I need help with snake game

[cpu_hacker4.0]

Ok I am making a snake game for turing and this is what I have so far. Basically, you control one ball with the arrow keys and have to "eat" other circles that get added on to the tail. I'm trying to use collision detection (to "eat" other balls), but it doesn't seem to be working. I put the code that's causing problems in green, just so you can see what I am trying to do. Fiirst run it as is, then remove the /* and */ to see what the problem is. Help would be greatly appreciated.

Turing:

const RADIUS : int := 10 var chars : array char of boolean var num : int := 1 var x, y : array 1 .. num of int var xInc, yInc : int := 0 var rx, ry : int proc RandBall     randint (rx, 0 + RADIUS, maxx - RADIUS)     randint (ry, 0 + RADIUS, maxy - RADIUS) end RandBall for a : 1 .. num     x (a) := maxx div 2     y (a) := maxy div 2 end for View.Set ("Offscreenonly") RandBall loop     for a : 1 .. num         x (a) := x (a) + xInc         y (a) := y (a) + yInc         drawfilloval (x (a), y (a), RADIUS, RADIUS, black)         drawfilloval (rx, ry, RADIUS, RADIUS, black)         View.Update         Input.KeyDown (chars)         if chars (KEY_UP_ARROW) then             xInc := 0             yInc := 1         elsif chars (KEY_DOWN_ARROW) then             xInc := 0             yInc := -1         elsif chars (KEY_RIGHT_ARROW) then             xInc := 1             yInc := 0         elsif chars (KEY_LEFT_ARROW) then             xInc := -1             yInc := 0         end if     end for     /*if x(a) > rx - 10 or x(a) < rx + 10 and y(a) > ry - 10 or y(a) < ry + 10 then         RandBall      end if*/     cls end loop

[HeavenAgain]

the commented part is not in your for loop
that's the "problem", and change the conditions to = rather than bigger or less, although that doesnt fix the dectection.
try searching through the turing forum, im sure there are a lot of snake games example >>snake game<<

[Saad]

The 'or's in if statement should be an "and" and that should be inside the for loop

[HeavenAgain]

yea, forget the equal to, just change the or to and.

[cpu_hacker4.0]

Alright thanks! That seems to have worked...but why is it and? I know now that or doesn't work, but I used or because my ball can either be on the left or right side of the other ball...it can't be on both.

Also, I need help with the next part. When I touch the other ball, I want it to act as a tail that follows my ball around, but I don't know how to use it. I know I need to make an array for the x and y values, but I'm not sure how to use it in the program. Thanks for helping!

Here is the updated code:

Turing:

const RADIUS : int := 10 var chars : array char of boolean var num : int := 1 var x, y : array 1 .. num of int var xInc, yInc : int := 0 var rx, ry : int proc RandBall     randint (rx, 0 + RADIUS, maxx - RADIUS)     randint (ry, 0 + RADIUS, maxy - RADIUS) end RandBall for a : 1 .. num     x (a) := maxx div 2     y (a) := maxy div 2 end for View.Set ("Offscreenonly") RandBall loop     for a : 1 .. num         x (a) := x (a) + xInc         y (a) := y (a) + yInc         drawfilloval (x (a), y (a), RADIUS, RADIUS, black)         drawfilloval (rx, ry, RADIUS, RADIUS, black)         View.Update         Input.KeyDown (chars)         if chars (KEY_UP_ARROW) then             xInc := 0             yInc := 1         elsif chars (KEY_DOWN_ARROW) then             xInc := 0             yInc := -1         elsif chars (KEY_RIGHT_ARROW) then             xInc := 1             yInc := 0         elsif chars (KEY_LEFT_ARROW) then             xInc := -1             yInc := 0         end if         if x (a) > rx - 15 and x (a) < rx + 15 and y (a) > ry - 15 and y (a) < ry + 15 then             RandBall         end if     end for     cls end loop

[Nick]

just make the x and y = the old x and y of ur snake and have each attaching part = the old x and y of the precedding part so:

Turing:

old x:=x oldy:=y x+=5 y+=0 %snake is moving right oldballx(1):=ballx(1) oldbally(1):=bally(1) ballx(1):=oldx bally(1):=oldy ballx(2):=oldballx(1) bally(2):=oldbally(1)

i havent actually tried this nor made a snake game but i did make a trailing string bounce program ill post so u can see how this works

