HTML Canvas particle animation
Ming Sun / May 07, 2023
4 min read • ––– views
React component
import { useEffect } from "react";
const CanvasAnimation = () => {
useEffect(() => {
let canvasParent = document.getElementById("canvasParent");
let canvas = document.getElementById("canvas1");
let ctx = canvas.getContext("2d");
canvas.width = canvasParent.offsetWidth;
canvas.height = 400;
let particleArray = [];
let hue = 0;
let mouse = { x: undefined, y: undefined };
canvas.addEventListener("mousemove", function (event) {
mouse.x = event.offsetX;
mouse.y = event.offsetY;
for (let i = 0; i < 2; i++) {
particleArray.push(new Particle());
}
});
class Particle {
constructor() {
this.x = mouse.x;
this.y = mouse.y;
// this.x = Math.random() * canvas.width;
// this.y = Math.random() * canvas.height;
this.radius = Math.random() * 15 + 1;
this.speed = 5;
this.speedX = (Math.random() - 0.5) * this.speed;
this.speedY = (Math.random() - 0.5) * this.speed;
this.color = "hsl(" + hue + ",100%,50%)";
}
update() {
this.x += this.speedX;
this.y += this.speedY;
if (this.x < 0 || this.x > canvas.width) {
this.speedX *= -1;
}
if (this.y < 0 || this.y > canvas.height) {
this.speedY *= -1;
}
if (this.radius > 0.2) this.radius -= 0.1;
}
draw() {
ctx.fillStyle = this.color;
ctx.beginPath();
ctx.arc(this.x, this.y, this.radius, 0, Math.PI * 2);
ctx.fill();
}
}
function handleParticles() {
for (let i = 0; i < particleArray.length; i++) {
particleArray[i].update();
particleArray[i].draw();
for (let j = i; j < particleArray.length; j++) {
let x1 = particleArray[i].x;
let y1 = particleArray[i].y;
let x2 = particleArray[j].x;
let y2 = particleArray[j].y;
let distance = Math.sqrt((x1 - x2) ** 2 + (y1 - y2) ** 2);
if (distance < 100) {
ctx.beginPath();
ctx.strokeStyle = particleArray[i].color;
ctx.lineWidth = 0.2;
ctx.moveTo(x1, y1);
ctx.lineTo(x2, y2);
ctx.closePath();
ctx.stroke();
}
}
if (particleArray[i].radius <= 0.3) {
particleArray.splice(i, 1);
i--;
}
}
}
function animate() {
ctx.clearRect(0, 0, canvas.width, canvas.height);
ctx.fillStyle = "rgb(0,0,0)";
ctx.fillRect(0, 0, canvas.width, canvas.height);
handleParticles();
hue++;
requestAnimationFrame(animate);
}
animate();
}, []);
return (
<div id="canvasParent" className="w-full">
<canvas id="canvas1"></canvas>
</div>
);
};
export default CanvasAnimation;