Snake Game Attempt - xelsed.ai

function setup() {
  createCanvas(windowWidth, windowHeight);
  resetGame(); // Initialize the game
}

function resetGame() {
  snake = [];
  score = 0;
  isGameOver = false;

  // Initialize snake segments at the center of the canvas
  let headPos = createVector(width / 2, height / 2);
  snake.push(headPos); // Head segment
  // Add initial body segments slightly behind the head
  for (let i = 1; i < INITIAL_LENGTH; i++) {
    snake.push(createVector(headPos.x - i * SEGMENT_SIZE, headPos.y));
  }

  generateFood(); // Place the first food item
}

function generateFood() {
  let validPos = false;
  let newFoodPos;
  let attempts = 0;
  const MAX_ATTEMPTS = 100; // Max attempts to find a valid food position

  // Loop to ensure food doesn't spawn on top of the snake
  while (!validPos && attempts < MAX_ATTEMPTS) {
    newFoodPos = createVector(
      random(FOOD_SIZE / 2, width - FOOD_SIZE / 2),
      random(FOOD_SIZE / 2, height - FOOD_SIZE / 2)
    );

    validPos = true;
    for (let i = 0; i < snake.length; i++) {
      // Check if new food position overlaps with any snake segment
      if (p5.Vector.dist(newFoodPos, snake[i]) < SEGMENT_SIZE + FOOD_SIZE) {
        validPos = false;
        break; // If overlap, try a new position
      }
    }
    attempts++;
  }

  // Fallback: if a valid position isn't found after max attempts, place it anyway
  if (!validPos) {
    console.warn("Could not find a valid food position after max attempts. Placing anyway.");
    newFoodPos = createVector(random(FOOD_SIZE / 2, width - FOOD_SIZE / 2), random(FOOD_SIZE / 2, height - FOOD_SIZE / 2));
  }

  food = newFoodPos;
}

function draw() {
  background(10, 20, 10); // Dark green background

  // If game is over, display game over screen and exit draw loop
  if (isGameOver) {
    displayGameOver();
    return;
  }

  // Game logic
  updateSnake();
  checkFoodCollision();
  checkSelfCollision();
  checkWallCollision();

  // Apply glow effect for all drawn elements in this push/pop block
  push();
  applyGlow();

  drawFood();
  drawSnake();

  pop(); // Reset drawing context to remove glow for subsequent elements (like score)

  displayScore();
}

function updateSnake() {
  // Move head towards the mouse cursor
  let targetHeadPos = createVector(mouseX, mouseY);
  snake[0].lerp(targetHeadPos, SPEED_LERP_AMOUNT); // Smoothly interpolates head position

  // Move body segments to follow the previous segment
  for (let i = snake.length - 1; i > 0; i--) {
    snake[i].lerp(snake[i - 1], BODY_LERP_AMOUNT); // Smoothly interpolates body segments
  }
}

function checkFoodCollision() {
  // Calculate distance between head and food
  if (p5.Vector.dist(snake[0], food) < SEGMENT_SIZE / 2 + FOOD_SIZE / 2) {
    score++; // Increase score
    // Grow snake by adding a new segment at the end, copying the last segment's position
    snake.push(snake[snake.length - 1].copy());
    generateFood(); // Generate new food
  }
}

function checkSelfCollision() {
  // Start checking from the 4th segment (index 3) to prevent immediate game over
  // This gives the snake a small "buffer" for sharp turns due to the lerping movement.
  for (let i = 3; i < snake.length; i++) {
    if (p5.Vector.dist(snake[0], snake[i]) < COLLISION_THRESHOLD) {
      isGameOver = true; // Set game over flag
      return;
    }
  }
}

function checkWallCollision() {
  let head = snake[0];
  if (head.x < 0 || head.x > width || head.y < 0 || head.y > height) {
    isGameOver = true;
  }
}

function drawSnake() {
  noStroke();
  fill(0, 255, 0); // Neon green color

  // Draw snake head as a circle
  circle(snake[0].x, snake[0].y, SEGMENT_SIZE);

  // Draw snake body as rectangles connecting the segments
  for (let i = 1; i < snake.length; i++) {
    let current = snake[i];
    let prev = snake[i - 1];

    // Calculate direction from current segment to previous segment
    let dir = p5.Vector.sub(prev, current);
    let angle = dir.heading(); // Get the angle of this direction

    push();
    translate(current.x, current.y); // Move origin to the current segment
    rotate(angle); // Rotate to align with the direction

    rectMode(CENTER);
    // Draw a rectangle that stretches between the current and previous segments
    // Length is the distance between them plus a small overlap for smoothness
    // Width is slightly less than SEGMENT_SIZE to make the circles more prominent
    rect(0, 0, dir.mag() + SEGMENT_SIZE * 0.5, SEGMENT_SIZE * 0.9);

    pop();
  }
}

function drawFood() {
  noStroke();
  fill(0, 255, 0); // Neon green color
  circle(food.x, food.y, FOOD_SIZE);
}

function applyGlow() {
  // `drawingContext` is the raw HTML canvas 2D rendering context
  drawingContext.shadowBlur = GLOW_STRENGTH;
  drawingContext.shadowColor = color(0, 255, 0); // Neon green glow color
}

function displayScore() {
  fill(0, 255, 0); // Neon green text color
  noStroke();
  textSize(32);
  textAlign(LEFT, TOP);
  text(`Score: ${score}`, 20, 20);
}

function displayGameOver() {
  fill(0, 255, 0); // Neon green text color
  noStroke();
  textSize(64);
  textAlign(CENTER, CENTER);
  text("GAME OVER!", width / 2, height / 2 - 40);
  textSize(24);
  text(`Final Score: ${score}`, width / 2, height / 2 + 20);
  text("Press any key to restart", width / 2, height / 2 + 60);
}

function keyPressed() {
  if (isGameOver) {
    resetGame(); // Restart the game if it's over
  }
}

function windowResized() {
  resizeCanvas(windowWidth, windowHeight);
  resetGame();
}