Fix release workflow: build native library (libosu_native.so) and include it in APK

The release workflow was producing APKs without the native library, making
Oboe low-latency audio and Vulkan probe features completely non-functional.

- Update CMakeLists.txt to use FetchContent for Oboe (self-contained build)
- Add conditional AndroidNativeLibrary items to csproj for each ABI
- Add NDK/CMake setup and native build steps to release workflow
- Add .gitignore entries for native build artifacts

Agent-Logs-Url: https://github.com/winnerspiros/osu/sessions/89b53171-bb76-44d0-9986-affb5059fb3c

Co-authored-by: winnerspiros <1675249+winnerspiros@users.noreply.github.com>

Author: Copilot

.github/workflows/release.yml

@@ -32,6 +32,34 @@ jobs:
       - name: Install .NET Android workload
         run: dotnet workload install android
 
+      - name: Ensure Android NDK and CMake are available
+        run: |
+          # The ubuntu-latest runner has $ANDROID_HOME pre-installed.
+          # Install a known NDK + CMake version if not already present.
+          yes | sdkmanager --licenses > /dev/null 2>&1 || true
+          sdkmanager --install "ndk;27.0.12077973" "cmake;3.22.1" > /dev/null 2>&1
+
+      - name: Build native library (libosu_native.so)
+        run: |
+          NDK_HOME="$ANDROID_HOME/ndk/27.0.12077973"
+          CMAKE_BIN="$ANDROID_HOME/cmake/3.22.1/bin/cmake"
+
+          for ABI in arm64-v8a armeabi-v7a x86; do
+            echo "::group::Building osu_native for $ABI"
+            "$CMAKE_BIN" -B "build-native/$ABI" -S osu.Android/Native \
+              -DCMAKE_TOOLCHAIN_FILE="$NDK_HOME/build/cmake/android.toolchain.cmake" \
+              -DANDROID_ABI="$ABI" \
+              -DANDROID_PLATFORM=android-30 \
+              -DCMAKE_BUILD_TYPE=Release
+            "$CMAKE_BIN" --build "build-native/$ABI" --config Release -j "$(nproc)"
+            mkdir -p "osu.Android/libs/$ABI"
+            cp "build-native/$ABI/libosu_native.so" "osu.Android/libs/$ABI/"
+            echo "::endgroup::"
+          done
+
+          echo "Native libraries built successfully:"
+          find osu.Android/libs -name "*.so" -exec ls -lh {} \;
+
       - name: Decode keystore
         id: keystore
         run: |

.gitignore

@@ -344,3 +344,7 @@ FodyWeavers.xsd
 
 .idea/.idea.osu.Desktop/.idea/misc.xml
 .idea/.idea.osu.Android/.idea/deploymentTargetDropDown.xml
+
+# Native library build artifacts (built by CMake/NDK in CI or locally)
+osu.Android/libs/
+build-native/

osu.Android/Native/CMakeLists.txt

@@ -7,7 +7,22 @@ set(CMAKE_CXX_STANDARD 17)
 set(CMAKE_CXX_FLAGS_RELEASE "-O2 -flto -fvisibility=hidden -DNDEBUG")
 set(CMAKE_C_FLAGS_RELEASE "-O2 -flto -fvisibility=hidden -DNDEBUG")
 
-find_package(oboe REQUIRED CONFIG)
+# Try pre-installed Oboe first (e.g. via Android NDK prefab or local install).
+# If not found, download and build from source for CI/hermetic builds.
+find_package(oboe QUIET CONFIG)
+
+if(oboe_FOUND)
+    set(OBOE_LIB oboe::oboe)
+else()
+    include(FetchContent)
+    FetchContent_Declare(oboe
+        URL https://github.com/google/oboe/archive/refs/tags/1.9.0.tar.gz
+        URL_HASH SHA256=e030276d25b8bdfaeb04f66646821b1ba4a2b6a580a7e84fb144a478eaecd663
+    )
+    FetchContent_MakeAvailable(oboe)
+    set(OBOE_LIB oboe)
+endif()
+
 find_library(vulkan-lib vulkan)
 find_library(log-lib log)
 find_library(android-lib android)
@@ -18,7 +33,7 @@ add_library(osu_native SHARED
 )
 
 target_link_libraries(osu_native
-    oboe::oboe
+    ${OBOE_LIB}
     ${vulkan-lib}
     ${log-lib}
     ${android-lib}

osu.Android/osu.Android.csproj

@@ -19,10 +19,17 @@
   <ItemGroup>
     <PackageReference Include="Microsoft.Maui.Essentials" Version="8.0.3" />
   </ItemGroup>
-  <!-- Exclude native C++ source files from the build. They are compiled separately via CMake/NDK. -->
+  <!-- Exclude native C++ source files from the managed build. They are compiled separately via CMake/NDK. -->
   <ItemGroup>
     <None Remove="Native\*.cpp" />
     <None Remove="Native\*.h" />
     <None Remove="Native\CMakeLists.txt" />
   </ItemGroup>
+  <!-- Include pre-built native libraries when present (built by the release workflow or local NDK build).
+       When absent, native features (Oboe audio, Vulkan probe) are gracefully disabled at runtime. -->
+  <ItemGroup>
+    <AndroidNativeLibrary Include="libs\arm64-v8a\libosu_native.so" Condition="Exists('libs\arm64-v8a\libosu_native.so')" Abi="arm64-v8a" />
+    <AndroidNativeLibrary Include="libs\armeabi-v7a\libosu_native.so" Condition="Exists('libs\armeabi-v7a\libosu_native.so')" Abi="armeabi-v7a" />
+    <AndroidNativeLibrary Include="libs\x86\libosu_native.so" Condition="Exists('libs\x86\libosu_native.so')" Abi="x86" />
+  </ItemGroup>
 </Project>