(a) A justice of the supreme court, a judge of the court of criminal appeals, or a justice of a court of appeals engaged in the discharge of official duties in a county other than the justice's or judge's county of residence is entitled to traveling and other necessary expenses, as provided by Chapter 660.
(b) A justice of the supreme court, a judge of the court of criminal appeals, or a justice of a court of appeals is entitled to receive from the state the actual and necessary postage, telegraph, and telephone expenses incurred in the discharge of official duties.
(c) The expenses shall be paid by the state on a sworn itemized account showing the expenses.