+#!/usr/bin/env bash
+# ---------------------------------------------------------------------------
+# Borderlands 2 - two-player split screen on Linux
+#
+# Borderlands 2 has NO native PC split screen, so this launches TWO independent
+# instances that connect over Goldberg's emulated Steam LAN. Each instance gets
+# its own save, its own Goldberg identity, one controller, and half the screen
+# (gamescope), auto-tiled side-by-side on KDE Plasma (KWin).
+#
+# Two build layouts are supported and AUTO-DETECTED:
+# * native - the Aspyr native Linux port (ELF `Borderlands2`) -> no Proton
+# * proton - the Windows build (`Binaries/Win32/Borderlands2.exe`) -> umu/Proton
+# Force one with: MODE=native|proton ./bl2-splitscreen.sh ...
+#
+# Usage:
+# ./bl2-splitscreen.sh check # verify prerequisites for the detected mode
+# ./bl2-splitscreen.sh setup # build the two patched game copies
+# ./bl2-splitscreen.sh run # launch both halves + tile them
+# ./bl2-splitscreen.sh tile # (re)tile the two windows on KDE
+# ./bl2-splitscreen.sh clean # remove generated copies (not the game)
+# ---------------------------------------------------------------------------
+set -uo pipefail
+
+# ============================ CONFIG =======================================
+GAME_DIR="/home/max/.local/share/Steam/steamapps/common/Borderlands 2"
+APPID=49520
+BASE="/home/max/Games/bl2-split"
+
+# --- Display geometry (per-player render size GW/GH and window position GX/GY) --
+# Monitors are read from KDE in LOGICAL px as "X,Y WxH", sorted left-to-right.
+_mons=$(kscreen-doctor -o 2>/dev/null | sed 's/\x1b\[[0-9;]*m//g' \
+ | awk '/^Output:/{e=0} /enabled/{e=1} /Geometry:/&&e{print $2,$3}' | sort -t, -k1 -n)
+_mi=1
+while read -r _pos _size; do
+ [ -z "$_pos" ] && continue
+ _MX[$_mi]=${_pos%,*}; _MY[$_mi]=${_pos#*,}
+ _MW[$_mi]=${_size%x*}; _MH[$_mi]=${_size#*x}
+ _mi=$((_mi+1))
+done <<< "$_mons"
+MON_COUNT=$((_mi-1))
+[ "${MON_COUNT:-0}" -ge 1 ] 2>/dev/null || { _MW[1]=2560; _MH[1]=1440; _MX[1]=0; _MY[1]=0; MON_COUNT=1; }
+
+# DISPLAY_MODE:
+# dual (default when >=2 monitors) -> each player gets a whole monitor, "fullscreen".
+# split (1 monitor) -> both on one monitor, side-by-side. Each half is 16:9 and
+# vertically centered, because a tall 8:9 window clips BL2's landscape UI,
+# and a full-width window would trip BL2 into exclusive fullscreen.
+if [ "$MON_COUNT" -ge 2 ]; then DISPLAY_MODE="${DISPLAY_MODE:-dual}"; else DISPLAY_MODE="${DISPLAY_MODE:-split}"; fi
+
+if [ "$DISPLAY_MODE" = dual ]; then
+ GW[1]=${_MW[1]}; GH[1]=${_MH[1]}; GX[1]=${_MX[1]}; GY[1]=${_MY[1]}
+ GW[2]=${_MW[2]}; GH[2]=${_MH[2]}; GX[2]=${_MX[2]}; GY[2]=${_MY[2]}
+else
+ _hw=$(( ${_MW[1]} / 2 )); _hh=$(( _hw * 9 / 16 ))
+ [ "$_hh" -gt "${_MH[1]}" ] && _hh=${_MH[1]}
+ _wy=$(( ${_MY[1]} + (${_MH[1]} - _hh) / 2 ))
+ GW[1]=$_hw; GH[1]=$_hh; GX[1]=${_MX[1]}; GY[1]=$_wy
+ GW[2]=$_hw; GH[2]=$_hh; GX[2]=$(( ${_MX[1]} + _hw )); GY[2]=$_wy
+fi
+
+# Controllers, matched by STABLE /dev/input/by-id names (survive replug/reboot).
