I am following a Mozilla 2D game tutorial. This is not my original code nor my original idea. Link below.
Mozilla Game
I have gotten stuck on a particular aspect of the game: collision detection of the ball with the bricks. Everything worked fine with the program until I called the collisionDetection() function.
Here is the function:
function collisionDetection() {
for(c=0; c<brickColumnCount; c++) {
for(r=0; r<brickRowCount; r++) {
var b = bricks[c][r];
if(x > b.x && x < b.x+brickWidth && y > b.y && y < b.y+brickHeight) {
dy = -dy;
}
}
}
}
Below calling this function, the ball flew around the canvas and the game mechanics worked perfectly. However, upon adding this call to my code, the ball stayed motionless at its starting point with no movement at all.
Obviously there is a problem with the collisionDetection() function but it all looks correct to me!
I also searched for a problem with the ball-to-wall and ball-to-paddle collision detection 'if statements' but everything seemed correct.
The entire code is below.
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8" />
<title>Gamedev Canvas Workshop</title>
<style>
* { padding: 0; margin: 0; }
canvas { background: #eee; display: block; margin: 0 auto; }
</style>
</head>
<body>
<canvas id="myCanvas" width="480" height="320"> </canvas>
<script>
var canvas = document.getElementById("myCanvas");
var ctx = canvas.getContext("2d");
// Circle variables
var radiusCircle = 10;
var xCircle = canvas.width/2;
var yCircle = canvas.height - radiusCircle;
var dx = 2;
var dy = -2;
// Keyboard movement variables
var keyLeft = false;
var keyRight = false;
// Paddle variables
var paddleHeight = 10;
var paddleWidth = 75;
var xPaddle = (canvas.width - paddleWidth)/2;
// Brick variables
var brickRowCount = 3;
var brickColumnCount = 5;
var brickWidth = 75;
var brickHeight = 20;
var brickPadding = 10;
var brickOffsetTop = 30;
var brickOffsetLeft = 30;
var bricks = [];
for(c=0; c<brickColumnCount; c++) {
bricks[c] = [];
for(r=0; r<brickRowCount; r++) {
bricks[c][r] = { x: 0, y: 0 };
}
}
document.addEventListener("keydown", keyDownHandler, false);
document.addEventListener("keyup", keyUpHandler, false);
function keyDownHandler(e) {
if(e.keyCode == 39) {
keyRight = true;
}
else if(e.keyCode == 37) {
keyLeft = true;
}
}
function keyUpHandler(e) {
if(e.keyCode == 39) {
keyRight = false;
}
else if(e.keyCode == 37) {
keyLeft = false;
}
}
function collisionDetection() {
for(c=0; c<brickColumnCount; c++) {
for(r=0; r<brickRowCount; r++) {
var b = bricks[c][r];
if(x > b.x && x < b.x+brickWidth && y > b.y && y < b.y+brickHeight) {
dy = -dy;
}
}
}
}
function drawBall() {
ctx.beginPath();
ctx.arc(xCircle, yCircle, radiusCircle, 0, Math.PI * 2, false);
ctx.fillStyle = "green";
ctx.fill();
ctx.closePath;
}
function drawPaddle() {
ctx.beginPath();
ctx.rect(xPaddle, canvas.height - paddleHeight, paddleWidth, paddleHeight);
ctx.fillStyle = "green";
ctx.fill();
ctx.closePath();
}
function drawBricks() {
for(c=0; c<brickColumnCount; c++) {
for(r=0; r<brickRowCount; r++) {
var brickX = (c*(brickWidth+brickPadding))+brickOffsetLeft;
var brickY = (r*(brickHeight+brickPadding))+brickOffsetTop;
bricks[c][r].x = brickX;
bricks[c][r].y = brickY;
ctx.beginPath();
ctx.rect(brickX, brickY, brickWidth, brickHeight);
ctx.fillStyle = "green";
ctx.fill();
ctx.closePath();
}
}
}
// Renders game
var draw = function() {
ctx.clearRect(0, 0, canvas.width, canvas.height);
drawBricks();
drawBall();
drawPaddle();
collisionDetection();
// Collision detection for ball and paddle and game over mechanic
if (xCircle + dx > canvas.width - radiusCircle || xCircle < radiusCircle) {
dx = -dx;
}
if (yCircle + dy < radiusCircle) {
dy = -dy;
}
else if (yCircle + dy > canvas.height - radiusCircle) {
if (xCircle > xPaddle && xCircle < xPaddle + paddleWidth) {
if (yCircle = yCircle - paddleHeight) {
dy = -dy;
}
}
else {
alert("GAME OVER!");
document.location.reload();
}
}
// Paddle movement mechanics
if (keyRight && xPaddle < canvas.width - paddleWidth) {
xPaddle += 5;
}
else if (keyLeft && xPaddle > 0) {
xPaddle += -5;
}
// Makes the ball move
xCircle += dx;
yCircle += dy;
}
setInterval(draw, 10);
</script>
</body>
</html>
Can someone please help me by pointing out an error in my code or or how the collisionDetection() function isn't working with another piece of code for the game mechanics? i.e. the ball movement or paddle movement.
I have also attached a photo of the game in its current, nonfunctional, state.
Thank you
Photo of game
In your code variables x and y does not defined. I suppose you mean xCircle and yCircle. Your collisionDetection function must looks like this:
function collisionDetection() {
for (c=0; c<brickColumnCount; c++) {
for (r=0; r<brickRowCount; r++) {
var b = bricks[c][r];
if (xCircle > b.x && xCircle < b.x+brickWidth && yCircle > b.y && yCircle < b.y+brickHeight) {
dy = -dy;
}
}
}
}
Related
So I was making a breakout game for class and finished it, so for fun, my teacher asked before I went off for Christmas break that I make the bricks change color, and yea I did that but it's WAY too fast. He says it's fine how it is- if it was slower, or if the colors changed every time a brick was hit. Can I get some help?
