add Linux build and launch support

scripts/bootstrap-linux.sh

@@ -0,0 +1,48 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+repo_root="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
+cd "$repo_root"
+
+missing=()
+
+require_cmd() {
+    local name="$1"
+    if ! command -v "$name" >/dev/null 2>&1; then
+        missing+=("$name")
+    fi
+}
+
+echo "Syncing submodule URLs..."
+git submodule sync --recursive
+
+echo "Initializing submodules..."
+jobs="$(nproc 2>/dev/null || echo 4)"
+git submodule update --init --recursive --jobs "$jobs"
+
+require_cmd git
+require_cmd cmake
+require_cmd ninja
+require_cmd pkg-config
+require_cmd clang-20
+require_cmd clang++-20
+require_cmd ld.lld-20
+
+if [[ ! -f third_party/rexglue-sdk/CMakeLists.txt ]]; then
+    echo "Missing third_party/rexglue-sdk/CMakeLists.txt after submodule init." >&2
+    exit 1
+fi
+
+if ((${#missing[@]})); then
+    echo
+    echo "Missing required build tools: ${missing[*]}" >&2
+    echo "On Ubuntu 24.04, install the core toolchain and Linux headers with:" >&2
+    echo "  sudo apt install git cmake ninja-build clang-20 lld-20 pkg-config build-essential libgtk-3-dev libx11-xcb-dev libvulkan-dev libasound2-dev libpulse-dev libpipewire-0.3-dev libudev-dev" >&2
+    echo "If clang-20 is unavailable from Ubuntu apt, install it from https://apt.llvm.org/." >&2
+    exit 1
+fi
+
+echo
+echo "Bootstrap checks passed."
+echo "Configure with:"
+echo "  cmake --preset linux-relwithdebinfo -DSKATE3_GAME_DATA_ROOT=\"\$PWD/game\""

scripts/run-linux.sh

@@ -0,0 +1,54 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+repo_root="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
+build_dir="$repo_root/out/build/linux-relwithdebinfo"
+rexglue_lib_dir="$repo_root/third_party/rexglue-sdk/out/linux-amd64"
+game_dir="${SKATE3_GAME_DATA_ROOT:-$repo_root/game}"
+exe="$build_dir/skate3"
+
+if [[ ! -x "$exe" ]]; then
+    echo "Missing executable: $exe" >&2
+    echo "Build it with:" >&2
+    echo "  cmake --build --preset linux-relwithdebinfo --parallel" >&2
+    exit 1
+fi
+
+if [[ ! -d "$rexglue_lib_dir" ]]; then
+    echo "Missing rexglue runtime library directory: $rexglue_lib_dir" >&2
+    echo "Build rexglue with:" >&2
+    echo "  cmake --build --preset linux-relwithdebinfo --target generate-all --parallel" >&2
+    exit 1
+fi
+
+export LD_LIBRARY_PATH="$rexglue_lib_dir${LD_LIBRARY_PATH:+:$LD_LIBRARY_PATH}"
+
+has_game_root_arg=0
+has_input_backend_arg=0
+has_mnk_mode_arg=0
+for arg in "$@"; do
+    case "$arg" in
+        --game_data_root|--game_data_root=*)
+            has_game_root_arg=1
+            ;;
+        --input_backend|--input_backend=*)
+            has_input_backend_arg=1
+            ;;
+        --mnk_mode|--no-mnk_mode)
+            has_mnk_mode_arg=1
+            ;;
+    esac
+done
+
+default_args=()
+if [[ "$has_game_root_arg" -eq 0 ]]; then
+    default_args+=(--game_data_root="$game_dir")
+fi
+if [[ "$has_input_backend_arg" -eq 0 ]]; then
+    default_args+=(--input_backend=sdl)
+fi
+if [[ "$has_mnk_mode_arg" -eq 0 && "${SKATE3_MNK:-0}" == "1" ]]; then
+    default_args+=(--mnk_mode)
+fi
+
+exec "$exe" "${default_args[@]}" "$@"