frame-autopass: automatic colour/IR passthrough for the Steam Frame

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

scripts/fetch-deps.sh

@@ -0,0 +1,29 @@
+#!/bin/sh
+# Fetch the build dependencies into gitignored directories. Nothing is
+# installed system-wide.
+set -eu
+cd "$(dirname "$0")/.."
+
+ZIG_VERSION=0.16.0
+ZIG_SHA256=70e49664a74374b48b51e6f3fdfbf437f6395d42509050588bd49abe52ba3d00
+OPENVR_COMMIT=0924064316de3effbcd1acf1e309182a2deb1c05  # OpenVR SDK 2.15.6
+
+if [ ! -x toolchain/zig-x86_64-linux-$ZIG_VERSION/zig ]; then
+    mkdir -p toolchain
+    tarball=zig-x86_64-linux-$ZIG_VERSION.tar.xz
+    curl -sSfL -o toolchain/$tarball https://ziglang.org/download/$ZIG_VERSION/$tarball
+    echo "$ZIG_SHA256  toolchain/$tarball" | sha256sum -c
+    tar -C toolchain -xf toolchain/$tarball
+    rm toolchain/$tarball
+fi
+
+if [ ! -f third_party/openvr/headers/openvr.h ]; then
+    mkdir -p third_party/openvr
+    git -C third_party/openvr init -q
+    git -C third_party/openvr fetch -q --depth 1 https://github.com/ValveSoftware/openvr $OPENVR_COMMIT
+    git -C third_party/openvr checkout -q FETCH_HEAD
+    # The SDK repo ships prebuilt binaries for every platform; only the
+    # headers and the loader source are needed.
+    rm -rf third_party/openvr/bin third_party/openvr/lib third_party/openvr/samples \
+        third_party/openvr/unity_package third_party/openvr/controller_callouts third_party/openvr/.git
+fi