canvas = document.getElementById("myCanvas");
ctx = canvas.getContext("2d");
ballRadius = 10;
x = canvas.width/2;
y = canvas.height-30;
dx = 2;
dy = -2;
const ballColor1 = "#0095DD";
const ballColor2 = "#ff0000";
var ballColor = ballColor1;
paddleHeight = 10;
paddleWidth = 75;
paddleX = (canvas.width-paddleWidth)/2;
rightPressed = false;
leftPressed = false;
const brickRowCount = 5;
const brickColumnCount = 3;
const brickWidth = 75;
const brickHeight = 20;
const brickPadding = 10;
const brickOffsetTop = 30;
const brickOffsetLeft = 30;
let score = 0;
let lives = 3;
const bricks = [];
for(let c=0; c<brickColumnCount; c++) {
bricks[c] = [];
for(let r=0; r<brickRowCount; r++) {
bricks[c][r] = { x: 0, y: 0, status: 1 };
}
}
function randBrick() {
return "#" + ((1 << 24) * Math.random() | 0).toString(16).padStart(6, "0")
}
console.log(randBrick());
document.addEventListener("keydown", keyDownHandler, false);
document.addEventListener("keyup", keyUpHandler, false);
document.addEventListener("mousemove", mouseMoveHandler, false);
document.getElementById("startAgain").addEventListener("click", function() {
document.location.reload();
clearInterval(interval);
});
document.getElementById("playAgain").addEventListener("click", function() {
document.location.reload();
clearInterval(interval);
});
function keyDownHandler(e) {
if(e.key == "Right" || e.key == "ArrowRight") {
rightPressed = true;
}
else if(e.key == "Left" || e.key == "ArrowLeft") {
leftPressed = true;
}
}
function keyUpHandler(e) {
if(e.key == "Right" || e.key == "ArrowRight") {
rightPressed = false;
}
else if(e.key == "Left" || e.key == "ArrowLeft") {
leftPressed = false;
}
}
function mouseMoveHandler(e) {
const relativeX = e.clientX - canvas.offsetLeft;
if(relativeX > 0 && relativeX < canvas.width) {
paddleX = relativeX - paddleWidth/2;
}
}
function collisionDetection() {
for(let c=0; c<brickColumnCount; c++) {
for(let r=0; r<brickRowCount; r++) {
const b = bricks[c][r];
if(b.status == 1) {
if(x > b.x && x < b.x+brickWidth && y > b.y && y < b.y+brickHeight) {
dy = -dy;
b.status = 0;
score++;
if(score == brickRowCount*brickColumnCount) {
document.getElementById('gameWin').style.display = 'block';
clearInterval(interval);
randBrick();
}
}
}
}
}
}
function drawBall() {
ctx.beginPath();
ctx.arc(x, y, ballRadius, 0, Math.PI*2);
ctx.fillStyle = ballColor;
ctx.fill();
ctx.closePath();
}
function drawPaddle() {
ctx.beginPath();
ctx.rect(paddleX, canvas.height-paddleHeight, paddleWidth, paddleHeight);
ctx.fillStyle = "#0095DD";
ctx.fill();
ctx.closePath();
}
function drawBricks() {
for(let c=0; c<brickColumnCount; c++) {
for(let r=0; r<brickRowCount; r++) {
if(bricks[c][r].status == 1) {
const brickX = (r*(brickWidth+brickPadding))+brickOffsetLeft;
const brickY = (c*(brickHeight+brickPadding))+brickOffsetTop;
bricks[c][r].x = brickX;
bricks[c][r].y = brickY;
ctx.beginPath();
ctx.rect(brickX, brickY, brickWidth, brickHeight);
ctx.fillStyle = "#" + ((1 << 24) * Math.random() | 0).toString(16).padStart(6, "0");
ctx.fill();
ctx.closePath();
}
}
}
}
function drawScore() {
ctx.font = "16px Arial";
ctx.fillStyle = "#0095DD";
ctx.fillText("Score: "+score, 8, 20);
}
function drawLives() {
ctx.font = "16px Arial";
ctx.fillStyle = "#0095DD";
ctx.fillText("Lives: "+lives, canvas.width-65, 20);
}
function draw() {
ctx.clearRect(0, 0, canvas.width, canvas.height);
drawBall();
drawBricks();
drawPaddle();
drawScore();
drawLives();
collisionDetection();
if(x + dx > canvas.width-ballRadius || x + dx < ballRadius) {
dx = -dx;
if (ballColor == ballColor1) {
ballColor = ballColor2;
} else {
ballColor = ballColor1;
}
}
if(y + dy < ballRadius) {
dy = -dy;
if (ballColor == ballColor1) {
ballColor = ballColor2;
} else {
ballColor = ballColor1;
}
}
else if(y + dy > canvas.height-ballRadius) {
if(x > paddleX && x < paddleX + paddleWidth) {
dy = -dy;
}
else {
lives--;
if(!lives) {
document.getElementById('gameOver').style.display = 'block';
clearInterval(interval);
}
else {
x = canvas.width/2;
y = canvas.height-30;
dx = 3;
dy = -3;
paddleX = (canvas.width-paddleWidth)/2;
}
}
}
if(rightPressed && paddleX < canvas.width-paddleWidth) {
paddleX += 7;
}
else if(leftPressed && paddleX > 0) {
paddleX -= 7;
}
x += dx;
y += dy;
requestAnimationFrame(draw);
}
draw();
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8" />
<title>Breakout</title>
<style>
* {
padding: 0;
margin: 0;
}
canvas {
background: #eee;
display: block;
margin: 0 auto;
border: 5px solid red;
}
</style>
</head>
<body>
<canvas id="myCanvas" width="480" height="320"></canvas>
<div id="gameOver" style="display: none; position: absolute; top: 50px; left: 50px; width: 200px;">
<h1>Game Over!</h1>
<button id="startAgain">Try Again?</button>
</div>
<div id="gameWin" style="display: none; position: absolute; top: 50px; left: 50px; width: 200px;">
<h1>You Win!</h1>
<button id="playAgain">Play Again?</button>
</div>
<script src=breakoutCode.js></script>
</body>
</html>
You're changing the color on every block draw. The Math.random() is getting called on every draw to the canvas thus that means it's changing every block's color on each draw.
Possible solutions:
Save the colors in an array + a the time you want to change them
Save the colors in an array and change them randomly
Don't re-draw the blocks on every re-draw (better for performance)
Here's one possible solution that stores the colors in an array and changes them randomly:
let blkColors = []
function drawBricks() {
for(let c=0; c<brickColumnCount; c++) {
for(let r=0; r<brickRowCount; r++) {
if(bricks[c][r].status == 1) {
const brickX = (r*(brickWidth+brickPadding))+brickOffsetLeft;
const brickY = (c*(brickHeight+brickPadding))+brickOffsetTop;
bricks[c][r].x = brickX;
bricks[c][r].y = brickY;
ctx.beginPath();
ctx.rect(brickX, brickY, brickWidth, brickHeight);
if (!blkColors[c] || !blkColors[c][r] || Math.random() > 0.97) { // new color
if (!blkColors[c])
blkColors[c] = [];
ctx.fillStyle = blkColors[c][r] = "#" + ((1 << 24) * Math.random() | 0).toString(16).padStart(6, "0");
} else {
ctx.fillStyle = blkColors[c][r];
}
ctx.fill();
ctx.closePath();
}
}
}
}
On JSFiddle
I am trying to code a Pause/Play button for my breakout-clone because I have some text and links planned for the site on which the game will be, so you can pause the game while reading the text or interacting with links. My code is written in JS and mostly consists of "function" and "var". If the CSS or the HTML file is needed for an answer then please contact me. This is my first time asking anything on stackoverflow and I would be glad for any help.
