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Trying to add this to my website on sqaurespace

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>

How to calculate intersection point of a line on a circle using p5.js

I have a line (se) that I know starts inside a circle, and I know ends outside of a circle. I'm trying to find a point l where the line crosses the circle.
I'm using the p5.js library and have access to all of its Vector functions.
My thoughts were, that if I can make a right angle on the line, to the radius, I can start solving some things.
// Get the vector between s and c
let scVector = p5.Vector.sub(start, circleCenter);
// Get the angle between se and sc
let escAngle = this.v.angleBetween(scVector);
// Get the distance between t (where the right angle hits the center of the circle) and c
let tcDistance = Math.sin(escAngle) * scVector.mag();
// Get the distance between t and where the line intersects the circle
let tlDistance = Math.sqrt(Math.pow(hole.r, 2) - Math.pow(tcDistance, 2));
// Get the distance between the start point and t
let stDistance = Math.sqrt(Math.pow(scVector.mag(), 2) - Math.pow(tcDistance, 2));
// Add the two distances together, giving me the distance between s and l
let totalDistance = tcDistance + stDistance;
// Create a new Vector at this angle, at the totalDistance Magnitude, then add it to the current position
let point = p5.Vector.fromAngle(this.v.heading(), totalDistance).add(start);
// Mark a point (hopefully l) on the edge of the circle.
points.push({
x: point.x,
y: point.y,
fill: '#ffffff'
})
Unfortunately, as my objects pass through the circle, they aren't leaving dots on the edge, but further away from the circle's edge.
The tiny dots are the marked positions, the coloured dots are the objects (which have a start and end point)
I have a demo here, the questionable bit is line 42 onwards:
https://codepen.io/EightArmsHQ/pen/be0461014f9868e3462868776d9c8f1a
Any help would be much appreciated.

To find the intersection of a point and a line, I recommend to use an existing algorithm, like that one of WolframMathWorld - Circle-Line Intersection.
The algorithm is short, well explained an can be expressed in an short function. The input parameters p1, p2, and cpt are of type p5.Vector, r is a scalar. This parameters define an endless line form p1 to p2 and a circle with the center point cpt and the radius r. The function returns a list of inter section points, with may be empty:
intersectLineCircle = function(p1, p2, cpt, r) {
let sign = function(x) { return x < 0.0 ? -1 : 1; };
let x1 = p1.copy().sub(cpt);
let x2 = p2.copy().sub(cpt);
let dv = x2.copy().sub(x1)
let dr = dv.mag();
let D = x1.x*x2.y - x2.x*x1.y;
// evaluate if there is an intersection
let di = r*r*dr*dr - D*D;
if (di < 0.0)
return [];
let t = sqrt(di);
ip = [];
ip.push( new p5.Vector(D*dv.y + sign(dv.y)*dv.x * t, -D*dv.x + p.abs(dv.y) * t).div(dr*dr).add(cpt) );
if (di > 0.0) {
ip.push( new p5.Vector(D*dv.y - sign(dv.y)*dv.x * t, -D*dv.x - p.abs(dv.y) * t).div(dr*dr).add(cpt) );
}
return ip;
}
If you want to verify, if a point is "in between" to other points, you can use the Dot product. If you know that 3 points on a line, then it is sufficient to calculate the distances between the points, to determine, if 1 point is in between the 2 other points.
