I have created a full demonstration of the problem I'm experiencing below:
const rng = (min, max) => Math.random() * (max - min + 1) + min;
const canvas = document.querySelector("canvas");
const ctx = canvas.getContext("2d");
ctx.strokeStyle = "#000";
ctx.lineWidth = 4;
ctx.fillStyle = "#ff0000";
function drawCircle(c) {
ctx.beginPath();
ctx.arc(c.x, c.y, c.r, 0, 2 * Math.PI);
ctx.stroke();
ctx.fill();
}
class Circle {
constructor(x, y, r) {
this.x = x;
this.y = y;
this.r = r;
this.vX = 0;
this.vY = 0;
}
}
const circles = [];
for (let i = 0; i < 300; i++) {
circles.push(new Circle(rng(0, canvas.width), rng(0, canvas.height), rng(12, 14)));
}
function processCollision(c1, c2) {
const deltaX = c2.x - c1.x;
const deltaY = c2.y - c1.y;
const sumRadius = c1.r + c2.r;
const centerDistance = Math.sqrt(deltaX * deltaX + deltaY * deltaY);
if (centerDistance === 0 || centerDistance > sumRadius) { return; } // not colliding
const circleDistance = centerDistance - sumRadius;
const aX = deltaX / centerDistance;
const aY = deltaY / centerDistance;
const force = 5;
c1.vX += aX * circleDistance * force;
c1.vY += aY * circleDistance * force;
}
function update() {
ctx.clearRect(0, 0, canvas.width, canvas.height);
for (const c of circles) {
c.vX = (canvas.width / 2) - c.x; // move towards center x
c.vY = (canvas.height / 2) - c.y; // move towards center y
}
for (const c1 of circles) {
for (const c2 of circles) {
c1 !== c2 && processCollision(c1, c2);
}
}
for (const c of circles) {
c.x += c.vX * (1 / 60);
c.y += c.vY * (1 / 60);
drawCircle(c);
}
}
setInterval(update, 16.6666);
<canvas width="600" height="600" style="border:1px solid #d3d3d3;">
Notice how all the circles gravitate around the center. However, they are all heavily colliding with one another. I would like to modify the processCollision function such that the circles no longer significantly overlap one another and instead are roughly evenly spread around the center point.
I tried increasing the force variable, but unfortunately while this does indeed cause greater spread, it also creates lot of shaky and jerky movement. The solution must be smooth, similar to the example above. I have been messing with this for weeks but unfortunately cannot seem to come to a solution.
This seems to behave the way you probably want (or close to it)... It uses a control theory model combined with a physics model, and one needs to tweak the constants k0, k1, strength, buffer, step_size...
const rng = (min, max) => Math.random() * (max - min + 1) + min;
const canvas = document.querySelector('canvas');
const ctx = canvas.getContext('2d');
ctx.strokeStyle = '#000';
ctx.lineWidth = 4;
ctx.fillStyle = '#ff0000';
const k0 = 1.5;
const k1 = 5;
const strength = 1000000;
const buffer = 2;
class Disc {
constructor(x, y, r) {
this.x = x;
this.y = y;
this.r = r;
this.vX = 0;
this.vY = 0;
return;
}
drawDisc(ctx) {
ctx.beginPath();
ctx.arc(this.x, this.y, this.r, 0, 2 * Math.PI);
ctx.stroke();
ctx.fill();
return;
}
addVelocity(step_size) {
this.x = this.x + step_size * this.vX;
this.y = this.y + step_size * this.vY;
return;
}
addAcceleration(aX, aY, step_size) {
this.vX = this.vX + step_size * aX;
this.vY = this.vY + step_size * aY;
return;
}
applyCentralAcceleration(step_size) {
const accelX = -k1 * this.vX - k0 * (this.x - canvas.width / 2);
const accelY = -k1 * this.vY - k0 * (this.y - canvas.height / 2);
this.addAcceleration(accelX, accelY, step_size);
return;
}
applyInteractionAcceleration(that, step_size) {
let dX = this.x - that.x;
let dY = this.y - that.y;
const dist = dX * dX + dY * dY;
const magnitude = strength / (dist - (this.r + buffer + that.r) ** 2) ** 2;
dX = magnitude * dX;
dY = magnitude * dY;
this.addAcceleration(dX, dY, step_size);
return;
}
}
class System {
constructor(numDiscs) {
this.n = numDiscs;
this.discs = [];
for (let i = 0; i < numDiscs; i++) {
this.discs.push(
new Disc(rng(0, canvas.width), rng(0, canvas.height), rng(6, 7))
);
}
return;
}
applyCentralAcceleration(step_size) {
for (let i = 0; i < this.n; i++) {
this.discs[i].applyCentralAcceleration(step_size);
}
}
applyInteractionAcceleration(step_size) {
for (let i = 0; i < this.n; i++) {
for (let j = 0; j < this.n; j++) {
if (i === j) {
continue;
}
this.discs[i].applyInteractionAcceleration(this.discs[j], step_size);
}
}
}
applyVelocity(step_size) {
for (let i = 0; i < this.n; i++) {
this.discs[i].addVelocity(step_size);
}
}
updateSystemState(step_size) {
this.applyCentralAcceleration(step_size);
this.applyInteractionAcceleration(step_size);
this.applyVelocity(step_size);
return;
}
drawSystemDiscs() {
for (let i = 0; i < this.n; i++) {
this.discs[i].drawDisc(ctx);
}
}
}
systemOfDiscs = new System(50);
function update() {
ctx.clearRect(0, 0, canvas.width, canvas.height);
const step_size = 1 / 100;
systemOfDiscs.updateSystemState(step_size);
systemOfDiscs.drawSystemDiscs();
return;
}
setInterval(update, 16.6666);
<canvas width="300" height="300" style="border: 1px solid #d3d3d3"></canvas>
I've been trying to add a (code pen) animation on my website and I'm honestly not sure what I'm missing on this one. I have tried running it in jsfiddle as well and it tells me that delaunay is not defined. https://codepen.io/hduffin1/pen/QOMZJg I'm not too sure what I'm doing wrong since the code works inside of code pen and I have been able to replicate other ones that I've tried using from code pen but for whatever reason, I can't seem to get this one to work.
