Turing RealTime Net

[Saad]

Real Time Internet



Requirements:
• Knowledge of Net Commands
• String Manipulation Skills

Turing’s Net Drawbacks:

If you start playing around with Turing’s Net Features, you will realize that you can send one data over the net to another person really fast, but if you tried sending more then 1 variable, it would not work properly.


So what to do to fix it?

Since one variable can be sent through the Net module safely, we need to find a way to combine all the information we want to send over the net. One method would be to use tokenized strings. A tokenized string is a string that is part of a bigger string, separated by delimiters.

To put all the data into one string should not be hard as you can easily convert to string and add the delimiter after. I.e.
var c := intstr (px) + "/" + intstr (py)

If the Player X and Player Y variables both had the value 250, our string would be “250/250”. We will send this over the net to the receiver. This saves us from sending two variables: Player X and then Player Y.

Now we have a new problem: how do we read this information? I have made a sample Get_Token function to assist us.

Turing:

body fcn Get_Token     var tmsg := msg     var toks : flexible array 1 .. 1 of string     var b := 1     if index (tmsg, del) = 0 then /* Checks if the delimeter is inside the string and if its not it will either result the message or if the token requested is > 1 then it will return null */         if num > 1 then             result "null"         else             result tmsg         end if     else /* If its in the string then it will do the process of splitting the string apart into tokens*/         loop             toks (b) := tmsg (1 .. index (tmsg, del) - 1)             tmsg := tmsg (index (tmsg, del) + 1 .. *)             exit when index (tmsg, del) = 0             b += 1             new toks, upper (toks) + 1         end loop         b += 1         new toks, upper (toks) + 1         toks (b) := tmsg     end if     new toks, upper (toks) + 1 /* If the token requested is greater then the number of tokens it retruns null */     if num > b then         result "null"     else         result toks (num)     end if end Get_Token

After we have sent the “250/250” string to our receiver, the receiver needs to read the tokens.
Token #1 results the X location and Token #2 results the Y location. This saves us from getting 2 variables from the net stream.

A slight drawback to this method is that Turing’s string's can be a maximum of 255 characters long, so you will have to be creative when sending the data. For example instead of base ten numbers like 15 you could send its hexadecimal value “F”. I will not get into detail here since that would require another tutorial.

I have attached a simple ball movement program in real time with two people.
Yes I could have used records but for simplicity I did not.


Example

Turing:

forward fcn Get_Token (msg : string, num : int, del : char) : string /* Real Time Internet by Saad Ahmad */ /* Limits are 255 string limit */ var choice : int loop     cls     put "1 -> Host"     put "2 -> Join"     get choice     exit when choice > 0 and choice < 3 end loop var stream : int var address : string const port := 5055 var px, py := 250 var msg := "250/250"   /* Default Location for players */ var key : array char of boolean var p2x, p2y := 100 if choice = 1 then     put "Your ip is ", Net.LocalAddress     stream := Net.WaitForConnection (port, address)     View.Set ("offscreenonly")     loop         var b := msg         if Net.TokenAvailable (stream) then  /* Checks if string is available */             get : stream, b : *         end if         Input.KeyDown (key)         if key (KEY_UP_ARROW) then             py += 10         end if         if key (KEY_DOWN_ARROW) then             py -= 10         end if         if key (KEY_LEFT_ARROW) then             px -= 10         end if         if key (KEY_RIGHT_ARROW) then             px += 10         end if         p2x := strint (Get_Token (b, 1, "/")) /* Gets the location X which we made token #1 */         p2y := strint (Get_Token (b, 2, "/")) /* Gets the location Y which we made token #2 */         msg := b         Draw.FillOval (px, py, 10, 10, red)         var c := intstr (px) + "/" + intstr (py) /* Makes information one string and sends it */         put : stream, c         Draw.FillOval (p2x, p2y, 10, 10, yellow)         View.Update         Time.DelaySinceLast (50)         cls     end loop end if if choice = 2 then     var a : string     put "Enter IP"     get a     stream := Net.OpenConnection (a, port)     View.Set ("offscreenonly")     if stream > 0 then         loop             var b := msg             if Net.TokenAvailable (stream) then /* Checks if string is available */                 get : stream, b : *             end if             msg := b             Input.KeyDown (key)             if key (KEY_UP_ARROW) then                 py += 10             end if             if key (KEY_DOWN_ARROW) then                 py -= 10             end if             if key (KEY_LEFT_ARROW) then                 px -= 10             end if             if key (KEY_RIGHT_ARROW) then                 px += 10             end if             p2x := strint (Get_Token (b, 1, "/"))  /* Gets the location X which we made token #1 */             p2y := strint (Get_Token (b, 2, "/")) /* Gets the location Y which we made token #2 */             msg := b             Draw.FillOval (px, py, 10, 10, red)             var c := intstr (px) + "/" + intstr (py) /* Makes information one string and sends it */             put : stream, c             Draw.FillOval (p2x, p2y, 10, 10, yellow)             View.Update             Time.DelaySinceLast (50)             cls         end loop     end if end if /* Main body of Get_Token  Tokens are just words in a string which are seperated by a delimeter  */ body fcn Get_Token     var tmsg := msg     var toks : flexible array 1 .. 1 of string     var b := 1     if index (tmsg, del) = 0 then         /* Checks if the delimeter is inside the string and if its not          it will either result the message or if the token requested is > 1          then it will return null */         if num > 1 then             result "null"         else             result tmsg         end if     else         /* If its in the string then it will do the process of splitting          the string apart into tokens*/         loop             toks (b) := tmsg (1 .. index (tmsg, del) - 1)             tmsg := tmsg (index (tmsg, del) + 1 .. *)             exit when index (tmsg, del) = 0             b += 1             new toks, upper (toks) + 1         end loop         b += 1         new toks, upper (toks) + 1         toks (b) := tmsg     end if     new toks, upper (toks) + 1     /* If the token requested is greater then the number of tokens it retruns null */     if num > b then         result "null"     else         result toks (num)     end if end Get_Token

At the end I would like to say this is a very effective method of achieving RealTime Net. Using records over the net stream will not work and also for me, putting lots of variables in the net stream wont work properly which I think is true for other people aswell.

I hope you liked this.

Also thanks Cervantes for checking over this tutorial


Saad

[LaZ3R]

Nice tutorial indeed, it's pretty much the same thing I did when making my first few online games in turing , very effective way of doing it.

[Cervantes]

Thanks!
+100 bits, and karma.

[Decadence666]

Psycho. Very useful. What I need now is a way to run two turing windows at the same time

[CodeMonkey2000]

What does the keyword forward do? Is that like a function prototype?

[Saad]

Pretty much, with forward you can declare the header of the function. This is usefull when you 2 procedures need to call on each other and also you can put all you functions at the end.

[Wolf_Destiny]

Decadence666 @ Sun Jun 24, 2007 9:49 pm wrote:

Psycho. Very useful. What I need now is a way to run two turing windows at the same time

That's easy, compile one of the two programs, then run the compiled program, and the uncompiled from Turing. (Or compile both, but that'd take a couple minutes more)
~Wolf_Destiny
P.S. Also if you just want to run two of the same program, once it's compiled you should be able to run as many of it as you want. But Turing is also a CPU hog, so more then two would probably be a bad thing.