build(deps): Add SUNSHINE_SYSTEM_VULKAN_HEADERS option (#5103)

Signed-off-by: James Le Cuirot <chewi@gentoo.org>

Author: chewi

cmake/compile_definitions/linux.cmake

@@ -122,8 +122,14 @@ endif()
 
 # vulkan video encoding (via FFmpeg)
 if(${SUNSHINE_ENABLE_VULKAN})
-    # use Vulkan headers from build-deps submodule (system headers may be too old, e.g. Ubuntu 22.04)
-    set(VULKAN_HEADERS_DIR "${CMAKE_SOURCE_DIR}/third-party/build-deps/third-party/FFmpeg/Vulkan-Headers/include")
+    if(NOT SUNSHINE_SYSTEM_VULKAN_HEADERS)
+        # use Vulkan headers from build-deps submodule (system headers may be too old, e.g. Ubuntu 22.04)
+        set(VULKAN_HEADERS_DIR "${CMAKE_SOURCE_DIR}/third-party/build-deps/third-party/FFmpeg/Vulkan-Headers/include")
+    else()
+        find_package(VulkanHeaders REQUIRED)
+        get_target_property(VULKAN_HEADERS_DIR Vulkan::Headers INTERFACE_INCLUDE_DIRECTORIES)
+    endif()
+
     if(NOT EXISTS "${VULKAN_HEADERS_DIR}/vulkan/vulkan.h")
         message(FATAL_ERROR "Vulkan headers not found in build-deps submodule")
     endif()

cmake/prep/options.cmake

@@ -18,6 +18,7 @@ option(SUNSHINE_CONFIGURE_ONLY "Configure special files only, then exit." OFF)
 
 option(SUNSHINE_ENABLE_TRAY "Enable system tray icon." ON)
 
+option(SUNSHINE_SYSTEM_VULKAN_HEADERS "Use system installation of vulkan-headers rather than the submodule." OFF)
 option(SUNSHINE_SYSTEM_WAYLAND_PROTOCOLS "Use system installation of wayland-protocols rather than the submodule." OFF)
 
 if(APPLE)