p1, p2, and px are of type p5.Vector. The points are on the same line. The function returns true, if px is between p1 and p2 and false else:
inBetween = function(p1, p2, px) {
let v = p2.copy().sub(p1);
let d = v.mag();
v = v.normalize();
let vx = px.copy().sub(p1);
let dx = v.dot(vx);
return dx >= 0 && dx <= d;
}
See the example, which I've implemented to test the function. The circle is tracked by the mouse and is intersected by an randomly moving line:
var sketch = function( p ) {
p.setup = function() {
let sketchCanvas = p.createCanvas(p.windowWidth, p.windowHeight);
sketchCanvas.parent('p5js_canvas')
}
let points = [];
let move = []
// Circle-Line Intersection
// http://mathworld.wolfram.com/Circle-LineIntersection.html
p.intersectLineCircle = function(p1, p2, cpt, r) {
let sign = function(x) { return x < 0.0 ? -1 : 1; };
let x1 = p1.copy().sub(cpt);
let x2 = p2.copy().sub(cpt);
let dv = x2.copy().sub(x1)
let dr = dv.mag();
let D = x1.x*x2.y - x2.x*x1.y;
// evaluate if there is an intersection
let di = r*r*dr*dr - D*D;
if (di < 0.0)
return [];
let t = p.sqrt(di);
ip = [];
ip.push( new p5.Vector(D*dv.y + sign(dv.y)*dv.x * t, -D*dv.x + p.abs(dv.y) * t).div(dr*dr).add(cpt) );
if (di > 0.0) {
ip.push( new p5.Vector(D*dv.y - sign(dv.y)*dv.x * t, -D*dv.x - p.abs(dv.y) * t).div(dr*dr).add(cpt) );
}
return ip;
}
p.inBetween = function(p1, p2, px) {
let v = p2.copy().sub(p1);
let d = v.mag();
v = v.normalize();
let vx = px.copy().sub(p1);
let dx = v.dot(vx);
return dx >= 0 && dx <= d;
}
p.endlessLine = function(x1, y1, x2, y2) {
p1 = new p5.Vector(x1, y1);
p2 = new p5.Vector(x2, y2);
let dia_len = new p5.Vector(p.windowWidth, p.windowHeight).mag();
let dir_v = p5.Vector.sub(p2, p1).setMag(dia_len);
let lp1 = p5.Vector.add(p1, dir_v);
let lp2 = p5.Vector.sub(p1, dir_v);
p.line(lp1.x, lp1.y, lp2.x, lp2.y);
}
p.draw = function() {
if (points.length == 0) {
points = [];
move = [];
for (let i=0; i < 2; ++i ) {
points.push( new p5.Vector(p.random(p.windowWidth-20)+10, p.random(p.windowHeight-20)+10));
move.push( new p5.Vector(p.random(2)-1, p.random(2)-1) );
}
points.push( new p5.Vector(p.mouseX, p.mouseY));
}
else
{
for (let i=0; i < 2; ++i ) {
points[i] = points[i].add(move[i]);
if (points[i].x < 10 || points[i].x > p.windowWidth-10)
move[i].x *= -1;
if (points[i].y < 10 || points[i].y > p.windowHeight-10)
move[i].y *= -1;
move[i].x = Math.max(-1, Math.min(1, move[i].x+p.random(0.2)-0.1))
move[i].y = Math.max(-1, Math.min(1, move[i].y+p.random(0.2)-0.1))
}
points[2].x = p.mouseX;
points[2].y = p.mouseY;
}
let circle_diameter = p.min(p.windowWidth, p.windowHeight) / 2.0;
let isectP = p.intersectLineCircle(...points, circle_diameter/2.0);
// draw the scene
p.background(192);
p.stroke(0, 0, 255);
p.fill(128, 128, 255);
for (let i=0; i < points.length; ++i ) {
p.ellipse(points[i].x, points[i].y, 10, 10);
}
for (let i=0; i < isectP.length; ++i ) {
if (p.inBetween(points[0], points[1], isectP[i])) {
p.stroke(255, 0, 0);
p.fill(255, 128, 0);
} else {
p.stroke(255, 128, 0);
p.fill(255, 255, 0);
}
p.ellipse(isectP[i].x, isectP[i].y, 10, 10);
}
p.stroke(0, 255, 0);
p.noFill();
p.endlessLine(points[0].x, points[0].y, points[1].x, points[1].y)
p.ellipse(points[2].x, points[2].y, circle_diameter, circle_diameter);
}
p.windowResized = function() {
p.resizeCanvas(p.windowWidth, p.windowHeight);
points = [];
}
p.mouseClicked = function() {
points = [];
}
p.keyPressed = function() {
points = []
}
};
var circle_line = new p5(sketch);
<script src="https://cdnjs.cloudflare.com/ajax/libs/p5.js/1.3.1/p5.min.js"></script>
<div id="p5js_canvas"></div>
Demo

hyperdrive effect in canvas across randomly placed circles

I'm trying to create a hyperdrive effect, like from Star Wars, where the stars have a motion trail. I've gotten as far as creating the motion trail on a single circle, it still looks like the trail is going down in the y direction and not forwards or positive in the z direction.
Also, how could I do this with (many) randomly placed circles as if they were stars?