+P1_PAD_GLOB="/dev/input/by-id/*Microsoft_Controller_*-event-joystick" # Xbox Series S|X (wired)
+P2_PAD_GLOB="/dev/input/by-id/*Wireless_Receiver*-event-joystick" # Xbox 360 Wireless Receiver
+P1_VIDPID="0x045e/0x0b12" # Xbox Series S|X (SDL hint; used in proton mode)
+P2_VIDPID="0x045e/0x0719" # Xbox 360 Wireless Receiver
+
+# Controller isolation: "bwrap" (mask other pad's /dev nodes; backend-agnostic)
+# or "sdl" (VID/PID hint; only works for SDL games). Default depends on MODE:
+# native -> bwrap (the Aspyr binary is NOT SDL; the hint does nothing)
+# proton -> sdl (Proton is SDL-based; avoids bwrap<->pressure-vessel nesting)
+ISOLATION="${ISOLATION:-}"
+
+# Proton build for umu (proton mode). Empty = umu auto-selects/downloads UMU-Proton.
+PROTONPATH="${PROTONPATH:-}"
+
+# Native mode: the 2012 Aspyr binary must run inside the Steam scout runtime (the
+# old libs it was built against) with the CLASSIC Mr_Goldberg emu. gbe_fork (both
+# experimental and regular) segfaults this binary; classic goldberg works.
+NATIVE_RUNTIME="${NATIVE_RUNTIME:-/home/max/.steam/steam/ubuntu12_32/steam-runtime/run.sh}"
+
+# Seconds to wait before auto-tiling, i.e. how long the intro logos/movies take to
+# clear on your machine. Bump it if the windows snap into place too early (while
+# still on the splash). You can always re-run `./bl2-splitscreen.sh tile`.
+SPLASH_WAIT="${SPLASH_WAIT:-45}"
+
+# Seconds to wait after launching Player 1 before launching Player 2. Giving P1
+# time to reach the menu and start hosting reduces a co-op-startup race that can
+# crash the second (fragile Aspyr) instance.
+STAGGER="${STAGGER:-25}"
+# ===========================================================================
+
+c_red=$'\e[31m'; c_grn=$'\e[32m'; c_yel=$'\e[33m'; c_dim=$'\e[2m'; c_rst=$'\e[0m'
+say() { printf '%s\n' "$*"; }
+ok() { printf '%s✓%s %s\n' "$c_grn" "$c_rst" "$*"; }
+warn() { printf '%s!%s %s\n' "$c_yel" "$c_rst" "$*"; }
+die() { printf '%s✗ %s%s\n' "$c_red" "$*" "$c_rst" >&2; exit 1; }
+
+# -------------------------------------------------------- mode detection ---
+WIN_EXE_REL="Binaries/Win32/Borderlands2.exe"
+NATIVE_BIN="Borderlands2"
+detect_mode() {
+ if [ -n "${MODE:-}" ]; then echo "$MODE"; return; fi
+ if [ -f "$GAME_DIR/$WIN_EXE_REL" ]; then echo proton
+ elif [ -x "$GAME_DIR/$NATIVE_BIN" ]; then echo native
+ else echo unknown; fi
+}
+MODE="$(detect_mode)"
+[ "$MODE" = unknown ] && die "Cannot find BL2 - neither $NATIVE_BIN nor $WIN_EXE_REL under $GAME_DIR"
+if [ -z "$ISOLATION" ]; then ISOLATION=bwrap; fi # device-masking works for both modes
+GOLDBERG_SO="$BASE/goldberg/libsteam_api.so" # native
+GOLDBERG_DLL="$BASE/goldberg/steam_api.dll" # proton
+
+resolve_pad() { local m; for m in $1; do [ -e "$m" ] && { readlink -f "$m"; return; }; done; }
+
+# ------------------------------------------------------------------ check ---
+cmd_check() {
+ local fail=0
+ say "== Mode: ${c_grn}$MODE${c_rst} (isolation=$ISOLATION) =="
+ say ""; say "== Prerequisites =="
+ command -v qdbus6 >/dev/null && ok "qdbus6 (KWin tiling)" || warn "qdbus6 missing - auto-tiling disabled ${c_dim}(sudo pacman -S qt6-tools)${c_rst}"
