User defined functions in 1.85

Posted October 15, 2002 · 2024-12-12T20:43:09Z

1.85 introduces new powerful scripting possibilities through user definable functions. This is implemented through the "call", "loadFile" and the "if-then-else,while-do... etc" functions.

What is the big difference between "call" and the old "exec"? -"call" allows you to return a value. This is imperative in creating larger and more complex scripts.

Here is a code example of a simple implementation of a fuction that adds two matrices. Thanks goes to Suma for the code. I have only made small adjustments to make it work with the 1.85 release syntax.

testm.sqs

</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Code Sample </td></tr><tr><td id="CODE">

_matrixA = [ [2,2], [2,2], [2,2],[1,2]]

_matrixB = [ [1,1], [1,1], [1,1],[2,3]]

_result = [_matrixA, _matrixB] call loadFile "matrixAdd.sqf"

titleText[format["Matrix A:%1\nMatrixB:%2\nA+B:%3",_matrixA,_matrixB,_result], "PLAIN",1]

matrixAdd.sqf:

</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Code Sample </td></tr><tr><td id="CODE">

comment

{

Â Â Â Demonstration of new expression possibilities

Â Â Â Note: this is not a script, this is single expression

Â Â Â Script constructs @,~, ? or goto are not possible here.

Â Â Â Semicolons are strictly required, as end of line has no special meaning

Â Â Â and is considered as normal space character.

};

comment

{

Â Â Â All this is implemented using new "while", "if" and "call" functions.

Â Â Â They are real functions taking string arguments and executing them.

Â Â Â Brackets {} are very similiar to quotes - expression closed in them

Â Â Â is string expression.

};

comment "Declare local variables";

private ["_matrixA","_matrixB","_rows","_cols","_diff","_result","_i","_j"];

_matrixA = _this select 0;

_matrixB = _this select 1;

_rows = count _matrixA;

_cols = count (_matrixA select 0);

_result = [];

_i = 0;

comment "Perform calculation in two while loops";

while "_i<_rows" do

{

Â Â Â

Â Â Â _j = 0;

Â Â Â _innerRow = [];

Â Â Â while "_j<_cols" do

Â Â Â {

Â Â Â Â Â Â _diff = ((_matrixA select _i) select _j) + ((_matrixB select _i) select _j);

Â Â Â Â Â Â _innerRow set [_j, _diff];

Â Â Â Â Â Â _j =_j + 1;

Â Â Â };

Â Â Â

Â Â Â _result set [_i,_innerRow];

Â Â Â _i=_i+1;

};

_result

Prospero · July 3, 2002

From the new ComRef:

"Many languague constructs (including forEach, if, while) use concept of "code strings". Code is passed as string to them and they interpret it as code if they wish. Since 1.85 string constants can be written in two ways: using double quotes (like "Hello") or curled braces (like {a=a+1}). While both ways are currently equivalent and string constant is created, we recommend to use curled braces for code only, as this makes scripts easier to read - moreover future versions of scripting language may precompile code enclosed in curled braces."

Precompiling eventually! Suma & BIS - good show!

Prospero

hovmand · January 8, 2002

Could someone explain to us "normals" what this means? Give us a small example of what can be done please.

RED · July 8, 2001

Basicly it lets you create a function (like adding 2 numbers together), using a function can keep scripts small if you are going to use the same function (adding 2 numbers together for example)

For example instead of putting this in your script file, you just call it (like a header file .h in C++) It will keep your scripts neater and a lot easier to read.

</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Code Sample </td></tr><tr><td id="CODE">

comment

{

Demonstration of new expression possibilities

Note: this is not a script, this is single expression

Script constructs @,~, ? or goto are not possible here.

Semicolons are strictly required, as end of line has no special meaning

and is considered as normal space character.

};

comment

{

All this is implemented using new "while", "if" and "call" functions.

They are real functions taking string arguments and executing them.

Brackets {} are very similiar to quotes - expression closed in them

is string expression.

