Snake Game

A classic Snake game implementation in C with SDL3, featuring both human-playable and AI-controlled modes. Inspired by this video.

Features

• Person Mode: Play the game yourself using keyboard controls
• Machine Mode: Watch the AI play using BFS plus a longest-path fallback
• SDL3 graphical versions and terminal versions of both modes(fully made by Opus 5)
• Customizable grid size
• Circular queue-based snake body management

Project Structure

Snake_algorithms/
├── include/
│   ├── const.h              # Game constants (grid size, window, speed)
│   ├── circular_queue.h     # Circular queue used for the snake body and BFS
│   ├── game.h               # GameState and game rules
│   ├── ai.h                 # AI decision (next_direction)
│   └── sdl_game.h           # SDL front-end switch (sdl_autopilot)
├── src/
│   ├── circular_queue.c
│   ├── game.c               # Init, apple generation, movement, win/lose
│   ├── ai.c                 # BFS, longest path, safety check
│   ├── sdl_game.c           # SDL window, input and drawing (shared by both modes)
│   ├── person/
│   │   ├── snake.c          # Terminal person mode
│   │   └── snake_ui.c       # SDL person mode (sdl_autopilot = false)
│   └── machine/
│       ├── snake.c          # Terminal machine mode
│       └── snake_ui.c       # SDL machine mode (sdl_autopilot = true)
├── CMakeLists.txt
└── algorithm.md             # Longest-path algorithm notes

The game rules and the AI live in one place (game.c and ai.c) and every executable reuses them. Both SDL executables share sdl_game.c; the only difference is whether the keyboard or the AI chooses the direction.

Requirements

• CMake 3.16 or higher
• SDL3 library
• C11 compiler (GCC, Clang, etc.)

Building

cmake -S . -B build
cmake --build build

The executables are built in build/bin/:

Executable	Mode
snake_person	Human player, SDL
snake_machine	AI, SDL
snake_person_console	Human player, terminal
snake_machine_console	AI, terminal

Running

./build/bin/snake_person
./build/bin/snake_machine
./build/bin/snake_person_console
./build/bin/snake_machine_console

Controls:

• SDL person mode: arrow keys. Only one turn per tick; reversing is ignored.
• Terminal person mode: type w, a, s or d and press Enter.

The terminal versions print the board every step: 0 empty, 1 snake, 2 apple.

Configuration

Edit include/const.h:

• ROWS and COLUMNS - Grid dimensions
• WIDTH and HEIGHT - Window size
• TIMER - SDL game speed in milliseconds
• PADDING - Visual padding around the grid

Then rebuild with cmake --build build.