Html
<canvas id="stars" width="300" height="300"></canvas>
CSS
html,
body {
margin: 0;
padding: 0;
}
body {
background-color: #31102f; //#280B29
background: radial-gradient(
ellipse at center,
rgba(49, 16, 47, 1) 0%,
rgba(40, 11, 41, 1) 100%
);
}
#stars {
display: block;
position: relative;
width: 100%;
height: 16rem;
height: 100vh;
z-index: 1;
}
JS
/**
* Stars
* Inspired by Steve Courtney's poster art for Celsius GS's Drifter - http://celsiusgs.com/drifter/posters.php
* by Cory Hughart - http://coryhughart.com
*/
// Settings
var particleCount = 40,
flareCount = 10,
motion = 0.05,
tilt = 0.05,
color = '#FFEED4',
particleSizeBase = 1,
particleSizeMultiplier = 0.5,
flareSizeBase = 100,
flareSizeMultiplier = 100,
lineWidth = 1,
linkChance = 75, // chance per frame of link, higher = smaller chance
linkLengthMin = 5, // min linked vertices
linkLengthMax = 7, // max linked vertices
linkOpacity = 0.25; // number between 0 & 1
linkFade = 90, // link fade-out frames
linkSpeed = 1, // distance a link travels in 1 frame
glareAngle = -60,
glareOpacityMultiplier = 0.05,
renderParticles = true,
renderParticleGlare = true,
renderFlares = true,
renderLinks = true,
renderMesh = false,
flicker = true,
flickerSmoothing = 15, // higher = smoother flicker
blurSize = 0,
orbitTilt = true,
randomMotion = true,
noiseLength = 1000,
noiseStrength = 1;
var canvas = document.getElementById('stars'),
//orbits = document.getElementById('orbits'),
context = canvas.getContext('2d'),
mouse = { x: 0, y: 0 },
m = {},
r = 0,
c = 1000, // multiplier for delaunay points, since floats too small can mess up the algorithm
n = 0,
nAngle = (Math.PI * 2) / noiseLength,
nRad = 100,
nScale = 0.5,
nPos = {x: 0, y: 0},
points = [],
vertices = [],
triangles = [],
links = [],
particles = [],
flares = [];
function init() {
var i, j, k;
// requestAnimFrame polyfill
window.requestAnimFrame = (function(){
return window.requestAnimationFrame ||
window.webkitRequestAnimationFrame ||
window.mozRequestAnimationFrame ||
function( callback ){
window.setTimeout(callback, 1000 / 60);
};
})();
// Fade in background
/*
var background = document.getElementById('background'),
bgImg = new Image(),
bgURL = '/img/background.jpg';
bgImg.onload = function() {
//console.log('background loaded');
background.style.backgroundImage = 'url("'+bgURL+'")';
background.className += ' loaded';
}
bgImg.src = bgURL;
*/
// Size canvas
resize();
mouse.x = canvas.clientWidth / 2;
mouse.y = canvas.clientHeight / 2;
// Create particle positions
for (i = 0; i < particleCount; i++) {
var p = new Particle();
particles.push(p);
points.push([p.x*c, p.y*c]);
}
//console.log(JSON.stringify(points));
// Delaunay triangulation
//var Delaunay = require('delaunay-fast');
vertices = Delaunay.triangulate(points);
//console.log(JSON.stringify(vertices));
// Create an array of "triangles" (groups of 3 indices)
var tri = [];
for (i = 0; i < vertices.length; i++) {
if (tri.length == 3) {
triangles.push(tri);
tri = [];
}
tri.push(vertices[i]);
}
//console.log(JSON.stringify(triangles));
// Tell all the particles who their neighbors are
for (i = 0; i < particles.length; i++) {
// Loop through all tirangles
for (j = 0; j < triangles.length; j++) {
// Check if this particle's index is in this triangle
k = triangles[j].indexOf(i);
// If it is, add its neighbors to the particles contacts list
if (k !== -1) {
triangles[j].forEach(function(value, index, array) {
if (value !== i && particles[i].neighbors.indexOf(value) == -1) {
particles[i].neighbors.push(value);
}
});
}
}
}
//console.log(JSON.stringify(particles));
if (renderFlares) {
// Create flare positions
for (i = 0; i < flareCount; i++) {
flares.push(new Flare());
}
}
// Motion mode
//if (Modernizr && Modernizr.deviceorientation) {
if ('ontouchstart' in document.documentElement && window.DeviceOrientationEvent) {
console.log('Using device orientation');
window.addEventListener('deviceorientation', function(e) {
mouse.x = (canvas.clientWidth / 2) - ((e.gamma / 90) * (canvas.clientWidth / 2) * 2);
mouse.y = (canvas.clientHeight / 2) - ((e.beta / 90) * (canvas.clientHeight / 2) * 2);
//console.log('Center: x:'+(canvas.clientWidth/2)+' y:'+(canvas.clientHeight/2));
//console.log('Orientation: x:'+mouse.x+' ('+e.gamma+') y:'+mouse.y+' ('+e.beta+')');
}, true);
}
else {
// Mouse move listener
console.log('Using mouse movement');
document.body.addEventListener('mousemove', function(e) {
//console.log('moved');
mouse.x = e.clientX;
mouse.y = e.clientY;
});
}
// Random motion
if (randomMotion) {
//var SimplexNoise = require('simplex-noise');
//var simplex = new SimplexNoise();
}
// Animation loop
(function animloop(){
requestAnimFrame(animloop);
resize();
render();
})();
}
function render() {
if (randomMotion) {
n++;
if (n >= noiseLength) {
n = 0;
}
nPos = noisePoint(n);
