Function projectm_set_preset_locked 

pub unsafe extern "C" fn projectm_set_preset_locked(
    instance: projectm_handle,
    lock: bool,
)

@brief Locks or unlocks the current preset.

Locking effectively disables automatic preset transitions, both hard and soft cuts. Programmatic preset switches will still be executed.

@param instance The projectM instance handle. @param lock True to lock the current preset, false to enable automatic transitions.