How to create an array of struct ?

[jlf]

Hi,

I need to send an array of structure to a C function (compiled as DLL). All is ok if I try to send only this struct (DllStructCreate + DllStructSetData).

At this time, my AutoIt code use a 2Darray (see 'test.au3' and $AliasList). I need to share this 2D array (in fact an array of struct, see 'global.h') between AutoIt and DLL. Each of them should be able to modify this array of struct.

I have done an small function (see 'MyFunction.c') that works fine but only with the first element of this array of struct.

__declspec(dllexport) int MyFunction(char *Channel,struct Alias AliasList[],int AliasListLength) {
fprintf(stdout,"Channel = %s\n",Channel );
fprintf(stdout,"AliasListLength = %d\n",AliasListLength );
fprintf(stdout,"AliasList[0].ScenarioName = %s\n",AliasList[0].ScenarioName);
fprintf(stdout,"AliasList[1].ScenarioName = %s\n",AliasList[1].ScenarioName);
fprintf(stdout,"AliasList[2].ScenarioName = %s\n",AliasList[2].ScenarioName);
fprintf(stdout,"AliasList[3].ScenarioName = %s\n",AliasList[3].ScenarioName);
fprintf(stdout,"AliasList[4].ScenarioName = %s\n",AliasList[4].ScenarioName);
fflush(NULL);
return(0);
}

I create the structure, assign an item to something, and call the dll.

1st test :

Local $struct = DllStructCreate("...")
DllStructSetData($struct,2,"this is my question")
DllCall("./MyCustomDll_x64.dll","int:cdecl","MyFunction","str","file12345678","struct*",DllStructGetPtr($struct),"int",$NB_ITEM)

==> only 'AliasList[0]' is providen, and 'AliasList[0].ScenarioName' return correct value --> all is ok (and dll can update this value, perfect !)

2nd test (3rd in providen 'test.au3')

DllCall("./MyCustomDll_x64.dll","int:cdecl","MyFunction","str","file12345678","ptr*",$AliasList,"int",$NB_ITEM)

I try to send whole 2D array, and what ? Nothing good...

Does someone could help me please ? Maybe it's a wrong call, or an wrong C declaration, or both, or something else, but I cannot found what...

I think also my 2D array in AutoIt should be rewritten to match the array of struc in C-style.

Makefile providen (just rename txt to bat)

Dll (x86 & x64) compiled providen in ZIP file if you don't want to compile it.

Thanks in advance

Best Regards

test.au3

MyFunction.c

_makefile_DLL_MinGW.txt

global.h

MyCustomDll.zip

[jlf]

Hi,

Posting this new post, maybe more simple : how to create an array of struct ? Like in C "struct struct_type MyStruct[ ]"

See more details in my previous post above

Thanks in advance

Edited February 10, 2013 by Melba23
Removed link as topics merged

[UEZ]

Something like this here?:

$tStruct = DllStructCreate("uint array[10]")
For $i = 1 To 10
    DllStructSetData($tStruct, "array", $i^2, $i)
Next

For $i = 1 To 10
    ConsoleWrite(DllStructGetData($tStruct, "array", $i) & @LF)
Next

Br,

UEZ

Edited February 10, 2013 by UEZ

[Shaggi]

Autoit doesn't allow arrays of user defined types inside other structs. One way to it is by allocating a raw block of memory sized to your array, and alias your way into it, kind of like this:

$tagMYSTRUCT = "int code; char msg[10];"

$mystruct = ArrayStruct($tagMYSTRUCT, 4)
$fourth_element = getElement($mystruct, 3, $tagMYSTRUCT) ; $fourth_element is an alias of '$mystruct[3]'
DllStructSetData($fourth_element, "code", 3);

DllCall(...., "struct*", $mystruct)


Func ArrayStruct($tagStruct, $numElements)
    $sizeOfMyStruct = DllStructGetSize(DllStructCreate($tagMYSTRUCT)) // assumes end padding is included
    $numElements = 4
    $bytesNeeded = $numElements * $sizeOfMyStruct
    return DllStructCreate("byte[" & $bytesNeeded & "]")
EndFunc


Func GetElement($Struct, $Element, $tagSTRUCT)
   return DllStructCreate($tagSTRUCT, DllStructGetPointer($Struct) + $Element * DllStructGetSize(DllStructCreate($tagStruct)))
EndFunc

Its the C equivalent of doing this:

typedef struct
{
    int code;
    char msg[10];
} MyStruct;


void example() {
    MyStruct structs[10];
    something(structs);

    //or

    MyStruct * ptrstructs = (MyStruct*) malloc(sizeof MyStruct * 10);
    something(ptrstructs);
}

void something(MyStruct input[]) {}

Edited February 10, 2013 by Shaggi

[Melba23]

jlf,

How about sticking to the one topic at a time - merged.

M23

[jlf]

Thanks you so much Shaggi !!!

After some test & change for my application, it works fine

[Xandy]

I did it with arrays in arrays.

Assign struct array

$struct= structname_make()
$subarray= $struct[3]
;work on array
$subarray[0][0]+= 100
;put it back
$struct[3]= $subarray
structname_showcell($struct, 0, 0)

func structname_make()
    local $struct[4]
    $struct[0]= 0;page
    $struct[1]= 1;pages
    $struct[2]= 0;curtile
    local $rect[200][4];sub array
    $struct[3]= $rect;rects on page
    return $struct
EndFunc;structname()

func structname_showcell($struct, $index, $data)
    $subarray= $struct[3]
    consolewrite($subarray[$index][$data])
EndFunc;

I'm working on a descent example.