var canvas = document.getElementById("TheCanvas");
var ctx = canvas.getContext("2d");
var x = canvas.width/2;
var y = canvas.height-50;
var dx = 2
var dy = -2;
var ballRadius = 10;
var paddleHeight = 15;
var paddleWidth = 80;
var paddleX = (canvas.width-paddleWidth) / 2;
var rightPressed = false;
var leftPressed = false;
var brickRowCount = 6;
var brickColumnCount = 4;
var brickWidth = 90;
var brickHeight = 20;
var brickPadding = 10;
var brickOffsetTop = 30;
var brickOffsetLeft = 15;
var score = 0;
var lives = 99;
var bricks = [];
for(var c=0; c<brickColumnCount; c++) {
bricks[c] = [];
for(var r=0; r<brickRowCount; r++) {
bricks[c][r] = { x: 0, y: 0,status: 1 };
}
}
document.addEventListener("keydown", keyDownHandler, false);
document.addEventListener("keyup", keyUpHandler, false);
document.addEventListener("mousemove", mouseMoveHandler, false);
function mouseMoveHandler(e) {
var relativeX = e.clientX - canvas.offsetLeft;
if(relativeX > 0 && relativeX < canvas.width) {
paddleX = relativeX - paddleWidth/2;
}
}
function keyDownHandler(e) {
if(e.key == "Right" || e.key == "ArrowRight") {
rightPressed = true;
}
else if(e.key === "Left" || e.key == "ArrowLeft") {
leftPressed = true;
}
}
function keyUpHandler(e) {
if(e.key === "Right" || e.key === "ArrowRight") {
rightPressed = false;
}
else if(e.key === "Left" || e.key === "ArrowLeft") {
leftPressed = false;
}
}
function collisionDetection() {
for(var c=0; c<brickColumnCount; c++) {
for(var r=0; r<brickRowCount; r++) {
var b = bricks[c][r];
if(b.status == 1) {
if(x > b.x && x < b.x+brickWidth && y > b.y && y < b.y+brickHeight) {
dy = -dy;
b.status = 0;
score++;
if(score == brickRowCount*brickColumnCount) {
alert("YOU WIN, WELL DONE!");
document.location.reload();
clearInterval(interval); // <- This is needed for the browser to end the game \\
}
}
}
}
}
}
function drawScore() {
ctx.font = "16px OCR A";
ctx.fillStyle = "#00ffd9"
ctx.fillText("Score: "+score, 8, 20);
}
function drawLives() {
ctx.font = "16px OCR A"
ctx.fillStyle = "00ffd9"
ctx.fillText("Lives: "+lives, canvas.width-85, 20);
}
function drawBall() {
// drawing code \\
ctx.beginPath();
ctx.arc(x, y, ballRadius, 0, Math.PI*2);
ctx.lineWidth=3
ctx.strokeStyle = "#00ff00";
ctx.stroke();
ctx.closePath();
}
function drawPaddle() {
ctx.beginPath();
ctx.rect(paddleX, canvas.height-15, paddleWidth, paddleHeight);
ctx.lineWidth=2
ctx.fillStyle = "#ff0000";
ctx.fill();
ctx.closePath();
}
function drawBricks() {
for(var c=0; c<brickColumnCount; c++) {
for(var r=0; r<brickRowCount; r++) {
if(bricks[c][r].status == 1) {
var brickX = (c*(brickWidth+brickPadding))+brickOffsetLeft;
var brickY = (r*(brickHeight+brickPadding))+brickOffsetTop;
bricks[c][r].x = brickX;
bricks[c][r].y = brickY;
ctx.beginPath();
ctx.rect(brickX, brickY, brickWidth, brickHeight);
ctx.strokeStyle = "#33FFFF";
ctx.stroke();
ctx.closePath();
}
}
}
}
function draw() {
ctx.clearRect(0, 0, canvas.width, canvas.height);
drawBricks();
drawBall();
drawPaddle();
drawScore();
drawLives();
collisionDetection();
if (x + dx > canvas.width - ballRadius || x + dx < ballRadius) {
dx = -dx;
}
if (y + dy < ballRadius) {
dy = -dy;
}
else if (y + dy > canvas.height - ballRadius) {
if (x > paddleX && x < paddleX + paddleWidth) {
dy = -dy;
}
else {
lives--;
if(!lives) {
alert("Game Over! Press 'Ok' to reload!");
document.location.reload();
clearInterval(interval); // Is needed for Browser to end the game \\
}
else {
x = canvas.width/2;
y = canvas.height-30
dx = 2;
dy = -2;
paddleX = (canvas.width-paddleWidth)/2;
}
}
}
if (rightPressed && paddleX < canvas.width - paddleWidth) {
paddleX += 3;
} else if (leftPressed && paddleX > 0) {
paddleX -= 3;
}
x += dx;
y += dy;
}
var interval = setInterval(draw, 9);
var checkbox = document.getElementById('darkmode');
function darkmode() {
if (checkbox.checked == true){
document.documentElement.style.setProperty('--primary-background', 'black');
document.documentElement.style.setProperty('--primary-color', 'white');
} else {
document.documentElement.style.setProperty('--primary-background', 'white');
document.documentElement.style.setProperty('--primary-color', 'black');
}
}
checkbox.addEventListener('click', darkmode);
darkmode();
I'm trying to get my head around using javascript in the html < canvas >, and I started with the MDN Breakout game tutorial. Here is how the complete game looks like. I'm stuck with one of the exercises and I really could not find any solution to my issue after an hour of googling!! :((. The following code generates a ball on the canvas.
ctx.beginPath();
ctx.arc(x, y, radius, 0, Math.PI * 2);
ctx.fillStyle = '#FFFFF';
ctx.fill();
ctx.closePath();
I needed the ball to change its colour after it collides with one of the bricks. In order to achieve that, I created a variable to store the colour value: let colour = '#FFFFF';, and later in a function which detects collisions, changed the value of this variable. It worked fine, however, whenever the ball changed its colour, so did the bricks and the paddle. As I tried to fix this, I found out that whenever I manually change the colour of either a ball, a brick or a paddle (all of which are set in different functions), all of the objects change the colour as well.