+ [ "$ISOLATION" = bwrap ] && { command -v bwrap >/dev/null && ok "bwrap" || { warn "bwrap missing"; fail=1; }; }
+ if [ "$MODE" = proton ]; then
+ command -v gamescope >/dev/null && ok "gamescope" || { warn "gamescope missing ${c_dim}(sudo pacman -S gamescope)${c_rst}"; fail=1; }
+ command -v umu-run >/dev/null && ok "umu-run" || { warn "umu-run missing ${c_dim}(sudo pacman -S umu-launcher)${c_rst}"; fail=1; }
+ else
+ [ -f "$NATIVE_RUNTIME" ] && ok "Steam scout runtime" || { warn "scout runtime missing: $NATIVE_RUNTIME"; fail=1; }
+ command -v strings >/dev/null && ok "strings (interface extraction)" || { warn "strings missing ${c_dim}(sudo pacman -S binutils)${c_rst}"; fail=1; }
+ fi
+
+ say ""; say "== Game =="
+ if [ "$MODE" = native ]; then
+ [ -x "$GAME_DIR/$NATIVE_BIN" ] && file "$GAME_DIR/$NATIVE_BIN" | grep -q ELF \
+ && ok "native ELF: $NATIVE_BIN" || { warn "native binary missing"; fail=1; }
+ else
+ [ -f "$GAME_DIR/$WIN_EXE_REL" ] && ok "Borderlands2.exe" || { warn "exe missing: $WIN_EXE_REL"; fail=1; }
+ fi
+
+ say ""; say "== Goldberg =="
+ if [ "$MODE" = native ]; then
+ if [ -f "$GOLDBERG_SO" ] && file "$GOLDBERG_SO" | grep -q "ELF 32-bit"; then ok "libsteam_api.so (classic Mr_Goldberg, 32-bit ELF)"
+ else warn "missing/invalid $GOLDBERG_SO (need classic Mr_Goldberg linux/x86 libsteam_api.so)"; fail=1; fi
+ else
+ if [ -f "$GOLDBERG_DLL" ] && file "$GOLDBERG_DLL" | grep -qi "PE32 .*i386"; then ok "steam_api.dll (PE32 i386)"
+ else warn "missing/invalid $GOLDBERG_DLL (need Windows x86 gbe_fork experimental)"; fail=1; fi
+ fi
+
+ say ""; say "== Controllers =="
+ local p1 p2 padfail=0; p1=$(resolve_pad "$P1_PAD_GLOB"); p2=$(resolve_pad "$P2_PAD_GLOB")
+ [ -n "$p1" ] && ok "Player 1 pad -> $p1" || { warn "Player 1 pad not connected"; padfail=1; }
+ [ -n "$p2" ] && ok "Player 2 pad -> $p2" || { warn "Player 2 pad not connected (turn it on)"; padfail=1; }
+ # Controllers only matter for 'run'; setup passes REQUIRE_PADS=0.
+ [ "${REQUIRE_PADS:-1}" = 1 ] && [ "$padfail" = 1 ] && fail=1
+
+ say ""
+ [ "$fail" = 0 ] && ok "All good - run: ./bl2-splitscreen.sh setup" || warn "Fix the above, then re-run check."
+ return $fail
+}
+
+# ------------------------------------------------------------------ setup ---
+write_goldberg_settings() { # $1=dir $2=account $3=steamid
+ local ss="$1/steam_settings"; mkdir -p "$ss"
+ printf '%s\n' "$APPID" > "$1/steam_appid.txt"
+ cat > "$ss/configs.user.ini" <<EOF
+[user::general]
+account_name=$2
+account_steamid=$3
+language=english
+ip_country=US
+EOF
+ printf '%s\n' "$2" > "$ss/account_name.txt"
+ printf '%s\n' "$2" > "$ss/force_account_name.txt" # classic goldberg name override
+ printf '%s\n' "$3" > "$ss/force_steamid.txt" # classic goldberg id override
+ printf '%s\n' "$3" > "$ss/user_steam_id.txt"
+ # Two same-host instances (each in its own Proton container) may not reach each
+ # other via UDP broadcast, so co-op hangs at "Creating online session". Tell the
+ # emu to send discovery directly to localhost so they always find each other.
