I have some js code that i copied from a youtube tutorial and adapted for my own project to fill the header, the code works as intended and it works when the viewport is smaller than around 1200px, however when i put firefox into full screen the animation does not play & the image is being stretched, not retaining its aspect ratio. I do have a 10/15 year old gpu so i'm guessing thats half my issue. The script uses a png image file of 100x100 pixels, which it then converts into particle color values. Can this be optimized or made to run better. it seems that the wider the viewport the longer the animation takes to kick in, until it finally stops & doesn't work. full screen= [2550x1440]...
The original tutorial is here: Pure Javascript Particle Animations & to convert an image to base64 encoding is here: Image to base64.
HTML:
<html>
<body>
<canvas id="CanV"></canvas>
</body>
</html>
CSS:
#Canv{
position:absolute;
top:-1px;left:-2px;
z-index:67;
width:100vw !important;
max-height: 264px !important;
min-height: 245px !important;
filter:blur(2.27px);
}
Javascript:
window.addEventListener("DOMContentLoaded",(e)=>{
const canv = document.getElementById('Canv');
const ctx = canv.getContext('2d');
canv.width = window.innerWidth;
canv.height = window.innerHeight/ 3.85;
let particleArray = [];
let mouse = {
x: null,
y: null,
radius: 74
}
window.addEventListener('mousemove',(e)=>{
mouse.x = event.x + canv.clientLeft/2;
mouse.y = event.y + canv.clientTop/1.2;
});
function drawImage(){
let imageWidth = png.width; //These to values crop if / sum no.
let imageHeight = png.height;
const data = ctx.getImageData(0, 0, imageWidth, imageHeight); //Gets img data for particles
ctx.clearRect(0,0, canv.width, canv.height); // Clears the original img as its now being stored in the variable data.
class Particle {
constructor(x, y, color, size){
this.x = x + canv.width/2 - png.width * 174, //Chngd Ok:74
this.y = y + canv.height/2 - png.height * 32, //Ch<2 Ok:16
this.color = color,
this.size = 2.28, // Particle Size > Changed this value. from 2 i think!.
this.baseX = x + canv.width/1.8 - png.width * 3.1, //Chngd ok:5.1
this.baseY = y + canv.height/1.2 - png.height * 2.8,
this.density = (Math.random() * 14) + 2;
}
draw() {
ctx.beginPath(); // this creates the sort of force field around the mouse pointer.
ctx.arc(this.x, this.y, this.size, 0, Math.PI * 2);
ctx.closePath();
ctx.fill();
}
update() {
ctx.fillStyle = this.color;
// Collision detection
let dx = mouse.x - this.x;
let dy = mouse.y - this.y;
let distance = Math.sqrt(dx * dx + dy * dy);
let forceDirectionX = dx / distance;
let forceDirectionY = dy / distance;
// Max distance, past that the force will be 0
const maxDistance = 144;
let force = (maxDistance - distance) / maxDistance;
if (force < 0) force = 0;
let directionX = (forceDirectionX * force * this.density * 0.6);
let directionY = (forceDirectionY * force * this.density * 8.7); //Ch.this
if (distance < mouse.radius + this.size) {
this.x -= directionX;
this.y -= directionY;
} else {
if (this.x !== this.baseX){
let dx = this.x - this.baseX;
this.x -= dx/54; // Speed Particles return to ori
} if (this.y !== this.baseY){
let dy = this.y - this.baseY;
this.y -= dy/17; // Speed Particles return to ori
}
}
this.draw();
}
}
function init(){
particleArray = [];
for(let y = 0, y2 = data.height; y<y2; y++){
for(let x =0, x2 = data.width; x<x2; x++){
if(data.data[(y * 4 * data.width) + (x*4) + 3] > 128){
let positionX = x + 25;
let positionY = y + 45; // Co-ords on Canv
let color = "rgb(" + data.data[(y * 4 * data.width) + (x * 4)] + "," +
data.data[(y * 4 * data.width) + (x * 4) + 1] + "," +
data.data[(y * 4 * data.width) + (x * 4) + 2] + ")";
particleArray.push(new Particle(positionX * 2, positionY * 2, color));
} /* These number effect png size but its to high */
}
}
}
function animate(){
requestAnimationFrame(animate);
ctx.fillStyle = 'rgba(0,0,0,.07)';
ctx.fillRect(0,0, innerWidth, innerHeight);
for(let i =0; i < particleArray.length; i++){
particleArray[i].update();
}
}
init();
animate();
}
const png = new Image();
png.src = "RemovedBase64StringToBig";
window.addEventListener('load',(e)=>{
console.log('page has loaded');
ctx.drawImage(png, 0, 0);
drawImage();
})
});
have managed to shorten it by about 100 characters by shortening all the variable names > PartArr, ImgWidth, DirX, DirY etc, but apart from minifying it is there any other ways to optimize this? and fix the full screen issue?
I tried to add it to a JSfiddle, So I could link to it here, but I don't think this is allowing the base64 string, its not loading anything anyway. The canvas loads, with the bg just no image or animation.
I've found out what part of the problem is with full screen, the cursor position is actually about 300px to the right of where the actual cursor is, but I still have no idea how to fix this or fix the major lagging performance issues. Guessing its alot to compute even just with 100x100.
One option I can think of to make this perform better would be to move it & its calculations, into its own dedicated web worker & convert the image to Webp but i'm still not very clued up about web workers or how to implement them properly.. Will play around & see what I can put together using All the suggestions in the comments & answers.
I'm adding these links only for future reference, when I come back to this later on:
MDN Canvas Optimizations
Html5Rocks Canvas Performance
Stack Question. Canv ~ Opti
Creating A blob From A Base 64 String in Js
Secondary bonus Question,
is there a maximum file size or max px dimensions,
that can be base64 encoded? only asking this as someone on facebook has recently sent me a question regarding another project with multiple base64 encoded images and I was unsure of the answer..
