53 #define MYMAX(a, b) ((a) > (b) ? (a) : (b))  argument
54 #define MYMIN(a, b) ((a) < (b) ? (a) : (b))  argument
56 #define VDOT(return, a, b) return = (a.x * b.x + a.y * b.y + a.z * b.z);  argument
58 #define RAYPNT(c, a, b)        \  argument
59     c.x = a.o.x + (a.d.x * b); \
60     c.y = a.o.y + (a.d.y * b); \
61     c.z = a.o.z + (a.d.z * b);
63 #define VSUB(a, b, c)  \  argument
64     c.x = (a.x - b.x); \
65     c.y = (a.y - b.y); \
66     c.z = (a.z - b.z);
68 #define VCROSS(a, b, c)                   \  argument
69     c->x = (a->y * b->z) - (a->z * b->y); \
70     c->y = (a->z * b->x) - (a->x * b->z); \
71     c->z = (a->x * b->y) - (a->y * b->x);