};

comment "Declare local variables";

private ["_matrixA","_matrixB","_rows","_cols","_diff","_result","_i","_j"];

_matrixA = _this select 0;

_matrixB = _this select 1;

_rows = count _matrixA;

_cols = count (_matrixA select 0);

_result = [];

_i = 0;

comment "Perform calculation in two while loops";

while "_i<_rows" do

{

_j = 0;

_innerRow = [];

while "_j<_cols" do

{

_diff = ((_matrixA select _i) select _j) + ((_matrixB select _i) select _j);

_innerRow set [_j, _diff];

_j =_j + 1;

};

_result set [_i,_innerRow];

_i=_i+1;

};

_result

RED

vektorboson · January 5, 2002

Yeah, and for even more hardcore-scripters there is preprocessFile instead of loadFile!

You may define your own C-like macros in your SQF-files. I've got a sample function pos2grid which converts ofp-position vector [x,y,z] to grid position "Ea64".

create a test.sqs with following content:

</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Code Sample </td></tr><tr><td id="CODE">

_gridpos = (getpos player) call preprocessFile "pos2grid.sqf"

hint format ["%1", _gridpos]

And create pos2grid.sqf:

</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Code Sample </td></tr><tr><td id="CODE">

#define DIV(_X, _Y) ((_X / _Y) - (_X / _Y) % 1)

#define MOD(_X, _Y) ((_X % _Y) - (_X % _Y) % 1)

private ["_a", "_b", "_result", "_big", "_small", "_num", "_g1", "_g2", "_g3", "_g4"];

_a = _this select 0;

_b = _this select 1;

_big Â = ["A", "B", "C", "D", "E", "F", "G", "H", "I", "J"];

_small = ["a", "b", "c", "d", "e", "f", "g", "h", "i", "j"];

_num Â = [9, 8, 7, 6, 5, 4, 3, 2, 1, 0];

_g1 = DIV(_a, 1280);

_g2 = DIV( MOD(_a, 1280), 128);

_g3 = DIV(_b, 1280);

_g4 = DIV( MOD(_b, 1280), 128);

_result = format ["%1%2%3%4", _big select _g1, _small select _g2, _num select _g3, _num select _g4];

_result

You see that even nested macros are allowed!

Now place some trigger and execute test.sqs! Now the gridpos of your player should be displayed!

Posted October 16, 2002 · 2024-12-12T20:43:09Z

</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote (Hovmand @ Oct. 15 2002,13:42)</td></tr><tr><td id="QUOTE">Could someone explain to us "normals" what this means? Give us a small example of what can be done please. Â <span id='postcolor'>

Example: Function that returns the sum of two numbers:

sum.sqf:

</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Code Sample </td></tr><tr><td id="CODE">

private ["_a","_b","_sum"];

_a = _this select 0;

_b = _this select 1;

_sum = _a+_b;

_sum

And you would call the function like this to get the sum of for example 2 + 3:

</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Code Sample </td></tr><tr><td id="CODE">

_sum = [2,3] call loadFile "sum.sqf"

Doolittle · January 7, 2002

Why did one of you use preprocessFile and the other use loadFile?!

Doolittle

Posted October 16, 2002 · 2024-12-12T20:43:09Z

PreprocessFile allows you to define macros while loadFile expects a clean format.

GAMEER_77 · May 10, 2002

Because in Bigpoppa's example, he's using the preprocess file to use the 'C-like' functionality. The code in his example only works using preprocess, not loadfile. (I'd imagine )

PEACE

Prospero · July 3, 2002

Any idea which is faster?

Prospero

suma · June 27, 2001

LoadFile is slightly faster, but both of them can be considered slow, as both of them require file access (which is also true for exec).

If you really want something to be fast (which is probably not the case of pos2grid, but may be for some other often executed fuctions), do not do:

</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Code Sample </td></tr><tr><td id="CODE">_gridpos = (getpos player) call preprocessFile "pos2grid.sqf"

hint format ["%1", _gridpos]

Preload content of the file to some global variable instead (once, in init.sqs).

</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Code Sample </td></tr><tr><td id="CODE">

GridPosFunction = preprocessFile "pos2grid.sqf"

....

_gridpos = (getpos player) call GridPosFunction

This way you will avoid reloading and releasing file at each use of the function (at some memory cost).

uiox · April 28, 2002

If I do this

</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Code Sample </td></tr><tr><td id="CODE"> _result =(_Pos) call loadFile "GridCoord.sqf" <span id='postcolor'>

Call execute ONE time and after bugs.

