#include <Constants.au3>
#include <StructureConstants.au3>
#include <WinAPI.au3>

Func LoadIcon($file, $Index)
	Local $hIcon
	Switch(StringRight($file, 4))
		Case ".dll"
			$hIcon = LoadIconFromDLL($file, $Index)
		Case ".exe"
			$hIcon = LoadIconFromEXE($file, $Index)
	EndSwitch
	Return $hIcon
EndFunc

Func LoadIconFromEXE($file, $Index)
	$DLLinst = GetModuleHandle(Ptr(0))
	Local $aResult = DllCall("shell32.dll", "ptr", "ExtractIcon", "ptr", $DLLinst, "str", $file, "int", $Index)
	If @error Then Return SetError(@error, @extended, 0)
	Return $aResult[0]
EndFunc   ;==>_WinAPI_ExtractIconEx

Func LoadIconFromDLL($file, $Index)
    Local Const $IMAGE_ICON = 1
	Local $DLLinst
	Local $hIcon

	$DLLinst = DLLCall("kernel32.dll","hwnd","LoadLibrary","str",$file)
    $DLLinst = $DLLinst[0]

	$hIcon = DLLCall("user32.dll","hwnd","LoadImage","hwnd",$DLLinst,"int",$Index, _
					 "int",$IMAGE_ICON,"int",0,"int",0,"int",0)
    $hIcon = $hIcon[0]

    DLLCall("kernel32.dll","int","FreeLibrary","hwnd",$DLLinst)
	Return $hIcon
EndFunc

Func GetModuleHandle($sModuleName)
	Local $tText, $aResult

	If $sModuleName <> "" Then
		$tText = DllStructCreate("char Text[4096]")
		DllStructSetData($tText, "Text", $sModuleName)
		$aResult = DllCall("kernel32.dll", "hwnd", "GetModuleHandle", "ptr", DllStructGetPtr($tText))
	Else
		$aResult = DllCall("kernel32.dll", "hwnd", "GetModuleHandle", "ptr", Ptr(0))
	EndIf
	Return $aResult[0]
EndFunc

Func _CreateIconFileFromHICON($hIcon, $sOutIcon)
	$sIco = _GetIconFromHICON($hIcon)
    ; Write the icon to a file.
    $FO = FileOpen($sOutIcon, 18)
    FileWrite($sOutIcon, Binary($sIco))
    FileClose($FO)

    ; Clear the structs
    $tBits = 0
    $tBI = 0
EndFunc   ;==>_CreateIconFileFromHICON

Func _GetIconFromHICON($hIcon)
    Local $aInfo, $sIco, $sBmp, $hCDC, $tBI, $tBits, $iSz, $sBD, $FO

    ; Start of single Icon Header 3 x 2 bytes = 6 bytes: 0000 Reserved / 0100 Icon / 0100 Numer of icons, total length will be 22 bytes for a single icon when finished
    $sIco = "0x000001000100"

    ; Start of the Bitmap data header 1 x 4bytes: length of the header will be 40 bytes when finished. Will be appended to the end of the icon header when finished
    $sBmp = "28000000"

    ; Get info about the HICON, this is mainly to get the pointers to the Color/Mask bitmaps data
    $aInfo = _WinAPI_GetIconInfo($hIcon)

    ; Create a memory Compatable DC
    $hCDC = _WinAPI_CreateCompatibleDC(0)

    ; Create a BITMAPINFO Struct to store the Bitmap Info, it needs to be inilialized by setting the struct size.
    $tBI = DllStructCreate($tagBITMAPINFO)
    DllStructSetData($tBI, "Size", DllStructGetSize($tBI))

    ; Pass a bitmap data pointer to the BITMAPINFO struct so we can recieve the details of the color bitmap data, we use it to write the headers
    _WinAPI_GetDIBits($hCDC, $aInfo[5], 0, 0, 0, DllStructGetPtr($tBI), 0)

    ; Now we have some the basic info to add to the Icon & Bitmap header so we'll add that to the headers.
    $sIco &= Hex(DllStructGetData($tBI, "Width"), 2) & Hex(DllStructGetData($tBI, "Height"), 2) & "00000100" & _RB(Hex(DllStructGetData($tBI, "BitCount"), 4))
    $sBmp &= _RB(Hex(DllStructGetData($tBI, "Width"))) & _RB(Hex(DllStructGetData($tBI, "Height") * 2)) & "0100" & _RB(Hex(DllStructGetData($tBI, "BitCount"), 4)) & "00000000"

