basic animation as per tutorial

This commit is contained in:
Asif Bacchus 2020-04-08 04:08:51 -06:00
parent b410e55915
commit 507c5f6e38

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/* create particles animation
based on the amazing tutorial by 'Franks Labratory'
https://youtu.be/d620nV6bp0A
*/
const canvas = document.getElementById('canvas1');
const canvasContext = canvas.getContext('2d');
canvas.width = window.innerWidth;
canvas.height = window.innerHeight;
let particlesArray;
// get mouse position
let mousePosition ={
x: null,
y: null,
radius: (canvas.height / 80) * (canvas.width / 80)
};
// add mouse position event listener
window.addEventListener('mousemove', function(event){
mousePosition.x = event.x;
mousePosition.y = event.y;
});
// create particle class
class Particle{
constructor(x, y, directionX, directionY, size, colour) {
this.x = x;
this.y = y;
this.directionX = directionX;
this.directionY = directionY;
this.size = size;
this.colour = colour;
}
// method to draw individual particles
draw(){
canvasContext.beginPath();
canvasContext.arc(this.x, this.y, this.size, 0, Math.PI * 2, false);
canvasContext.fillStyle = '#8c5523';
canvasContext.fill();
}
// check particle position, mouse position, move particle and draw it
update(){
// check if particle is still within canvas
if (this.x > canvas.width || this.x < 0){
this.directionX = -this.directionX;
}
if (this.y > canvas.height || this.y < 0){
this.directionY = -this.directionY;
}
// collision detection between mouse and particles
let dx = mousePosition.x - this.x;
let dy = mousePosition.y - this.y;
let distance = Math.sqrt((dx * dx) + (dy * dy));
if (distance < mousePosition.radius + this.size){
if (mousePosition.x < this.x && this.x < canvas.width - this.size * 10){
this.x += 10;
}
if (mousePosition.x > this.x && this.x > this.size * 10){
this.x -= 10;
}
if (mousePosition.y < this.y && this.y < canvas.height - this.size * 10){
this.y += 10;
}
if (mousePosition.y > this.y && this.y > this.size * 10){
this.y -= 10;
}
}
// move particle
this.x += this.directionX;
this.y += this.directionY;
// draw particle
this.draw();
}
}
// create particle array
function init(){
particlesArray = [];
let numberOfParticles = (canvas.height * canvas.width) / 9000;
for (let i = 0; i < numberOfParticles * 2; i++){
let size = (Math.random() * 5) + 1;
let x = (Math.random() * ((innerWidth - size * 2) - (size * 2)) + size * 2);
let y = (Math.random() * ((innerHeight - size * 2) - (size * 2)) + size * 2);
let directionX = (Math.random() * 5) - 2.5;
let directionY = (Math.random() * 5) - 2.5;
let colour = '#8c5523';
particlesArray.push(new Particle(x, y, directionX, directionY, size, colour));
}
}
// check if particles are close enough to connect to eachother
function connect(){
let opacityValue = 1;
for (let a = 0; a < particlesArray.length; a++){
for (let b = a; b < particlesArray.length; b++){
let distance = ((particlesArray[a].x - particlesArray[b].x) * (particlesArray[a].x - particlesArray[b].x)) + ((particlesArray[a].y - particlesArray[b].y) * (particlesArray[a].y - particlesArray[b].y));
if (distance < (canvas.width / 7) * (canvas.height / 7)){
opacityValue = 1 - (distance / 20000);
canvasContext.strokeStyle = `rgba(140, 85, 31, ${opacityValue})`;
canvasContext.lineWidth = 1;
canvasContext.beginPath();
canvasContext.moveTo(particlesArray[a].x, particlesArray[a].y);
canvasContext.lineTo(particlesArray[b].x, particlesArray[b].y);
canvasContext.stroke();
}
}
}
}
// animation loop
function animate(){
requestAnimationFrame(animate);
canvasContext.clearRect(0, 0, innerWidth, innerHeight);
for (let i = 0; i < particlesArray.length; i++){
particlesArray[i].update();
}
connect();
}
// resize event
window.addEventListener('resize', function(){
canvas.width = innerWidth;
canvas.height = innerHeight;
mousePosition.radius = ((canvas.height / 80) * (canvas.width / 80));
init();
});
// mouse-out event (mouse leaving the window)
window.addEventListener('mouseout', function(){
mousePosition.x = undefined;
mousePosition.y = undefined;
});
init();
animate();