ZiKT1229 · November 6, 2018 07:03 · J0513-301 · Nov 29, 2023 · svenwlive · Nov 29, 2023
diff --git a/README.md b/README.md
diff --git a/snake.html b/snake.html
 <!DOCTYPE html>
 <html>
 <head>
  <title></title>
  <style>
  html, body {
    height: 100%;
    margin: 0;
  }

  body {
    background: black;
    display: flex;
    align-items: center;
    justify-content: center;
  }
  canvas {
    border: 1px solid white;
  }
  </style>
 </head>
 <body>
 <canvas width="400" height="400" id="game"></canvas>
 <script>
 var canvas = document.getElementById('game');
 var context = canvas.getContext('2d');

 var grid = 16;
 var count = 0;
  
 var snake = {
  x: 160,
  y: 160,
  
  // snake velocity. moves one grid length every frame in either the x or y direction
  dx: grid,
  dy: 0,
  
  // keep track of all grids the snake body occupies
  cells: [],
  
  // length of the snake. grows when eating an apple
  maxCells: 4
 };
 var apple = {
  x: 320,
  y: 320
 };

 // get random whole numbers in a specific range
 // @see https://stackoverflow.com/a/1527820/2124254
 function getRandomInt(min, max) {
  return Math.floor(Math.random() * (max - min)) + min;
 }

 // game loop
 function loop() {
  requestAnimationFrame(loop);

  // slow game loop to 15 fps instead of 60 (60/15 = 4)
  if (++count < 4) {
    return;
  }

  count = 0;
  context.clearRect(0,0,canvas.width,canvas.height);

  // move snake by it's velocity
  snake.x += snake.dx;
  snake.y += snake.dy;

  // wrap snake position horizontally on edge of screen
  if (snake.x < 0) {
    snake.x = canvas.width - grid;
  }
  else if (snake.x >= canvas.width) {
    snake.x = 0;
  }
  
  // wrap snake position vertically on edge of screen
  if (snake.y < 0) {
    snake.y = canvas.height - grid;
  }
  else if (snake.y >= canvas.height) {
    snake.y = 0;
  }

  // keep track of where snake has been. front of the array is always the head
  snake.cells.unshift({x: snake.x, y: snake.y});

  // remove cells as we move away from them
  if (snake.cells.length > snake.maxCells) {
    snake.cells.pop();
  }

  // draw apple
  context.fillStyle = 'red';
  context.fillRect(apple.x, apple.y, grid-1, grid-1);

  // draw snake one cell at a time
  context.fillStyle = 'green';
  snake.cells.forEach(function(cell, index) {
    
    // drawing 1 px smaller than the grid creates a grid effect in the snake body so you can see how long it is
    context.fillRect(cell.x, cell.y, grid-1, grid-1);  

    // snake ate apple
    if (cell.x === apple.x && cell.y === apple.y) {
      snake.maxCells++;

      // canvas is 400x400 which is 25x25 grids 
      apple.x = getRandomInt(0, 25) * grid;
      apple.y = getRandomInt(0, 25) * grid;
    }

    // check collision with all cells after this one (modified bubble sort)
    for (var i = index + 1; i < snake.cells.length; i++) {
      
      // snake occupies same space as a body part. reset game
      if (cell.x === snake.cells[i].x && cell.y === snake.cells[i].y) {
        snake.x = 160;
        snake.y = 160;
        snake.cells = [];
        snake.maxCells = 4;
        snake.dx = grid;
        snake.dy = 0;

        apple.x = getRandomInt(0, 25) * grid;
        apple.y = getRandomInt(0, 25) * grid;
      }
    }
  });
 }

 // listen to keyboard events to move the snake
 document.addEventListener('keydown', function(e) {
  // prevent snake from backtracking on itself by checking that it's 
  // not already moving on the same axis (pressing left while moving
  // left won't do anything, and pressing right while moving left
  // shouldn't let you collide with your own body)
  
  // left arrow key
  if (e.which === 37 && snake.dx === 0) {
    snake.dx = -grid;
    snake.dy = 0;
  }
  // up arrow key
  else if (e.which === 38 && snake.dy === 0) {
    snake.dy = -grid;
    snake.dx = 0;
  }
  // right arrow key
  else if (e.which === 39 && snake.dx === 0) {
    snake.dx = grid;
    snake.dy = 0;
  }
  // down arrow key
  else if (e.which === 40 && snake.dy === 0) {
    snake.dy = grid;
    snake.dx = 0;
  }
 });

