// This is my very first p5js project! :)

//

// A version of this lives on the p5js editor: 

//  - https://editor.p5js.org/jonfroehlich/sketches/S327HfhYu

// as well as my p5js github:

//  - https://github.com/jonfroehlich/p5js

// I try my best to keep my github and the p5js editor sync'd.

//

// By Jon Froehlich

// @jonfroehlich

// http://makeabilitylab.io/

//

// Feel free to use this source code for inspiration or in your

// own projects. If you do, I'd love to hear about it. Email me

// at jonf@cs.uw.edu or Tweet @jonfroehlich.

//

// Based on Daniel Shiffman's 'Snake Game Redux'

//  - https://thecodingtrain.com/CodingChallenges/115-snake-game-redux.html

//  - https://youtu.be/OMoVcohRgZA

//

// The arcade font is a Google Open Font

//  - https://fonts.google.com/specimen/Press+Start+2P?selection.family=Press+Start+2P

//

// Ideas for extensions:

//   - Let a bot control another snake

//   - have a fluid that moves around when snake goes through it

//   - make Snake2 with two player (wasd and arrows)

//   - make game faster (harder) as snake grows (just update frame rate?)

//   - have more than one food piece?

//   - have walls?

//

// Experiment with input

//   - whistling?

//   - posenet?

//   - sound classification?

//

// TODO:

//  - add in comments: https://javascript.info/comments

//  - add code to github (and a runnable version from github.io)?

​

let snake;

let food;

let grid;

let arcadeFont;

let isGameOver = false;

​

function preload() {

  // I originally tried to load a font like this example, but it didn't work

  //  - Example: https://editor.p5js.org/allison.parrish/sketches/ByyxP7Gbe

  arcadeFont = loadFont('arcadefont.ttf');

}

​

function setup() {

  frameRate(4);

  textFont(arcadeFont);

  //textFont('Coiny');

  grid = new Grid(); // Snake is based on a grid of cells

  createCanvas(grid.getWidth(), grid.getHeight()); // the canvas is derived from grid size

  setupGameEntities();

}

​

function setupGameEntities() {

  snake = new Snake(grid.cellSize, grid.getRandomLoc());

  food = new Food(grid.cellSize, grid.getRandomLoc());

}

​

function draw() {

  background(220);

​

  if (isGameOver == false) {

    if (snake.isOverFood(food)) {

      food = new Food(grid.cellSize, grid.getRandomLoc());

      snake.grow();

    }

​

    snake.update();

    if (snake.checkRanOffScreen()) {

      isGameOver = true;

    }

  }

​

  grid.draw();

  food.draw();

  snake.draw();

​

  // draw the score

  drawScore();

}

​

function drawScore() {

​

  fill(0);

  textAlign(LEFT);

  textSize(15);

  text('Score:' + (snake.getLength() - 1), 10, 20);

​

  if (isGameOver) {

​

    // dark overlay

    fill(0, 0, 0, 100);

    rect(0, 0, width, height);

​

    // draw game over text

    textAlign(CENTER);

    textSize(35);

    fill(255);

    text('GAME OVER!', width / 2, height / 3);

    textSize(12);

    text('Press SPACE BAR to play again.', width / 2, height / 2);

  }

}

​

function keyPressed() {

  let hasRunIntoSelf = false;

  switch (keyCode) {

    case LEFT_ARROW:

      hasRunIntoSelf = !snake.setDir(DIRECTION.LEFT);

      break;

    case RIGHT_ARROW:

      hasRunIntoSelf = !snake.setDir(DIRECTION.RIGHT);

      break;

    case UP_ARROW:

      hasRunIntoSelf = !snake.setDir(DIRECTION.UP);

      break;

    case DOWN_ARROW:

      hasRunIntoSelf = !snake.setDir(DIRECTION.DOWN);

      break;

  }

  if (hasRunIntoSelf){

    isGameOver = true;  

  }

​

  if (isGameOver == true && key === ' ') {

    setupGameEntities();

    isGameOver = false;

  }

}

​

class Grid {

​

  constructor() {

    this.cellSize = 20;

    this.numCols = 20;

    this.numRows = 20;

  }

​

  getWidth() {

    return floor(this.cellSize * this.numCols);

  }

​

  getHeight() {

    return floor(this.cellSize * this.numRows);

  }

​

  getRandomLoc() {

    let randCol = floor(random(0, this.numCols));

    let randRow = floor(random(0, this.numRows));

    return createVector(randCol * this.cellSize, randRow * this.cellSize);

  }

​

  draw() {

    // mainly for debugging

    stroke(144, 144, 144, 100);

    for (let col = 0; col < this.numCols; col++) {

      let xLoc = floor(col * this.cellSize);

      line(xLoc, 0, xLoc, height);

    }

​

    for (let row = 0; row < this.numRows; row++) {

      let yLoc = floor(row * this.cellSize);

      line(0, yLoc, width, yLoc);

    }

  }

}

​

class Food {

  constructor(foodSize, loc) {

    this.size = foodSize;

    this.loc = loc;

    this.color = color(255, 0, 0);

  }

​

  draw() {

    fill(255, 0, 0);

    noStroke();

    rect(this.loc.x, this.loc.y, this.size, this.size);

  }

}