Develop Reference

How to auto generate divs with javascript?

I made a basic javascript code so you can poke divs with you mouse.
Unfortunately I have to add them manualy but i wanna add so much of them with a pattern.
First i decided to use grid but i guessed it wont work because divs (which i call them squares from now on :D) can change their position.
So I was about to ask, how can I create a javascript code that i can spawn them until they fill the screen.
Also i have another question which is realted to this project, How can i make these squares just decors. I mean by decors i dont want them to effect the webside at all, when the blocks goes out of the screen the body starts to expend, is there any way to avoid that?
(Also it will be better if you make the snippet full screen!)
EDIT: I put the refresh-button on the top left on the main div so you can draw squares by clicking it!
let mouse = {
speedX: 0,
speedY: 0,
posX: 0,
posY: 0,
movement: 0,
speed: 0
}
//on mousemove update the moouse object
document.onmousemove = function(e) {
mouse.speedX = e.movementX;
mouse.speedY = e.movementY
mouse.posX = e.pageX;
mouse.posY = e.pageY;
}
//refresh the mouse movement and speed every 100ms
setInterval(() => {
mouse.movement =
Math.sqrt(Math.pow(mouse.speedX, 2) + Math.pow(mouse.speedY, 2));
mouse.speed = mouse.movement * 10;
}, 100);
//add a square div in parent element
function addSquare(parent) {
const newDiv = document.createElement("div");
newDiv.classList.add("square")
parent.appendChild(newDiv)
return newDiv;
}
//add squares in the parent element filling the available size
//gap is the space between squares, size is the edge of the square
//if skipbefore is false it will begin to draw the next square also if it won't fit entirely
function addSquares(parent, gap, size, skipbefore = true) {
const squares = [];
let rect = parent.getBoundingClientRect();
const availableWidth = rect.width;
const availableHeight = rect.height;
let top = 100;
while (top < availableHeight) {
let left = 0;
if (skipbefore && top + size > availableHeight)
break;
while (left < availableWidth) {
if (skipbefore && left + size > availableWidth)
break;
const square = addSquare(parent);
square.style.left = `${left}px`;
square.style.top = `${top}px`;
squares.push(square);
left += gap + size;
}
top += gap + size;
}
return squares;
}
//onmoveover event handler
const squareOnMouseOver = (event) => {
const element = event.target;
const y = mouse.speedY;
const x = mouse.speedX;
const rad = Math.atan2(y, x);
yAxis = mouse.movement * Math.sin(rad);
xAxis = mouse.movement * Math.cos(rad);
const rect = element.getBoundingClientRect();
const left = Math.round(rect.x + xAxis * 3);
const top = Math.round(rect.y + yAxis * 3);
element.style.left = `${left}px`;
element.style.top = `${top}px`;
const o = rad * (180 / Math.PI);