+ printf '127.0.0.1\n' > "$ss/custom_broadcasts.txt"
+}
+
+# Old games hard-crash if the emu returns interfaces they don't expect. Extract
+# the exact interface versions from the game's ORIGINAL Steam lib.
+extract_interfaces() { # $1=steam_settings dir $2=path to original steam_api lib
+ strings -n 5 "$2" 2>/dev/null | grep -E \
+ '^(SteamClient|SteamGameServerStats|SteamGameServer|SteamUserStats|SteamUser|SteamFriends|SteamUtils|SteamMatchMakingServers|SteamMatchMaking|SteamRemoteStorage|SteamScreenshots|SteamHTTP|SteamController|SteamUGC|SteamAppList|SteamApps|SteamMusicRemote|SteamMusic|SteamHTMLSurface|SteamInventory|SteamVideo|SteamParentalSettings|SteamInput|SteamNetworkingUtils|SteamNetworkingSockets|SteamNetworkingMessages|SteamNetworking|SteamParties|STEAMAPPS|STEAMUSERSTATS|STEAMHTTP|STEAMSCREENSHOTS|STEAMUGC|STEAMREMOTESTORAGE|STEAMCONTROLLER|STEAMMUSIC|STEAMAPPLIST|STEAMUSER|STEAMFRIENDS|STEAMUTILS|STEAMNETWORKING)[A-Za-z0-9_]*[0-9]{3}$' \
+ | sort -u > "$1/steam_interfaces.txt"
+}
+
+build_player() { # $1=n $2=account $3=steamid
+ local n="$1" acct="$2" sid="$3" pg="$BASE/p$1/game"
+ say " [$n] symlink game copy -> $pg"
+ rm -rf "$BASE/p$n/game"; mkdir -p "$BASE/p$n/home"
+ cp -as "$GAME_DIR/." "$pg/" || die "cp -as failed (need GNU coreutils)"
+ if [ "$MODE" = native ]; then
+ rm -f "$pg/libsteam_api.so"; cp "$GOLDBERG_SO" "$pg/libsteam_api.so"
+ write_goldberg_settings "$pg" "$acct" "$sid"
+ extract_interfaces "$pg/steam_settings" "$GAME_DIR/libsteam_api.so"
+ [ -s "$pg/steam_settings/steam_interfaces.txt" ] || warn " [$n] no interfaces extracted (game may crash)"
+ else
+ local w="$pg/Binaries/Win32"
+ # Wine resolves a SYMLINKED exe to its target directory and loads DLLs from
+ # THERE (the real steam_api.dll -> "Steam must be running"), bypassing our
+ # Goldberg dll. Make the exes real copies so DLL search happens in our dir.
+ local e real
+ for e in Borderlands2.exe Launcher.exe; do
+ [ -L "$w/$e" ] && { real=$(readlink -f "$w/$e"); cp --remove-destination "$real" "$w/$e"; }
+ done
+ # keep a copy of the original Windows lib before overwriting, for interfaces
+ [ -f "$w/steam_api.dll.orig" ] || cp -L "$w/steam_api.dll" "$w/steam_api.dll.orig" 2>/dev/null
+ write_goldberg_settings "$w" "$acct" "$sid"
+ extract_interfaces "$w/steam_settings" "$w/steam_api.dll.orig"
+ rm -f "$w/steam_api.dll"; cp "$GOLDBERG_DLL" "$w/steam_api.dll"
+ mkdir -p "$BASE/p$n/prefix"
+ fi
+ ok " [$n] account '$acct' (steamid $sid)"
+}
+
+cmd_setup() {
+ REQUIRE_PADS=0 cmd_check || die "check failed - resolve the above before setup"
+ say ""; say "== Building player copies ($MODE) =="
+ build_player 1 "Player1" "76561197960287930"
+ build_player 2 "Player2" "76561197960287931"
+ say ""; ok "Setup complete. Launch with: ./bl2-splitscreen.sh run"
+}
+
+# -------------------------------------------------------------------- run ---
+# Pin the game to windowed half-screen in its own config, so it doesn't apply a
+# saved fullscreen mode after loading (which overrides -windowed and unstacks the
+# tiling). Section-aware: ResX/Fullscreen appear in several sections.
