Made a couple more tweaks:
#SingleInstance, force
SetTitleMatchMode, 1
ScreenW := A_ScreenWidth
ScreenH := A_ScreenHeight
FontSize := 64
SubTextY := (ScreenH - FontSize) / 2
; Move the mouse to the bottom right:
MouseMove % ScreenW, ScreenH, 0
; Display a single image as a SplashImage:
SplashImage, , b w%ScreenW% h%ScreenH% x0 y0 zw%ScreenW% zh%SubTextY% fs%FontSize% ctWhite cwBlack, Loading..., , demulSplashWindow, OneTwoPunchBB-Italic
RomName := A_Args[1]
Run %ComSpec% /c "demul.exe -run=naomi -rom=%RomName%", , Hide
; Run %ComSpec% /c "demul.exe -run=naomi -rom=mvsc2", , Hide
; When demul.exe loads a rom, its title changes to a string beginning with gpuDX11hw:
; (Could change dep. on DirectX ver., but just checking the process jumps the gun)
WinWaitActive, gpuDX11hw, , 10
SplashImage, Off
Send !{Enter}
return
#IfWinActive, ahk_exe demul.exe
Esc::
WinClose, A
ExitApp
#IfWinActive
No external image file needed: I didn't realize ahk's SplashImage can be left blank and a background color provided as an option. This works for me! (in conjunction with the following batch file):
@echo off
dfs.exe %1
Unrelated (well, partially), but Reicast: is it possible to use without retroarch? I'm really an emulation noob, so I apologize if that's a stupid question!