AHK Crosshair Overlay

Crosshair Overlay.ahk

#NoEnv ; For performance and compatibility with future AutoHotkey releases

Gui, -Caption +AlwaysOnTop +ToolWindow +LastFound +E0x20 ; +E0x20 makes the window click-through
Gui, Margin, 0, 0 ; Remove margins to get perfect alignment with center of screen
Gui, Add, Picture, , Crosshair.png ; Picture file name, in the same folder as the script
Controlgetpos, , , picW, picH, , ; Store picture width and height in variables
xPos := A_ScreenWidth/2 - picW/2
yPos := A_ScreenHeight/2 - picH/2 ; Used to align picture center with screen center
Gui, Show, x%xPos% y%yPos% NA ; Crosshair can be moved by manually setting X and Y numbers
Gui, Color, 0000FF ; Set background color. You might need to change this color to one not contained in the crosshair
WinSet, TransColor, 0000FF ; Make the background color transparent

Gdip Crosshair Overlay.ahk

; Uses a GDI+ Library made by tic (Tariq Porter). Download it here(required): ahkscript.org/boards/viewtopic.php?t=6517
; Requires Gdip.ahk either in your Lib folder as standard library or using #Include
#Include, Gdip.ahk

#NoEnv ; For performance and compatibility with future AutoHotkey releases

If !pToken := Gdip_Startup(){
	MsgBox, 48, gdiplus error!, Gdiplus failed to start. Please ensure you have gdiplus on your system
	ExitApp
}
OnExit, Exit

Gui, -Caption +AlwaysOnTop +ToolWindow +LastFound +OwnDialogs +E0x80000 +HwndCHhwnd +E0x20 ; Create layered window (+E0x80000 is required for UpdateLayeredWindow). +HwndName creates a variable with a name of your choice, containing the Hwnd of the window. +E0x20 makes the window click-through
Gui, Show, NA ; Show window without activating it

pBitmap := Gdip_CreateBitmapFromFile("Crosshair.png") ; Get bitmap from the image
If !pBitmap { ; Ensure we actually got a bitmap from the file, in case the file was corrupt or other error
	MsgBox, 48, File loading error!, Could not load 'Crosshair.png'
	ExitApp
}

width := Gdip_GetImagewidth(pBitmap), height := Gdip_GetImageheight(pBitmap)

hbm := CreateDIBSection(width, height) ; Create a gdi bitmap with width and height of what we are going to draw into it. This is the drawing area for everything
hdc := CreateCompatibleDC() ; Get a device context compatible with the screen
obm := SelectObject(hdc, hbm) ; Select the bitmap into the device context
gPointer := Gdip_GraphicsFromHDC(hdc) ; Get a pointer to the bitmap graphics

; DrawImage draws the bitmap we took from the file into the graphics of the bitmap we created
; Gdip_DrawImage(pGraphics, pBitmap, dx, dy, dw, dh, sx, sy, sw, sh, Matrix) d = destination and s = source. The matrix is for changing colours when drawing
Gdip_DrawImage(gPointer, pBitmap, 0, 0, width, height, 0, 0, width, height)

; Update the window(CHhwnd) with a handle to our bitmap (hdc), specifying screen coordinates and size (x,y,w,h)
; A_Screenwidth/2-width/2 aligns the center of the image with the center of your screen
UpdateLayeredWindow(CHhwnd, hdc, A_Screenwidth/2-width/2, A_Screenheight/2-height/2, width, height)


SelectObject(hdc, obm) ; Select the object back into the hdc
DeleteObject(hbm) ; The bitmap may now be deleted
DeleteDC(hdc) ; The device context related to the bitmap may be deleted
Gdip_DeleteGraphics(gPointer) ; The graphics may now be deleted
Gdip_DisposeImage(pBitmap) ; The bitmap we made from the image may be deleted
return

Exit:
	Gdip_Shutdown(pToken)
	ExitApp
return

It's almost perfect, I would just change the following line:

Gui, -Caption +AlwaysOnTop +ToolWindow +LastFound +OwnDialogs +E0x80000 +HwndCHhwnd

If we add +E0x20 the crosshair becomes click-through!

Gui, -Caption +AlwaysOnTop +ToolWindow +LastFound +OwnDialogs +E0x80000 +HwndCHhwnd +E0x20

I made it to detect the game with these additions and its toggles off automatically when alt tabbing or closing game.

SetTimer, process1check, 1000
process1check:
IfWinActive, ahk_exe RustClient.exe
		Gui, Show, NA ; Show window without activating it
	else
		Gui, Show, hide
return