To make an array of struct is also pretty easy from here.

EDIT: I didn't know we were talking about DLL.

Shaggi and UEZ's example are helping me learn about DllStruct.

Edited February 11, 2013 by Xandy

[Shaggi]

Glad it worked out

I did it with arrays in arrays.

Assign struct array

$struct= structname_make()
$subarray= $struct[3]
;work on array
$subarray[0][0]+= 100
;put it back
$struct[3]= $subarray
structname_showcell($struct, 0, 0)

func structname_make()
local $struct[4]
$struct[0]= 0;page
$struct[1]= 1;pages
$struct[2]= 0;curtile
local $rect[200][4];sub array
$struct[3]= $rect;rects on page
return $struct
EndFunc;structname()

func structname_showcell($struct, $index, $data)
$subarray= $struct[3]
consolewrite($subarray[$index][$data])
EndFunc;

I have been messing with code like that but it just sucks you cant reference the subarray directly (only through byref func calls, and this has an obvious problem with multiple nesting)

Also glad the example helped you but keep in mind it's not exactly how you're supposed to use the unmanaged autoit system (eg. avoiding the type system and does no bounds checking what so ever)..

[Xandy]

Yeah, I really didn't know how I was going to do it.

It seemed AutoItObject wouldn't work with array properties or byref parameters.

I wanted 2 tilewindows a list of tiles of variable size and a list of chosen tiles to replace.

With functions to setup and calculate area of rects drawn.

Now I can work with collections instead of bunch of individual arrays.

I don't know anything about Dll, so every little can get me more comfortable.

[JohnOne]

Anything stopping you from just storing an array of pointers to your structs?

[guinness]

Am I missing something: see trancexx's comment.

[Shaggi]

Am I missing something: see trancexx's comment.

In the op's case, it's an 'api requirement'.

Dunno about xandy

[guinness]

Thanks.

[prazetto]

Thanks Shaggi.

Here the other example using Array Struct.

expandcollapse popup

; Drawing a Shaded Rectangle
; http://msdn.microsoft.com/en-us/library/windows/desktop/dd162485(v=vs.85).aspx

#include <GUIConstantsEx.au3>
#include <WindowsConstants.au3>
#include <WinAPI.au3>

$tagTRIVERTEX = 'LONG x;LONG y;USHORT Red;USHORT Green;USHORT Blue;USHORT Alpha'
$tagGRADIENT_RECT = 'ULONG UpperLeft;ULONG LowerRight'

$hWnd = GUICreate("Form1", 483, 339, 192, 124)
$hDC = _WinAPI_GetDC($hWnd)

GUISetState(@SW_SHOW)

$tGRADIENT_RECT = DllStructCreate($tagGRADIENT_RECT)

$taTRIVERTEX = ArrayStruct($tagTRIVERTEX, 2)

$tTRIVERTEX0 = getElement($taTRIVERTEX, 0, $tagTRIVERTEX)
$tTRIVERTEX1 = getElement($taTRIVERTEX, 1, $tagTRIVERTEX)

DllStructSetData($tTRIVERTEX0, 'x', 0)
DllStructSetData($tTRIVERTEX0, 'y', 0)
DllStructSetData($tTRIVERTEX0, 'Red', 0x0000)
DllStructSetData($tTRIVERTEX0, 'Green', 0x8000)
DllStructSetData($tTRIVERTEX0, 'Blue', 0x8000)
DllStructSetData($tTRIVERTEX0, 'Alpha', 0x0000)

DllStructSetData($tTRIVERTEX1, 'x', 300)
DllStructSetData($tTRIVERTEX1, 'y', 80)
DllStructSetData($tTRIVERTEX1, 'Red', 0x0000)
DllStructSetData($tTRIVERTEX1, 'Green', 0xD000)
DllStructSetData($tTRIVERTEX1, 'Blue', 0xD000)
DllStructSetData($tTRIVERTEX1, 'Alpha', 0x0000)

DllStructSetData($tGRADIENT_RECT, 'UpperLeft', 0)
DllStructSetData($tGRADIENT_RECT, 'LowerRight', 1)

DllCall('msimg32.dll', 'bool', 'GradientFill', 'hwnd', $hDC, 'ptr', DllStructGetPtr($taTRIVERTEX), 'ulong', 2, 'ptr', DllStructGetPtr($tGRADIENT_RECT), 'ulong', 1, 'ulong', 0)
; Equivalent
; DllCall('gdi32.dll', 'bool', 'GdiGradientFill', 'hwnd', $hDC, 'ptr', DllStructGetPtr($taTRIVERTEX), 'ulong', 2, 'ptr', DllStructGetPtr($tGRADIENT_RECT), 'ulong', 1, 'ulong', 0)

_WinAPI_ReleaseDC($hWnd, $hDC)

While 1
$nMsg = GUIGetMsg()
Switch $nMsg
Case $GUI_EVENT_CLOSE
Exit
EndSwitch
WEnd

Func ArrayStruct($tagStruct, $numElements)
$sizeOfMyStruct = DllStructGetSize(DllStructCreate($tagStruct)) ; assumes end padding is included
$numElements = 4
$bytesNeeded = $numElements * $sizeOfMyStruct
return DllStructCreate("byte[" & $bytesNeeded & "]")
EndFunc

Func GetElement($Struct, $Element, $tagSTRUCT)
return DllStructCreate($tagSTRUCT, DllStructGetPtr($Struct) + $Element * DllStructGetSize(DllStructCreate($tagStruct)))
EndFunc

Edited April 9, 2013 by prazetto