+patch_native_config() { # $1=player home $2=width $3=height
+ local f
+ f=$(find "$1" -ipath "*willowgame/config/willowengine.ini" 2>/dev/null | head -1)
+ [ -f "$f" ] || return 0
+ # Config uses CRLF: strip trailing CR for matching, re-add it on output.
+ awk -v W="$2" -v H="$3" '
+ { cr = (sub(/\r$/,"") ? "\r" : "") }
+ /^\[/ { sec=$0 }
+ {
+ l=$0
+ if (sec=="[WinDrv.WindowsClient]") {
+ if (l ~ /^StartupFullscreen=/) l="StartupFullscreen=False"
+ else if (l ~ /^StartupResolutionX=/) l="StartupResolutionX=" W
+ else if (l ~ /^StartupResolutionY=/) l="StartupResolutionY=" H
+ } else if (sec=="[SystemSettings]") {
+ if (l ~ /^Fullscreen=/) l="Fullscreen=False"
+ else if (l ~ /^WindowedFullscreen=/) l="WindowedFullscreen=False"
+ else if (l ~ /^ResX=/) l="ResX=" W
+ else if (l ~ /^ResY=/) l="ResY=" H
+ } else if (sec=="[FullScreenMovie]") {
+ if (l ~ /^StartupMovies=/) next # drop the intro logos
+ else if (l ~ /^bForceNoMovies=/) l="bForceNoMovies=TRUE"
+ }
+ printf "%s%s\n", l, cr
+ }' "$f" > "$f.tmp" && mv "$f.tmp" "$f"
+}
+
+# Proton keeps its config inside the Wine prefix; drop the intro movies there so
+# the game goes straight to the menu (resolution is handled by -ResX/-ResY args).
+patch_proton_config() { # $1 = prefix dir
+ local f
+ f=$(find "$1/drive_c/users" -ipath "*Borderlands 2*Config/WillowEngine.ini" 2>/dev/null | head -1)
+ [ -f "$f" ] || return 0
+ awk '
+ { cr = (sub(/\r$/,"") ? "\r" : "") }
+ /^\[/ { sec=$0 }
+ { l=$0
+ if (sec=="[FullScreenMovie]") { if (l ~ /^StartupMovies=/) next; else if (l ~ /^bForceNoMovies=/) l="bForceNoMovies=TRUE" }
+ printf "%s%s\n", l, cr }' "$f" > "$f.tmp" && mv "$f.tmp" "$f"
+}
+
+mask_other_pad_args() { # bwrap args hiding every pad except kept node $1
+ local keep="$1" node other g m
+ for g in $P1_PAD_GLOB $P2_PAD_GLOB; do for m in $g; do
+ [ -e "$m" ] || continue
+ node=$(readlink -f "$m"); [ "$node" = "$keep" ] && continue
+ printf -- '--bind /dev/null %s ' "$node"
+ other="${m%-event-joystick}-joystick"
+ [ -e "$other" ] && printf -- '--bind /dev/null %s ' "$(readlink -f "$other")"
+ done; done
+}
+
+launch_player() { # $1=n $2=pad-node $3=vidpid -> sets LAUNCHED_PID
+ local n="$1" pad="$2" vidpid="$3" pg="$BASE/p$1/game" wd
+ local rw="${GW[$n]}" rh="${GH[$n]}" # this player's render size
+ local -a env cmd
+ # No gamescope in either mode: it doesn't pass raw controllers to nested clients,
+ # so the game sees no pad. Run the game windowed and let KWin place it.
