-#include <simgear/screen/extensions.hxx>
-
-class SGSky;
-extern SGSky *thesky;
-
-extern glPointParameterfProc glPointParameterfPtr;
-extern glPointParameterfvProc glPointParameterfvPtr;
-extern bool glPointParameterIsSupported;
-
-void fgLoadDCS (void);
-void fgUpdateDCS (void);
-void fgBuildRenderStates( void );
-void fgInitVisuals( void );
-void fgRenderFrame();