TakeScreenshots.ahk

; AutoHotkey v1.1.x
; F9 to start the capture run. Esc to abort.
; Captures the entire virtual screen (all monitors) every waitMs ms for totalMs ms, simulating a click before each capture.

#NoEnv
#SingleInstance, Force
SetBatchLines, -1
SetWorkingDir, %A_ScriptDir%
CoordMode, Mouse, Screen

global __gdipToken := 0
global __gdipModule := 0

F9::
{
    ; Configuration
    waitMs  := 2000         ; wait between click and screenshot
    nPages  := 1300          ; number of pages to capture
    totalMs := nPages * waitMs     ; total duration
  
    outDir  := A_ScriptDir . "\Screenshots"

    FileCreateDir, %outDir%

    if (!GDIp_Startup())
    {
        MsgBox, 16, Error, Failed to initialize GDI+ (gdiplus.dll).`n`nMake sure gdiplus.dll is available on this system.
        return
    }

    start := A_TickCount
    end   := start + totalMs
    i := 0

    TrayTip, AutoHotkey, Starting 200-second click + screenshot capture..., 2, 1

    while (A_TickCount < end)
    {
        ; Left mouse click at current cursor position
        Click

        ; Wait waitMs ms before the screenshot
        Sleep, %waitMs%

        ; Build unique filename
        i++
        FormatTime, ts, , yyyyMMdd_HHmmss
        fn := outDir . "\shot_" . Format("{:04}", i) . "_" . ts  . ".png"

        ; Capture the entire virtual screen (all monitors) to file
        if (!CaptureScreenToFile(fn))
        {
            ; Optional: notify on failure and continue
            ; Tooltip, Failed to save screenshot #%i% to %fn%, 800, 600
        }
    }

    GDIp_Shutdown()
    TrayTip, AutoHotkey, Done. Saved %i% screenshots to:`n%outDir%, 5, 1
    return
}

Esc::
    GDIp_Shutdown()
    ExitApp


; ---------------------------
; GDI+ helpers and screenshot
; ---------------------------

GDIp_Startup()
{
    global __gdipToken, __gdipModule

    if (__gdipToken)  ; already started
        return true

    ; Explicitly load gdiplus.dll
    if (!__gdipModule)
    {
        __gdipModule := DllCall("LoadLibrary", "Str", "gdiplus.dll", "Ptr")
        if (!__gdipModule)
            return false
    }

    ; GdiplusStartupInput structure
    ; Size: 16 bytes on 32-bit, 24 bytes on 64-bit
    VarSetCapacity(si, A_PtrSize=8?24:16, 0)
    ; IMPORTANT: Set GdiplusVersion = 1
    NumPut(1, si, 0, "UInt")

    status := DllCall("gdiplus\GdiplusStartup", "PtrP", token, "Ptr", &si, "Ptr", 0, "UInt")
    if (status != 0 || !token)
    {
        ; If startup fails, free the module we loaded
        if (__gdipModule)
        {
            DllCall("FreeLibrary", "Ptr", __gdipModule)
            __gdipModule := 0
        }
        return false
    }
    __gdipToken := token
    return true
}

GDIp_Shutdown()
{
    global __gdipToken, __gdipModule
    if (__gdipToken)
    {
        DllCall("gdiplus\GdiplusShutdown", "Ptr", __gdipToken)
        __gdipToken := 0
    }
    if (__gdipModule)
    {
        DllCall("FreeLibrary", "Ptr", __gdipModule)
        __gdipModule := 0
    }
}

; Captures the entire virtual desktop (all monitors) and saves to a PNG file.
CaptureScreenToFile(filePath)
{
    ; Get virtual screen origin and size (handles multi-monitor and negative coords)
    x := DllCall("GetSystemMetrics", "Int", 76, "Int") ; SM_XVIRTUALSCREEN
    y := DllCall("GetSystemMetrics", "Int", 77, "Int") ; SM_YVIRTUALSCREEN
    w := DllCall("GetSystemMetrics", "Int", 78, "Int") ; SM_CXVIRTUALSCREEN
    h := DllCall("GetSystemMetrics", "Int", 79, "Int") ; SM_CYVIRTUALSCREEN

    if (w <= 0 || h <= 0)
        return false

    hdcScreen := DllCall("GetDC", "Ptr", 0, "Ptr")
    if (!hdcScreen)
        return false

    hdcMem := DllCall("gdi32\CreateCompatibleDC", "Ptr", hdcScreen, "Ptr")
    if (!hdcMem)
    {
        DllCall("ReleaseDC", "Ptr", 0, "Ptr", hdcScreen)
        return false
    }

    hbm := DllCall("gdi32\CreateCompatibleBitmap", "Ptr", hdcScreen, "Int", w, "Int", h, "Ptr")
    if (!hbm)
    {
        DllCall("gdi32\DeleteDC", "Ptr", hdcMem)
        DllCall("ReleaseDC", "Ptr", 0, "Ptr", hdcScreen)
        return false
    }

    obm := DllCall("gdi32\SelectObject", "Ptr", hdcMem, "Ptr", hbm, "Ptr")
    ; SRCCOPY = 0x00CC0020
    ok := DllCall("gdi32\BitBlt", "Ptr", hdcMem, "Int", 0, "Int", 0, "Int", w, "Int", h
                                , "Ptr", hdcScreen, "Int", x, "Int", y, "UInt", 0x00CC0020)

    ; Restore and cleanup DCs
    DllCall("gdi32\SelectObject", "Ptr", hdcMem, "Ptr", obm, "Ptr")
    DllCall("gdi32\DeleteDC", "Ptr", hdcMem)
    DllCall("ReleaseDC", "Ptr", 0, "Ptr", hdcScreen)

    if (!ok)
    {
        DllCall("gdi32\DeleteObject", "Ptr", hbm)
        return false
    }

    ; Create a GDI+ Bitmap from HBITMAP
    if DllCall("gdiplus\GdipCreateBitmapFromHBITMAP", "Ptr", hbm, "Ptr", 0, "PtrP", pBitmap)
    {
        DllCall("gdi32\DeleteObject", "Ptr", hbm)
        return false
    }

    ; CLSID for PNG encoder: {557CF406-1A04-11D3-9A73-0000F81EF32E}
    VarSetCapacity(clsid, 16, 0)
    NumPut(0x557CF406, clsid, 0, "UInt")
    NumPut(0x1A04,     clsid, 4, "UShort")
    NumPut(0x11D3,     clsid, 6, "UShort")
    NumPut(0x9A,       clsid, 8,  "UChar")
    NumPut(0x73,       clsid, 9,  "UChar")
    NumPut(0x00,       clsid, 10, "UChar")
    NumPut(0x00,       clsid, 11, "UChar")
    NumPut(0xF8,       clsid, 12, "UChar")
    NumPut(0x1E,       clsid, 13, "UChar")
    NumPut(0xF3,       clsid, 14, "UChar")
    NumPut(0x2E,       clsid, 15, "UChar")

    status := DllCall("gdiplus\GdipSaveImageToFile", "Ptr", pBitmap, "WStr", filePath, "Ptr", &clsid, "Ptr", 0)

    ; Cleanup
    DllCall("gdiplus\GdipDisposeImage", "Ptr", pBitmap)
    DllCall("gdi32\DeleteObject", "Ptr", hbm)

    return (status = 0)
}