+#define DotProduct2(a,b) ((a)[0]*(b)[0]+(a)[1]*(b)[1])
+#define Vector2Clear(a) ((a)[0]=(a)[1]=0)
+#define Vector2Compare(a,b) (((a)[0]==(b)[0])&&((a)[1]==(b)[1]))
+#define Vector2Copy(a,b) ((b)[0]=(a)[0],(b)[1]=(a)[1])
+#define Vector2Negate(a,b) ((b)[0]=-((a)[0]),(b)[1]=-((a)[1]))
+#define Vector2Set(a,b,c,d,e) ((a)[0]=(b),(a)[1]=(c))
+