Forgot to add find_package(PhysFS)

CMakeLists.txt

@@ -14,6 +14,7 @@ IF(MSVC)
 	ENDIF(USE_MSVC_FAST_FLOATINGPOINT)
 ENDIF(MSVC)
 
+FIND_PACKAGE(PhysFS REQUIRED)
 FIND_PACKAGE(OpenGL REQUIRED)
 FIND_PACKAGE(OpenAL REQUIRED)
 FIND_PACKAGE(Freetype REQUIRED)