If I do this

</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Code Sample </td></tr><tr><td id="CODE">_result =[_Pos] call loadFile "GridCoord.sqf"<span id='postcolor'>

No bug, why () works one time?

And for OFP scripters without knowledge of C, in sqf you can do this :

</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Code Sample </td></tr><tr><td id="CODE">

private ["_result","_GrandeLettre","_PetiteLettre","_Chiffre", "_Chiffrestring","_Pos"];

_Pos = _This select 0;

_Chiffrestring ="";

_result = "";

_GrandeLettre = (((_Pos select 0) - ((_Pos select 0) Mod 1280))/1280); Â Â Â Â Â Â Â Â Â Â Â Â Â Â

_PetiteLettre =((((_Pos select 0) Mod 1280)- (((_Pos select 0) Mod 1280)Mod 128))/128); Â

_Chiffre = (99 - ((_Pos select 1) - ((_Pos select 1) Mod 128))/128); Â Â Â Â

_Chiffrestring = Format["%1",_Chiffre];

If (_Chiffre < 10) then Â {_Chiffrestring = "0" + _Chiffrestring };

If (_Chiffre != 0) then Â {nobody globalchat "Bonjour";nobody globalchat "Au revoir" };

_result = (( ArrayMajuscForGrid select _GrandeLettre) + ( ArrayMinusForGrid select _PetiteLettre) +_Chiffrestring);

_result<span id='postcolor'>

Very near of OFP scripting I think...

vektorboson · January 5, 2002

@uiox

because one time it's an array of array [_pos] and the other it's just an array (_pos)

[_pos] = [ [_x, _y, _z] ]

(_pos) = [_x, _y, _z]

uiox · April 28, 2002

OK,

So the right syntax is : [] call gridCoordFunction.

suma · June 27, 2001

</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote (uiox @ Oct. 16 2002,13:18)</td></tr><tr><td id="QUOTE">So the right syntax is : [] call gridCoordFunction.<span id='postcolor'>

Both syntax is correct. If you will use (_pos) call gridCoordFunction, _this will be _pos. If you will use [_pos] call gridCoordFunction, _this will be [_pos] - make your choice.

Prospero · July 3, 2002

</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote (Suma @ Oct. 16 2002,12:15)</td></tr><tr><td id="QUOTE">LoadFile is slightly faster, but both of them can be considered slow, as both of them require file access (which is also true for exec).<span id='postcolor'>

I always suspected this from my empirical tests, but many thanks for confirming it, Suma. That's very helpful. I suspect I am correct in saying that calling scripts from the Drop command also depends on file access, and is therefore similarly relatively slow.

Thanks again Suma.

Prospero

Prospero · July 3, 2002

</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote (Suma @ Oct. 16 2002,12:15)</td></tr><tr><td id="QUOTE">If you really want something to be fast, [edit] preload content of the file to some global variable instead (once, in init.sqs).

</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Code Sample </td></tr><tr><td id="CODE">

GridPosFunction = preprocessFile "pos2grid.sqf"

....

_gridpos = (getpos player) call GridPosFunction

This way you will avoid reloading and releasing file at each use of the function (at some memory cost).<span id='postcolor'>

Could I somehow preload a Drop command into a global variable this way?

Prospero

Doolittle · January 7, 2002

Umm, you can't use #define's in a loadFile?? I'm getting

|x|#define FOO ...

when I load the function. I suppose this makes sense (use preprocessfile instead???), but there's no #ifndef #endif stuff.

Maybe this has already been mentioned?? #define does not work with any function you call with loadFile.

Doolittle

suma · June 27, 2001

</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote (Doolittle @ Oct. 22 2002,09:56)</td></tr><tr><td id="QUOTE">#define does not work with any function you call with loadFile.<span id='postcolor'>

#define works with text files (including functions) loaded by preprocessFile.

svrec · November 7, 2002

I have question about command private ["_i","_j","_k"].

What that it function?For example,if I delete this

function in pos2grid.sqf(see above),this script been work too.

I'm sorry!I not programmer but I want understand this.

Can Your cite example were this function it is necessary.

p.s.sorry for my english.

User defined functions in 1.85

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