diff --git a/pong.html b/pong.html
index bea5015..d72eea5 100644
--- a/pong.html
+++ b/pong.html
@@ -1,198 +1,14 @@
+
- Basic Pong HTML Game
-
-
+ Basic Pong HTML Game
+
+
-
-
+
+
+
diff --git a/scripts.js b/scripts.js
new file mode 100644
index 0000000..6c34c91
--- /dev/null
+++ b/scripts.js
@@ -0,0 +1,171 @@
+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);
\ No newline at end of file
diff --git a/style.css b/style.css
new file mode 100644
index 0000000..e2cb8fa
--- /dev/null
+++ b/style.css
@@ -0,0 +1,11 @@
+html, body {
+ height: 100%;
+ margin: 0;
+}
+
+body {
+ background: black;
+ display: flex;
+ align-items: center;
+ justify-content: center;
+}
\ No newline at end of file