Pro496951 · March 24, 2020 16:56
diff --git a/Gun Fight.html b/Gun Fight.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;
  }
  </style>
 </head>
 <body>
 <canvas width="565" height="500" id="game"></canvas>
 <script>
 const canvas = document.getElementById('game');
 const context = canvas.getContext('2d');
 const grid = 15;
 const playerHeight = grid * 3; // 45
 const maxPlayerY = canvas.height - grid - playerHeight;

 var playerSpeed = 4;

 const leftPlayer = {
  // start in the middle of the game on the left side
  x: grid * 2,
  y: canvas.height / 2 - playerHeight / 2,
  width: grid,
  height: playerHeight,
  
  // shooting cooldown
  cooldown: 0,
  
  // player velocity
  dy: 0
 };

 const rightPlayer = {
  // start in the middle of the game on the right side
  x: canvas.width - grid * 3,
  y: canvas.height / 2 - playerHeight / 2,
  width: grid,
  height: playerHeight,
  
  // shooting cooldown
  cooldown: 0,
  
  // player velocity
  dy: 0
 };

 const bullets = {
  speed: 5,
  array: []
 }

 // check for collision between two objects using axis-aligned bounding box (AABB)
 // @see https://developer.mozilla.org/en-US/docs/Games/Techniques/2D_collision_detection
 function collides(obj1, obj2) {
  return obj1.x < obj2.x + obj2.width &&
         obj1.x + obj1.width > obj2.x &&
         obj1.y < obj2.y + obj2.height &&
         obj1.y + obj1.height > obj2.y;
 }

 // game loop
 function loop() {
  requestAnimationFrame(loop);
  context.clearRect(0,0,canvas.width,canvas.height);
  
  // bullet cooldowns
  // left player
  if (leftPlayer.cooldown > 0) {
    leftPlayer.cooldown--;
  }
  // right player
  if (rightPlayer.cooldown > 0) {
    rightPlayer.cooldown--;
  }
  
  // move players by their velocity
  leftPlayer.y += leftPlayer.dy;
  rightPlayer.y += rightPlayer.dy;
  
  // prevent players from going through walls
  if (leftPlayer.y < grid) {
    leftPlayer.y = grid;
  }
  else if (leftPlayer.y > maxPlayerY) {
    leftPlayer.y = maxPlayerY;
  }
  
  if (rightPlayer.y < grid) {
    rightPlayer.y = grid;
  }
  else if (rightPlayer.y > maxPlayerY) {
    rightPlayer.y = maxPlayerY;
  }
  
  // draw bullets
  context.fillStyle = 'yellow';
  bullets.array.forEach(function(bullet, index) {
    context.fillRect(bullet.x, bullet.y, 10, 5);
 	
 	// check if the bullet hits a player
 	// left player
 	if (collides(bullet, leftPlayer)) {
 	  bullets.array.splice(index, 1);
 	  leftPlayer.y = canvas.height / 2 - playerHeight / 2;
 	  rightPlayer.y = canvas.height / 2 - playerHeight / 2;
 	  bullets.array.length = 0;
 	}
 	// right player
 	else if (collides(bullet, rightPlayer)) {
 	  bullets.array.splice(index, 1);
 	  leftPlayer.y = canvas.height / 2 - playerHeight / 2;
 	  rightPlayer.y = canvas.height / 2 - playerHeight / 2;
 	  bullets.array.length = 0;
 	}
    
    // move bullets
    bullet.x += bullet.dx;
 	
 	// remove bullets that leave the screen
    if (bullet.x < 0 || bullet.x > canvas.width) {
      bullets.array.splice(index, 1);
    }
  });
  
  // draw paddles
  context.fillStyle = 'gold';
  context.fillRect(leftPlayer.x, leftPlayer.y, leftPlayer.width, leftPlayer.height);
  context.fillRect(rightPlayer.x, rightPlayer.y, rightPlayer.width, rightPlayer.height);

  // draw walls
  context.fillStyle = 'lightgray';
  context.fillRect(0, 0, canvas.width, grid);
  context.fillRect(0, canvas.height - grid, canvas.width, canvas.height);
 }

 // listen to keyboard events to move the players
 document.addEventListener('keydown', function(e) {
  // up arrow key
  if (e.which === 38) {
    rightPlayer.dy = -playerSpeed;
  }
  // down arrow key
  else if (e.which === 40) {
    rightPlayer.dy = playerSpeed;
  }
  
  // w key
  if (e.which === 87) {
    leftPlayer.dy = -playerSpeed;
  }
  // a key
  else if (e.which === 83) {
    leftPlayer.dy = playerSpeed;
  }
  
  // shooting
  // left arrow key
  if (e.which === 37 && rightPlayer.cooldown === 0) {
    bullets.array.push({
 	  x: rightPlayer.x - 10, 
 	  y: rightPlayer.y + 20, 
 	  width: 10,
 	  height: 5,
 	  dx: -bullets.speed
 	});
 	rightPlayer.cooldown = 25;
  }
  // d key
  if (e.which === 68 && leftPlayer.cooldown === 0) {
    bullets.array.push({
 	  x: leftPlayer.x + 15, 
 	  y: leftPlayer.y + 20, 
 	  width: 10,
 	  height: 5,
 	  dx: bullets.speed
 	});
 	leftPlayer.cooldown = 25;
  }
 });
 // listen to keyboard events to stop the player if key is released
 document.addEventListener('keyup', function(e) {
  if (e.which === 38 || e.which === 40) {
    rightPlayer.dy = 0;
  }
  
  if (e.which === 83 || e.which === 87) {
    leftPlayer.dy = 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;
	}
	</style>
	</head>
	<body>
	<canvas width="565" height="500" id="game"></canvas>
	<script>
	const canvas = document.getElementById('game');
	const context = canvas.getContext('2d');
	const grid = 15;
	const playerHeight = grid * 3; // 45
	const maxPlayerY = canvas.height - grid - playerHeight;

	var playerSpeed = 4;

	const leftPlayer = {
	// start in the middle of the game on the left side
	x: grid * 2,
	y: canvas.height / 2 - playerHeight / 2,
	width: grid,
	height: playerHeight,