My code is on jsfiddle (https://jsfiddle.net/5m7x5zxu/) and below:
var canvas = document.querySelector("canvas");
var context = canvas.getContext("2d");
var xPos = 180;
var yPos = 100;
var motionTrailLength = 16;
var positions = [];
function storeLastPosition(xPos, yPos) {
// push an item
positions.push({
x: xPos,
y: yPos
});
//get rid of first item
if (positions.length > motionTrailLength) {
positions.pop();
}
}
function update() {
context.clearRect(0, 0, canvas.width, canvas.height);
for (var i = positions.length-1; i > 0; i--) {
var ratio = (i - 1) / positions.length;
drawCircle(positions[i].x, positions[i].y, ratio);
}
drawCircle(xPos, yPos, "source");
var k=2;
storeLastPosition(xPos, yPos);
// update position
if (yPos > 125) {
positions.pop();
}
else{
yPos += k*1.1;
}
requestAnimationFrame(update);
}
update();
function drawCircle(x, y, r) {
if (r == "source") {
r = 1;
} else {
r*=1.1;
}
context.beginPath();
context.arc(x, y, 3, 0, 2 * Math.PI, true);
context.fillStyle = "rgba(255, 255, 255, " + parseFloat(1-r) + ")";
context.fill();
}

Canvas feedback and particles.
This type of FX can be done many ways.
You could just use a particle systems and draw stars (as lines) moving away from a central point, as the speed increase you increase the line length. When at low speed the line becomes a circle if you set ctx.lineWidth > 1 and ctx.lineCap = "round"
To add to the FX you can use render feedback as I think you have done by rendering the canvas over its self. If you render it slightly larger you get a zoom FX. If you use ctx.globalCompositeOperation = "lighter" you can increase the stars intensity as you speed up to make up for the overall loss of brightness as stars move faster.
Example
I got carried away so you will have to sift through the code to find what you need.
The particle system uses the Point object and a special array called bubbleArray to stop GC hits from janking the animation.
You can use just an ordinary array if you want. The particles are independent of the bubble array. When they have moved outside the screen they are move to a pool and used again when a new particle is needed. The update function moves them and the draw Function draws them I guess LOL
The function loop is the main loop and adds and draws particles (I have set the particle count to 400 but should handle many more)
The hyper drive is operated via the mouse button. Press for on, let go for off. (It will distort the text if it's being displayed)
The canvas feedback is set via that hyperSpeed variable, the math is a little complex. The sCurce function just limits the value to 0,1 in this case to stop alpha from going over or under 1,0. The hyperZero is just the sCurve return for 1 which is the hyper drives slowest speed.
I have pushed the feedback very close to the limit. In the first few lines of the loop function you can set the top speed if(mouse.button){ if(hyperSpeed < 1.75){ Over this value 1.75 and you will start to get bad FX, at about 2 the whole screen will just go white (I think that was where)
Just play with it and if you have questions ask in the comments.
const ctx = canvas.getContext("2d");
// very simple mouse
const mouse = {x : 0, y : 0, button : false}
function mouseEvents(e){
mouse.x = e.pageX;
mouse.y = e.pageY;
mouse.button = e.type === "mousedown" ? true : e.type === "mouseup" ? false : mouse.button;
}
["down","up","move"].forEach(name => document.addEventListener("mouse"+name,mouseEvents));
// High performance array pool using buubleArray to separate pool objects and active object.
// This is designed to eliminate GC hits involved with particle systems and
// objects that have short lifetimes but used often.
// Warning this code is not well tested.
const bubbleArray = () => {
const items = [];
var count = 0;
return {
clear(){ // warning this dereferences all locally held references and can incur Big GC hit. Use it wisely.
this.items.length = 0;
count = 0;
},
update() {
var head, tail;
head = tail = 0;
while(head < count){
if(items[head].update() === false) {head += 1 }