//console.log('NOISE x:'+nPos.x+' y:'+nPos.y);
}
// Clear
context.clearRect(0, 0, canvas.width, canvas.height);
if (blurSize > 0) {
context.shadowBlur = blurSize;
context.shadowColor = color;
}
if (renderParticles) {
// Render particles
for (var i = 0; i < particleCount; i++) {
particles[i].render();
}
}
if (renderMesh) {
// Render all lines
context.beginPath();
for (var v = 0; v < vertices.length-1; v++) {
// Splits the array into triplets
if ((v + 1) % 3 === 0) { continue; }
var p1 = particles[vertices[v]],
p2 = particles[vertices[v+1]];
//console.log('Line: '+p1.x+','+p1.y+'->'+p2.x+','+p2.y);
var pos1 = position(p1.x, p1.y, p1.z),
pos2 = position(p2.x, p2.y, p2.z);
context.moveTo(pos1.x, pos1.y);
context.lineTo(pos2.x, pos2.y);
}
context.strokeStyle = color;
context.lineWidth = lineWidth;
context.stroke();
context.closePath();
}
if (renderLinks) {
// Possibly start a new link
if (random(0, linkChance) == linkChance) {
var length = random(linkLengthMin, linkLengthMax);
var start = random(0, particles.length-1);
startLink(start, length);
}
// Render existing links
// Iterate in reverse so that removing items doesn't affect the loop
for (var l = links.length-1; l >= 0; l--) {
if (links[l] && !links[l].finished) {
links[l].render();
}
else {
delete links[l];
}
}
}
if (renderFlares) {
// Render flares
for (var j = 0; j < flareCount; j++) {
flares[j].render();
}
}
/*
if (orbitTilt) {
var tiltX = -(((canvas.clientWidth / 2) - mouse.x + ((nPos.x - 0.5) * noiseStrength)) * tilt),
tiltY = (((canvas.clientHeight / 2) - mouse.y + ((nPos.y - 0.5) * noiseStrength)) * tilt);
orbits.style.transform = 'rotateY('+tiltX+'deg) rotateX('+tiltY+'deg)';
}
*/
}
function resize() {
canvas.width = window.innerWidth * (window.devicePixelRatio || 1);
canvas.height = canvas.width * (canvas.clientHeight / canvas.clientWidth);
}
function startLink(vertex, length) {
//console.log('LINK from '+vertex+' (length '+length+')');
links.push(new Link(vertex, length));
}
// Particle class
var Particle = function() {
this.x = random(-0.1, 1.1, true);
this.y = random(-0.1, 1.1, true);
this.z = random(0,4);
this.color = color;
this.opacity = random(0.1,1,true);
this.flicker = 0;
this.neighbors = []; // placeholder for neighbors
};
Particle.prototype.render = function() {
var pos = position(this.x, this.y, this.z),
r = ((this.z * particleSizeMultiplier) + particleSizeBase) * (sizeRatio() / 1000),
o = this.opacity;
if (flicker) {
var newVal = random(-0.5, 0.5, true);
this.flicker += (newVal - this.flicker) / flickerSmoothing;
if (this.flicker > 0.5) this.flicker = 0.5;
if (this.flicker < -0.5) this.flicker = -0.5;
o += this.flicker;
if (o > 1) o = 1;
if (o < 0) o = 0;
}
context.fillStyle = this.color;
context.globalAlpha = o;
context.beginPath();
context.arc(pos.x, pos.y, r, 0, 2 * Math.PI, false);
context.fill();
context.closePath();
if (renderParticleGlare) {
context.globalAlpha = o * glareOpacityMultiplier;
/*
context.ellipse(pos.x, pos.y, r * 30, r, 90 * (Math.PI / 180), 0, 2 * Math.PI, false);
context.fill();
context.closePath();
*/
context.ellipse(pos.x, pos.y, r * 100, r, (glareAngle - ((nPos.x - 0.5) * noiseStrength * motion)) * (Math.PI / 180), 0, 2 * Math.PI, false);
context.fill();
context.closePath();
}
context.globalAlpha = 1;
};
// Flare class
var Flare = function() {
this.x = random(-0.25, 1.25, true);
this.y = random(-0.25, 1.25, true);
this.z = random(0,2);
this.color = color;
this.opacity = random(0.001, 0.01, true);
};
Flare.prototype.render = function() {
var pos = position(this.x, this.y, this.z),
r = ((this.z * flareSizeMultiplier) + flareSizeBase) * (sizeRatio() / 1000);
// Feathered circles
/*
var grad = context.createRadialGradient(x+r,y+r,0,x+r,y+r,r);
grad.addColorStop(0, 'rgba(255,255,255,'+f.o+')');
grad.addColorStop(0.8, 'rgba(255,255,255,'+f.o+')');
grad.addColorStop(1, 'rgba(255,255,255,0)');
context.fillStyle = grad;
context.beginPath();
context.fillRect(x, y, r*2, r*2);
context.closePath();
*/
context.beginPath();
context.globalAlpha = this.opacity;
context.arc(pos.x, pos.y, r, 0, 2 * Math.PI, false);
context.fillStyle = this.color;
context.fill();
context.closePath();
context.globalAlpha = 1;
};
// Link class
var Link = function(startVertex, numPoints) {
this.length = numPoints;
this.verts = [startVertex];
this.stage = 0;
this.linked = [startVertex];
this.distances = [];
this.traveled = 0;
this.fade = 0;
this.finished = false;
};
Link.prototype.render = function() {
// Stages:
// 0. Vertex collection
// 1. Render line reaching from vertex to vertex
// 2. Fade out
// 3. Finished (delete me)
var i, p, pos, points;
switch (this.stage) {
// VERTEX COLLECTION STAGE
case 0:
// Grab the last member of the link
var last = particles[this.verts[this.verts.length-1]];
//console.log(JSON.stringify(last));