	// shooting cooldown
	cooldown: 0,

	// player velocity
	dy: 0
	};

	const rightPlayer = {
	// start in the middle of the game on the right side
	x: canvas.width - grid * 3,
	y: canvas.height / 2 - playerHeight / 2,
	width: grid,
	height: playerHeight,

	// shooting cooldown
	cooldown: 0,

	// player velocity
	dy: 0
	};

	const bullets = {
	speed: 5,
	array: []
	}

	// check for collision between two objects using axis-aligned bounding box (AABB)
	// @see https://developer.mozilla.org/en-US/docs/Games/Techniques/2D_collision_detection
	function collides(obj1, obj2) {
	return obj1.x < obj2.x + obj2.width &&
	obj1.x + obj1.width > obj2.x &&
	obj1.y < obj2.y + obj2.height &&
	obj1.y + obj1.height > obj2.y;
	}

	// game loop
	function loop() {
	requestAnimationFrame(loop);
	context.clearRect(0,0,canvas.width,canvas.height);

	// bullet cooldowns
	// left player
	if (leftPlayer.cooldown > 0) {
	leftPlayer.cooldown--;
	}
	// right player
	if (rightPlayer.cooldown > 0) {
	rightPlayer.cooldown--;
	}

	// move players by their velocity
	leftPlayer.y += leftPlayer.dy;
	rightPlayer.y += rightPlayer.dy;

	// prevent players from going through walls
	if (leftPlayer.y < grid) {
	leftPlayer.y = grid;
	}
	else if (leftPlayer.y > maxPlayerY) {
	leftPlayer.y = maxPlayerY;
	}

	if (rightPlayer.y < grid) {
	rightPlayer.y = grid;
	}
	else if (rightPlayer.y > maxPlayerY) {
	rightPlayer.y = maxPlayerY;
	}

	// draw bullets
	context.fillStyle = 'yellow';
	bullets.array.forEach(function(bullet, index) {
	context.fillRect(bullet.x, bullet.y, 10, 5);

	// check if the bullet hits a player
	// left player
	if (collides(bullet, leftPlayer)) {
	bullets.array.splice(index, 1);
	leftPlayer.y = canvas.height / 2 - playerHeight / 2;
	rightPlayer.y = canvas.height / 2 - playerHeight / 2;
	bullets.array.length = 0;
	}
	// right player
	else if (collides(bullet, rightPlayer)) {
	bullets.array.splice(index, 1);
	leftPlayer.y = canvas.height / 2 - playerHeight / 2;
	rightPlayer.y = canvas.height / 2 - playerHeight / 2;
	bullets.array.length = 0;
	}

	// move bullets
	bullet.x += bullet.dx;

	// remove bullets that leave the screen
	if (bullet.x < 0 \|\| bullet.x > canvas.width) {
	bullets.array.splice(index, 1);
	}
	});

	// draw paddles
	context.fillStyle = 'gold';
	context.fillRect(leftPlayer.x, leftPlayer.y, leftPlayer.width, leftPlayer.height);
	context.fillRect(rightPlayer.x, rightPlayer.y, rightPlayer.width, rightPlayer.height);

	// draw walls
	context.fillStyle = 'lightgray';
	context.fillRect(0, 0, canvas.width, grid);
	context.fillRect(0, canvas.height - grid, canvas.width, canvas.height);
	}

	// listen to keyboard events to move the players
	document.addEventListener('keydown', function(e) {
	// up arrow key
	if (e.which === 38) {
	rightPlayer.dy = -playerSpeed;
	}
	// down arrow key
	else if (e.which === 40) {
	rightPlayer.dy = playerSpeed;
	}

	// w key
	if (e.which === 87) {
	leftPlayer.dy = -playerSpeed;
	}
	// a key
	else if (e.which === 83) {
	leftPlayer.dy = playerSpeed;
	}

	// shooting
	// left arrow key
	if (e.which === 37 && rightPlayer.cooldown === 0) {
	bullets.array.push({
	x: rightPlayer.x - 10,
	y: rightPlayer.y + 20,
	width: 10,
	height: 5,
	dx: -bullets.speed
	});
	rightPlayer.cooldown = 25;
	}
	// d key
	if (e.which === 68 && leftPlayer.cooldown === 0) {
	bullets.array.push({
	x: leftPlayer.x + 15,
	y: leftPlayer.y + 20,
	width: 10,
	height: 5,
	dx: bullets.speed
	});
	leftPlayer.cooldown = 25;
	}
	});
	// listen to keyboard events to stop the player if key is released
	document.addEventListener('keyup', function(e) {
	if (e.which === 38 \|\| e.which === 40) {
	rightPlayer.dy = 0;
	}

	if (e.which === 83 \|\| e.which === 87) {
	leftPlayer.dy = 0;
	}
	});
	// start the game
	requestAnimationFrame(loop);
	</script>
	</body>
	</html>