This is very strange, because if in an emply .js file I make just two shapes and colour them differently it works fine:
const canvas = document.getElementById('canvas');
const ctx = canvas.getContext('2d');
ctx.beginPath();
ctx.rect(0, 0, 20, 40);
ctx.fillStyle = 'cyan';
ctx.fill();
ctx.closePath();
ctx.beginPath();
ctx.arc(50, 50, 20, 0, Math.PI*2);
ctx.fillStyle = 'black';
ctx.fill();
ctx.closePath();
But with all the game code I have right now, I can not assign different colour to different objects, they all change colour instead! I have no idea how to fix this and change just the colour of the ball! Anyone knows what might be causing the issue? Please help, thank you so much in advance 🙏
const canvas = document.getElementById('canvas');
const ctx = canvas.getContext('2d');
//Ball variables
const radius = 10;
let colour = '#FFFFF';
let x = canvas.width / 2;
let y = canvas.height - 30;
let dx = 2;
let dy = -2;
//Paddle
const paddleHeight = 10;
let paddleWidth = 100;
let paddleX = (canvas.width - paddleWidth) / 2;
//Paddle movement
var rightPressed = false;
var leftPressed = false;
//Bricks
var brickRowCount = 3;
var brickColumnCount = 5;
var brickWidth = 75;
var brickHeight = 20;
var brickPadding = 10;
var brickOffsetTop = 30;
var brickOffsetLeft = 30;
var bricks = [];
for (var c = 0; c < brickColumnCount; c++) {
bricks[c] = [];
for (var r = 0; r < brickRowCount; r++) {
bricks[c][r] = {
x: 0,
y: 0,
status: 1
};;
}
}
function draw() {
ctx.clearRect(0, 0, canvas.width, canvas.height);
drawBall();
drawPaddle();
drawBricks();
collisionDetection();
x += dx;
y += dy;
if (rightPressed && paddleX < canvas.width - paddleWidth) {
paddleX += 7;
} else if (leftPressed && paddleX > 0) {
paddleX -= 7;
}
}
function drawBall() {
ctx.beginPath();
ctx.arc(x, y, radius, 0, Math.PI * 2);
ctx.fillStyle = colour;
ctx.fill();
ctx.closePath();
//Bounce off the walls
if (x + dx > canvas.width - radius || x + dx < radius) {
dx = -dx;
}
if (y + dy < radius) {
dy = -dy;
} else if (y + dy > canvas.height - radius) {
//Collision detection (ball + paddle)
if (x > paddleX && x < paddleX + paddleWidth) {
dy = -dy;
} else {
//alert("GAME OVER");
document.location.reload();
}
}
}
function drawPaddle() {
ctx.beginPath();
ctx.rect(paddleX, canvas.height - paddleHeight, paddleWidth, paddleHeight);
ctx.fillStyle = '#FFFFF';
ctx.fill();
ctx.closePath();
}
function drawBricks() {
for (var c = 0; c < brickColumnCount; c++) {
for (var r = 0; r < brickRowCount; r++) {
if (bricks[c][r].status == 1) {
var brickX = (c * (brickWidth + brickPadding)) + brickOffsetLeft;
var brickY = (r * (brickHeight + brickPadding)) + brickOffsetTop;
bricks[c][r].x = brickX;
bricks[c][r].y = brickY;
ctx.beginPath();
ctx.rect(brickX, brickY, brickWidth, brickHeight);
ctx.fillStyle = "#FFFFF";
ctx.fill();
ctx.closePath();
}
}
}
}
document.addEventListener("keydown", keyDownHandler, false);
document.addEventListener("keyup", keyUpHandler, false);
function keyDownHandler(e) {
if (e.key == "Right" || e.key == "ArrowRight") {
rightPressed = true;
} else if (e.key == "Left" || e.key == "ArrowLeft") {
leftPressed = true;
}
}
function keyUpHandler(e) {
if (e.key == "Right" || e.key == "ArrowRight") {
rightPressed = false;
} else if (e.key == "Left" || e.key == "ArrowLeft") {
leftPressed = false;
}
}
function collisionDetection() {
for (var c = 0; c < brickColumnCount; c++) {
for (var r = 0; r < brickRowCount; r++) {
var b = bricks[c][r];
if (b.status == 1) {
if (x > b.x && x < b.x + brickWidth && y > b.y && y < b.y + brickHeight) {
dy = -dy;
b.status = 0;
colour = '#ff9ecb';
}
}
}
}
}
var interval = setInterval(draw, 10);
<!DOCTYPE html>
<html>
<head>
<title>Breakout Game</title>
</head>
<body>
<canvas id='canvas' height='320' width='480'></canvas>
<script src="app.js"></script>
</body>
</html>
Looks like a minor error with the colour hex codes you're using for your fillStyle, which are invalid. See the corrections in the snippet below from:
let colour = '#FFFFF'; // Six characters invalid
To:
let colour = '#FF0000'; // Seven characters valid
const canvas = document.getElementById('canvas');
const ctx = canvas.getContext('2d');
//Ball variables
const radius = 10;
// Fix colour
let colour = '#FF0000';
let x = canvas.width / 2;
let y = canvas.height - 30;
let dx = 2;
let dy = -2;
//Paddle
const paddleHeight = 10;
let paddleWidth = 100;
let paddleX = (canvas.width - paddleWidth) / 2;
//Paddle movement
var rightPressed = false;
var leftPressed = false;
//Bricks
var brickRowCount = 3;
var brickColumnCount = 5;
var brickWidth = 75;
var brickHeight = 20;
var brickPadding = 10;
var brickOffsetTop = 30;
var brickOffsetLeft = 30;
var bricks = [];
for (var c = 0; c < brickColumnCount; c++) {
bricks[c] = [];
for (var r = 0; r < brickRowCount; r++) {
bricks[c][r] = {
x: 0,
y: 0,
status: 1
};;
}
}
function draw() {
ctx.clearRect(0, 0, canvas.width, canvas.height);
drawBall();
drawPaddle();
drawBricks();
collisionDetection();
x += dx;
y += dy;
if (rightPressed && paddleX < canvas.width - paddleWidth) {
paddleX += 7;
} else if (leftPressed && paddleX > 0) {
paddleX -= 7;
}
}
function drawBall() {
// Update to valid colour
ctx.fillStyle = colour;
ctx.beginPath();
ctx.arc(x, y, radius, 0, Math.PI * 2);
ctx.fill();
ctx.closePath();
//Bounce off the walls
if (x + dx > canvas.width - radius || x + dx < radius) {
dx = -dx;
}
if (y + dy < radius) {
dy = -dy;
} else if (y + dy > canvas.height - radius) {
//Collision detection (ball + paddle)
if (x > paddleX && x < paddleX + paddleWidth) {
dy = -dy;
} else {
//alert("GAME OVER");
document.location.reload();
}
}
}
function drawPaddle() {
// Update to valid colour
ctx.fillStyle = '#00FF00';
// Consider using fillRect
ctx.fillRect(paddleX, canvas.height - paddleHeight, paddleWidth, paddleHeight);
}
function drawBricks() {
for (var c = 0; c < brickColumnCount; c++) {
for (var r = 0; r < brickRowCount; r++) {
if (bricks[c][r].status == 1) {
var brickX = (c * (brickWidth + brickPadding)) + brickOffsetLeft;
var brickY = (r * (brickHeight + brickPadding)) + brickOffsetTop;
bricks[c][r].x = brickX;
bricks[c][r].y = brickY;
// Update to valid colour
ctx.fillStyle = "#FFFFaa";
// Consider using fillRect
ctx.fillRect(brickX, brickY, brickWidth, brickHeight);
}
}
}
}
document.addEventListener("keydown", keyDownHandler, false);
document.addEventListener("keyup", keyUpHandler, false);
function keyDownHandler(e) {
if (e.key == "Right" || e.key == "ArrowRight") {
rightPressed = true;
} else if (e.key == "Left" || e.key == "ArrowLeft") {
leftPressed = true;
}
}
function keyUpHandler(e) {
if (e.key == "Right" || e.key == "ArrowRight") {
rightPressed = false;
} else if (e.key == "Left" || e.key == "ArrowLeft") {
leftPressed = false;
}
}
function collisionDetection() {
for (var c = 0; c < brickColumnCount; c++) {
for (var r = 0; r < brickRowCount; r++) {
var b = bricks[c][r];
if (b.status == 1) {
if (x > b.x && x < b.x + brickWidth && y > b.y && y < b.y + brickHeight) {
dy = -dy;
b.status = 0;
colour = '#ff9ecb';
}
}
}
}
}
var interval = setInterval(draw, 10);
<!DOCTYPE html>
<html>
<head>
<title>Breakout Game</title>
</head>
<body>
<canvas id='canvas' height='320' width='480'></canvas>
<script src="app.js"></script>
</body>
</html>
Also, consider using fillRect() as shown above, for a slightly simpler implementation. Hope that helps!
