```
sudo pacman -S umu-launcher qt6-tools bubblewrap libarchive curl binutils
```
-- **Recommended:** an entropy daemon so the second instance doesn't stall on
- startup waiting for randomness (see Troubleshooting):
- ```
- sudo pacman -S haveged && sudo systemctl enable --now haveged
- ```
+- *Optional:* `gamemode` (+ `lib32-gamemode`) — the script runs each game under
+ `gamemoderun` if present (performance CPU governor while playing). Not required.
- Two Xbox controllers (any two distinguishable pads).
## Setup
```
./bl2-splitscreen.sh run
```
- With two monitors each game opens fullscreen on its own display; with one, they
- tile side-by-side. In-game: **Player 1** *Play → host over LAN*; **Player 2**
- *Play → Join → pick the LAN game*. `Ctrl-C` kills both.
+ Both instances launch at once. While they load, **wiggle the mouse** until both
+ reach the main menu (the script prints a loud reminder), and leave the windows
+ alone — after ~30 s the script moves each onto its screen (fullscreen per monitor
+ with two displays, side-by-side with one). In-game: **Player 1** *Play → host over
+ LAN*; **Player 2** *Play → Join → pick the LAN game*. `Ctrl-C` kills both.
## Commands
`rm p{1,2}/game/Binaries/Win32/steam_settings/configs.main.ini`
- **They don't see each other on LAN:** Player 1 hosts first (the script staggers
launches). Discovery uses `custom_broadcasts.txt` (localhost).
-- **The 2nd instance takes ages to reach the menu — and speeds up when you jiggle
- the mouse:** classic **entropy starvation** — something in the Wine/Goldberg/crypto
- path blocks on `/dev/random` waiting for randomness, and mouse movement feeds the
- pool. Fix it with an entropy daemon (also in Requirements):
- `sudo pacman -S haveged && sudo systemctl enable --now haveged`.
- The two instances also share a DXVK shader cache (`dxvk-cache/`) so the 2nd reuses
- the 1st's shaders; if still slow, raise the launch gap: `STAGGER=45 ./bl2-splitscreen.sh run`.
+- **The 2nd instance is visible but stuck on the loading screen — and only advances
+ when you jiggle the mouse.** Root cause: BL2's `bPauseOnLossOfFocus=TRUE` — the
+ game **pauses itself whenever its window isn't focused**. In split-screen only one
+ window is focused at a time, so the unfocused instance freezes until an input event
+ wakes it. `setup`/`run` patch each prefix's `WillowEngine.ini` to
+ `bPauseOnLossOfFocus=FALSE` so every instance keeps running unfocused. (This was
+ *not* CPU scaling, entropy, or window occlusion — those were dead ends.) The
+ instances also share a DXVK shader cache so the 2nd reuses the 1st's compiled
+ shaders; `STAGGER=45` further separates their loads if a cold first run is slow.
+- **Two soundtracks at once:** each instance sets `bMuteAudioWhenNotInFocus=TRUE`, so
+ only the focused window plays audio — the sound follows whichever instance you're
+ focused on, instead of both playing together.
- **In-game "Quit Borderlands 2 → Yes" does nothing / hangs:** the game's shutdown
path stalls under Goldberg (Steam-networking cleanup, worse with offline mode).
Don't use in-game Quit — close with **`./bl2-splitscreen.sh kill`** or **Ctrl-C**