Mostly redo the steam build script to link with an older glibc so tha…

…t we can run on steamdeck. Uses cargo-zigbuild for now. (#193)

scripts/build_thetawave_for_steam.sh

@@ -7,23 +7,44 @@ set -exo pipefail
 #│  └── thetawave
 #└── windows
 #   └── thetawave.exe
-# The only positional argument is the out directory
+# The only positional argument is the out directory. This script _always_ expects to be run on linux. It will
+# cross-compile for windows as needed.
+#
+# This MUST be run with the git/game repo root as the current working directory to find all of the config files.
 
 
 function build_thetawave_executable_to_directory(){
         # Put executable for rustc target $1 in $2/$3
         # $1 = rustc target
         # $2 = output directory (will be created if it doesn't exist)
         # $3 = executable name (thetawave or thetawave.exe)
-        rustup target add "$1"
-        cargo build --release --target "$1" --features storage --features cli
+        # $4 cargo build command. Either `build` or `zigbuild`
+        local baseTargetName
+        local cargoBuildCommand="${4:-build}"
+        # cargo-zigbuild allows adding a suffix with the glib version to the rustc target, but that is removed for most
+        # purposes. Removes everything after the first '.', preserving the rustc target if it is "nomal"/directly a
+        # rustc target.
+        baseTargetName=$(echo "$1" | cut -d '.' -f 1)
+        rustup target add "$baseTargetName"
+        cargo "$cargoBuildCommand" --release --target "$1" --features storage --features cli --features arcade
         mkdir -p "./$2/"
-        cp -R "./target/$1/release/$3" "./$2/$3"
+        cp -R "./target/$baseTargetName/release/$3" "./$2/$3"
 
 }
 function buildThetawaveForSteamMain() {
-        local outDir="${1:steam_out}"
-        build_thetawave_executable_to_directory "x86_64-unknown-linux-gnu" "$outDir/linux/" thetawave
+        local twRepoRoot # like ../ if run from the script location. git/game repo root
+        twRepoRoot="$(dirname "$(dirname realpath "$0")")"
+        local outDir="${1:-$twRepoRoot/steam_out}"
+        echo "Building thetawave game at path $outDir"
+        # Currently we only use zigbuild to link with older glibc versions. If cargo gets a nice way to do that, we can
+        # drop this dependency. An alternative could be to compile in a VM/container with an older glibc version
+        # See https://kobzol.github.io/rust/ci/2021/05/07/building-rust-binaries-in-ci-that-work-with-older-glibc.html#solution)
+        # and https://stackoverflow.com/questions/57749127/how-can-i-specify-the-glibc-version-in-cargo-build-for-rust .
+        cargo install cargo-zigbuild
+        # We _need_ to link against a lower version of glibc for steamdeck. Lower this number to increase compatibility
+        # with linux distros that do not update glibc frequently. Lowering the glibc version (strictly?) increases
+        # compatibility while increasing it _might_ improve performance and security (citation needed on the last part)
+        build_thetawave_executable_to_directory "x86_64-unknown-linux-gnu.2.34" "$outDir/linux/" thetawave "zigbuild"
         build_thetawave_executable_to_directory "x86_64-pc-windows-gnu" "$outDir/windows/" thetawave.exe
 }
 buildThetawaveForSteamMain "$@"