SRL Archive - Outdated Tutorials

Intro.
Lately I have seen many people using procedures when they should be using functions and visa verse. Maybe they do not know the usage's of them the benefits and drawbacks. In this tutorial I will explain to the beginner scriptwriter on the usages of procedures and functions. I'll also touch on the interdependence of the two (how they need each other)


The Procedure (Proc)
The procedure is widely used to achieve something through a given way. It doesn't output a result but can change one.

Definition - Defines a subroutine that does not return a value

Version 1. The procedure looks like this:

Procedure Work;

This procedure operates with no parameters, thus meaning that it will preform a task which cannot be altered by the user without tankering with the procedure itself.

Version 2.

Procedure Work(Physically : Boolean);

This procedure operates within given parameters and is specified to work within them depending on the boolean; for instance here is the procedure

Procedure Work(Physically : Boolean);
Begin
  If Physically Then
    WriteLn('Hard physical labour')
  Else
    WriteLn('yoga');
End;

If you change Physically to True it will output - Hard Physical Labour
Otherwise it will output - Yoga


The Function(func)
The function is widely used to return a value of result which shall effect the way a script shall run.

Definition - Defines a subroutine that returns a value

Version 1. The function looks like this:

Function Eat : Boolean;

This function will return a data-type only one value can be returned from a function.

Version 2.

Function Eat(What : String) : Boolean;

This returns a datatype as same as the first one but it also has parameters to work in. So it will be influenced by it and will also return a result.

For instance:

Function Eat(What : String) : Boolean;
Begin
  If GetDebugLine(GetDebugLineCount - 1) = 'yoga' Then
    Result := False
  Else
    Result := True;
End;

What this will do is return a result based on what the work procedure outputs in the debug box.

Please note that when you make a function SCAR automatically creates a boolean for it.

Functions can also be used as so:

To Output a string - 'Function Thing:String;'

To Output an Integer - 'Function Thing:LongInt;'

Many otherways can be used all you do is 'shove' a datatype at the end.



Interdependance

Procedures and functions can depend on each other every good scripter will know about the advantages of having functions in procedures and so on.

For example say using our Work procedure and our Eat function we want to make the person who did manual labour to get GoodFood

So:

Function Eat : Boolean;
Begin
  If GetDebugLine(GetDebugLineCount - 1) = 'yoga' Then
    Result := False
  Else
    Result := True;
End;

Procedure Work(Physically : Boolean);
Begin
  If Physically Then
    WriteLn('Hard physical labour')
  Else
    WriteLn('yoga');
End;

Begin
  If Random(2) = 0 Then Work(True) Else Work(False);
  If Eat Then WriteLn('Ate food') Else WriteLn('STOP YOGA!!');
End.

In this example The function Eat relies on The procedure Work, therefore they work with each other.

As an example In real-time Scar-scripting I used:

Procedure DetectGas;
Begin
  If GasFinder(x, y) then
    begin
      MouseFlag(MMCX, MMCY, 20, 20, 0);
      SleepAndMoveMouse(7000 + Random(300));
    end;
end;

The function GasFinder :

function GasFinder(GX, GY : Integer): Boolean;   //Thanks Wizzup!
Var
   x1, y1, x2, y2, I, time, c: Integer;
   R, G, B: Integer;
   H, S, L: ExtEnded;
   X, Y, Z: ExtEnded;
   Gas, Gas2: TPointArray;
   Colors, C2: TIntegerArray;
begin
  Try
    x1 := gx - 35;
    If x1 < 0 Then
      x1 := 0;
    y1 := gy - 35;
    If y1 < 0 Then
      y1 := 0;
    x2 := gx + 35;
    If x2 > 515 Then
      x2 := 515;
    y2 := gy + 35;
    If y2 > 336 Then
      y2 := 336;
    Time := GetSystemTime;
    Result := False;
    c := GetColorToleranceSpeed;
    ColorToleranceSpeed(2);
    SetColorSpeed2ModIfiers(0.2, 0.2);
    FindColorsTolerance(Gas, 8886170, x1, y1, x2, y2, 20);
    ColorToleranceSpeed(c);
    If length(Gas) < 10 Then
      Exit;
    Colors := GetColors(Gas);
    C2 := Colors;
    ClearSameIntegers(C2);
  //  writeln('Colors Length: ' + inttostr(length(colors)));
   // writeln('C2 Length: ' + inttostr(length(C2)));
    If Length(C2) < 40 Then
      Exit;
    For I := 0 To High(Gas) Do
    Begin
      ColorToRGB(Colors[I], R, G, B);
      If Abs(R - G) <= 10.0 Then
      Begin
        ColorToHSL(Colors[I], H, S, L);
        If (H > 11.5) And (H < 16.0) And (S < 12.0) Then
        Begin
          ColorToXYZ(Colors[I], X, Y, Z);
          If (Abs(X - Y) < 5.0) And (Abs(X - Z) < 5.0) And (Abs(Y - Z) < 5.0) Then
          Begin
            SetLength(Gas2, Length(Gas2) + 1);
            Gas2[High(Gas2)] := Gas[I];
          End;
        End;
      End;
    End;
    //WriteLn('time: ' + IntToStr(GetSystemTime - Time));
    //WriteLn('gas2 length: ' + IntToStr(Length(Gas2)));
    Result := (Length(Gas2) > 30); // The only number you might want to tweak.
    //debugtpa(Gas2, '');
    if result then
    begin
      SaveScreenshot(ScriptPath + 'Found WIZZUP gas ' + TimeRunning + '.bmp')
      Exit;
    end;
    //debugtpa(gas2, '');
  Except WriteLn('No window selected'); end;
End;

Will try to detect a gas leak whilst mining and will alter the procedure according to its result.

It can be used in many other ways, such as in my firemaking script.

Procedure Relocate;
Begin
  MFF(MMCX-Random(5), MMCY+Random(4), 5, 5);
  FFlag(0)
end;

Function CantLight : Boolean;
Begin
  If FindBlackChatMessage('ight a fir') Then
    Result := True;
end;


Procedure WaitWhileFireMaking;
Begin
  If Cantlight Then
  Begin
   Relocate; //here

This uses the function CantLight to trigger the procedure Relocate.


Thanks all.

From Uncle Hermpie:

From: Hermen
if something then result :=true else result := false;
can be replaced by:

Result := something

e.g

Result := GetColor(304, 809) = 55656

(its 5 am here so if I missed something or goofed something up, its because i am shattered).

There is also a version 3 of a function or procedure this involves using it as a type such a SRL_Procs

:)

you're making too many tuts. lol

glad you made this though.. now make one saying that leechers should stop being stupid D:<

I already knew this, though it's very handy to see it all in 1 tut :)

I dont make that many tutorials, I haven't released one for about 2 months, so this is only a warm-up :p.

Thanks for the comments.

Functions can do everything procedures can do and more.

From: NaumanAkhlaQ

Please note that when you make a function SCAR automatically creates a boolean for it.

Function IsThisWrong: string;
begin
  if true then
    Result := 'yes'
  else
    Result := 'well, it is';
end;

i wonder what boolean was created there?

~RM

Please note that when you create a function in SCAR it automatically creates a result variable which is what returns the value.

if something then result :=true else result := false;
can be replaced by:

Result := something

Thanks Rep+++