}
#define VectorRandom(v) do{(v)[0] = lhrandom(-1, 1);(v)[1] = lhrandom(-1, 1);(v)[2] = lhrandom(-1, 1);}while(DotProduct(v, v) > 1)
#define VectorLerp(v1,lerp,v2,c) ((c)[0] = (v1)[0] + (lerp) * ((v2)[0] - (v1)[0]), (c)[1] = (v1)[1] + (lerp) * ((v2)[1] - (v1)[1]), (c)[2] = (v1)[2] + (lerp) * ((v2)[2] - (v1)[2]))
+#define VectorReflect(a,r,b,c) do{double d;d = DotProduct((a), (b)) * -(1.0 + (r));VectorMA((a), (d), (b), (c));}while(0)
#define BoxesOverlap(a,b,c,d) ((a)[0] <= (d)[0] && (b)[0] >= (c)[0] && (a)[1] <= (d)[1] && (b)[1] >= (c)[1] && (a)[2] <= (d)[2] && (b)[2] >= (c)[2])
#define TriangleNormal(a,b,c,n) ((n)[0] = ((a)[1] - (b)[1]) * ((c)[2] - (b)[2]) - ((a)[2] - (b)[2]) * ((c)[1] - (b)[1]), (n)[1] = ((a)[2] - (b)[2]) * ((c)[0] - (b)[0]) - ((a)[0] - (b)[0]) * ((c)[2] - (b)[2]), (n)[2] = ((a)[0] - (b)[0]) * ((c)[1] - (b)[1]) - ((a)[1] - (b)[1]) * ((c)[0] - (b)[0]))