if (last && last.neighbors && last.neighbors.length > 0) {
// Grab a random neighbor
var neighbor = last.neighbors[random(0, last.neighbors.length-1)];
// If we haven't seen that particle before, add it to the link
if (this.verts.indexOf(neighbor) == -1) {
this.verts.push(neighbor);
}
// If we have seen that article before, we'll just wait for the next frame
}
else {
//console.log(this.verts[0]+' prematurely moving to stage 3 (0)');
this.stage = 3;
this.finished = true;
}
if (this.verts.length >= this.length) {
// Calculate all distances at once
for (i = 0; i < this.verts.length-1; i++) {
var p1 = particles[this.verts[i]],
p2 = particles[this.verts[i+1]],
dx = p1.x - p2.x,
dy = p1.y - p2.y,
dist = Math.sqrt(dx*dx + dy*dy);
this.distances.push(dist);
}
//console.log('Distances: '+JSON.stringify(this.distances));
//console.log('verts: '+this.verts.length+' distances: '+this.distances.length);
//console.log(this.verts[0]+' moving to stage 1');
this.stage = 1;
}
break;
// RENDER LINE ANIMATION STAGE
case 1:
if (this.distances.length > 0) {
points = [];
//var a = 1;
// Gather all points already linked
for (i = 0; i < this.linked.length; i++) {
p = particles[this.linked[i]];
pos = position(p.x, p.y, p.z);
points.push([pos.x, pos.y]);
}
var linkSpeedRel = linkSpeed * 0.00001 * canvas.width;
this.traveled += linkSpeedRel;
var d = this.distances[this.linked.length-1];
// Calculate last point based on linkSpeed and distance travelled to next point
if (this.traveled >= d) {
this.traveled = 0;
// We've reached the next point, add coordinates to array
//console.log(this.verts[0]+' reached vertex '+(this.linked.length+1)+' of '+this.verts.length);
this.linked.push(this.verts[this.linked.length]);
p = particles[this.linked[this.linked.length-1]];
pos = position(p.x, p.y, p.z);
points.push([pos.x, pos.y]);
if (this.linked.length >= this.verts.length) {
//console.log(this.verts[0]+' moving to stage 2 (1)');
this.stage = 2;
}
}
else {
// We're still travelling to the next point, get coordinates at travel distance
// http://math.stackexchange.com/a/85582
var a = particles[this.linked[this.linked.length-1]],
b = particles[this.verts[this.linked.length]],
t = d - this.traveled,
x = ((this.traveled * b.x) + (t * a.x)) / d,
y = ((this.traveled * b.y) + (t * a.y)) / d,
z = ((this.traveled * b.z) + (t * a.z)) / d;
pos = position(x, y, z);
//console.log(this.verts[0]+' traveling to vertex '+(this.linked.length+1)+' of '+this.verts.length+' ('+this.traveled+' of '+this.distances[this.linked.length]+')');
points.push([pos.x, pos.y]);
}
this.drawLine(points);
}
else {
//console.log(this.verts[0]+' prematurely moving to stage 3 (1)');
this.stage = 3;
this.finished = true;
}
break;
// FADE OUT STAGE
case 2:
if (this.verts.length > 1) {
if (this.fade < linkFade) {
this.fade++;
// Render full link between all vertices and fade over time
points = [];
var alpha = (1 - (this.fade / linkFade)) * linkOpacity;
for (i = 0; i < this.verts.length; i++) {
p = particles[this.verts[i]];
pos = position(p.x, p.y, p.z);
points.push([pos.x, pos.y]);
}
this.drawLine(points, alpha);
}
else {
//console.log(this.verts[0]+' moving to stage 3 (2a)');
this.stage = 3;
this.finished = true;
}
}
else {
//console.log(this.verts[0]+' prematurely moving to stage 3 (2b)');
this.stage = 3;
this.finished = true;
}
break;
// FINISHED STAGE
case 3:
default:
this.finished = true;
break;
}
};
Link.prototype.drawLine = function(points, alpha) {
if (typeof alpha !== 'number') alpha = linkOpacity;
if (points.length > 1 && alpha > 0) {
//console.log(this.verts[0]+': Drawing line '+alpha);
context.globalAlpha = alpha;
context.beginPath();
for (var i = 0; i < points.length-1; i++) {
context.moveTo(points[i][0], points[i][1]);
context.lineTo(points[i+1][0], points[i+1][1]);
}
context.strokeStyle = color;
context.lineWidth = lineWidth;
context.stroke();
context.closePath();
context.globalAlpha = 1;
}
};
// Utils
function noisePoint(i) {
var a = nAngle * i,
cosA = Math.cos(a),
sinA = Math.sin(a),
//value = simplex.noise2D(nScale * cosA + nScale, nScale * sinA + nScale),
//rad = nRad + value;
rad = nRad;
return {
x: rad * cosA,
y: rad * sinA
};
}
function position(x, y, z) {
return {
x: (x * canvas.width) + ((((canvas.width / 2) - mouse.x + ((nPos.x - 0.5) * noiseStrength)) * z) * motion),
y: (y * canvas.height) + ((((canvas.height / 2) - mouse.y + ((nPos.y - 0.5) * noiseStrength)) * z) * motion)
};
}
function sizeRatio() {
return canvas.width >= canvas.height ? canvas.width : canvas.height;
}
function random(min, max, float) {
return float ?
Math.random() * (max - min) + min :
Math.floor(Math.random() * (max - min + 1)) + min;
}
// init
if (canvas) init();
When I entered 'https://codepen.io/hduffin1/pen/QOMZJg', 'delaunay.js' is included in the setting.
Add the following script and it should work.
