externals: allow user to use system openal (#7145)

externals/CMakeLists.txt

@@ -344,6 +344,11 @@ endif()
 
 # OpenAL Soft
 if (ENABLE_OPENAL)
+    if(USE_SYSTEM_OPENAL)
+        add_library(OpenAL INTERFACE)
+        find_package(OpenAL REQUIRED)
+        target_link_libraries(OpenAL INTERFACE OpenAL::OpenAL)
+    else()
         set(ALSOFT_EMBED_HRTF_DATA OFF CACHE BOOL "")
         set(ALSOFT_EXAMPLES OFF CACHE BOOL "")
         set(ALSOFT_INSTALL OFF CACHE BOOL "")
@@ -353,6 +358,7 @@ if (ENABLE_OPENAL)
         set(ALSOFT_UTILS OFF CACHE BOOL "")
         set(LIBTYPE "STATIC" CACHE STRING "")
         add_subdirectory(openal-soft EXCLUDE_FROM_ALL)
+    endif()
 endif()
 
 # VMA

externals/cmake-modules/CitraHandleSystemLibs.cmake

@@ -22,6 +22,7 @@ option(USE_SYSTEM_ENET "Use the system libenet (instead of the bundled one)" OFF
 option(USE_SYSTEM_CRYPTOPP "Use the system cryptopp (instead of the bundled one)" OFF)
 option(USE_SYSTEM_CUBEB "Use the system cubeb (instead of the bundled one)" OFF)
 option(USE_SYSTEM_LODEPNG "Use the system lodepng (instead of the bundled one)" OFF)
+option(USE_SYSTEM_OPENAL "Use the system OpenAL (instead of the bundled one)" OFF)
 
 # Qt and MoltenVK are handled separately
 CMAKE_DEPENDENT_OPTION(DISABLE_SYSTEM_SDL2 "Disable system SDL2" OFF "USE_SYSTEM_LIBS" OFF)
@@ -43,6 +44,7 @@ CMAKE_DEPENDENT_OPTION(DISABLE_SYSTEM_ENET "Disable system libenet" OFF "USE_SYS
 CMAKE_DEPENDENT_OPTION(DISABLE_SYSTEM_CRYPTOPP "Disable system cryptopp" OFF "USE_SYSTEM_LIBS" OFF)
 CMAKE_DEPENDENT_OPTION(DISABLE_SYSTEM_CUBEB "Disable system cubeb" OFF "USE_SYSTEM_LIBS" OFF)
 CMAKE_DEPENDENT_OPTION(DISABLE_SYSTEM_LODEPNG "Disable system lodepng" OFF "USE_SYSTEM_LIBS" OFF)
+CMAKE_DEPENDENT_OPTION(DISABLE_SYSTEM_OPENAL "Disable system OpenAL" OFF "USE_SYSTEM_LIBS" OFF)
 
 set(LIB_VAR_LIST
     SDL2
@@ -64,6 +66,7 @@ set(LIB_VAR_LIST
     CRYPTOPP
     CUBEB
     LODEPNG
+    OPENAL
     )
 
 # First, check that USE_SYSTEM_XXX is not used with USE_SYSTEM_LIBS

externals/cmake-modules/FindOpenAL.cmake

@@ -0,0 +1,36 @@
+if(NOT OPENAL_FOUND)
+    pkg_check_modules(OOPENAL_TMP libopanal)
+
+    find_path(OPENAL_INCLUDE_DIRS NAMES al.h
+            PATHS
+            ${OPENAL_TMP_INCLUDE_DIRS}
+            /usr/include/AL
+            /usr/include
+            /usr/local/include/AL
+            /usr/local/include
+            )
+
+    find_library(OPENAL_LIBRARY_DIRS NAMES openal
+            PATHS
+            ${OPENAL_TMP_LIBRARY_DIRS}
+            /usr/lib
+            /usr/local/lib
+            )
+
+    if(OPENAL_INCLUDE_DIRS AND OPENAL_LIBRARY_DIRS)
+        set(OPENAL_FOUND TRUE CACHE INTERNAL "OpenAL found")
+        message(STATUS "Found OpenAL: ${OPENAL_LIBRARY_DIRS}, ${OPENAL_INCLUDE_DIRS}")
+    else()
+        set(OPENAL_FOUND FALSE CACHE INTERNAL "OpenAL found")
+        message(STATUS "OpenAL not found.")
+    endif()
+endif()
+
+if(OPENAL_FOUND AND NOT TARGET OpenAL::OpenAL)
+    add_library(OpenAL::OpenAL UNKNOWN IMPORTED)
+    set_target_properties(OpenAL::OpenAL PROPERTIES
+            INCLUDE_DIRECTORIES ${OPENAL_INCLUDE_DIRS}
+            INTERFACE_LINK_LIBRARIES ${OPENAL_LIBRARY_DIRS}
+            IMPORTED_LOCATION ${OPENAL_LIBRARY_DIRS}
+            )
+endif()