don't execute at the same time, they execute out of order. You should have zero processes. None. You should only have procedures and functions. Processes shouldn't even be taught in school.

If your code executes out of order, you can wind up in a situation where a process wants to look at arrow n, but then it pauses to let your arrowHit process run, which deletes arrow n. The first process then resumes and tries to look at arrow n, but can't, because it's been deleted. The program then crashes.

There is no point even trying to debug the code when unpredictable things like this can happen. You absolutely must rewrite this to completely eliminate processes.

Hexzeus · **Posted:** Thu Jun 15, 2017 6:10 pm

ok thanks

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