<script src="https://rawgit.com/ironwallaby/delaunay/master/delaunay.js"></script>
/**
* Stars
* Inspired by Steve Courtney's poster art for Celsius GS's Drifter - http://celsiusgs.com/drifter/posters.php
* by Cory Hughart - http://coryhughart.com
*/
// Settings
var particleCount = 40,
flareCount = 10,
motion = 0.05,
tilt = 0.05,
color = '#FFEED4',
particleSizeBase = 1,
particleSizeMultiplier = 0.5,
flareSizeBase = 100,
flareSizeMultiplier = 100,
lineWidth = 1,
linkChance = 75, // chance per frame of link, higher = smaller chance
linkLengthMin = 5, // min linked vertices
linkLengthMax = 7, // max linked vertices
linkOpacity = 0.25; // number between 0 & 1
linkFade = 90, // link fade-out frames
linkSpeed = 1, // distance a link travels in 1 frame
glareAngle = -60,
glareOpacityMultiplier = 0.05,
renderParticles = true,
renderParticleGlare = true,
renderFlares = true,
renderLinks = true,
renderMesh = false,
flicker = true,
flickerSmoothing = 15, // higher = smoother flicker
blurSize = 0,
orbitTilt = true,
randomMotion = true,
noiseLength = 1000,
noiseStrength = 1;
var canvas = document.getElementById('stars'),
//orbits = document.getElementById('orbits'),
context = canvas.getContext('2d'),
mouse = { x: 0, y: 0 },
m = {},
r = 0,
c = 1000, // multiplier for delaunay points, since floats too small can mess up the algorithm
n = 0,
nAngle = (Math.PI * 2) / noiseLength,
nRad = 100,
nScale = 0.5,
nPos = {x: 0, y: 0},
points = [],
vertices = [],
triangles = [],
links = [],
particles = [],
flares = [];
function init() {
var i, j, k;
// requestAnimFrame polyfill
window.requestAnimFrame = (function(){
return window.requestAnimationFrame ||
window.webkitRequestAnimationFrame ||
window.mozRequestAnimationFrame ||
function( callback ){
window.setTimeout(callback, 1000 / 60);
};
})();
// Fade in background
/*
var background = document.getElementById('background'),
bgImg = new Image(),
bgURL = '/img/background.jpg';
bgImg.onload = function() {
//console.log('background loaded');
background.style.backgroundImage = 'url("'+bgURL+'")';
background.className += ' loaded';
}
bgImg.src = bgURL;
*/
// Size canvas
resize();
mouse.x = canvas.clientWidth / 2;
mouse.y = canvas.clientHeight / 2;
// Create particle positions
for (i = 0; i < particleCount; i++) {
var p = new Particle();
particles.push(p);
points.push([p.x*c, p.y*c]);
}
//console.log(JSON.stringify(points));
// Delaunay triangulation
//var Delaunay = require('delaunay-fast');
vertices = Delaunay.triangulate(points);
//console.log(JSON.stringify(vertices));
// Create an array of "triangles" (groups of 3 indices)
var tri = [];
for (i = 0; i < vertices.length; i++) {
if (tri.length == 3) {
triangles.push(tri);
tri = [];
}
tri.push(vertices[i]);
}
//console.log(JSON.stringify(triangles));
// Tell all the particles who their neighbors are
for (i = 0; i < particles.length; i++) {
// Loop through all tirangles
for (j = 0; j < triangles.length; j++) {
// Check if this particle's index is in this triangle
k = triangles[j].indexOf(i);
// If it is, add its neighbors to the particles contacts list
if (k !== -1) {
triangles[j].forEach(function(value, index, array) {
if (value !== i && particles[i].neighbors.indexOf(value) == -1) {
particles[i].neighbors.push(value);
}
});
}
}
}
//console.log(JSON.stringify(particles));
if (renderFlares) {
// Create flare positions
for (i = 0; i < flareCount; i++) {
flares.push(new Flare());
}
}
// Motion mode
//if (Modernizr && Modernizr.deviceorientation) {
if ('ontouchstart' in document.documentElement && window.DeviceOrientationEvent) {
console.log('Using device orientation');
window.addEventListener('deviceorientation', function(e) {
mouse.x = (canvas.clientWidth / 2) - ((e.gamma / 90) * (canvas.clientWidth / 2) * 2);
mouse.y = (canvas.clientHeight / 2) - ((e.beta / 90) * (canvas.clientHeight / 2) * 2);
//console.log('Center: x:'+(canvas.clientWidth/2)+' y:'+(canvas.clientHeight/2));
//console.log('Orientation: x:'+mouse.x+' ('+e.gamma+') y:'+mouse.y+' ('+e.beta+')');
}, true);
}
else {
// Mouse move listener
console.log('Using mouse movement');
document.body.addEventListener('mousemove', function(e) {
//console.log('moved');
mouse.x = e.clientX;
mouse.y = e.clientY;
});
}
// Random motion
if (randomMotion) {
//var SimplexNoise = require('simplex-noise');
//var simplex = new SimplexNoise();
}
// Animation loop
(function animloop(){
requestAnimFrame(animloop);
resize();
render();
})();
}
function render() {
if (randomMotion) {
n++;
if (n >= noiseLength) {
n = 0;
}
nPos = noisePoint(n);
//console.log('NOISE x:'+nPos.x+' y:'+nPos.y);
}
// Clear
context.clearRect(0, 0, canvas.width, canvas.height);
if (blurSize > 0) {
context.shadowBlur = blurSize;
context.shadowColor = color;
}
if (renderParticles) {
// Render particles
for (var i = 0; i < particleCount; i++) {
particles[i].render();
}
}
if (renderMesh) {
// Render all lines
context.beginPath();
for (var v = 0; v < vertices.length-1; v++) {
// Splits the array into triplets
if ((v + 1) % 3 === 0) { continue; }
var p1 = particles[vertices[v]],
p2 = particles[vertices[v+1]];
//console.log('Line: '+p1.x+','+p1.y+'->'+p2.x+','+p2.y);
var pos1 = position(p1.x, p1.y, p1.z),
pos2 = position(p2.x, p2.y, p2.z);
context.moveTo(pos1.x, pos1.y);
context.lineTo(pos2.x, pos2.y);
}
context.strokeStyle = color;
context.lineWidth = lineWidth;
context.stroke();
context.closePath();
}
if (renderLinks) {
// Possibly start a new link
if (random(0, linkChance) == linkChance) {
var length = random(linkLengthMin, linkLengthMax);
var start = random(0, particles.length-1);
startLink(start, length);
}
// Render existing links