else{
if(tail < head){
const temp = items[head];
items[head] = items[tail];
items[tail] = temp;
}
head += 1;
tail += 1;
}
}
return count = tail;
},
createCallFunction(name, earlyExit = false){
name = name.split(" ")[0];
const keys = Object.keys(this);
if(Object.keys(this).indexOf(name) > -1){ throw new Error(`Can not create function name '${name}' as it already exists.`) }
if(!/\W/g.test(name)){
let func;
if(earlyExit){
func = `var items = this.items; var count = this.getCount(); var i = 0;\nwhile(i < count){ if (items[i++].${name}() === true) { break } }`;
}else{
func = `var items = this.items; var count = this.getCount(); var i = 0;\nwhile(i < count){ items[i++].${name}() }`;
}
!this.items && (this.items = items);
this[name] = new Function(func);
}else{ throw new Error(`Function name '${name}' contains illegal characters. Use alpha numeric characters.`) }
},
callEach(name){var i = 0; while(i < count){ if (items[i++][name]() === true) { break } } },
each(cb) { var i = 0; while(i < count){ if (cb(items[i], i++) === true) { break } } },
next() { if (count < items.length) { return items[count ++] } },
add(item) {
if(count === items.length){
items.push(item);
count ++;
}else{
items.push(items[count]);
items[count++] = item;
}
return item;
},
getCount() { return count },
}
}
// Helpers rand float, randI random Int
// doFor iterator
// sCurve curve input -Infinity to Infinity out -1 to 1
// randHSLA creates random colour
// CImage, CImageCtx create image and image with context attached
const randI = (min, max = min + (min = 0)) => (Math.random() * (max - min) + min) | 0;
const rand = (min = 1, max = min + (min = 0)) => Math.random() * (max - min) + min;
const doFor = (count, cb) => { var i = 0; while (i < count && cb(i++) !== true); }; // the ; after while loop is important don't remove
const sCurve = (v,p) => (2 / (1 + Math.pow(p,-v))) -1;
const randHSLA = (h, h1, s = 100, s1 = 100, l = 50, l1 = 50, a = 1, a1 = 1) => { return `hsla(${randI(h,h1) % 360},${randI(s,s1)}%,${randI(l,l1)}%,${rand(a,a1)})` }
const CImage = (w = 128, h = w) => (c = document.createElement("canvas"),c.width = w,c.height = h, c);
const CImageCtx = (w = 128, h = w) => (c = CImage(w,h), c.ctx = c.getContext("2d"), c);
// create image to hold text
var textImage = CImageCtx(1024, 1024);
var c = textImage.ctx;
c.fillStyle = "#FF0";
c.font = "64px arial black";
c.textAlign = "center";
c.textBaseline = "middle";
const text = "HYPER,SPEED FX,VII,,Battle of Jank,,Hold the mouse,button to increase,speed.".split(",");
text.forEach((line,i) => { c.fillText(line,512,i * 68 + 68) });
const maxLines = text.length * 68 + 68;
function starWarIntro(image,x1,y1,x2,y2,pos){
var iw = image.width;
var ih = image.height;
var hh = (x2 - x1) / (y2 - y1); // Slope of left edge
var w2 = iw / 2; // half width
var z1 = w2 - x1; // Distance (z) to first line
var z2 = (z1 / (w2 - x2)) * z1 - z1; // distance (z) between first and last line
var sk,t3,t3a,z3a,lines, z3, dd = 0, a = 0, as = 2 / (y2 - y1);
for (var y = y1; y < y2 && dd < maxLines; y++) { // for each line
t3 = ((y - y1) * hh) + x1; // get scan line top left edge
t3a = (((y+1) - y1) * hh) + x1; // get scan line bottom left edge
z3 = (z1 / (w2 - t3)) * z1; // get Z distance to top of this line
z3a = (z1 / (w2 - t3a)) * z1; // get Z distance to bottom of this line
dd = ((z3 - z1) / z2) * ih; // get y bitmap coord
a += as;
ctx.globalAlpha = a < 1 ? a : 1;
dd += pos; // kludge for this answer to make text move
// does not move text correctly
lines = ((z3a - z1) / z2) * ih-dd; // get number of lines to copy
ctx.drawImage(image, 0, dd , iw, lines, t3, y, w - t3 * 2, 1.5);
}
}
// canvas settings
var w = canvas.width;
var h = canvas.height;
var cw = w / 2; // center
var ch = h / 2;
// diagonal distance used to set point alpha (see point update)
var diag = Math.sqrt(w * w + h * h);
// If window size is changed this is called to resize the canvas
// It is not called via the resize event as that can fire to often and
// debounce makes it feel sluggish so is called from main loop.