Turing:

var word : array 1 .. 5 of string put "Enter the word or sentence to bounce:" get word (1) : * var row, col : array 1 .. 5 of int var len : int := length (word (1)) var a, b : int := 1 var timer : int put "how fast (1,2 or 3)" get timer if timer = 1 then     timer := 10 elsif timer = 2 then     timer := 30 elsif timer = 3 then     timer := 50 else     timer := 1000 end if for i : 1 .. 5     word (i) := word (1)     row (i) := 10     col (i) := 10 end for cls loop     locate (row (1), col (1))     color (red)     put word (1) ..     locate (row (2), col (2))     color (green)     put word (2) ..     locate (row (3), col (3))     color (brown)     put word (3) ..     locate (row (4), col (4))     color (black)     put word (4) ..     locate (row (5), col (5))     color (blue)     put word (5) ..     col (5) := col (4)     col (4) := col (3)     col (3) := col (2)     col (2) := col (1)     col (1) := col (1) + a     row (5) := row (4)     row (4) := row (3)     row (3) := row (2)     row (2) := row (1)     row (1) := row (1) + b     if row (1) >= 25 then         b := -1     end if     if col (1) >= 80 - len then         a := -1     end if     if row (1) <= 1 then         b := +1     end if     if col (1) <= 1 then         a := +1     end if     delay (timer)     cls end loop

[cpu_hacker4.0]

Ok thanks...I think I understand how it works, but I'm using a variable for the last number of the array, because it depends on how many times the ball disappears. So I don't really know how to put that in my code...how would I do it?[/quote]

[HeavenAgain]

i cant rememebr who it was, but someone made a nice snake game a while back, and it was only a few lines (and it was great)
like i said, go and search for it, its in the turing sections somewhere.
and it seems like you dont know hwo does the array works? you can have a nice look at the tutorials section, here

[cpu_hacker4.0]

No I know how to use arrays, just don't know what to do with the code

[CodeMonkey2000]

There is a ridiculously easy way to make a snake game. I'm too lazy to explain it so meh. Ther a re a lot of ways you can optimize this though.

code:

View.Set ("graphics:330;330") type node :     record         x : int         y : int     end record var square : array 1 .. 30, 1 .. 30 of int var nodes : flexible array 0 .. 0 of node var key : array char of boolean var xInc : int := 1 var yInc : int := 0 nodes (0).x := 15 nodes (0).y := 15 for x : 1 .. 30     for y : 1 .. 30         square (x, y) := 0     end for end for square (Rand.Int (1, 30), Rand.Int (1, 30)) := 2 proc reDraw     for x : 1 .. 30         for y : 1 .. 30             Draw.FillBox (x * 10, y * 10, x * 10 + 10, y * 10 + 10, black)             if square (x, y) = 2 then                 Draw.FillOval (x * 10 + 4, y * 10 + 4, 5, 5, yellow)             end if             if square (x, y) = 1 then                 Draw.FillOval (x * 10 + 4, y * 10 + 4, 5, 5, green)             end if         end for     end for end reDraw proc addNode     new nodes, upper (nodes) + 1     nodes (upper (nodes)).x := nodes (upper (nodes) - 1).x     nodes (upper (nodes)).y := nodes (upper (nodes) - 1).y     square (Rand.Int (1, 30), Rand.Int (1, 30)) := 2 end addNode loop     Input.KeyDown (key)     if key (KEY_UP_ARROW) then         xInc := 0         yInc := 1     elsif key (KEY_DOWN_ARROW) then         xInc := 0         yInc := -1     elsif key (KEY_RIGHT_ARROW) then         xInc := 1         yInc := 0     elsif key (KEY_LEFT_ARROW) then         xInc := -1         yInc := 0     end if     square (nodes (0).x, nodes (0).y) := 0     for decreasing x : upper (nodes) .. 0         if x > 0 then             square (nodes (x).x, nodes (x).y) := 0             nodes (x).x := nodes (x - 1).x             nodes (x).y := nodes (x - 1).y         end if     end for     if nodes (0).x + xInc > 0 and nodes (0).x + xInc < 31 then         nodes (0).x += xInc     end if     if nodes (0).y + yInc > 0 and nodes (0).y + yInc < 31 then         nodes (0).y += yInc     end if     if square (nodes (0).x, nodes (0).y) = 2 then         addNode     end if     for x : 0 .. upper (nodes)         square (nodes (x).x, nodes (x).y) := 1     end for     reDraw     delay (100) end loop