// Iterate in reverse so that removing items doesn't affect the loop
for (var l = links.length-1; l >= 0; l--) {
if (links[l] && !links[l].finished) {
links[l].render();
}
else {
delete links[l];
}
}
}
if (renderFlares) {
// Render flares
for (var j = 0; j < flareCount; j++) {
flares[j].render();
}
}
/*
if (orbitTilt) {
var tiltX = -(((canvas.clientWidth / 2) - mouse.x + ((nPos.x - 0.5) * noiseStrength)) * tilt),
tiltY = (((canvas.clientHeight / 2) - mouse.y + ((nPos.y - 0.5) * noiseStrength)) * tilt);
orbits.style.transform = 'rotateY('+tiltX+'deg) rotateX('+tiltY+'deg)';
}
*/
}
function resize() {
canvas.width = window.innerWidth * (window.devicePixelRatio || 1);
canvas.height = canvas.width * (canvas.clientHeight / canvas.clientWidth);
}
function startLink(vertex, length) {
//console.log('LINK from '+vertex+' (length '+length+')');
links.push(new Link(vertex, length));
}
// Particle class
var Particle = function() {
this.x = random(-0.1, 1.1, true);
this.y = random(-0.1, 1.1, true);
this.z = random(0,4);
this.color = color;
this.opacity = random(0.1,1,true);
this.flicker = 0;
this.neighbors = []; // placeholder for neighbors
};
Particle.prototype.render = function() {
var pos = position(this.x, this.y, this.z),
r = ((this.z * particleSizeMultiplier) + particleSizeBase) * (sizeRatio() / 1000),
o = this.opacity;
if (flicker) {
var newVal = random(-0.5, 0.5, true);
this.flicker += (newVal - this.flicker) / flickerSmoothing;
if (this.flicker > 0.5) this.flicker = 0.5;
if (this.flicker < -0.5) this.flicker = -0.5;
o += this.flicker;
if (o > 1) o = 1;
if (o < 0) o = 0;
}
context.fillStyle = this.color;
context.globalAlpha = o;
context.beginPath();
context.arc(pos.x, pos.y, r, 0, 2 * Math.PI, false);
context.fill();
context.closePath();
if (renderParticleGlare) {
context.globalAlpha = o * glareOpacityMultiplier;
/*
context.ellipse(pos.x, pos.y, r * 30, r, 90 * (Math.PI / 180), 0, 2 * Math.PI, false);
context.fill();
context.closePath();
*/
context.ellipse(pos.x, pos.y, r * 100, r, (glareAngle - ((nPos.x - 0.5) * noiseStrength * motion)) * (Math.PI / 180), 0, 2 * Math.PI, false);
context.fill();
context.closePath();
}
context.globalAlpha = 1;
};
// Flare class
var Flare = function() {
this.x = random(-0.25, 1.25, true);
this.y = random(-0.25, 1.25, true);
this.z = random(0,2);
this.color = color;
this.opacity = random(0.001, 0.01, true);
};
Flare.prototype.render = function() {
var pos = position(this.x, this.y, this.z),
r = ((this.z * flareSizeMultiplier) + flareSizeBase) * (sizeRatio() / 1000);
// Feathered circles
/*
var grad = context.createRadialGradient(x+r,y+r,0,x+r,y+r,r);
grad.addColorStop(0, 'rgba(255,255,255,'+f.o+')');
grad.addColorStop(0.8, 'rgba(255,255,255,'+f.o+')');
grad.addColorStop(1, 'rgba(255,255,255,0)');
context.fillStyle = grad;
context.beginPath();
context.fillRect(x, y, r*2, r*2);
context.closePath();
*/
context.beginPath();
context.globalAlpha = this.opacity;
context.arc(pos.x, pos.y, r, 0, 2 * Math.PI, false);
context.fillStyle = this.color;
context.fill();
context.closePath();
context.globalAlpha = 1;
};
// Link class
var Link = function(startVertex, numPoints) {
this.length = numPoints;
this.verts = [startVertex];
this.stage = 0;
this.linked = [startVertex];
this.distances = [];
this.traveled = 0;
this.fade = 0;
this.finished = false;
};
Link.prototype.render = function() {
// Stages:
// 0. Vertex collection
// 1. Render line reaching from vertex to vertex
// 2. Fade out
// 3. Finished (delete me)
var i, p, pos, points;
switch (this.stage) {
// VERTEX COLLECTION STAGE
case 0:
// Grab the last member of the link
var last = particles[this.verts[this.verts.length-1]];
//console.log(JSON.stringify(last));
if (last && last.neighbors && last.neighbors.length > 0) {
// Grab a random neighbor
var neighbor = last.neighbors[random(0, last.neighbors.length-1)];
// If we haven't seen that particle before, add it to the link
if (this.verts.indexOf(neighbor) == -1) {
this.verts.push(neighbor);
}
// If we have seen that particle before, we'll just wait for the next frame
}
else {
//console.log(this.verts[0]+' prematurely moving to stage 3 (0)');
this.stage = 3;
this.finished = true;
}
if (this.verts.length >= this.length) {
// Calculate all distances at once
for (i = 0; i < this.verts.length-1; i++) {
var p1 = particles[this.verts[i]],
p2 = particles[this.verts[i+1]],
dx = p1.x - p2.x,
dy = p1.y - p2.y,
dist = Math.sqrt(dx*dx + dy*dy);
this.distances.push(dist);
}
//console.log('Distances: '+JSON.stringify(this.distances));
//console.log('verts: '+this.verts.length+' distances: '+this.distances.length);
//console.log(this.verts[0]+' moving to stage 1');
this.stage = 1;
}
break;
// RENDER LINE ANIMATION STAGE
case 1:
if (this.distances.length > 0) {
points = [];
//var a = 1;
// Gather all points already linked
for (i = 0; i < this.linked.length; i++) {
p = particles[this.linked[i]];
pos = position(p.x, p.y, p.z);
points.push([pos.x, pos.y]);
}
var linkSpeedRel = linkSpeed * 0.00001 * canvas.width;
this.traveled += linkSpeedRel;
var d = this.distances[this.linked.length-1];
// Calculate last point based on linkSpeed and distance travelled to next point
if (this.traveled >= d) {
this.traveled = 0;
// We've reached the next point, add coordinates to array
//console.log(this.verts[0]+' reached vertex '+(this.linked.length+1)+' of '+this.verts.length);
this.linked.push(this.verts[this.linked.length]);
p = particles[this.linked[this.linked.length-1]];
pos = position(p.x, p.y, p.z);
points.push([pos.x, pos.y]);
if (this.linked.length >= this.verts.length) {
//console.log(this.verts[0]+' moving to stage 2 (1)');