function resizeCanvas(){
points.clear();
canvas.width = innerWidth;
canvas.height = innerHeight;
w = canvas.width;
h = canvas.height;
cw = w / 2; // center
ch = h / 2;
diag = Math.sqrt(w * w + h * h);
}
// create array of points
const points = bubbleArray();
// create optimised draw function itterator
points.createCallFunction("draw",false);
// spawns a new star
function spawnPoint(pos){
var p = points.next();
p = points.add(new Point())
if (p === undefined) { p = points.add(new Point()) }
p.reset(pos);
}
// point object represents a single star
function Point(pos){ // this function is duplicated as reset
if(pos){
this.x = pos.x;
this.y = pos.y;
this.dead = false;
}else{
this.x = 0;
this.y = 0;
this.dead = true;
}
this.alpha = 0;
var x = this.x - cw;
var y = this.y - ch;
this.dir = Math.atan2(y,x);
this.distStart = Math.sqrt(x * x + y * y);
this.speed = rand(0.01,1);
this.col = randHSLA(220,280,100,100,50,100);
this.dx = Math.cos(this.dir) * this.speed;
this.dy = Math.sin(this.dir) * this.speed;
}
Point.prototype = {
reset : Point, // resets the point
update(){ // moves point and returns false when outside
this.speed *= hyperSpeed; // increase speed the more it has moved
this.x += Math.cos(this.dir) * this.speed;
this.y += Math.sin(this.dir) * this.speed;
var x = this.x - cw;
var y = this.y - ch;
this.alpha = (Math.sqrt(x * x + y * y) - this.distStart) / (diag * 0.5 - this.distStart);
if(this.alpha > 1 || this.x < 0 || this.y < 0 || this.x > w || this.h > h){
this.dead = true;
}
return !this.dead;
},
draw(){ // draws the point
ctx.strokeStyle = this.col;
ctx.globalAlpha = 0.25 + this.alpha *0.75;
ctx.beginPath();
ctx.lineTo(this.x - this.dx * this.speed, this.y - this.dy * this.speed);
ctx.lineTo(this.x, this.y);
ctx.stroke();
}
}
const maxStarCount = 400;
const p = {x : 0, y : 0};
var hyperSpeed = 1.001;
const alphaZero = sCurve(1,2);
var startTime;
function loop(time){
if(startTime === undefined){
startTime = time;
}
if(w !== innerWidth || h !== innerHeight){
resizeCanvas();
}
// if mouse down then go to hyper speed
if(mouse.button){
if(hyperSpeed < 1.75){
hyperSpeed += 0.01;
}
}else{
if(hyperSpeed > 1.01){
hyperSpeed -= 0.01;
}else if(hyperSpeed > 1.001){
hyperSpeed -= 0.001;
}
}
var hs = sCurve(hyperSpeed,2);
ctx.globalAlpha = 1;
ctx.setTransform(1,0,0,1,0,0); // reset transform
//==============================================================
// UPDATE the line below could be the problem. Remove it and try
// what is under that
//==============================================================
//ctx.fillStyle = `rgba(0,0,0,${1-(hs-alphaZero)*2})`;
// next two lines are the replacement
ctx.fillStyle = "Black";
ctx.globalAlpha = 1-(hs-alphaZero) * 2;
//==============================================================
ctx.fillRect(0,0,w,h);
// the amount to expand canvas feedback
var sx = (hyperSpeed-1) * cw * 0.1;
var sy = (hyperSpeed-1) * ch * 0.1;
// increase alpha as speed increases
ctx.globalAlpha = (hs-alphaZero)*2;
ctx.globalCompositeOperation = "lighter";
// draws feedback twice
ctx.drawImage(canvas,-sx, -sy, w + sx*2 , h + sy*2)
ctx.drawImage(canvas,-sx/2, -sy/2, w + sx , h + sy)
ctx.globalCompositeOperation = "source-over";
// add stars if count < maxStarCount
if(points.getCount() < maxStarCount){
var cent = (hyperSpeed - 1) *0.5; // pulls stars to center as speed increases
doFor(10,()=>{
p.x = rand(cw * cent ,w - cw * cent); // random screen position
p.y = rand(ch * cent,h - ch * cent);
spawnPoint(p)
})
}
// as speed increases make lines thicker
ctx.lineWidth = 2 + hs*2;
ctx.lineCap = "round";
points.update(); // update points
points.draw(); // draw points
ctx.globalAlpha = 1;
// scroll the perspective star wars text FX
var scrollTime = (time - startTime) / 5 - 2312;
if(scrollTime < 1024){
starWarIntro(textImage,cw - h * 0.5, h * 0.2, cw - h * 3, h , scrollTime );
}
requestAnimationFrame(loop);
}
requestAnimationFrame(loop);
canvas { position : absolute; top : 0px; left : 0px; }
<canvas id="canvas"></canvas>

Here's another simple example, based mainly on the same idea as Blindman67, concetric lines moving away from center at different velocities (the farther from center, the faster it moves..) also no recycling pool here.