element.style.transform = `rotate(${o}deg)`;
}
//resets the .target parent and redraw the squares inside it
function drawSquares() {
const parent = document.querySelector('.target');
parent.innerHTML = '';
const squares = addSquares(parent, 25, 75);
const colors = [
'lightcoral',
'bisque',
'aquamarine',
'cadetblue',
'greenyellow',
'yellowgreen'
];
squares.forEach(square => {
const iColor = Math.floor(Math.random() * (colors.length - 1));
const color = colors[iColor];
square.style.background = color;
square.addEventListener('mouseover', squareOnMouseOver);
});
}
body{
margin: 0;
width: 100vw;
height: 100vh;
display: flex;
justify-content: center;
align-items: center;
background-color: rgb(242, 239, 231);
color: rgb(10, 10, 9);
}
.square{
background-color: lightcoral;
width: 75px;
height: 75px;
position: absolute;
transform: rotate(0deg);
transition: all ease-out 0.5s;
}
.background {
display: flex;
align-items: center;
justify-content: center;
width: 100%;
height: 100%;
}
.container .row .col > * {
display: inline-block;
}
.target {
display: block;
width: 100%;
height: 100%;
}
#draw {
font-size: 20px;
padding: .2em 1em;
cursor: pointer;
}
.name{
font-size: 40px;
}
#main-container{
position: absolute;
padding: 35px 45px;
width: 950px;
height: 285px;
box-shadow: 0px 2px 5px 2px rgb(191, 188, 182);
}
.links{
display: flex;
justify-content: center;
align-items: center;
}
.icons{
width: 55px;
height: auto;
margin: 0px 25px;
padding: 10px;
border-radius: 5px;
transition: all ease-in 0.2s;
}
.icons:hover{
background-color: rgb(144, 144, 144);
}
.refresh{
position: absolute;
}
.refresh-button{
width: 25px;
height: auto;
}
.btn:hover{
background-color: rgb(144, 144, 144);
}
<!DOCTYPE html>
<html lang="en">
<head>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.6.0/jquery.min.js"></script>
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/3.4.1/js/bootstrap.min.js"></script>
<link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootstrap/4.4.1/css/bootstrap.min.css">
<link rel="stylesheet" href="css.css">
<meta charset="UTF-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Document</title>
</head>
<body>
<div class="background">
<div class="target"></div>
<div class="container text-center" id="main-container">
<div class="">
<div class="refresh">
<button class="btn" id="draw" onclick="drawSquares()"><img class="refresh-button" src="SVG/arrow-clockwise.svg"></button>
</div>
<div class="name">Berk Efe Keskin</div>
<br>
<i>This website is working in progress right now...</i>
<br>
<i>Here is some useful links.</i>
<br>
<br>
<div class="links">
<img class="icons" src="SVG/github.svg">
<img class="icons" src="SVG/linkedin.svg">
<img class="icons" src="SVG/stack-overflow.svg">
</div>
</div>
</div>
</div>
<script type="text/javascript" src = "javascript.js"></script>
</body>
</html>