this.stage = 2;
}
}
else {
// We're still travelling to the next point, get coordinates at travel distance
// http://math.stackexchange.com/a/85582
var a = particles[this.linked[this.linked.length-1]],
b = particles[this.verts[this.linked.length]],
t = d - this.traveled,
x = ((this.traveled * b.x) + (t * a.x)) / d,
y = ((this.traveled * b.y) + (t * a.y)) / d,
z = ((this.traveled * b.z) + (t * a.z)) / d;
pos = position(x, y, z);
//console.log(this.verts[0]+' traveling to vertex '+(this.linked.length+1)+' of '+this.verts.length+' ('+this.traveled+' of '+this.distances[this.linked.length]+')');
points.push([pos.x, pos.y]);
}
this.drawLine(points);
}
else {
//console.log(this.verts[0]+' prematurely moving to stage 3 (1)');
this.stage = 3;
this.finished = true;
}
break;
// FADE OUT STAGE
case 2:
if (this.verts.length > 1) {
if (this.fade < linkFade) {
this.fade++;
// Render full link between all vertices and fade over time
points = [];
var alpha = (1 - (this.fade / linkFade)) * linkOpacity;
for (i = 0; i < this.verts.length; i++) {
p = particles[this.verts[i]];
pos = position(p.x, p.y, p.z);
points.push([pos.x, pos.y]);
}
this.drawLine(points, alpha);
}
else {
//console.log(this.verts[0]+' moving to stage 3 (2a)');
this.stage = 3;
this.finished = true;
}
}
else {
//console.log(this.verts[0]+' prematurely moving to stage 3 (2b)');
this.stage = 3;
this.finished = true;
}
break;
// FINISHED STAGE
case 3:
default:
this.finished = true;
break;
}
};
Link.prototype.drawLine = function(points, alpha) {
if (typeof alpha !== 'number') alpha = linkOpacity;
if (points.length > 1 && alpha > 0) {
//console.log(this.verts[0]+': Drawing line '+alpha);
context.globalAlpha = alpha;
context.beginPath();
for (var i = 0; i < points.length-1; i++) {
context.moveTo(points[i][0], points[i][1]);
context.lineTo(points[i+1][0], points[i+1][1]);
}
context.strokeStyle = color;
context.lineWidth = lineWidth;
context.stroke();
context.closePath();
context.globalAlpha = 1;
}
};
// Utils
function noisePoint(i) {
var a = nAngle * i,
cosA = Math.cos(a),
sinA = Math.sin(a),
//value = simplex.noise2D(nScale * cosA + nScale, nScale * sinA + nScale),
//rad = nRad + value;
rad = nRad;
return {
x: rad * cosA,
y: rad * sinA
};
}
function position(x, y, z) {
return {
x: (x * canvas.width) + ((((canvas.width / 2) - mouse.x + ((nPos.x - 0.5) * noiseStrength)) * z) * motion),
y: (y * canvas.height) + ((((canvas.height / 2) - mouse.y + ((nPos.y - 0.5) * noiseStrength)) * z) * motion)
};
}
function sizeRatio() {
return canvas.width >= canvas.height ? canvas.width : canvas.height;
}
function random(min, max, float) {
return float ?
Math.random() * (max - min) + min :
Math.floor(Math.random() * (max - min + 1)) + min;
}
// init
if (canvas) init();
html,
body {
margin: 0;
padding: 0;
}
body {
background-color: #31102F;
background: radial-gradient(ellipse at center, #31102f 0%, #280b29 100%);
}
#stars {
display: block;
position: relative;
width: 100%;
height: 16rem;
height: 100vh;
z-index: 1;
}
<script src="https://rawgit.com/ironwallaby/delaunay/master/delaunay.js"></script>
<canvas id="stars" width="300" height="300"></canvas>
Hi I try to create an animation with a circle. The function drawRandom(drawFunctions) should pic one of the three drawcircle functions and should bring it on the canvas. Now the problem is that this function become executed every second (main loop) and the circle change his colour. How can I fix that?
window.onload = window.onresize = function() {
var C = 1; // canvas width to viewport width ratio
var el = document.getElementById("myCanvas");
var viewportWidth = window.innerWidth;
var viewportHeight = window.innerHeight;
var canvasWidth = viewportWidth * C;
var canvasHeight = viewportHeight;
el.style.position = "fixed";
el.setAttribute("width", canvasWidth);
el.setAttribute("height", canvasHeight);
var x = canvasWidth / 100;
var y = canvasHeight / 100;
var ballx = canvasWidth / 100;
var n;
window.ctx = el.getContext("2d");
ctx.clearRect(0, 0, canvasWidth, canvasHeight);
// draw triangles
function init() {
ballx;
return setInterval(main_loop, 1000);
}
function drawcircle1()
{
var radius = x * 5;
ctx.beginPath();
ctx.arc(ballx * 108, canvasHeight / 2, radius, 0, 2 * Math.PI, false);
ctx.fillStyle = 'yellow';
ctx.fill();
}
function drawcircle2()
{
var radius = x * 5;
ctx.beginPath();
ctx.arc(ballx * 108, canvasHeight / 2, radius, 0, 2 * Math.PI, false);
ctx.fillStyle = 'blue';
ctx.fill();
}
function drawcircle3()
{
var radius = x * 5;
ctx.beginPath();
ctx.arc(ballx * 105, canvasHeight / 2, radius, 0, 2 * Math.PI, false);
ctx.fillStyle = 'orange';
ctx.fill();
}
function draw() {
var counterClockwise = false;
ctx.clearRect(0, 0, canvasWidth, canvasHeight);
//first halfarc
ctx.beginPath();
ctx.arc(x * 80, y * 80, y * 10, 0 * Math.PI, 1 * Math.PI, counterClockwise);
ctx.lineWidth = y * 1;
ctx.strokeStyle = 'black';
ctx.stroke();
// draw stop button
ctx.beginPath();
ctx.moveTo(x * 87, y * 2);
ctx.lineTo(x * 87, y * 10);
ctx.lineWidth = x;
ctx.stroke();
ctx.beginPath();
ctx.moveTo(x * 95, y * 2);
ctx.lineTo(x * 95, y * 10);
ctx.lineWidth = x;
ctx.stroke();
function drawRandom(drawFunctions){
//generate a random index
var randomIndex = Math.floor(Math.random() * drawFunctions.length);
//call the function
drawFunctions[randomIndex]();
}
drawRandom([drawcircle1, drawcircle2, drawcircle3]);
}
function update() {
ballx -= 0.1;
if (ballx < 0) {
ballx = -radius;
}
}
function main_loop() {
draw();
update();
collisiondetection();
}
init();
function initi() {
console.log('init');
// Get a reference to our touch-sensitive element