    ; Get the size of the Bitmap data from the BITMAPINFO Struct, we'll use this in the headers further on.
    $iSz = DllStructGetData($tBI, "SizeImage")

    ; Create a struct to store the Bitmap data Bits of the first bitmap, reset the BITMAPINFO struct
    $tBits = DllStructCreate("byte[" & DllStructGetData($tBI, "SizeImage") & "]")

    ; Get the color bitmap dib bits into the $tBits struct.
    DllCall('gdi32.dll', 'int', 'GetBitmapBits', 'ptr', $aInfo[5], 'int', $iSz, 'ptr', DllStructGetPtr($tBits))

    ; Get GetBitmapBits returns Bottom to Top dib, so I turn it to Top to Bottom dib ;)
    ; ATM I'm only assuming that GetBitmapBits returns a Bottom to Top dib, maybe the bitmap bits you use could be Top Down already?.
    For $i = DllStructGetData($tBI, "SizeImage") + 1 To 0 Step -(DllStructGetData($tBI, "SizeImage") / DllStructGetData($tBI, "Height"))
        $sBD &= StringTrimLeft(BinaryMid(DllStructGetData($tBits, 1), $i, (DllStructGetData($tBI, "SizeImage") / DllStructGetData($tBI, "Height"))), 2)
    Next

    ;Clear the BITMAPINFO & $tBits Struct as we'll use the same variables again for the mask bitmap data
    $tBits = 0
    $tBI = 0

    ; Create a BITMAPINFO Struct to store the Bitmap Info again, it needs to be inilialized by setting the struct size.
    $tBI = DllStructCreate($tagBITMAPINFO)
    DllStructSetData($tBI, "Size", DllStructGetSize($tBI))

    ; Pass a bitmap data pointer to the BITMAPINFO struct so we can recieve the details of the bitmask bitmap data
    _WinAPI_GetDIBits($hCDC, $aInfo[4], 0, 0, 0, DllStructGetPtr($tBI), 0)

    ; We've finished with the Compatable DC, delete it.
    _WinAPI_DeleteDC($hCDC)

    ; Add the size of the of the color + bitmask bitmap data as we need this for both the Icon & Bitmap header
    $iSz += DllStructGetData($tBI, "SizeImage")

    ; combine the bitmap data size with the bitmap header, I'm padding the rest of the 40 byte bitmap header with 0's., that's the Bitmap header done
    $sBmp &= _RB(Hex($iSz)) & "00000000000000000000000000000000"

    ; Now add the size of the Bitmap data + bitmap header size and combine the icon header together with the bitmap header and color bitmap data
    $sIco &= _RB(Hex($iSz + 40)) & _RB(Hex("22")) & $sBmp & $sBD

    ; Create a struct to store the Bitmap dib Bits of the mask bitmap
    $tBits = DllStructCreate("byte[" & DllStructGetData($tBI, "SizeImage") & "]")

    ; Get the mask bitmap dib bits into the $tBits struct.
    DllCall('gdi32.dll', 'int', 'GetBitmapBits', 'ptr', $aInfo[4], 'int', DllStructGetData($tBI, "SizeImage"), 'ptr', DllStructGetPtr($tBits))

    ; Get GetBitmapBits returns Bottom to Top dib, so I turn it to a Top to Bottom dib and append the mask bitmap data to the icon
    For $i = DllStructGetData($tBI, "SizeImage") + 1 To 0 Step -(DllStructGetData($tBI, "SizeImage") / DllStructGetData($tBI, "Height"))
        $sIco &= StringTrimLeft(BinaryMid(DllStructGetData($tBits, 1), $i, (DllStructGetData($tBI, "SizeImage") / DllStructGetData($tBI, "Height"))), 2)
    Next
	Return $sIco
EndFunc

; Reverse Byte String
Func _RB($sByte)
    Local $aX = StringRegExp($sByte, "(.{2})", 3), $sX = ''
    For $i = UBound($aX) - 1 To 0 Step -1
        $sX &= $aX[$i]
    Next
    Return $sX
EndFunc   ;==>_RB