You may have a function that given a container will be filled with how many squares can fit inside as long as there is still avaiable width and available height in the target.
Here in this demo I better factored your code and added a main function called drawSquares that gets called when the button reDRAW is clicked. Each time the squares are redrawn, the target content is emptied.
I'm using a button to trigger the box drawing because the available space depends on the size of the area when the action is fired. For example you can expand the snippet and decide to redraw the squares to have the whole new area filled again.
You may decide to call the action on document ready or when the window gets resized.
let mouse = {
speedX: 0,
speedY: 0,
posX: 0,
posY: 0,
movement: 0,
speed: 0
}
//on mousemove update the moouse object
document.onmousemove = function(e) {
mouse.speedX = e.movementX;
mouse.speedY = e.movementY
mouse.posX = e.pageX;
mouse.posY = e.pageY;
}
//refresh the mouse movement and speed every 100ms
setInterval(() => {
mouse.movement =
Math.sqrt(Math.pow(mouse.speedX, 2) + Math.pow(mouse.speedY, 2));
mouse.speed = mouse.movement * 10;
}, 100);
//add a square div in parent element
function addSquare(parent) {
const newDiv = document.createElement("div");
newDiv.classList.add("square")
parent.appendChild(newDiv)
return newDiv;
}
//add squares in the parent element filling the available size
//gap is the space between squares, size is the edge of the square
//if skipbefore is false it will begin to draw the next square also if it won't fit entirely
function addSquares(parent, gap, size, skipbefore = true) {
const squares = [];
let rect = parent.getBoundingClientRect();
const availableWidth = rect.width;
const availableHeight = rect.height;
let top = 100;
while (top < availableHeight) {
let left = 0;
if (skipbefore && top + size > availableHeight)
break;
while (left < availableWidth) {
if (skipbefore && left + size > availableWidth)
break;
const square = addSquare(parent);
square.style.left = `${left}px`;
square.style.top = `${top}px`;
squares.push(square);
left += gap + size;
}
top += gap + size;
}
return squares;
}
//onmoveover event handler
const squareOnMouseOver = (event) => {
const element = event.target;
const y = mouse.speedY;
const x = mouse.speedX;
const rad = Math.atan2(y, x);
yAxis = mouse.movement * Math.sin(rad);
xAxis = mouse.movement * Math.cos(rad);
const rect = element.getBoundingClientRect();
const left = Math.round(rect.x + xAxis * 3);
const top = Math.round(rect.y + yAxis * 3);
element.style.left = `${left}px`;
element.style.top = `${top}px`;
const o = rad * (180 / Math.PI);
element.style.transform = `rotate(${o}deg)`;
}
//resets the .target parent and redraw the squares inside it
function drawSquares() {
const parent = document.querySelector('.target');
parent.innerHTML = '';
const squares = addSquares(parent, 25, 75);
const colors = [
'lightcoral',
'bisque',
'aquamarine',
'cadetblue',
'greenyellow',
'yellowgreen'
];
squares.forEach(square => {
const iColor = Math.floor(Math.random() * (colors.length - 1));
const color = colors[iColor];
square.style.background = color;
square.addEventListener('mouseover', squareOnMouseOver);
});
}
body {
margin: 0;
width: 100vw;
height: 100vh;
display: flex;
}
.square {
background-color: lightcoral;
width: 75px;
height: 75px;
position: absolute;
transform: rotate(0deg);
transition: all ease-out 0.5s;
}
#Header {
font-size: italic;
}
.background {
width: 100%;
height: 100%;
}
.target {
position: relative;
display: block;
width: 100%;
height: 100%;
z-index: -1;
}
#draw {
font-size: 20px;
padding: .2em 1em;
cursor: pointer;
}
.container .row .col > * {
display: inline-block;
}
<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.6.0/jquery.min.js"></script>
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/3.4.1/js/bootstrap.min.js"></script>
<link el="stylesheet" href="https://stackpath.bootstrapcdn.com/bootstrap/4.4.1/css/bootstrap.min.css">
<body>
<div class="background">
<span>Work in progress...</span>
<div class="container text-center">
<div class="row">
<div class="col">
<h1 id="Header">Work in progress...</h1>
<button id="draw" onclick="drawSquares()">reDRAW</button>
</div>
</div>
</div>
<div class="target"></div>
</div>
</body>

