tetris-ai

An algorithm that plays Tetris better that you, visualized.

Watch as the AI drops a few dozen tetrominoes per second!

• Based on Minimax
• Supports Android, GUI and CLI.

Supports easy extending with

• different user interfaces
• different AI algorithms

Installation

go get github.com/ozhi/tetris-ai

sudo apt install \
  libglu1-mesa-dev \
  libgles2-mesa-dev \
  libxrandr-dev \
  libxcursor-dev \
  libxinerama-dev \
  libxi-dev \
  libasound2-dev
go get github.com/ozhi/tetris-ai

Running

Android	GUI	CLI
gomobile build	go run main.go	go run main.go -cli
Press the buttons	Press the buttons or <space> - drop next, A - automatic mode	Automatic mode only

Documentation

Code documentation on godoc.org/github.com/ozhi/tetris-ai.

Tetris-AI has four packages:

• tetris contains structs and behaviour of the basic components of the tetris game - the board and tetromino.

• ai contains the artificial intelligence that plays tetris.

  For each move, it searches the state space of the game - all possible board states that can be reached after dropping the current and next tetromino. Each of those states is evaluated and the "best" is chosen.

  The AI evaluates boards using the minimax algorithm - how "good" will the state be even if the next tetromino happens to be very "bad".

  How "good" a board is is determined with a utility function that takes in to account:

  • the number of lines cleared in the game (more is better)
  • the aggregated height of the columns (less is better)
  • the 'bumpiness' of the board (difference in column heights) (less is better)
  • the number of 'holes' in the board (less is better)

  Each of these is taken with a different coefficient, chosen with trial and error.

  In order for the AI to play fast enough (tens of tetrominoes every second), the alpha-beta pruning optimization is used to reduce the size of the state tree to be searched.

• gui contains the graphical user interface of the app.

  It uses the ebiten library for visualizations.

• cli contains the command-line interface of the app.

  It is simple and boring.

License

Tetris-ai is licensed under MIT license. See LICENSE.