- Use vector interpolation functions from math_vector module in

curve subdivision operator.
- Added function interp_v4_v4v4().

source/blender/blenlib/intern/math_vector.c

@@ -55,6 +55,16 @@ void interp_v3_v3v3(float target[3], const float a[3], const float b[3], const f
 	target[2]= s*a[2] + t*b[2];
 }
 
+void interp_v4_v4v4(float target[4], const float a[4], const float b[4], const float t)
+{
+	float s = 1.0f-t;
+
+	target[0]= s*a[0] + t*b[0];
+	target[1]= s*a[1] + t*b[1];
+	target[2]= s*a[2] + t*b[2];
+	target[3]= s*a[3] + t*b[3];
+}
+
 /* weight 3 vectors,
  * 'w' must be unit length but is not a vector, just 3 weights */
 void interp_v3_v3v3v3(float p[3], const float v1[3], const float v2[3], const float v3[3], const float w[3])