Why is my cursor and my line of draw are in diffrent sides?

I am attempting to create a drawing app in JS, however, whenever anything is drawn, it is positioned away from my cursor depending on where it is on the canvas, when I am on the furthest left/bottom side of the canvas, you can draw where your cursor is, but the further right/up I move, the more the brush begins to "drift" and go further than where my cursor is.
const canvas = document.getElementById("canvas");
const increaseBtn = document.getElementById("increase");
const decreaseBtn = document.getElementById("decrease");
const sizeEl = document.getElementById("size");
const colorEl = document.getElementById("color");
const clearEl = document.getElementById("clear");
//Core Drawing Functionality (with some research)
const ctx = canvas.getContext("2d");
let size = 5;
let isPressed = false;
let color = "black";
let x;
let y;
let fakeSize = 1;
canvas.addEventListener("mousedown", (e) => {
isPressed = true;
x = e.offsetX;
y = e.offsetY;
});
canvas.addEventListener("mouseup", (e) => {
isPressed = false;
x = undefined;
y = undefined;
});
canvas.addEventListener("mousemove", (e) => {
if (isPressed) {
const x2 = e.offsetX;
const y2 = e.offsetY;
drawCircle(x2, y2);
drawLine(x, y, x2, y2);
x = x2;
y = y2;
}
});
function drawCircle(x, y) {
ctx.beginPath();
ctx.arc(x, y, size, 0, Math.PI * 2);
ctx.fillStyle = color;
ctx.fill();
}
function drawLine(x1, y1, x2, y2) {
ctx.beginPath();
ctx.moveTo(x1, y1);
ctx.lineTo(x2, y2);
ctx.strokeStyle = color;
ctx.lineWidth = size * 2;
ctx.stroke();
}
function updateSizeOnScreen() {
sizeEl.innerHTML = fakeSize;
}
increaseBtn.addEventListener("click", () => {
size += 5;
fakeSize++;
if (fakeSize > 10) {
fakeSize = 10;
}
if (size > 50) {
size = 50;
}
updateSizeOnScreen();
});
decreaseBtn.addEventListener("click", () => {
size -= 5;
fakeSize--;
if (fakeSize < 1) {
fakeSize = 1;
}
if (size < 5) {
size = 5;
}
updateSizeOnScreen();
});
colorEl.addEventListener("change", (e) => {
color = e.target.value;
});
clearEl.addEventListener("click", () => {
ctx.clearRect(0, 0, canvas.width, canvas.height);
});
//Eraser and Pencil Actions (my own algorithm)
const eraser = document.getElementById("eraser");
const pencil = document.getElementById("pencil");
eraser.addEventListener("click", () => {
localStorage.setItem("colorEl", JSON.stringify(color));
color = "#fff";
colorEl.disabled = true;
canvas.classList.add("eraseractive");
eraser.classList.add("eraseractive");
colorEl.classList.add("eraseractive");
canvas.classList.remove("pencilactive");
eraser.classList.remove("pencilactive");
colorEl.classList.remove("pencilactive");
});
pencil.addEventListener("click", () => {
JSON.parse(localStorage.getItem("colorEl"));
color = colorEl.value;
colorEl.disabled = false;
canvas.classList.remove("eraseractive");
eraser.classList.remove("eraseractive");
colorEl.classList.remove("eraseractive");
canvas.classList.add("pencilactive");
eraser.classList.add("pencilactive");
colorEl.classList.add("pencilactive");
});
// Dark/Light Mode
const darkMode = document.getElementById("darkMode");
const lightMode = document.getElementById("lightMode");
const toolbox = document.getElementById("toolbox");
darkMode.addEventListener("click", () => {
darkMode.classList.add("mode-active");
lightMode.classList.remove("mode-active");
lightMode.classList.add("rotate");
darkMode.classList.remove("rotate");
toolbox.style.backgroundColor = "#293462";
document.body.style.backgroundImage =
"url('/assets/images/darkModeBackground.svg')";