"use strict"
var c = document.createElement("canvas");
document.body.append(c);
var ctx = c.getContext("2d");
var w = window.innerWidth;
var h = window.innerHeight;
var ox = w / 2;
var oy = h / 2;
c.width = w; c.height = h;
const stars = 120;
const speed = 0.5;
const trailLength = 90;
ctx.fillStyle = "#000";
ctx.fillRect(0, 0, w, h);
ctx.fillStyle = "#fff"
ctx.fillRect(ox, oy, 1, 1);
init();
function init() {
var X = [];
var Y = [];
for(var i = 0; i < stars; i++) {
var x = Math.random() * w;
var y = Math.random() * h;
X.push( translateX(x) );
Y.push( translateY(y) );
}
drawTrails(X, Y)
}
function translateX(x) {
return x - ox;
}
function translateY(y) {
return oy - y;
}
function getDistance(x, y) {
return Math.sqrt(x * x + y * y);
}
function getLineEquation(x, y) {
return function(n) {
return y / x * n;
}
}
function drawTrails(X, Y) {
var count = 1;
ctx.fillStyle = "#000";
ctx.fillRect(0, 0, w, h);
function anim() {
for(var i = 0; i < X.length; i++) {
var x = X[i];
var y = Y[i];
drawNextPoint(x, y, count);
}
count+= speed;
if(count < trailLength) {
window.requestAnimationFrame(anim);
}
else {
init();
}
}
anim();
}
function drawNextPoint(x, y, step) {
ctx.fillStyle = "#fff";
var f = getLineEquation(x, y);
var coef = Math.abs(x) / 100;
var dist = getDistance( x, y);
var sp = speed * dist / 100;
for(var i = 0; i < sp; i++) {
var newX = x + Math.sign(x) * (step + i) * coef;
var newY = translateY( f(newX) );
ctx.fillRect(newX + ox, newY, 1, 1);
}
}
body {
overflow: hidden;
}
canvas {
position: absolute;
left: 0;
top: 0;
}

Drawing a nice looking Laser (Star Wars) on the canvas

Im currently in the process of animation some laser effects on the canvas for the purpose of making my game a bit more enjoyable.
For the purpose of that, i require the drawing and animation of "laser" weapons fire, something along the lines of Star Wars.
So far, im basicly only drawing a short line in red or blue and then drawing a thinner, white, line on top of it, so it gives the impression of a gradient.
I also use linecap = "round";
my current code:
function drawProjectile(weapon, ox, oy, x, y){
var trailEnd = getPointInDirection(weapon.projSize*-2, getAngleFromTo({x: ox, y: oy}, {x: x, y: y}), x, y);
fxCtx.lineCap = "round";
fxCtx.beginPath(); //the background, wider beam
fxCtx.moveTo(x+cam.o.x, y+cam.o.y);
fxCtx.lineTo(trailEnd.x+cam.o.x, trailEnd.y+cam.o.y);
fxCtx.closePath();
fxCtx.strokeStyle = weapon.animColor //blue or red
fxCtx.lineWidth = weapon.projSize;
fxCtx.stroke();
fxCtx.globalAlpha = 0.5; // the inner, thin, white beam
fxCtx.strokeStyle = "white";
fxCtx.lineWidth = 2;
fxCtx.stroke();
fxCtx.globalAlpha = 1;
fxCtx.lineCap = "butt";
}
Can someone advice how to improve my laser beam effect ?

Using canvas as images, glows, and more.
The demo below creates all the graphics it needs as offscreen canvases. The background is also drawn on to leave a burn mark when a laser hits the ground.
Lasers
Laser shots are 3 layered ctx.drawImage calls. The first 2 are glow with ctx.globalCompositeOperation = "lighter" . One has fixed alpha, the second has a random alpha. The last is drawn ctx.globalCompositeOperation = "source-over" and is just an image of a line.
There are 4 images (canvas) for the laaser called laserRed, laserGRed, laserGreen, and laserGGreen. the ones with the extra G are the laser glow.
When the laser shot is at the end I draw 4 frames of expanding glow from pre- rendered image. In the first of the 4 frames I draw to the background canvas leaving a burn mark.
Pre rendered images
All the graphics used are rendered in the function onResize which is called on resize from the boilerplate code.
The function display is called once every frame and handles all the animation.
There is an object called imageTools that has some helper functions to make the coding a little simplier. var image = imageTools.createImage(width,height) creates a canvas. The image has the context attached image.ctx so you can draw to it just like any canvas. You can then draw that image onto the global canvas with imageTools.drawImage(image,x,y,scale,rotation,alpha) The image is drawn at it center point with a scale, rotation, and alpha.
The bullets use an object pool so that the GC (Garbage collection) does not interfere to much.
I did not set any limits so those with high res devices or those with low end machines may see some slowdown. If its a problem OP you can reduce the bullet count by making them go a little faster, you can also reduce the rendering to just two or one layer. But this is a lot faster than if you were rendering with canvas vector calls, shadows, etc...
I will leave the rest for you to work out. Its a bit sparse in the comments but I did not have much time.
There is also some boilerplate at the bottom that is not very readable.
Left click to start the war.
/*************************************************************************************
* Called from boilerplate code and is debounced by 100ms
* Creates all the images used in the demo.
