+noref vector _vlen2;
+#define vlen2(v) (_vlen2 = (v), dotproduct(_vlen2, _vlen2))
+
+#if 1
+noref float _vdist_f;
+/** Vector distance comparison, avoids sqrt() */
+#define vdist(v, cmp, f) (vlen2(v) cmp (_vdist_f = (f), _vdist_f * _vdist_f))
+#else
+#define vdist(v, cmp, f) (vlen(v) cmp (f))
+#endif
+
+#if 1
+#define dotproduct(a, b) ((a) * (b))
+#else
+noref vector _dotproduct_a, _dotproduct_b;
+#define dotproduct(a, b) \
+ (_dotproduct_a = (a), _dotproduct_b = (b), \
+ _dotproduct_a.x * _dotproduct_b.x \
+ + _dotproduct_a.y * _dotproduct_b.y \
+ + _dotproduct_a.z * _dotproduct_b.z)
+#endif
+
+#if 1