document.body.style.backgroundSize = "1920px 1080px";
canvas.style.borderColor = "#293462";
toolbox.style.borderColor = "#293462";
});
lightMode.addEventListener("click", () => {
lightMode.classList.add("mode-active");
darkMode.classList.remove("mode-active");
darkMode.classList.add("rotate");
lightMode.classList.remove("rotate");
toolbox.style.backgroundColor = "#293462";
document.body.style.backgroundImage =
"url('/assets/images/lightModeBackground.svg')";
document.body.style.backgroundSize = "1920px 1080px";
canvas.style.borderColor = "#293462";
toolbox.style.borderColor = "#293462";
});
* {
box-sizing: border-box;
font-size: 20px !important;
}
body {
background: url("https://drawing-app-green.vercel.app/assets/images/lightModeBackground.svg");
display: flex;
flex-direction: column;
align-items: center;
justify-content: center;
height: 100%;
margin: 0;
position: relative;
max-height: 100vh;
overflow: hidden;
}
::selection {
background: transparent;
}
::-moz-selection {
background: transparent;
}
.mode {
display: flex;
position: absolute;
top: 10px;
right: 25px;
cursor: pointer;
}
.light-mode {
color: yellow;
}
.dark-mode {
color: #16213e;
}
.container {
display: flex;
flex-direction: column;
max-width: 1200px;
width: 100%;
max-height: 600px;
height: 100%;
}
canvas {
display: flex;
border: 2px solid #293462;
cursor: url("https://drawing-app-green.vercel.app/assets/images/pencilCursor.png") 2 48, pointer;
background-color: #fff;
margin-top: 3rem;
width: 100%;
height: 600px;
}
.toolbox {
background-color: #293462;
border: 1px solid #293462;
display: flex;
width: 100%;
align-items: center;
justify-content: center;
padding: 0.2rem;
}
.toolbox > * {
background-color: #fff;
border: none;
display: inline-flex;
align-items: center;
justify-content: center;
font-size: 2rem;
height: 30px;
width: 30px;
margin: 0.25rem;
padding: 0.25rem;
cursor: pointer;
}
.toolbox > *:last-child {
margin-left: auto;
}
canvas.eraseractive {
cursor: url("https://drawing-app-green.vercel.app/assets/images/eraserCursor.png") 2 48, pointer;
}
#color.eraseractive {
cursor: not-allowed;
}
canvas.pencilactive {
cursor: url("https://drawing-app-green.vercel.app/assets/images/pencilCursor.png") 2 48, pointer;
}
.mode-active {
visibility: hidden;
}
.rotate {
transform: rotate(360deg);
transition: transform 1s linear;
}
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8" />
<meta http-equiv="X-UA-Compatible" content="IE=edge" />
<meta name="viewport" content="width=device-width, initial-scale=1.0" />
<title>Drawing App</title>
<link
rel="stylesheet"
href="https://cdnjs.cloudflare.com/ajax/libs/font-awesome/6.2.0/css/all.min.css"
integrity="sha512-xh6O/CkQoPOWDdYTDqeRdPCVd1SpvCA9XXcUnZS2FmJNp1coAFzvtCN9BmamE+4aHK8yyUHUSCcJHgXloTyT2A=="
crossorigin="anonymous"
referrerpolicy="no-referrer"
/>
</head>
<body>
<i class="fa-solid fa-moon dark-mode fa-2x mode" id="darkMode"></i>
<i
class="fa-solid fa-sun light-mode fa-2x mode mode-active"
id="lightMode"
></i>
<div class="container">
<canvas id="canvas" width="1024" height="600"></canvas>
<div class="toolbox" id="toolbox">
<button id="decrease">-</button>
<span id="size">1</span>
<button id="increase">+</button>
<input type="color" id="color" />
<button id="pencil">
<img src="assets/images/pencilCursor.png" alt="" />
</button>
<button id="eraser">
<img src="assets/images/eraserCursor.png" alt="" />
</button>
<button id="clear">X</button>
</div>
</div>
<script src="assets/js/script.js"></script>
</body>
</html>

