CMAKE: don't compile sdl tests

Author: mgerhardy

libs/CMakeLists.txt

@@ -7,19 +7,15 @@ add_subdirectory(libvorbis-1.3.7)
 add_subdirectory(opus-1.3.1)
 add_subdirectory(opusfile-0.12)
 add_subdirectory(zlib)
-if (UNIX)
-	if (USE_INTERNAL_SDL)
-		add_subdirectory(SDL2)
-	else()
-		find_package(PkgConfig)
-		pkg_check_modules(SDL2 REQUIRED sdl2)
-		add_library(SDL2_system INTERFACE)
-		add_library(SDL2_main INTERFACE)
-		target_include_directories(SDL2_system INTERFACE ${SDL2_INCLUDE_DIRS})
-		target_link_libraries(SDL2_system INTERFACE ${SDL2_LINK_LIBRARIES})
-		add_library(SDL2::SDL2 ALIAS SDL2_system)
-		add_library(SDL2::SDL2main ALIAS SDL2_main)
-	endif()
+if (UNIX AND NOT USE_INTERNAL_SDL)
+	find_package(PkgConfig)
+	pkg_check_modules(SDL2 REQUIRED sdl2)
+	add_library(SDL2_system INTERFACE)
+	add_library(SDL2_main INTERFACE)
+	target_include_directories(SDL2_system INTERFACE ${SDL2_INCLUDE_DIRS})
+	target_link_libraries(SDL2_system INTERFACE ${SDL2_LINK_LIBRARIES})
+	add_library(SDL2::SDL2 ALIAS SDL2_system)
+	add_library(SDL2::SDL2main ALIAS SDL2_main)
 else()
 	set(OUTPUT_DIRECTORY "${ROOT_DIR}/${ENGINE_BINARY_DIR}")
 	set(CMAKE_RUNTIME_OUTPUT_DIRECTORY_DEBUG "${OUTPUT_DIRECTORY}")