While the Rocks'n'Diamonds comes with its own replay feature, the implemented version which the controller uses is more practical for our use cases.
Replay files are saved in the ./src/ai/replays directory as simple text files. A folder is created for each program run, with the folder name being a combination of the datetime and PID of the client when it is ran. The first 3 lines are the current engine random seed, the level-set name, and the level number. This allows the client to know what level to load when replaying that run. The engine random seed is so that the engine random state can be set to what it was during the run, for reproducibility in stochastic environments.
The subsequent lines are the actions sent by the controller to the agent, in order they appear. If the controller requested a restart, then an action of restart is sent. The name of replay files are the level number that is being ran by the controller.
The replay file contains all moves made over all replays of a level. This file is called complete.txt. Since this can be quite long, the complete replay file needs to be enabled using the -save_run command as explained below. For each level completed by the controller, an additional replay file is created titled i.txt, where i is the level number. These replay files only contain the run on the last play through, which is the one which solves the level. This is ideal for when you only want to view what the agent has done to solve the level.
To enable the replay save feature for all runs, use the command line argument -save_run.
./rocksndiamonds_headless -controller MCTS -levelset hard_deadlock -loadlevel 1 -save_runWhen loading a replay file, the engine assumes that it exists in the ./src/ai/replays directory. To load a replay file, use the -replay command line argument and specify the file name. For example, to load the replay file of the complete runs ./src/ai/replays/2020-01-01_01:22:33_12345/complete.txt, use
./rocksndiamonds -replay "2020-01-01_01:22:33_12345/complete.txt"Similarly, to load the replay file of the single run for level 1 ./src/ai/replays/2020-01-01_01:22:33_12345/1.txt, use
./rocksndiamonds -replay "2020-01-01_01:22:33_12345/1.txt"