Your problem is that your canvas dimentions don't match with the dimentions of the HTML element that contains it. You see: your canvas has a fixed width="" and height="" attributes set. But in your HTML your canvas element has a width of 100%. So that means that the container vairies in dimentions but the canvas inside it not. This result in the canvas trying to resize to show inside the container thus giving you issues with calculating exacly what pixel you are clicking.
You have two options:
Option 1: calculate your click position taking into account canvas deformation
If you want your canvas to resize, then calculate the real position using a simple ratio formula. If for example your canvas has a width of 100 but right now its container is 10px wide, then if you click on pixel 5 you expect a dot to be drawn at pixel 50. In other words if your canvas is smaller by a factor of 10 then you need to multiply your position by a factor of 10.
In your code it would look something like this:
// this is your same code in lines 33 ana34 but see that I added a multiplication by the ratio between the canvas size and the canvas container
const x2 = e.offsetX * (canvas.width / ctx.canvas.getBoundingClientRect().width);
const y2 = e.offsetY * (canvas.height / ctx.canvas.getBoundingClientRect().height);
Option #2: Dont allow your canvas to deform
Remove the container class, and remove the width:100% from your canvas css. Your canvas will overflow and cause a scrollbar but the positions will be calculated properly with your code.

How can I draw JavaScript graphical elements on top of custom image?

I have some Javascript drawing random square elements in the DOM. I have a gif (Image) I want these elements to appear over but they keep appearing underneath the gif. I tried defining z-depth and layout parameters to move these elements on top of the image here, but this produced no difference.
Any assistance in achieving the result (drawing elements onclick, on top of this gif) would be much appreciated.
I ultimately want to draw various other images over this image onclick, restricted to this particular area on top of the gif. If someone can suggest a solution to this as well I would be very much grateful!
(Code features some unused elements from my past attempts)
<!DOCTYPE html>
<html>
<head>
<link rel="stylesheet" type="text/css" href="div.css" />
</head>
<body>
<div style="cursor: pointer;" id="boxy" >
<img src="bg.gif" alt="unfinished bingo card" onclick="create()" />
</div>
</div>
<script>
var body = document.getElementsByTagName("body")[0];
var canvas = document.createElement("canvas");
canvas.height = 1300;
canvas.width = 1300;
var context = canvas.getContext("2d");
body.appendChild(canvas);
var rects = [];
function create() {
// Opacity
context.globalAlpha = 0.7;
var color = '#' + Math.round(0xffffff * Math.random()).toString(16);
context.fillStyle = color;
//Each rectangle's size is (20 ~ 100, 20 ~ 100)
var coordx = Math.random() * canvas.width;
var coordy = Math.random() * canvas.width;
var width = Math.random() * 80 + 20;
var height = Math.random() * 80 + 20;
var rect = {
x: coordx,
y: coordy,
w: width,
h: height
}
var ok = true;
rects.forEach(function (item) {
if (isCollide(rect, item)) {
console.log("collide");
ok = false;
} else {
console.log("no collision");
}
})
if (ok) {
context.fillRect(coordx, coordy, width, height);
rects.push(rect);
} else {
console.log('rect dropped');
}
console.log(rects);
}
function isCollide(a, b) {
return !(
((a.y + a.h) < (b.y)) ||
(a.y > (b.y + b.h)) ||
((a.x + a.w) < b.x) ||
(a.x > (b.x + b.w))
);
}
document.getElementById('boxy').addEventListener('click', create);
document.getElementById('canvas').style.position = "relative";
document.getElementById('canvas').style.zIndex = "10";
</script>
</body>
</html>
#my-div {
width: 1300x;
height: 1300px;
z-index: -1;
}
a.fill-div {
display: block;
height: 100%;
width: 100%;
text-decoration: none;
}
#boxy {
display: inline-block;
height: 100%;
width: 100%;
text-decoration: none;
z-index: -1;
}
.canvas {
display: inline-block;
height: 100%;
width: 100%;
text-decoration: none;
z-index: 10;
}

You have to use position:absolute; to take it out of the html flow.
Now anything added after the image will be placed like the image was never there.
img {
width: 100vw;
height: 100vh;
position: absolute;
top: 0;
left: 0;
z-index: -10;
}
div {
font-size: 2rem;
color: white;
}
<img src="https://images.unsplash.com/photo-1664273107076-b6d1fbfb973b?ixlib=rb-1.2.1&ixid=MnwxMjA3fDB8MHxwaG90by1wYWdlfHx8fGVufDB8fHx8&auto=format&fit=crop&w=1171&q=80">
<div>Hello i am on top of the image
</div>

