Add square distance functions to xs.inc

plugins/include/xs.inc

@@ -627,6 +627,37 @@ stock Float:xs_vec_distance_2d(const Float:vec1[], const Float:vec2[])
 	               (vec1[1]-vec2[1]) * (vec1[1]-vec2[1]));
 }
 
+/**
+ * Computes the square of the distance between two vectors (points).
+ * This is faster than the distance.
+ *
+ * @param vec1          First vector.
+ * @param vec2          Second vector.
+ *
+ * @return              The square of the distance between two vectors.
+ */
+stock Float:xs_vec_sqdistance(const Float:vec1[], const Float:vec2[])
+{
+	return (vec1[0]-vec2[0]) * (vec1[0]-vec2[0]) +
+	               (vec1[1]-vec2[1]) * (vec1[1]-vec2[1]) +
+	               (vec1[2]-vec2[2]) * (vec1[2]-vec2[2]);
+}
+
+/**
+ * Computes the square of the distance between two 2D vectors (points).
+ * This is faster than the distance.
+ *
+ * @param vec1          First vector.
+ * @param vec2          Second vector.
+ *
+ * @return              The square of the distance between two vectors.
+ */
+stock Float:xs_vec_sqdistance_2d(const Float:vec1[], const Float:vec2[])
+{
+	return (vec1[0]-vec2[0]) * (vec1[0]-vec2[0]) +
+	               (vec1[1]-vec2[1]) * (vec1[1]-vec2[1]);
+}
+
 /**
  * Normalizes a vector. Normalized vector is a vector with the length of 1 unit,
  * but with the same direction as the original vector.