Modifying Ardupilot 3.2.1 's code

I’m from korea and I’m interested in programming my own code(it is just my hobby but I’m studying hard these days)

and I’m really really respect and admire people who are concerned in this ArduPilot.

I’m learning C and C++ these days.

I recently have bought APM 2.6, and tried to examine its code.

I followed all instruction in the link :

and there must be shown up the libraries, but there are no library.

just occured this menu.

I found the directory.

I think the file’s format shouldn’t be cpp or h (shown in the picture.)

for Arduino IDE, file’s format must be something different with .cpp or .h

I think the Ardupilot version is more than 3.2.1 and don’t compatible with APM 2.6 board.

how can I handle Arduino IDE with APM 2.6 board and ArduPilot 3.2.1…?