I want to create several moving circles in Canvas in Javascript

I want make aimbooster. (http://www.aimbooster.com/)
I don't know how to make several circles that change in size at the same time.
My drawing process is...
Create a circle.
Draw a circle changing its size.
Reset the x- and y-coordinates when a circle is clicked.
Repeat this process.
The way I've tried to solve this problem is...
I tried to combine the draw function and the CircleForm function into a class and use a repeat statement.
I keep getting errors.
How do you make multiple circles?
var canvas = document.getElementById('myCanvas');
var context = canvas.getContext('2d');
// canvas maximum, minimum size
var max_x = 610,
min_x = 30,
min_y = 30,
max_y = 466;
// Initial Circle State
var x = 200,
y = 200,
r = 1,
startAngle = 0,
endAngle = Math.PI*2;
var moving;
var inc = true;
// -------------------------------------------------------------------
class Ball {
move(){
moving = setInterval(draw, 1);
}
stop(){
clearInterval(moving);
}
position(){
x = Math.floor(Math.random() * ((max_x) - (min_x))+min_x);
y = Math.floor(Math.random() * ((max_y) - (min_y))+min_y);
}
first_size(){
r = 1;
}
moving_size(){
var size_fast = 0.09; //0.09
if(inc){
r+=size_fast;
}else{
r-=size_fast;
}
}
}
let ball = new Ball();
// ---------------------------------------------------------------------------
function macroBall(){
ball.stop();
ball.position();
ball.first_size();
ball.move();
}
function CircleForm(x,y,r,startAngle, endAngle){
var canvas = document.getElementById('myCanvas');
var context = canvas.getContext('2d');
context.beginPath();
context.arc(x,y,r,startAngle, endAngle);
context.fillStyle = "orange";
context.fill();
context.stroke();
}
function draw(){
context.clearRect(0,0,canvas.width,canvas.height);
CircleForm(x,y,r,startAngle, endAngle);
rad_check(r);
ball.moving_size();
}
// Circle radius check
function rad_check(r){
if(r>=30){
inc = false;
}
if(r<=2){
inc = true;
}
}
canvas.addEventListener('mousedown', function(e) {
getCursorPosition(canvas, e)}
);
function getCursorPosition(canvas, event) {
const rect = canvas.getBoundingClientRect()
const xpos = event.clientX - rect.left
const ypos = event.clientY - rect.top
console.log("x: " + xpos + " y: " + ypos);
judgeHit(xpos,ypos);
}
// circle click event
function judgeHit(xpos, ypos,moving){
if(Math.abs(x-xpos)<=r && Math.abs(y-ypos)<=r){
macroBall();
}
}
ball.move();
*{
margin:0;
}
html, body{
height:100%;
}
body{
background:#376481 url(bg.jpg);
background-size: 100% 100%;
}
#page-container{
width:100%;
min-height:100%;
background:url(bg_stripes.png);
}
#column{
width: 640px;
margin-left: auto;
margin-right: auto;
display:grid;
}
#top{
height:80px;
}
.nav{
height:20px;
background-color:#CCCCCC;
}
.nav ul{
padding:0px;
margin-left:220px;
text-align: center;
}
.nav ul li{
font-size:10pt;
list-style:none;
float:left
}
.nav ul li a{
text-decoration:none;
color:#4477BB;
}
#myCanvas{
background-color:white;
}
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Aim_Boost</title>
<link rel="stylesheet" href="styles.css">
</head>
<body>
<div id="page-container">
<div id="top"></div>
<div id="column">
<img src="header.png" style="width: 640px; height: 116px;" alt="AimBooster">
<div id="page">
<div class="nav">
<ul>
<li>Play</li>
<li> • News</li>
<li> • FAQ</li>
<li> • Feedback</li>
<li> • Donate</li>
</ul>
</div>
<div id="thi">
<canvas id="myCanvas" width="640px" height="497px"></canvas>
</div>
</div>
</div>
</div>
<script src="javas.js"></script>
</body>
</html>

