static-member over extern-global

engine/game_dispatch.cpp

@@ -21,7 +21,7 @@ namespace engine {
   
   game_dispatch::game_dispatch( )
   : screen_size( { 1920.f, 1080.f } )
-  , minimum_frame_duration( engine::FPS60 )
+  , minimum_frame_duration( engine::fps::v60 )
   , scenes( )
   , current_timestamp( clock::now( ) )
   , curr_scene( ) {

engine/time.cpp

@@ -11,8 +11,9 @@ namespace engine {
   using std::chrono::duration_cast;
   using std::chrono::nanoseconds;
   
-  duration const FPS30 { nanoseconds{ 33333333 } };
-  duration const FPS60 { nanoseconds{ 16666666 } };
-  duration const FPS120{ nanoseconds{  8333333 } };
-  duration const FPS144{ nanoseconds{  6944444 } };
+  duration const fps::v24 { nanoseconds{ 41666666 } };
+  duration const fps::v30 { nanoseconds{ 33333333 } };
+  duration const fps::v60 { nanoseconds{ 16666666 } };
+  duration const fps::v120{ nanoseconds{  8333333 } };
+  duration const fps::v144{ nanoseconds{  6944444 } };
 }

engine/time.hpp

@@ -14,10 +14,13 @@ namespace engine {
   using timestamp = std::chrono::time_point<clock>;
   using duration = clock::duration;
   
-  extern duration const FPS30;
-  extern duration const FPS60;
-  extern duration const FPS120;
-  extern duration const FPS144;
+  struct fps {
+    static duration const v24;
+    static duration const v30;
+    static duration const v60;
+    static duration const v120;
+    static duration const v144;
+  };
   
   struct tick {
     timestamp now;