minor include stuff

src/rntviewer.cpp

@@ -28,7 +28,7 @@
 
 #define GLFW_INCLUDE_NONE
 #include <GLFW/glfw3.h>
-#endif
+#endif // RNT_NO_GFX
 
 #define V_MAJOR "0"
 #define V_MINOR "2"
@@ -46,8 +46,11 @@
 #include "render.h"
 #include "app_state.h"
 
-// @Platform
+#if defined(R__LINUX)
 #include "platform_linux.h"
+#else
+#error "Unsupported platform"
+#endif
 
 namespace chr = std::chrono;
 
@@ -60,7 +63,7 @@ namespace chr = std::chrono;
 #ifndef RNT_NO_GFX
 #include "render.cpp"
 #include "mainloop.cpp"
-#endif
+#endif // RNT_NO_GFX
 
 internal
 void app_cleanup(App_State &app)