Step by step instructions to Make Basic HTML STEEMIT GAME!.

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This is an essential source code of the steemit game back in time atari distributed game, yet it's feeling the loss of a couple of things not by, botches yet yes deliberately and they're left as further investigation for you to investigate.

< !DOCTYPE html>

< html>

< head>

< title>steemit GAME

< style>

html, body {

height: 100%;

margin: 0;

}

body {

background: black;

display: flex;

align-items: center;

justify-content: center;

}

< /style>

< /head>

< body>

< canvas width="750" height="585" id="game">< /canvas>

< script>

const canvas = document.getElementById('game');

const context = canvas.getContext('2d');

const grid = 15;

const paddleHeight = grid * 5; // 80

const maxPaddleY = canvas.height - grid - paddleHeight;

var paddleSpeed = 6;

var ballSpeed = 5;

const leftPaddle = {

// start in the middle of the game on the left side

x: grid * 2,

y: canvas.height / 2 - paddleHeight / 2,

width: grid,

height: paddleHeight,

// paddle velocity

dy: 0

};

const rightPaddle = {

// start in the middle of the game on the right side

x: canvas.width - grid * 3,

y: canvas.height / 2 - paddleHeight / 2,

width: grid,

height: paddleHeight,

// paddle velocity

dy: 0

};

const ball = {

// start in the middle of the game

x: canvas.width / 2,

y: canvas.height / 2,

width: grid,

height: grid,

// keep track of when need to reset the ball position

resetting: false,

// ball velocity (start going to the top-right corner)

dx: ballSpeed,

dy: -ballSpeed

};

// 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);

// move paddles by their velocity

leftPaddle.y += leftPaddle.dy;

rightPaddle.y += rightPaddle.dy;

// prevent paddles from going through walls

if (leftPaddle.y < grid) {

leftPaddle.y = grid;

}

else if (leftPaddle.y > maxPaddleY) {

leftPaddle.y = maxPaddleY;

}

if (rightPaddle.y < grid) {

rightPaddle.y = grid;

}

else if (rightPaddle.y > maxPaddleY) {

rightPaddle.y = maxPaddleY;

}

// draw paddles

context.fillStyle = 'white';

context.fillRect(leftPaddle.x, leftPaddle.y, leftPaddle.width, leftPaddle.height);

context.fillRect(rightPaddle.x, rightPaddle.y, rightPaddle.width, rightPaddle.height);

// move ball by its velocity

ball.x += ball.dx;

ball.y += ball.dy;

// prevent ball from going through walls by changing its velocity

if (ball.y < grid) {

ball.y = grid;

ball.dy *= -1;

}

else if (ball.y + grid > canvas.height - grid) {

ball.y = canvas.height - grid * 2;

ball.dy *= -1;

}

// reset ball if it goes past paddle (but only if we haven't already done so)

if ( (ball.x < 0 || ball.x > canvas.width) && !ball.resetting) {

ball.resetting = true;

// give some time for the player to recover before launching the ball again

setTimeout(() => {

  ball.resetting = false;

  ball.x = canvas.width / 2;

  ball.y = canvas.height / 2;

}, 400);

}

// check to see if ball collides with paddle. if they do change x velocity

if (collides(ball, leftPaddle)) {

ball.dx *= -1;

// move ball next to the paddle otherwise the collision will happen again

// in the next frame

ball.x = leftPaddle.x + leftPaddle.width;

}

else if (collides(ball, rightPaddle)) {

ball.dx *= -1;

// move ball next to the paddle otherwise the collision will happen again

// in the next frame

ball.x = rightPaddle.x - ball.width;

}

// draw ball

context.fillRect(ball.x, ball.y, ball.width, ball.height);

// draw walls

context.fillStyle = 'lightgrey';

context.fillRect(0, 0, canvas.width, grid);

context.fillRect(0, canvas.height - grid, canvas.width, canvas.height);

// draw dotted line down the middle

for (let i = grid; i < canvas.height - grid; i += grid * 2) {

context.fillRect(canvas.width / 2 - grid / 2, i, grid, grid);

}

}

// listen to keyboard events to move the paddles

document.addEventListener('keydown', function(e) {

// up arrow key

if (e.which === 38) {

rightPaddle.dy = -paddleSpeed;

}

// down arrow key

else if (e.which === 40) {

rightPaddle.dy = paddleSpeed;

}

// w key

if (e.which === 87) {

leftPaddle.dy = -paddleSpeed;

}

// a key

else if (e.which === 83) {

leftPaddle.dy = paddleSpeed;

}

});

// listen to keyboard events to stop the paddle if key is released

document.addEventListener('keyup', function(e) {

if (e.which === 38 || e.which === 40) {

rightPaddle.dy = 0;

}

if (e.which === 83 || e.which === 87) {

leftPaddle.dy = 0;

}

});

// start the game

requestAnimationFrame(loop);

< /script>

< /body>

< /html>

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you got my 100% vote on random curation

cheers

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