// Coding Challenge #3: The Snake Game

// https://youtu.be/AaGK-fj-BAM

​

​

var s; //snake

var food;

var scl = 40; //pixel size

var score = 0;

var Hscore = 0;

var lvl = 5; //level

var boxW, boxH;

var ox, oy, nx, ny;

​

function setup() {

  createCanvas(scl * floor(windowWidth / scl), scl * floor(windowHeight / scl));

  boxW = width - 2 * scl;

  boxH = height - 3 * scl;

​

  s = new snake();

  strokeWeight(scl * 0.15);

  picklocation();

}

​

​

function draw() {

  frameRate(lvl);

  background(200);

​

  drawGrid();

  drawFood();

​

  //draw snake

  s.update();

  s.show();

  s.death();

  strokeWeight(scl * 0.15);

  drawGame();

}

​

​

function picklocation() {

  let cols = floor(boxW / scl);

  let rows = floor(boxH / scl);

  food = createVector(1 + floor(random(cols)), 2 + floor(random(rows)));

  food.mult(scl);

  for (let i = 0; i < s.tail.length; i++) {

    if (s.tail[i] == food) {

      picklocation()

    }

  }

}

​

function keyPressed() {

  if (keyCode == UP_ARROW) {

    s.dir(0, -1);

  } else if (keyCode == DOWN_ARROW) {

    s.dir(0, 1);

  } else if (keyCode == LEFT_ARROW) {

    s.dir(-1, 0);

  } else if (keyCode == RIGHT_ARROW) {

    s.dir(1, 0);

  }

}

​

function drawGrid() {

  fill(190);

  stroke(200);

  for (let i = scl; i < width - scl; i += scl) {

    for (let j = 2 * scl; j < height - scl; j += scl) {

      rect(i, j, scl, scl)

    }

  }

}

​

function drawGame() {

  // draw game box

  noFill();

  stroke(51)

  rect(scl, 2 * scl, boxW, boxH)

​

  //draw score

  fill(51);

  noStroke()

  textSize(0.7 * scl);

  text('Score: ' + score, scl, 0.8 * scl)

  text('High Score: ' + Hscore, scl, 1.55 * scl)

}

​

​

function drawFood() {

  if (s.eat(food)) {

    lvl += (1 / lvl);

    score += floor(lvl);

    if (score > Hscore) {

      Hscore = score;

    }

    picklocation();

  }

  fill(255, 0, 0);

  ellipse(food.x + scl * 0.5, food.y + scl * 0.5, scl, scl);

}

​

function touchStarted() {

  ox = mouseX;

  oy = mouseY;

}

​

function touchEnded() {

  nx = mouseX;

  ny = mouseY;

​

  if (abs((nx - ox) / (ny - oy)) > 1.5) {

    if (ox > nx) {

      s.dir(-1, 0);

    } else {

      s.dir(1, 0);

    }

  } else if (abs((ny - oy) / (nx - ox)) > 1.5) {

    if (oy < ny) {

      s.dir(0, 1);

    } else {

      s.dir(0, -1);

    }

  }

​

}