You will need to add a constructor() method to the class to start. Read about it here developer.mozilla.org. Once you have that you can use the constructor to assign the objects properties.
Push all of the objects to any array and then iterate over them to animate. This a a very basic example showing how to create multiple circles. You can also create them without a loop.
let ball1 = new Ball();
let ball2 = new Ball();
var canvas = document.getElementById("myCanvas");
var context = canvas.getContext("2d");
let balls = [];
var inc = true;
class Ball {
constructor() {
this.x = Math.random() * canvas.width;
this.y = Math.random() * canvas.height;
this.r = 4;
this.c = "orange";
this.speed = 0.5;
}
draw() {
context.beginPath();
context.arc(this.x, this.y, this.r, 0, Math.PI * 2);
context.fillStyle = this.c;
context.fill();
context.stroke();
}
grow() {
if (inc) {
this.r += this.speed;
} else {
this.r -= this.speed;
}
}
incCheck() {
if (this.r >= 30) {
inc = false;
} else if (this.r < 2) {
inc = true;
}
}
}
function createBalls() {
for (let i = 0; i < 50; i++) {
balls.push(new Ball());
}
}
createBalls();
function drawBalls() {
for (let i = 0; i < balls.length; i++) {
balls[i].draw();
balls[i].grow();
balls[i].incCheck();
}
}
setInterval(() => {
context.clearRect(0, 0, canvas.width, canvas.height);
drawBalls()
}, 50)
*{
margin:0;
}
html, body{
height:100%;
}
body{
background:#376481 url(bg.jpg);
background-size: 100% 100%;
}
#page-container{
width:100%;
min-height:100%;
background:url(bg_stripes.png);
}
#column{
width: 640px;
margin-left: auto;
margin-right: auto;
display:grid;
}
#top{
height:80px;
}
.nav{
height:20px;
background-color:#CCCCCC;
}
.nav ul{
padding:0px;
margin-left:220px;
text-align: center;
}
.nav ul li{
font-size:10pt;
list-style:none;
float:left
}
.nav ul li a{
text-decoration:none;
color:#4477BB;
}
#myCanvas{
background-color:white;
}
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Aim_Boost</title>
<link rel="stylesheet" href="styles.css">
</head>
<body>
<div id="page-container">
<div id="top"></div>
<div id="column">
<img src="header.png" style="width: 640px; height: 116px;" alt="AimBooster">
<div id="page">
<div class="nav">
<ul>
<li>Play</li>
<li> • News</li>
<li> • FAQ</li>
<li> • Feedback</li>
<li> • Donate</li>
</ul>
</div>
<div id="thi">
<canvas id="myCanvas" width="640px" height="497px"></canvas>
</div>
</div>
</div>
</div>
<script src="javas.js"></script>
</body>
</html>

Drawing with HTML 5 canvas rectangles (pixel size) gets a black rectangle instead of blue?

I expect to draw a large blue rectangle of 320 X 240 pixels on the Canvas in Firefox but instead I get a black rectangle. I'm drawing pixels actually just to experiment and for some reason this doesn't work properly. Everything in the code seems to make sense inside the JavaScript draw function but it's a nogo? Any ideas, here's the code,
<html>
<head>
<title>Canvas</title>
<script type="text/javascript">
function draw()
{
var canvas = document.getElementById("canvas");
if (canvas.getContext)
{
var ctx = canvas.getContext("2d");
var red = 0;
var green = 0;
var blue = 255;
ctx.fillStyle = "rgb( red, green, blue)";
for(var i = 0; i < 320; i++)
{
for(var j = 0; j < 240; j++)
{
ctx.fillRect (i , j , 1, 1);
}
}
}
}
</script>
<style type="text/css">
body
{
margin: 50px 50px;
}
canvas
{
border: 1px solid black;
}
#container
{
position: relative;
width: 640px;
height: 480px;
margin: 0 auto;
}
</style>
</head>
<body onload="draw();">
<div id = "container">
<canvas id="canvas" width="640px" height="480px"></canvas>
</div>
</body>
</html>

You need to use ..." + variable + "... to let the String use the variable's values. As it is you were passing rgb( red, green, blue) as the fillStyle, which then defaults to black because it's invalid
ctx.fillStyle = "rgb("+red+","+green+","+blue+")";
Demo

ctx.fillStyle = "rgb(" + [red,green,blue].join(',') + ")";