************************************************************************************/
var onResize = function(){
// create a background as drawable image
background = imageTools.createImage(canvas.width,canvas.height);
// create tile image
tile = imageTools.createImage(64,64);
tile.ctx.fillStyle = imageTools.createGradient(ctx,"linear",0,0,64,64,["#555","#666"]);
tile.ctx.fillRect(0,0,64,64);
tile.ctx.fillStyle = "#333"; // add colour
tile.ctx.globalCompositeOperation = "lighter";
tile.ctx.fillRect(0,0,62,2);
tile.ctx.fillRect(0,0,2,62);
tile.ctx.fillStyle = "#AAA"; // multiply colour to darken
tile.ctx.globalCompositeOperation = "multiply";
tile.ctx.fillRect(62,1,2,62);
tile.ctx.fillRect(1,62,62,2);
for(var y = -32; y < canvas.height; y += 64 ){
for(var x = -32; x < canvas.width; x += 64 ){
background.ctx.drawImage(tile,x,y);
}
}
background.ctx.globalCompositeOperation = "multiply"; // setup for rendering burn marks
burn = imageTools.createImage(flashSize/2,flashSize/2);
burn.ctx.fillStyle = imageTools.createGradient(ctx,"radial",flashSize/4,flashSize/4,0,flashSize/4,["#444","#444","#333","#000","#0000"]);
burn.ctx.fillRect(0,0,flashSize/2,flashSize/2);
glowRed = imageTools.createImage(flashSize,flashSize);
glowRed.ctx.fillStyle = imageTools.createGradient(ctx,"radial",flashSize/2,flashSize/2,0,flashSize/2,["#855F","#8000"]);
// #855F is non standard colour last digit is alpha
// 8,8 is ceneter 0 first radius 8 second
glowRed.ctx.fillRect(0,0,flashSize,flashSize);
glowGreen = imageTools.createImage(flashSize,flashSize);
glowGreen.ctx.fillStyle = imageTools.createGradient(ctx,"radial",flashSize/2,flashSize/2,0,flashSize/2,["#585F","#0600"]);
// #855F is non standard colour last digit is alpha
// 8,8 is ceneter 0 first radius 8 second
glowGreen.ctx.fillRect(0,0,flashSize,flashSize);
// draw the laser
laserLen = 32;
laserWidth = 4;
laserRed = imageTools.createImage(laserLen,laserWidth);
laserGreen = imageTools.createImage(laserLen,laserWidth);
laserRed.ctx.lineCap = laserGreen.ctx.lineCap = "round";
laserRed.ctx.lineWidth = laserGreen.ctx.lineWidth = laserWidth;
laserRed.ctx.strokeStyle = "#F33";
laserGreen.ctx.strokeStyle = "#3F3";
laserRed.ctx.beginPath();
laserGreen.ctx.beginPath();
laserRed.ctx.moveTo(laserWidth/2 + 1,laserWidth/2);
laserGreen.ctx.moveTo(laserWidth/2 + 1,laserWidth/2);
laserRed.ctx.lineTo(laserLen - (laserWidth/2 + 1),laserWidth/2);
laserGreen.ctx.lineTo(laserLen - (laserWidth/2 + 1),laserWidth/2);
laserRed.ctx.stroke();
laserGreen.ctx.stroke();
// draw the laser glow FX
var glowSize = 8;
laserGRed = imageTools.createImage(laserLen + glowSize * 2,laserWidth + glowSize * 2);
laserGGreen = imageTools.createImage(laserLen + glowSize * 2,laserWidth + glowSize * 2);
laserGRed.ctx.lineCap = laserGGreen.ctx.lineCap = "round";
laserGRed.ctx.shadowBlur = laserGGreen.ctx.shadowBlur = glowSize;
laserGRed.ctx.shadowColor = "#F33"
laserGGreen.ctx.shadowColor = "#3F3";
laserGRed.ctx.lineWidth = laserGGreen.ctx.lineWidth = laserWidth;
laserGRed.ctx.strokeStyle = "#F33";
laserGGreen.ctx.strokeStyle = "#3F3";
laserGRed.ctx.beginPath();
laserGGreen.ctx.beginPath();
laserGRed.ctx.moveTo(laserWidth/2 + 1 + glowSize,laserWidth/2 + glowSize);
laserGGreen.ctx.moveTo(laserWidth/2 + 1 + glowSize,laserWidth/2 + glowSize);
laserGRed.ctx.lineTo(laserLen + glowSize * 2 - (laserWidth/2 + 1 + glowSize),laserWidth/2 + glowSize);
laserGGreen.ctx.lineTo(laserLen + glowSize * 2 - (laserWidth/2 + 1 + glowSize),laserWidth/2 + glowSize);
laserGRed.ctx.stroke();
laserGGreen.ctx.stroke();
readyToRock = true;
}
var flashSize = 16;
const flashBrightNorm = 4 * (flashSize/2) * (flashSize/2) * Math.PI; // area of the flash
var background,tile,glowRed,glowGreen,grad, laserGreen,laserRed,laserGGreen,laserGRed,readyToRock,burn;
readyToRock = false;
/*************************************************************************************
* create or reset a bullet
************************************************************************************/
function createShot(x,y,xx,yy,speed,type,bullet){ // create a bullet object
if(bullet === undefined){
bullet = {};
}
var nx = xx-x; // normalise
var ny = yy-y;
var dist = Math.sqrt(nx*nx+ny*ny);
nx /= dist;
ny /= dist;
bullet.x = x;
bullet.y = y;
bullet.speed = speed;
bullet.type = type;
bullet.xx = xx;
bullet.yy = yy;
bullet.nx = nx; // normalised vector
bullet.ny = ny;
bullet.rot = Math.atan2(ny,nx); // will draw rotated so get the rotation
bullet.life = Math.ceil(dist/speed); // how long to keep alive
return bullet;
}
// semi static array with object pool.