I am trying to create a scoreboard for my game by using local storage to carry over the score variable after a game is finished by a user. However, this is not working for some reason. I am relatively new to coding so I did some research on local storage but couldn't get the code to work to no avail. Could someone help me with this code thanks.
Page 1:
<html>
<title>Level Selector</title>
<canvas id="myCanvas" width="750" height="400"></canvas>
<style type="text/css">
canvas { background: #eee; }
</style>
<script>
document.addEventListener('load', draw);
var canvas = document.getElementById("myCanvas");
var ctx = canvas.getContext("2d");
var x = canvas.width/2;
var y = canvas.height-30;
var dx = 2;//Ball is moving in x direction at a constant rate
var dy = -2;//Ball is moving in y direction at a constant rate
var ballRadius = 10;//To see if ball is colliding with brick/canvas
var paddleHeight = 10;
var paddleWidth = 75;
var paddleX = (canvas.width-paddleWidth)/2;
var rightPressed = false;//This variable is false because the 'right arrow' key is not pressed.
var leftPressed = false;//This variable is false because the 'left arrow' key is not pressed.
var brickRowCount = 5;
var brickColumnCount = 8;
var brickWidth = 75;
var brickHeight = 20;
var brickPadding = 10;
var brickOffsetTop = 30;
var brickOffsetLeft = 30;
var score = 0;
var lives = 3;
var paused = false;
var bricks = [];//this is an array holding all the bricks
for(var c=0; c<brickColumnCount; c++) {
bricks[c] = [];
for(var r=0; r<brickRowCount; r++) {
bricks[c][r] = { x: 0, y: 0, status: 1 };//If status is '1' then draw it. However, is status is '0', fill in with background
}
}
document.addEventListener("keydown", keyDownHandler, false);//Functions only when key is pressed
document.addEventListener("keyup", keyUpHandler, false);//Functions only when key is not pressed
document.addEventListener("mousemove", mouseMoveHandler, false);//Functions only when mouse curcor moves
//keyCode(39) is the code for the 'right arrow' key and keyCode(37) is the code for the 'left arrow' key
function keyDownHandler(e) {
if(e.keyCode == 39) {
rightPressed = true;
}
else if(e.keyCode == 37) {
leftPressed = true;
}
}
function keyUpHandler(e) {
if(e.keyCode == 39) {
rightPressed = false;
}
else if(e.keyCode == 37) {
leftPressed = false;
}
}
function mouseMoveHandler(e) {
var relativeX = e.clientX - canvas.offsetLeft;//This represents the hoizontal mouse movement.
if(relativeX > 0 && relativeX < canvas.width) {
paddleX = relativeX - paddleWidth/2;
}
}
window.addEventListener('keydown', pauseGameKeyHandler, false);
function pauseGameKeyHandler(e) {
var keyCode = e.keyCode;
switch(keyCode){
case 80: //p
togglePause();
break;
}
}
function togglePause() {
paused = !paused;
draw();
}
/*************************************************************/
// NEW
const ballPowerupHalfWidth = 30;
const paddlePowerupHalfWidth = 30;
let ballPowerups = [];
let paddlePowerups = [];
// This function adds powerup to random position
function addPowerups() {
// I check only if none exist, you could
// add more than 1 powerup if you want
if (ballPowerups.length < 1) {
// otherwise half the triangle could be outside canvas
const padding = 50;
const xMin = 0 + padding;
const xMax = canvas.width - padding;
const yMin = 0 + padding;
const yMax = canvas.height - padding;
ballPowerups.push({
x: Math.floor(Math.random()*(xMax-xMin+1)+xMin),
y: Math.floor(Math.random()*(yMax-yMin+1)+yMin),
});
}
// I check only if none exist, you could
// add more than 1 powerup if you want
if (paddlePowerups.length < 1) {
// otherwise half the triangle could be outside canvas
const padding = 50;
const xMin = 0 + padding;
const xMax = canvas.width - padding;
const yMin = 0 + padding;
const yMax = canvas.height - padding;
paddlePowerups.push({
x: Math.floor(Math.random()*(xMax-xMin+1)+xMin),
y: Math.floor(Math.random()*(yMax-yMin+1)+yMin),
});
}
}
// NEW: do all collision detections
function doCollisionDetection() {
// ball powerups
ballPowerups.forEach((powerup, i) => {
rectangleCollisionDetection(
{x: powerup.x, y: powerup.y},
{w: ballPowerupHalfWidth, h: ballPowerupHalfWidth},
() => {
console.log('BALL POWERUP COLLISION');
// remove powerup
ballPowerups.splice(i, 1);
dy = dy/2
setTimeout(() => { dy=2 }, 5000)
// to make effect last 10 seconds:
// 1. add effect
// 2. and setTimeout(() => { /* code that removes effect */ }, 10000);
});
});
// paddle powerups
paddlePowerups.forEach((powerup, i) => {
rectangleCollisionDetection(
{x: powerup.x, y: powerup.y},
{w: ballPowerupHalfWidth, h: ballPowerupHalfWidth},
() => {
console.log('PADDLE POWERUP COLLISION');
// remove powerup
paddlePowerups.splice(i, 1);
paddleHeight = paddleHeight*1.5
paddleWidth = paddleWidth*1.5
setTimeout(() => { paddleHeight=10; }, 10000)
});
});
// bricks
for(var c=0; c<brickColumnCount; c++) {
for(var r=0; r<brickRowCount; r++) {
var b = bricks[c][r];
if(b.status == 1) {
rectangleCollisionDetection(b, {w: brickWidth, h: brickHeight}, () => {
console.log('BRICK COLLISION');
dy = -dy;
b.status = 0;
score++;
if(score == brickRowCount*brickColumnCount) {
alert("YOU WIN, CONGRATULATIONS!");
window.location = "Intro Screen.html";
}
});
}
}
}