 // start the game
 requestAnimationFrame(loop);
 </script>
 </body>
 </html>
	<!DOCTYPE html>
	<html>
	<head>
	<title></title>
	<style>
	html, body {
	height: 100%;
	margin: 0;
	}

	body {
	background: black;
	display: flex;
	align-items: center;
	justify-content: center;
	}
	canvas {
	border: 1px solid white;
	}
	</style>
	</head>
	<body>
	<canvas width="400" height="400" id="game"></canvas>
	<script>
	var canvas = document.getElementById('game');
	var context = canvas.getContext('2d');

	var grid = 16;
	var count = 0;

	var snake = {
	x: 160,
	y: 160,

	// snake velocity. moves one grid length every frame in either the x or y direction
	dx: grid,
	dy: 0,

	// keep track of all grids the snake body occupies
	cells: [],

	// length of the snake. grows when eating an apple
	maxCells: 4
	};
	var apple = {
	x: 320,
	y: 320
	};

	// get random whole numbers in a specific range
	// @see https://stackoverflow.com/a/1527820/2124254
	function getRandomInt(min, max) {
	return Math.floor(Math.random() * (max - min)) + min;
	}

	// game loop
	function loop() {
	requestAnimationFrame(loop);

	// slow game loop to 15 fps instead of 60 (60/15 = 4)
	if (++count < 4) {
	return;
	}

	count = 0;
	context.clearRect(0,0,canvas.width,canvas.height);

	// move snake by it's velocity
	snake.x += snake.dx;
	snake.y += snake.dy;

	// wrap snake position horizontally on edge of screen
	if (snake.x < 0) {
	snake.x = canvas.width - grid;
	}
	else if (snake.x >= canvas.width) {
	snake.x = 0;
	}

	// wrap snake position vertically on edge of screen
	if (snake.y < 0) {
	snake.y = canvas.height - grid;
	}
	else if (snake.y >= canvas.height) {
	snake.y = 0;
	}

	// keep track of where snake has been. front of the array is always the head
	snake.cells.unshift({x: snake.x, y: snake.y});

	// remove cells as we move away from them
	if (snake.cells.length > snake.maxCells) {
	snake.cells.pop();
	}

	// draw apple
	context.fillStyle = 'red';
	context.fillRect(apple.x, apple.y, grid-1, grid-1);

	// draw snake one cell at a time
	context.fillStyle = 'green';
	snake.cells.forEach(function(cell, index) {

	// drawing 1 px smaller than the grid creates a grid effect in the snake body so you can see how long it is
	context.fillRect(cell.x, cell.y, grid-1, grid-1);

	// snake ate apple
	if (cell.x === apple.x && cell.y === apple.y) {
	snake.maxCells++;

	// canvas is 400x400 which is 25x25 grids
	apple.x = getRandomInt(0, 25) * grid;
	apple.y = getRandomInt(0, 25) * grid;
	}

	// check collision with all cells after this one (modified bubble sort)
	for (var i = index + 1; i < snake.cells.length; i++) {

	// snake occupies same space as a body part. reset game
	if (cell.x === snake.cells[i].x && cell.y === snake.cells[i].y) {
	snake.x = 160;
	snake.y = 160;
	snake.cells = [];
	snake.maxCells = 4;
	snake.dx = grid;
	snake.dy = 0;

	apple.x = getRandomInt(0, 25) * grid;
	apple.y = getRandomInt(0, 25) * grid;
	}
	}
	});
	}

	// listen to keyboard events to move the snake
	document.addEventListener('keydown', function(e) {
	// prevent snake from backtracking on itself by checking that it's
	// not already moving on the same axis (pressing left while moving
	// left won't do anything, and pressing right while moving left
	// shouldn't let you collide with your own body)

	// left arrow key
	if (e.which === 37 && snake.dx === 0) {
	snake.dx = -grid;
	snake.dy = 0;
	}
	// up arrow key
	else if (e.which === 38 && snake.dy === 0) {
	snake.dy = -grid;
	snake.dx = 0;
	}
	// right arrow key
	else if (e.which === 39 && snake.dx === 0) {
	snake.dx = grid;
	snake.dy = 0;
	}
	// down arrow key
	else if (e.which === 40 && snake.dy === 0) {
	snake.dy = grid;
	snake.dx = 0;
	}
	});

	// start the game
	requestAnimationFrame(loop);
	</script>
	</body>
	</html>