ref: 25bcd2fab4c8c6bdc15f72140c966612a2409c44
dir: /scroll.h/
typedef struct Scroll Scroll; struct Scroll { Rectangle r; uint p₀, p₁, tot; Image *image, *cols[NCOL]; }; Rectangle scrollinit(Scroll *s, Rectangle r, Image *b, Image **cols); void scrollpos(Scroll *s, uint p₀, uint p₁, uint tot); int scrollactive(Scroll *s, Mouse *m); uint scrollscr(Scroll *s, Mouse *m);