extern int mScrollX_last, mScrollY_last;
-extern void InitScrollPlayfield();
+extern void InitScrollPlayfield(void);
extern void UpdatePlayfield(boolean);
-extern void RestorePlayfield();
+extern void RestorePlayfield(void);
extern void DDScrollBuffer_ScrollTo(int X, int Y);
extern void DDScrollBuffer_ScrollTowards(int X, int Y, double Step);