+ if [ "$MODE" = native ]; then
+ local home="$BASE/p$n/home"; wd="$pg"
+ patch_native_config "$home" "$rw" "$rh" # pin windowed size in the config
+ env=( "HOME=$home" "XDG_DATA_HOME=$home/.local/share" "XDG_CONFIG_HOME=$home/.config"
+ "LD_LIBRARY_PATH=$pg:${LD_LIBRARY_PATH:-}"
+ "SteamAppId=$APPID" "SteamGameId=$APPID"
+ "SDL_JOYSTICK_ALLOW_BACKGROUND_EVENTS=1" )
+ cmd=( "$NATIVE_RUNTIME" "./$NATIVE_BIN" -windowed "-ResX=$rw" "-ResY=$rh" )
+ else
+ wd="$pg/Binaries/Win32"
+ patch_proton_config "$BASE/p$n/prefix" # skip intro movies (if prefix exists)
+ env=( "WINEPREFIX=$BASE/p$n/prefix" "GAMEID=0" "STORE=none" )
+ # Only use the SDL VID/PID filter in "sdl" mode. With bwrap masking it is
+ # redundant AND can over-filter (it wrongly dropped the 360 pad), so skip it.
+ [ "$ISOLATION" = sdl ] && env+=( "SDL_GAMECONTROLLER_IGNORE_DEVICES_EXCEPT=$vidpid" )
+ [ -n "$PROTONPATH" ] && env+=( "PROTONPATH=$PROTONPATH" )
+ cmd=( umu-run "$pg/$WIN_EXE_REL" -windowed "-ResX=$rw" "-ResY=$rh" )
+ fi
+
+ # bwrap (if used) masks the other pad's /dev/input nodes for this instance.
+ local -a inner
+ if [ "$ISOLATION" = bwrap ]; then
+ local -a maskargs=(); read -ra maskargs < <(mask_other_pad_args "$pad")
+ inner=( bwrap --dev-bind / / --die-with-parent --chdir "$wd" "${maskargs[@]}" -- "${cmd[@]}" )
+ else
+ inner=( "${cmd[@]}" )
+ fi
+
+ say "${c_dim}[$n] pad=$pad ${rw}x${rh} @ ${GX[$n]},${GY[$n]} log=$BASE/p$n/log${c_rst}"
+ # Background in the CURRENT shell (not a $() subshell) so the job is a real
+ # child that cmd_run can wait on; hand the PID back via a global.
+ ( cd "$wd" || exit 1; exec env "${env[@]}" "${inner[@]}" ) >"$BASE/p$n/log" 2>&1 &
+ LAUNCHED_PID=$!
+}
+
+# --------------------------------------------------------- KDE/KWin tiling --
+# One-shot: place each BL2 window on its half in LOGICAL coordinates. Run AFTER
+# the splash movies so the game has settled at its configured size (tiling during
+# the splash fights the game and looks wrong). All geometry is logical px.
+cmd_tile() {
+ command -v qdbus6 >/dev/null || { warn "qdbus6 not found - cannot auto-tile (drag windows manually)"; return 0; }
+ # Left/right split, both windows vertically centered (WIN_Y).
+ # Per-window geometry: window[0]=player1, window[1]=player2 (launch order).
+ local js; js="$(mktemp --suffix=.js)"
+ cat > "$js" <<EOF
+(function(){
+ var geo=[{x:${GX[1]},y:${GY[1]},w:${GW[1]},h:${GH[1]}},
+ {x:${GX[2]},y:${GY[2]},w:${GW[2]},h:${GH[2]}}];
+ var l=(workspace.windowList?workspace.windowList():workspace.clientList());
+ var wins=l.filter(function(w){
+ var s=((w.resourceClass||"")+" "+(w.resourceName||"")+" "+(w.caption||"")).toLowerCase();
+ return s.indexOf("borderlands")>=0 || s.indexOf("steam_app")>=0;
+ });
+ wins.sort(function(a,b){ return (""+a.internalId)<(""+b.internalId)?-1:1; });
+ for(var i=0;i<wins.length && i<2;i++){
+ var w=wins[i], g=geo[i];
+ try{w.fullScreen=false;}catch(e){}
+ try{w.setMaximize(false,false);}catch(e){}
+ try{w.noBorder=true;}catch(e){}
+ w.frameGeometry={x:g.x,y:g.y,width:g.w,height:g.h};
+ }
+})();
+EOF
+ qdbus6 org.kde.KWin /Scripting org.kde.kwin.Scripting.loadScript "$js" bl2tile >/dev/null 2>&1
+ qdbus6 org.kde.KWin /Scripting org.kde.kwin.Scripting.start >/dev/null 2>&1
+ qdbus6 org.kde.KWin /Scripting org.kde.kwin.Scripting.unloadScript bl2tile >/dev/null 2>&1
+ rm -f "$js"
+ ok "Placed windows (${DISPLAY_MODE}: ${GW[1]}x${GH[1]} + ${GW[2]}x${GH[2]})."
