Functional Tetris

01. Overview

Engineered a Scala-based implementation of the classic game Tetris, emphasizing high-level functional programming patterns and elegant architectural design. The project focuses on building a robust game engine that handles complex geometric transformations and state transitions without relying on side effects or mutable state.

The implementation features a complete set of tetrominoes (I, J, L, O, S, T, Z), each with specialized rotation behaviors and anchor-based positioning logic.

02. Engineering & Design Patterns

The project leverages a hybrid approach, combining the strengths of functional immutability with object-oriented subclassing to solve complex game logic problems.

• Immutability: The entire game state is managed using strictly immutable data structures. By avoiding mutable containers and local variables, the engine ensures that every state transition is predictable and easy to test.
• Higher-Order Logic: Extensively utilized higher-order functions like map, filter, and exists to process grid data and tetromino coordinates, resulting in concise and expressive code.
• Abstract Rotation Framework: Implemented an abstract Tetromino class with specific subclasses to handle three distinct rotation behaviors. This includes standard 90-degree pivots for J/L/S/T/Z pieces, no-op rotations for the O-piece, and specialized logic for the I-piece.
• Hard Drop Implementation: Engineered a collision-aware "hard drop" mechanic that calculates the lowest possible valid position for a tetromino based on existing board obstacles.

03. Technical Rigor

The primary challenge was ensuring consistent behavior for tetrominoes that do not rotate around a single central block, such as the I and O pieces.

By representing pieces as sets of points relative to a dynamic anchor (rather than a fixed grid), I was able to implement a mathematically consistent rotation system across all piece types. This project demonstrates the ability to translate complex, real-time requirements into a clean, modular Scala codebase that prioritizes maintainability and logical correctness.