// NEW: collision detection between ball and rectangle shaped
// collision boundary (only need center(x, y) and half width)
function rectangleCollisionDetection(center, size, callback) {
if(
x > center.x &&
x < center.x+size.w &&
y > center.y &&
y < center.y+size.h
) {
callback && callback();
}
}
function drawBallpowerup() {
ballPowerups.forEach(powerup => {
ctx.beginPath();
ctx.moveTo(powerup.x, powerup.y);
ctx.lineTo(powerup.x+ballPowerupHalfWidth, powerup.y+ballPowerupHalfWidth);
ctx.lineTo(powerup.x+ballPowerupHalfWidth*2, powerup.y);
ctx.fillStyle = "#42f445";
ctx.fill();
ctx.closePath();
});
}
function drawPaddlepowerup() {
paddlePowerups.forEach(powerup => {
ctx.beginPath();
ctx.moveTo(powerup.x, powerup.y);
ctx.lineTo(powerup.x+paddlePowerupHalfWidth, powerup.y+paddlePowerupHalfWidth);
ctx.lineTo(powerup.x+paddlePowerupHalfWidth*2, powerup.y);
ctx.fillStyle = "#ce6210";
ctx.fill();
ctx.closePath();
});
}
// my big changes end here
/*************************************************************/
//this is the score variable of the game
function drawScore() {
ctx.font = "16px Arial";
ctx.fillStyle = "#0095DD";
ctx.fillText("Score: "+score, 8, 20);
}
//this is the lives variable of the game
function drawLives() {
ctx.font = "16px Arial";
ctx.fillStyle = "#0095DD";
ctx.fillText("Lives: "+lives, canvas.width-65, 20);
}
//this creates the ball
function drawBall() {
ctx.beginPath();
ctx.arc(x, y, ballRadius, 0, Math.PI*2);
ctx.fillStyle = "#0095DD";
ctx.fill();
ctx.closePath();
}
//this creates the paddle
function drawPaddle() {
ctx.beginPath();
ctx.rect(paddleX, canvas.height-paddleHeight, paddleWidth, paddleHeight);
ctx.fillStyle = "#0095DD";
ctx.fill();
ctx.closePath();
}
//this creates the bricks
function drawBricks() {
for(var c=0; c<brickColumnCount; c++) {
for(var r=0; r<brickRowCount; r++) {
if(bricks[c][r].status == 1) {
var brickX = (c*(brickWidth+brickPadding))+brickOffsetLeft;
var brickY = (r*(brickHeight+brickPadding))+brickOffsetTop;
bricks[c][r].x = brickX;
bricks[c][r].y = brickY;
ctx.beginPath();
ctx.rect(brickX, brickY, brickWidth, brickHeight);
ctx.fillStyle = "#0095DD";
ctx.fill();
ctx.closePath();
}
}
}
}
function draw() {
// clears canvas content from previous frame
ctx.clearRect(0, 0, canvas.width, canvas.height);
drawBall();//this code draws the ball onto the canvas
drawPaddle();//this code draws the paddle onto the canvas
drawBricks();//this code draws the bricks onto the canvas
addPowerups();
doCollisionDetection();
drawScore();//this code draws the score variable onto the canvas
drawLives();//this code draws the lives variable onto the canvas
drawBallpowerup();
drawPaddlepowerup();
//Reverse Ball movement when the ball collides with wall in 'x' direction (Left/Right wall)
if(x + dx > canvas.width-ballRadius || x + dx < ballRadius) {
dx = -dx;
}
//Reverse Ball movement when the ball collides with wall in 'y' direction (Top/Bottom wall)
if(y + dy < ballRadius) {
dy = -dy;
} else if(y + dy > canvas.height-ballRadius) {
if(x > paddleX && x < paddleX + paddleWidth) {
dy = -dy;//If the ball collides with the paddle, the ball is rebounded in the opposite direction.
}
else {
lives--;
if(!lives) {
alert("GAME OVER");
localStorage.setItem("score", score);
}
window.location = "Intro Screen.html";
}
else {
x = canvas.width/2;
y = canvas.height-30;
dx = 2;
dy = -2;
paddleX = (canvas.width-paddleWidth)/2;
}
}
}
if(rightPressed && paddleX < canvas.width-paddleWidth) {//limits paddle movement in between the canvas width
paddleX += 7;//Paddle shifts 7 pixels in the positive x direction
}
else if(leftPressed && paddleX > 0) {//limits paddle movement in between the canvas width
paddleX -= 7;//Paddle shifts 7 pixels in the negative x direction
}
x += dx;//Ball is updated by painting it over each position it moves in
y += dy;//Ball is updated by painting it over each position it moves in
if(!paused) {
requestAnimationFrame(draw);
}
}
draw();
</script>
<body onload="draw();>
</body>
</html>
Page 2:
if (typeof(Storage) !== "undefined") {
// Retrieve
document.getElementById("result").innerHTML = localStorage.getItem("score"));
}
When I run it and after playing the game, the score should be added onto the scoreboard in decending order (highest to lowest). I have trouble bringing over the variable.
While there are no standard specifications about it, most browsers will consider different pages served from the file:// protocol as being different-origin.
This means your two pages will be considered as different-origin and will thus have their own Storage Area that they won't be able to share, just like you won't be able to access the Storage Area from www.xxxxx.com from www.yyyyy.com.
To overcome this limitation, the easiest is to run a local web-server on your machine. Many OSes comes with preinstalled such server, and all it requires is to activate it, and for the ones that don't do it, there are many free and easy solutions.
And if you are planning to play with web standards, it's a must have anyway.
I have seen various pages on how to pause my canvas game but I am having no luck! I have used this code now but still, nothing happens. I want to use the 'p' key to pause and then play the game.