var touchzone = document.getElementById("myCanvas");
// Add an event handler for the touchstart event
touchzone.addEventListener("mousedown", touchHandler, false);
}
function touchHandler(event) {
// Get a reference to our coordinates div
var can = document.getElementById("myCanvas");
// Write the coordinates of the touch to the div
if (event.pageX < x * 50 && event.pageY > y * 10) {
ballx += 1;
} else if (event.pageX > x * 50 && event.pageY > y * 10 ) {
ballx -= 1;
}
console.log(event, x, ballx);
draw();
}
initi();
draw();
}
Take a look at my code that I wrote:
var lastTime = 0;
function requestMyAnimationFrame(callback, time)
{
var t = time || 16;
var currTime = new Date().getTime();
var timeToCall = Math.max(0, t - (currTime - lastTime));
var id = window.setTimeout(function(){ callback(currTime + timeToCall); }, timeToCall);
lastTime = currTime + timeToCall;
return id;
}
var canvas = document.getElementById("canvas");
var context = canvas.getContext("2d");
canvas.width = window.innerWidth - 20;
canvas.height = window.innerHeight - 20;
canvas.style.width = canvas.width + "px";
canvas.style.height = canvas.height + "px";
var circles = [];
var mouse =
{
x: 0,
y: 0
}
function getCoordinates(x, y)
{
return "(" + x + ", " + y + ")";
}
function getRatio(n, d)
{
// prevent division by 0
if (d === 0 || n === 0)
{
return 0;
}
else
{
return n/d;
}
}
function Circle(x,y,d,b,s,c)
{
this.x = x;
this.y = y;
this.diameter = Math.round(d);
this.radius = Math.round(d/2);
this.bounciness = b;
this.speed = s;
this.color = c;
this.deltaX = 0;
this.deltaY = 0;
this.drawnPosition = "";
this.fill = function()
{
context.beginPath();
context.arc(this.x+this.radius,this.y+this.radius,this.radius,0,Math.PI*2,false);
context.closePath();
context.fill();
}
this.clear = function()
{
context.fillStyle = "#ffffff";
this.fill();
}
this.draw = function()
{
if (this.drawnPosition !== getCoordinates(this.x, this.y))
{
context.fillStyle = this.color;
// if commented, the circle will be drawn if it is in the same position
//this.drawnPosition = getCoordinates(this.x, this.y);
this.fill();
}
}
this.keepInBounds = function()
{
if (this.x < 0)
{
this.x = 0;
this.deltaX *= -1 * this.bounciness;
}
else if (this.x + this.diameter > canvas.width)
{
this.x = canvas.width - this.diameter;
this.deltaX *= -1 * this.bounciness;
}
if (this.y < 0)
{
this.y = 0;
this.deltaY *= -1 * this.bounciness;
}
else if (this.y+this.diameter > canvas.height)
{
this.y = canvas.height - this.diameter;
this.deltaY *= -1 * this.bounciness;
}
}
this.followMouse = function()
{
// deltaX/deltaY will currently cause the circles to "orbit" around the cursor forever unless it hits a wall
var centerX = Math.round(this.x + this.radius);
var centerY = Math.round(this.y + this.radius);
if (centerX < mouse.x)
{
// circle is to the left of the mouse, so move the circle to the right
this.deltaX += this.speed;
}
else if (centerX > mouse.x)
{
// circle is to the right of the mouse, so move the circle to the left
this.deltaX -= this.speed;
}
else
{
//this.deltaX = 0;
}
if (centerY < mouse.y)
{
// circle is above the mouse, so move the circle downwards
this.deltaY += this.speed;
}
else if (centerY > mouse.y)
{
// circle is under the mouse, so move the circle upwards
this.deltaY -= this.speed;
}
else
{
//this.deltaY = 0;
}
this.x += this.deltaX;
this.y += this.deltaY;
this.x = Math.round(this.x);
this.y = Math.round(this.y);
}
}
function getRandomDecimal(min, max)
{
return Math.random() * (max-min) + min;
}
function getRoundedNum(min, max)
{
return Math.round(getRandomDecimal(min, max));
}
function getRandomColor()
{
// array of three colors
var colors = [];
// go through loop and add three integers between 0 and 255 (min and max color values)
for (var i = 0; i < 3; i++)
{
colors[i] = getRoundedNum(0, 255);
}
// return rgb value (RED, GREEN, BLUE)
return "rgb(" + colors[0] + "," + colors[1] + ", " + colors[2] + ")";
}
function createCircle(i)
{
// diameter of circle
var minDiameter = 25;
var maxDiameter = 50;
// bounciness of circle (changes speed if it hits a wall)
var minBounciness = 0.2;
var maxBounciness = 0.65;
// speed of circle (how fast it moves)
var minSpeed = 0.3;
var maxSpeed = 0.45;
// getRoundedNum returns a random integer and getRandomDecimal returns a random decimal
var x = getRoundedNum(0, canvas.width);
var y = getRoundedNum(0, canvas.height);
var d = getRoundedNum(minDiameter, maxDiameter);
var c = getRandomColor();
var b = getRandomDecimal(minBounciness, maxBounciness);
var s = getRandomDecimal(minSpeed, maxSpeed);
// create the circle with x, y, diameter, bounciness, speed, and color
circles[i] = new Circle(x,y,d,b,s,c);
}
function makeCircles()
{
var maxCircles = getRoundedNum(2, 5);
for (var i = 0; i < maxCircles; i++)
{
createCircle(i);
}
}
function drawCircles()
{
var ii = 0;
for (var i = 0; ii < circles.length; i++)
{
if (circles[i])
{
circles[i].draw();
ii++;
}
}
}
function clearCircles()
{
var ii = 0;
for (var i = 0; ii < circles.length; i++)
{
if (circles[i])
{
circles[i].clear();
ii++;
}
}
}
function updateCircles()
{
var ii = 0;
for (var i = 0; ii < circles.length; i++)
{
if (circles[i])
{
circles[i].keepInBounds();
circles[i].followMouse();
ii++;
}
}
}
function update()
{
requestMyAnimationFrame(update,10);
updateCircles();
}
function draw()
{
requestMyAnimationFrame(draw,1000/60);
context.clearRect(0,0,canvas.width,canvas.height);
drawCircles();
}
window.addEventListener("load", function()
{
window.addEventListener("mousemove", function(e)
{
mouse.x = e.layerX || e.offsetX;
mouse.y = e.layerY || e.offsetY;
});
makeCircles();
update();
draw();
});