Reference: Fataawa wa Rasaa.il Shaykh ‘Abdur-Razzaaq ‘Afeefee – Volume 1, Page 189, Fatwa No.20
Question: What is the ruling regarding drawing lines on the masjid [floor] to [assist in] straightening the rows?
Response: If the people are unable to straighten the rows except with [the aid of these lines], then there is no harm [in drawing lines on the masjid floor].
Some masaajid are built deviating away from the qiblah (direction of the Ka’bah in Makkah), and the rows are unable to be straightened except by drawing these lines.
There is no harm in that (i.e. drawing lines on the masjid floor), in shaa.-Allaah.