Sketch 2026-03-04 02:18

function setup() {
  createCanvas(windowWidth, windowHeight);
  // Tip: Use windowWidth/windowHeight for responsive canvas
  
  direction = createVector(0, 0); // Initial direction (not moving)
  frameRate(10); // Snake speed (frames per second)

  // Initialize snake
  snake = [];
  let headX = floor(width / 2 / scale) * scale;
  let headY = floor(height / 2 / scale) * scale;
  snake.push(createVector(headX, headY)); // Head
  // Add a few segments for starting length
  snake.push(createVector(headX - scale, headY));
  snake.push(createVector(headX - 2 * scale, headY));

  // Place initial food
  pickLocation();
}

function draw() {
  background(220);

  if (gameIsOver) {
    displayGameOver();
    return; // Stop draw loop if game is over
  }

  // Update snake position
  updateSnake();

  // Check for food collision
  if (snake[0].x === food.x && snake[0].y === food.y) {
    score++;
    pickLocation();
    growSnake();
  }

  // Check for wall collision
  checkWallCollision();

  // Check for self-collision
  checkSelfCollision();

  // Draw snake
  for (let i = 0; i < snake.length; i++) {
    fill(0, 255, 0); // Green snake
    if (i === 0) {
      fill(0, 200, 0); // Darker green for head
    }
    noStroke();
    rect(snake[i].x, snake[i].y, scale, scale);
  }

  // Draw food
  fill(255, 0, 100); // Pink food
  noStroke();
  rect(food.x, food.y, scale, scale);

  // Display score
  fill(0);
  textSize(24);
  textAlign(LEFT, TOP);
  text("Score: " + score, 10, 10);
}

function updateSnake() {
  // Only move if a direction is set
  if (direction.x === 0 && direction.y === 0) {
    return;
  }

  // Create a new head position
  let head = snake[0].copy();
  head.x += direction.x * scale;
  head.y += direction.y * scale;

  // Add the new head to the beginning of the snake
  snake.unshift(head);

  // Remove the tail segment (unless we just ate food)
  if (!checkFoodCollision()) { // Check if the new head is on food
    snake.pop();
  }
}

function checkFoodCollision() {
  return snake[0].x === food.x && snake[0].y === food.y;
}

function growSnake() {
  // When food is eaten, the snake naturally grows because we don't pop the tail
  // You could also explicitly add a new segment at the tail if desired
}

function pickLocation() {
  let cols = floor(width / scale);
  let rows = floor(height / scale);

  // Keep picking until food is not on the snake
  while (true) {
    let x = floor(random(cols)) * scale;
    let y = floor(random(rows)) * scale;
    food = createVector(x, y);

    let onSnake = false;
    for (let i = 0; i < snake.length; i++) {
      if (food.x === snake[i].x && food.y === snake[i].y) {
        onSnake = true;
        break;
      }
    }
    if (!onSnake) {
      break; // Found a valid location
    }
  }
}

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

function checkSelfCollision() {
  let head = snake[0];
  for (let i = 1; i < snake.length; i++) {
    if (head.x === snake[i].x && head.y === snake[i].y) {
      gameOver();
      break;
    }
  }
}

function gameOver() {
  gameIsOver = true;
  noLoop(); // Stop the draw loop
}

function displayGameOver() {
  fill(255, 0, 0); // Red text
  textSize(64);
  textAlign(CENTER, CENTER);
  text("GAME OVER", width / 2, height / 2 - 40);
  textSize(32);
  text("Score: " + score, width / 2, height / 2 + 20);
  textSize(24);
  text("Press R to Restart", width / 2, height / 2 + 80);
}

function keyPressed() {
  // Arrow keys control direction, but prevent immediate reversal
  // e.g., if moving right, can't immediately move left
  if (keyCode === LEFT_ARROW && direction.x !== 1) {
    direction.set(-1, 0);
  } else if (keyCode === RIGHT_ARROW && direction.x !== -1) {
    direction.set(1, 0);
  } else if (keyCode === UP_ARROW && direction.y !== 1) {
    direction.set(0, -1);
  } else if (keyCode === DOWN_ARROW && direction.y !== -1) {
    direction.set(0, 1);
  } else if (keyCode === 82 && gameIsOver) { // 'R' key to restart
    restartGame();
  }
}

function restartGame() {
  score = 0;
  gameIsOver = false;
  direction.set(0, 0); // Reset direction
  frameRate(10); // Reset speed

  // Reinitialize snake
  snake = [];
  let headX = floor(width / 2 / scale) * scale;
  let headY = floor(height / 2 / scale) * scale;
  snake.push(createVector(headX, headY));
  snake.push(createVector(headX - scale, headY));
  snake.push(createVector(headX - 2 * scale, headY));

  pickLocation(); // Place new food
  loop(); // Resume the draw loop
}

function windowResized() {
  resizeCanvas(windowWidth, windowHeight);
  // Called when preview panel is resized
  // Re-center snake and food if the canvas size changes drastically
  if (!gameIsOver) {
    let headX = floor(width / 2 / scale) * scale;
    let headY = floor(height / 2 / scale) * scale;
    snake[0].set(headX, headY);
    pickLocation();
  }
}