<html>
<title>Level Selector</title>
<canvas id="myCanvas" width="750" height="400"></canvas>
<style type="text/css">
canvas { background: #eee; }
</style>
<script>
var canvas = document.getElementById("myCanvas");
var ctx = canvas.getContext("2d");
var x = canvas.width/2;
var y = canvas.height-30;
var dx = 2;//Ball is moving in x direction at a constant rate
var dy = -2;//Ball is moving in y direction at a constant rate
var ballRadius = 10;//To see if ball is colliding with brick/canvas
var paddleHeight = 10;
var paddleWidth = 75;
var paddleX = (canvas.width-paddleWidth)/2;
var rightPressed = false;//This variable is false because the 'right arrow' key is not pressed.
var leftPressed = false;//This variable is false because the 'left arrow' key is not pressed.
var brickRowCount = 5;
var brickColumnCount = 8;
var brickWidth = 75;
var brickHeight = 20;
var brickPadding = 10;
var brickOffsetTop = 30;
var brickOffsetLeft = 30;
var score = 0;
var lives = 3;
var paused = false;
var bricks = [];//this is an array holding all the bricks
for(var c=0; c<brickColumnCount; c++) {
bricks[c] = [];
for(var r=0; r<brickRowCount; r++) {
bricks[c][r] = { x: 0, y: 0, status: 1 };//If status is '1' then draw it. However, is status is '0', fill in with background
}
}
document.addEventListener("keydown", keyDownHandler, false);//Functions only when key is pressed
document.addEventListener("keyup", keyUpHandler, false);//Functions only when key is not pressed
document.addEventListener("mousemove", mouseMoveHandler, false);//Functions only when mouse curcor moves
//keyCode(39) is the code for the 'right arrow' key and keyCode(37) is the code for the 'left arrow' key
function keyDownHandler(e) {
if(e.keyCode == 39) {
rightPressed = true;
}
else if(e.keyCode == 37) {
leftPressed = true;
}
}
function keyUpHandler(e) {
if(e.keyCode == 39) {
rightPressed = false;
}
else if(e.keyCode == 37) {
leftPressed = false;
}
}
function mouseMoveHandler(e) {
var relativeX = e.clientX - canvas.offsetLeft;//This represents the hoizontal mouse movement.
if(relativeX > 0 && relativeX < canvas.width) {
paddleX = relativeX - paddleWidth/2;
}
}
function paused{
if (e.keyCode == 80) pauseGame();
}
function pauseGame{
if (!paused)
{
paused = true;
} else if (paused)
{
paused= false;
}
}
//Collisions only true when:
// -The x position of the ball is greater than the x position of the brick.
// -The x position of the ball is less than the x position of the brick plus its width.
// -The y position of the ball is greater than the y position of the brick.
// -The y position of the ball is less than the y position of the brick plus its height.
function collisionDetection() {
for(var c=0; c<brickColumnCount; c++) {
for(var r=0; r<brickRowCount; r++) {
var b = bricks[c][r];
if(b.status == 1) {
if(x > b.x && x < b.x+brickWidth && y > b.y && y < b.y+brickHeight) {
dy = -dy;
b.status = 0;
score++;
if(score == brickRowCount*brickColumnCount) {
alert("YOU WIN, CONGRATULATIONS!");
document.location.reload();
}
}
}
}
}
}
//this is the score variable of the game
function drawScore() {
ctx.font = "16px Arial";
ctx.fillStyle = "#0095DD";
ctx.fillText("Score: "+score, 8, 20);
}
//this is the lives variable of the game
function drawLives() {
ctx.font = "16px Arial";
ctx.fillStyle = "#0095DD";
ctx.fillText("Lives: "+lives, canvas.width-65, 20);
}
//this creates the ball
function drawBall() {
ctx.beginPath();
ctx.arc(x, y, ballRadius, 0, Math.PI*2);
ctx.fillStyle = "#0095DD";
ctx.fill();
ctx.closePath();
}
//this creates the paddle
function drawPaddle() {
ctx.beginPath();
ctx.rect(paddleX, canvas.height-paddleHeight, paddleWidth, paddleHeight);
ctx.fillStyle = "#0095DD";
ctx.fill();
ctx.closePath();
}
//this creates the bricks
function drawBricks() {
for(var c=0; c<brickColumnCount; c++) {
for(var r=0; r<brickRowCount; r++) {
if(bricks[c][r].status == 1) {
var brickX = (c*(brickWidth+brickPadding))+brickOffsetLeft;
var brickY = (r*(brickHeight+brickPadding))+brickOffsetTop;
bricks[c][r].x = brickX;
bricks[c][r].y = brickY;
ctx.beginPath();
ctx.rect(brickX, brickY, brickWidth, brickHeight);
ctx.fillStyle = "#0095DD";
ctx.fill();
ctx.closePath();
}
}
}
}
function draw() {
ctx.clearRect(0, 0, canvas.width, canvas.height);//clears canvas content from previous frame
drawBall();//this code draws the ball onto the canvas
drawPaddle();//this code draws the paddle onto the canvas
collisionDetection();//this codes enables the collision detection for the ball and bricks
drawBricks();//this code draws the bricks onto the canvas
drawScore();//this code draws the score variable onto the canvas
drawLives();//this code draws the lives variable onto the canvas
//Reverse Ball movement when the ball collides with wall in 'x' direction (Left/Right wall)
if(x + dx > canvas.width-ballRadius || x + dx < ballRadius) {
dx = -dx;
}
//Reverse Ball movement when the ball collides with wall in 'y' direction (Top/Bottom wall)
if(y + dy < ballRadius) {
dy = -dy;
} else if(y + dy > canvas.height-ballRadius) {
if(x > paddleX && x < paddleX + paddleWidth) {
dy = -dy;//If the ball collides with the paddle, the ball is rebounded in the opposite direction.
}
else {
lives--;
if(!lives) {
alert("GAME OVER");
document.location.reload();
}
else {
x = canvas.width/2;
y = canvas.height-30;
dx = 2;
dy = -2;
paddleX = (canvas.width-paddleWidth)/2;
}
}
}
if(rightPressed && paddleX < canvas.width-paddleWidth) {//limits paddle movement in between the canvas width
paddleX += 7;//Paddle shifts 7 pixels in the positive x direction
}
else if(leftPressed && paddleX > 0) {//limits paddle movement in between the canvas width
paddleX -= 7;//Paddle shifts 7 pixels in the negative x direction
}
x += dx;//Ball is updated by painting it over each position it moves in
y += dy;//Ball is updated by painting it over each position it moves in
requestAnimationFrame(draw);
}
if(!paused)
{
update();
}
</script>
<body>
</body>
</html>
As you can see, everything else about the code is good apart from the pause feature. I am completely bemused and don't know how to make it work at all. Please give a tips or a solution thanks.
EDit: I have put in a pause variable and function but its not working still.
First remove all errors appearing in your console:
1) Add a "paused" var to you code:
var paused = false;
2) Remove unnecessary code:
if(!paused)
{
update();
}
3) Your togglePause function is using a keycode var that does not exists. Change it to:
function togglePause() {
paused = !paused;
draw();
}
Calling the draw function will do the trick to continue the game when paused.
