Tetris Game

This Elixir project implements a Tetris game engine and provides a Mix task that plays Tetris according to the given inputs, outputting the final grid height for each game.

Installation

1. Install Elixir: Follow the official Elixir installation guide for your operating system.

2. Install dependencies (if any):

   mix deps.get

3. Compile the project:

   mix compile

Running the Game

To run the game and output the final grid height for each game input, use the following command, where input.txt contains the game inputs:

```bash
mix tetris.play < input.txt
```

Example Input Format:

Each line of the input file should be a comma-separated list of tetromino shapes and the column in which they should be placed:

I0,I4,Q8
I0,I4,Q8,I0,I4
L0,J2,L4,J6,Q8

Example Usage:

mix tetris.play < input.txt

Example Output:

1
0
2

How it Works

Tetris Module

The Tetris module serves as the entry point to the game. It provides a play/2 function that takes a list of inputs (a list of Input structs) and processes them to return the final game grid.

Inputs: Each input consists of a tetromino and the column where it should be placed. The Input.new/2 function can be used to instantiate the inputs. Non-cascading Mode: The game engine doesn't cascade rows when they are cleared. Rows above a cleared row remain in place. Input/output Handling: The Tetris module does not handle input or output. This is managed by the calling module, which, in this case, is the Mix.Tasks.Tetris.Play task.

Tetris.Tetromino Module

This module represents the tetrominoes used in the game. Each tetromino is defined as a sequence of bits, which makes operations like shifting, dropping, and clearing easier to handle.

Bitwise Operations: Tetrominoes are manipulated using bitwise operations. Please see the source code for more details.

Shape Representation: The tetromino shapes are represented as binary masks. For instance, the Q tetromino is represented as:

1100000000000000
1100000000000000

Tetris.Grid Module

This module defines the game grid. The grid is represented as a large integer where each bit represents a cell. The size of the grid is limited to 10 columns (represented by 16 bits per row). Since the size is fixed to 10 columns it was decided to use a 16-bit integer to represent the grid to simplify the implementation.