How did the mediopassive voice function in Hittite and Luwian?

In the Anatolian languages, including Hittite and Luwian, the mediopassive voice functions as a grammatical category distinct from the active voice to mark specific relationships between the subject and the action.1

Its primary functions include:

• Reflexive actions: It marks actions that affect the subject, such as the contrast between the active neyanzi ("they turn someone or something else") and the mediopassive neyantari ("they turn themselves").1
• Internal states: It is used for actions that are inherently internal to the subject, such as the verb for "lies" or "reclines" (Hittite kittari, Luwian zīyar).1
• Passive meaning: It is employed when a subject has an action performed upon it, as seen in the Hittite dattari ("is taken").1

This voice serves as a versatile tool for expressing middle and passive meanings within the verbal system of these ancient languages.1