4) And fix the function that calls it:
function pauseGameKeyHandler(e) {
var keyCode = e.keyCode;
switch(keyCode){
case 80: //p
togglePause();
break;
}
}
5) At the end of your draw function add a test to the paused variable:
if(!paused) {
requestAnimationFrame(draw);
}
Full code with the changes:
<html>
<title>Level Selector</title>
<canvas id="myCanvas" width="750" height="400"></canvas>
<style type="text/css">
canvas { background: #eee; }
</style>
<script>
var canvas = document.getElementById("myCanvas");
var ctx = canvas.getContext("2d");
var x = canvas.width/2;
var y = canvas.height-30;
var dx = 2;//Ball is moving in x direction at a constant rate
var dy = -2;//Ball is moving in y direction at a constant rate
var ballRadius = 10;//To see if ball is colliding with brick/canvas
var paddleHeight = 10;
var paddleWidth = 75;
var paddleX = (canvas.width-paddleWidth)/2;
var rightPressed = false;//This variable is false because the 'right arrow' key is not pressed.
var leftPressed = false;//This variable is false because the 'left arrow' key is not pressed.
var brickRowCount = 5;
var brickColumnCount = 8;
var brickWidth = 75;
var brickHeight = 20;
var brickPadding = 10;
var brickOffsetTop = 30;
var brickOffsetLeft = 30;
var score = 0;
var lives = 3;
var paused = false;
var bricks = [];//this is an array holding all the bricks
for(var c=0; c<brickColumnCount; c++) {
bricks[c] = [];
for(var r=0; r<brickRowCount; r++) {
bricks[c][r] = { x: 0, y: 0, status: 1 };//If status is '1' then draw it. However, is status is '0', fill in with background
}
}
document.addEventListener("keydown", keyDownHandler, false);//Functions only when key is pressed
document.addEventListener("keyup", keyUpHandler, false);//Functions only when key is not pressed
document.addEventListener("mousemove", mouseMoveHandler, false);//Functions only when mouse curcor moves
//keyCode(39) is the code for the 'right arrow' key and keyCode(37) is the code for the 'left arrow' key
function keyDownHandler(e) {
if(e.keyCode == 39) {
rightPressed = true;
}
else if(e.keyCode == 37) {
leftPressed = true;
}
}
function keyUpHandler(e) {
if(e.keyCode == 39) {
rightPressed = false;
}
else if(e.keyCode == 37) {
leftPressed = false;
}
}
function mouseMoveHandler(e) {
var relativeX = e.clientX - canvas.offsetLeft;//This represents the hoizontal mouse movement.
if(relativeX > 0 && relativeX < canvas.width) {
paddleX = relativeX - paddleWidth/2;
}
}
window.addEventListener('keydown', pauseGameKeyHandler, false);
function pauseGameKeyHandler(e) {
var keyCode = e.keyCode;
switch(keyCode){
case 80: //p
togglePause();
break;
}
}
function togglePause() {
paused = !paused;
draw();
}
//Collisions only true when:
// -The x position of the ball is greater than the x position of the brick.
// -The x position of the ball is less than the x position of the brick plus its width.
// -The y position of the ball is greater than the y position of the brick.
// -The y position of the ball is less than the y position of the brick plus its height.
function collisionDetection() {
for(var c=0; c<brickColumnCount; c++) {
for(var r=0; r<brickRowCount; r++) {
var b = bricks[c][r];
if(b.status == 1) {
if(x > b.x && x < b.x+brickWidth && y > b.y && y < b.y+brickHeight) {
dy = -dy;
b.status = 0;
score++;
if(score == brickRowCount*brickColumnCount) {
alert("YOU WIN, CONGRATULATIONS!");
document.location.reload();
}
}
}
}
}
}
//this is the score variable of the game
function drawScore() {
ctx.font = "16px Arial";
ctx.fillStyle = "#0095DD";
ctx.fillText("Score: "+score, 8, 20);
}
//this is the lives variable of the game
function drawLives() {
ctx.font = "16px Arial";
ctx.fillStyle = "#0095DD";
ctx.fillText("Lives: "+lives, canvas.width-65, 20);
}
//this creates the ball
function drawBall() {
ctx.beginPath();
ctx.arc(x, y, ballRadius, 0, Math.PI*2);
ctx.fillStyle = "#0095DD";
ctx.fill();
ctx.closePath();
}
//this creates the paddle
function drawPaddle() {
ctx.beginPath();
ctx.rect(paddleX, canvas.height-paddleHeight, paddleWidth, paddleHeight);
ctx.fillStyle = "#0095DD";
ctx.fill();
ctx.closePath();
}
//this creates the bricks
function drawBricks() {
for(var c=0; c<brickColumnCount; c++) {
for(var r=0; r<brickRowCount; r++) {
if(bricks[c][r].status == 1) {
var brickX = (c*(brickWidth+brickPadding))+brickOffsetLeft;
var brickY = (r*(brickHeight+brickPadding))+brickOffsetTop;
bricks[c][r].x = brickX;
bricks[c][r].y = brickY;
ctx.beginPath();
ctx.rect(brickX, brickY, brickWidth, brickHeight);
ctx.fillStyle = "#0095DD";
ctx.fill();
ctx.closePath();
}
}
}
}
function draw() {
ctx.clearRect(0, 0, canvas.width, canvas.height);//clears canvas content from previous frame
drawBall();//this code draws the ball onto the canvas
drawPaddle();//this code draws the paddle onto the canvas
collisionDetection();//this codes enables the collision detection for the ball and bricks
drawBricks();//this code draws the bricks onto the canvas
drawScore();//this code draws the score variable onto the canvas
drawLives();//this code draws the lives variable onto the canvas
//Reverse Ball movement when the ball collides with wall in 'x' direction (Left/Right wall)
if(x + dx > canvas.width-ballRadius || x + dx < ballRadius) {
dx = -dx;
}
//Reverse Ball movement when the ball collides with wall in 'y' direction (Top/Bottom wall)
if(y + dy < ballRadius) {
dy = -dy;
} else if(y + dy > canvas.height-ballRadius) {
if(x > paddleX && x < paddleX + paddleWidth) {
dy = -dy;//If the ball collides with the paddle, the ball is rebounded in the opposite direction.
}
else {
lives--;
if(!lives) {
alert("GAME OVER");
document.location.reload();
}
else {
x = canvas.width/2;
y = canvas.height-30;
dx = 2;
dy = -2;
paddleX = (canvas.width-paddleWidth)/2;
}
}
}
if(rightPressed && paddleX < canvas.width-paddleWidth) {//limits paddle movement in between the canvas width
paddleX += 7;//Paddle shifts 7 pixels in the positive x direction
}
else if(leftPressed && paddleX > 0) {//limits paddle movement in between the canvas width
paddleX -= 7;//Paddle shifts 7 pixels in the negative x direction
}
x += dx;//Ball is updated by painting it over each position it moves in
y += dy;//Ball is updated by painting it over each position it moves in
if(!paused) {
requestAnimationFrame(draw);
}
}
draw();
</script>
<body>
</body>
</html>