AutoPlayCPU

How can I turn AutoPlayCPU on?
Also, what files should I look at in the source code for AutoPlayCPU and AutoPlay? I'm curious as to how it works.
Thanks.

How can I turn AutoPlayCPU on?
Hold Shift while pressing F8 in gameplay.

Also, what files should I look at in the source code for AutoPlayCPU and AutoPlay? I'm curious as to how it works.
The code is mostly in two files:
* Player.cpp contains various autoplay logic. (This appears to be the bulk of the code.)
* PlayerAI.cpp loads the AI settings and contains PlayerAI::GetTapNoteScore(const PlayerState* pPlayerState).

m_PlayerController is a good thing to search for, as well as PC_CPU and PC_AUTOPLAY.