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Snake Game — Assignment 1

by Hamhuo

🕹 Introduction

This project is a classic Snake game implemented using Java AWT and a custom GameEngine.
The player controls a snake moving on a 25×25 grid, growing longer by eating apples.
The game ends if the snake hits the wall or collides with itself.

✨ Highlights

1. Efficient Direction Control

• The snake’s movement direction is managed using numeric encoding combined with XOR operations.
• Direct reversal (e.g., moving from LEFT to RIGHT immediately) is prevented with a simple and efficient one-line check:

if ((direction.getValue() ^ d.getValue()) != 2) {  
    this.direction = d;  
}

• This approach is cleaner and more efficient than traditional if-else chains.

2. Flexible Speed and Length Configuration

Before starting the game, a settings dialog allows players to customize:

• Initial snake length
• Movement speed (cells per second)
• Grass background color

3. Smooth Time-Step Movement

• Snake movement is controlled by accumulated elapsed time rather than frame count.
• This ensures consistent movement speed across different machines or frame rates.
• The snake moves only when accumulated time exceeds its speed threshold.

  public void init(int length, Direction d, Double s) {  
  
    speed = 1 / s;  
    // Set the snake's initial length  
    initLength = length;  
  
    // Initialize the snake's body as an ArrayList of Points  
    snakeBody = new ArrayList<>();  
  
    // Add points to the snake's body, starting at position (3, 5)  
    for (int i = 3; i < initLength + 3; i++) {  
        snakeBody.add(new Point(i, 5)); // Add each segment of the snake to the body  
    }  
  
    // Set the snake's head to be the first point in the body  
    snakeHead = snakeBody.get(0);  
  
    direction = d;  
}

4. Resource Loading and Image Rendering

Separate sprite images are used for:

• Snake head
• Snake body
• Apples
• Proper resource management ensures a polished and visually consistent appearance.

🛠 Technical Features

• Object-Oriented Design (OOD) with clear class separation:
  • Snake class handles snake logic (movement, growth, shrink).
  • MainGame class manages overall game state, rendering, and input.
• Collision detection:
  • Wall collision leads to gradual shrinking.
  • Self-collision (snake colliding with its body) triggers immediate game over.
• Score tracking:
  • The current score is displayed near the apple’s position.
• Restart mechanism:
  • Pressing R after game over will reset and restart the game.

📦 How to Run

1. Open the project with IntelliJ IDEA or any Java IDE.
2. Ensure the resource images (apple.png, dot.png, head.png) are correctly placed under src/main/resources/.
3. Run MainGame.java.
4. Set your desired snake length, speed, and background color via the settings dialog.
5. Play and enjoy!