ref: 9090c1e8d2c462e217ab723c684f5a151295a0f6
dir: /dat.h/
#define Eg 9.81 /* earth's gravity (m·s⁻²) */ #define Cd 0.45 /* drag coefficient for a sphere */ #define ρ 1.293 /* air density (kg·m⁻³) */ #define M2PIX (1.0/PIX2M) enum { Stheta = 0, Spos, Svel, Sdrag, Sdeltax, Seta, Sscale, SLEN, }; typedef struct Projectile Projectile; struct Projectile { Point2 p, v; double mass; double r; };