JSFiddle - React, Tailwind, and code Playground
by FZambia
HTML
<canvas id="canvas" width="300" height="300"></canvas>
JavaScript
//Lets create a simple particle system in HTML5 canvas and JS
//Initializing the canvas
var canvas = document.getElementById("canvas");
var ctx = canvas.getContext("2d");
//Canvas dimensions
var W = 300; var H = 300;
//Lets create an array of particles
var particles = [];
for(var i = 0; i < 50; i++)
{
//This will add 50 particles to the array with random positions
particles.push(new create_particle());
}
//Lets create a function which will help us to create multiple particles
function create_particle()
{
//Random position on the canvas
this.x = Math.random()*W;
this.y = Math.random()*H;
//Lets add random velocity to each particle
this.vx = Math.random()*20-10;
this.vy = Math.random()*20-10;
//Random colors
var r = Math.random()*255>>0;
var g = Math.random()*255>>0;
var b = Math.random()*255>>0;
this.color = "rgba("+r+", "+g+", "+b+", 0.5)";
//Random size
this.radius = Math.random()*10+20;
}
var x = 100; var y = 100;
//Lets animate the particle
function draw()
{
requestAnimationFrame(draw);
//Moving this BG paint code insde draw() will help remove the trail
//of the particle
//Lets paint the canvas black
//But the BG paint shouldn't blend with the previous frame
ctx.globalCompositeOperation = "source-over";
//Lets reduce the opacity of the BG paint to give the final touch
ctx.fillStyle = "rgba(0, 0, 0, 0.3)";
ctx.fillRect(0, 0, W, H);
//Lets blend the particle with the BG
ctx.globalCompositeOperation = "lighter";
//Lets draw particles from the array now
for(var t = 0; t < particles.length; t++)
{
var p = particles[t];
ctx.beginPath();
//Time for some colors
var gradient = ctx.createRadialGradient(p.x, p.y, 0, p.x, p.y, p.radius);
gradient.addColorStop(0, "white");
gradient.addColorStop(0.4, "white");
gradient.addColorStop(0.4, p.color);
gradient.addColorStop(1, "black");
ctx.fillStyle = gradient;
ctx.arc(p.x, p.y, p.radius, Math.PI*2, false);
ctx.fill();
//Lets use the...