+}
+
+cmd_run() {
+ [ -d "$BASE/p1/game" ] && [ -d "$BASE/p2/game" ] || die "run setup first"
+ local p1 p2; p1=$(resolve_pad "$P1_PAD_GLOB"); p2=$(resolve_pad "$P2_PAD_GLOB")
+ [ -n "$p1" ] || die "Player 1 controller not connected"
+ [ -n "$p2" ] || die "Player 2 controller not connected (turn it on)"
+
+ # Steam Input (active while Steam runs) injects VIRTUAL gamepads that SDL grabs
+ # instead of the real pads, which defeats per-instance controller isolation.
+ # Goldberg replaces Steam, so it isn't needed while playing.
+ if pgrep -x steam >/dev/null; then
+ warn "Steam is running - Steam Input's virtual gamepads can break per-player"
+ warn "controller isolation. If a pad drives the wrong window, QUIT STEAM"
+ warn "(Goldberg replaces it). Continuing in 5s..."
+ sleep 5
+ fi
+
+ say "== Launching Borderlands 2 (mode=$MODE, isolation=$ISOLATION, display=$DISPLAY_MODE) =="
+ say "${c_dim}P1 ${GW[1]}x${GH[1]}@${GX[1]},${GY[1]} P2 ${GW[2]}x${GH[2]}@${GX[2]},${GY[2]}${c_rst}"
+ local pid1 pid2
+ launch_player 1 "$p1" "$P1_VIDPID"; pid1=$LAUNCHED_PID
+ sleep "$STAGGER"
+ launch_player 2 "$p2" "$P2_VIDPID"; pid2=$LAUNCHED_PID
+
+ # Place windows AFTER the splash (the game resizes itself during it). Fire a few
+ # times so both instances get caught once settled.
+ ( sleep "$SPLASH_WAIT"; cmd_tile >/dev/null 2>&1
+ sleep 10; cmd_tile >/dev/null 2>&1
+ sleep 15; cmd_tile >/dev/null 2>&1 ) &
+
+ say ""
+ ok "Both instances launching (pids $pid1 / $pid2)."
+ say "In-game: ${c_grn}Player 1${c_rst} → Play → host over LAN. ${c_grn}Player 2${c_rst} → Play → Join → pick the LAN game."
+ local where="their monitors"; [ "$DISPLAY_MODE" = split ] && where="their halves"
+ say "${c_dim}Windows settle onto $where ~${SPLASH_WAIT}s in (after the splash)."
+ say "Re-place any time with: ./bl2-splitscreen.sh tile${c_rst}"
+ say ""; say "Press Ctrl-C to kill both instances."
+ trap 'kill "$pid1" "$pid2" 2>/dev/null' INT TERM
+ wait "$pid1" "$pid2"
+}
+
+# ------------------------------------------------------------------ clean ---
+cmd_clean() { say "Removing generated copies/saves (real game untouched)..."; rm -rf "$BASE/p1" "$BASE/p2"; ok "Done."; }
+
+case "${1:-}" in
+ check) cmd_check ;;
+ setup) cmd_setup ;;
+ run) cmd_run ;;
+ tile) cmd_tile ;;
+ clean) cmd_clean ;;
+ *) say "Usage: $0 {check|setup|run|tile|clean} (MODE=native|proton to force)"; exit 1 ;;
+esac