var bullets=[]; // array of bullets
var bulletPool=[]; // array of used bullets. Use to create new bullets this stops GC messing with frame rate
const BULLET_TYPES = {
red : 0,
green : 1,
}
/*************************************************************************************
* Add a bullet to the bullet array
************************************************************************************/
function addBullet(xx,yy,type){
var bullet,x,y;
if(bulletPool.length > 0){
bullet = bulletPool.pop(); // get bullet from pool
}
if(type === BULLET_TYPES.red){
x = canvas.width + 16 + 32 * Math.random();
y = Math.random() * canvas.height;
}else if(type === BULLET_TYPES.green){
x = - 16 - 32 * Math.random();
y = Math.random() * canvas.height;
}
// randomise shoot to position
var r = Math.random() * Math.PI * 2;
var d = Math.random() * 128 + 16;
xx += Math.cos(r)* d;
yy += Math.sin(r)* d;
bullets[bullets.length] = createShot(x,y,xx,yy,16,type,bullet);
}
/*************************************************************************************
* update and draw bullets
************************************************************************************/
function updateDrawAllBullets(){
var i,img,imgGlow;
for(i = 0; i < bullets.length; i++){
var b = bullets[i];
b.life -= 1;
if(b.life <= 0){ // bullet end remove it and put it in the pool
bulletPool[bulletPool.length] = bullets.splice(i,1)[0];
i--; // to stop from skipping a bullet
}else{
if(b.life < 5){
if(b.life===4){
b.x += b.nx * b.speed * 0.5; // set to front of laser
b.y += b.ny * b.speed * 0.5;
var scale = 0.9 + Math.random() *1;
background.ctx.setTransform(scale,0,0,scale,b.x,b.y);
background.ctx.globalAlpha = 0.1 + Math.random() *0.2;;
background.ctx.drawImage(burn,-burn.width /2 ,-burn.height/2);
}
if(b.type === BULLET_TYPES.red){
img = glowRed;
}else{
img = glowGreen;
}
ctx.globalCompositeOperation = "lighter";
imageTools.drawImage(img,b.x,b.y,(4-b.life)*(4-b.life),b.rot,1);//b.life/4);
imageTools.drawImage(img,b.x,b.y,4,b.rot,b.life/4);
ctx.globalCompositeOperation = "source-over";
}else{
b.x += b.nx * b.speed;
b.y += b.ny * b.speed;
if(b.type === BULLET_TYPES.red){
img = laserRed;
imgGlow = laserGRed;
}else{
img = laserGreen;
imgGlow = laserGGreen;
}
ctx.globalCompositeOperation = "lighter";
imageTools.drawImage(imgGlow,b.x,b.y,1,b.rot,1);
imageTools.drawImage(imgGlow,b.x,b.y,2,b.rot,Math.random()/2);
ctx.globalCompositeOperation = "source-over";
imageTools.drawImage(img,b.x,b.y,1,b.rot,1);
}
}
}
}
/*************************************************************************************
* Main display loop
************************************************************************************/
function display() {
if(readyToRock){
ctx.setTransform(1, 0, 0, 1, 0, 0); // reset transform
ctx.globalAlpha = 1; // reset alpha
ctx.drawImage(background,0,0);
ctx.globalCompositeOperation = "source-over";
if(mouse.buttonRaw & 1){
addBullet(mouse.x,mouse.y,BULLET_TYPES.red);
addBullet(mouse.x,mouse.y,BULLET_TYPES.green);
}
updateDrawAllBullets();
}
}
/*************************************************************************************
* Tools for creating canvas images and what not
************************************************************************************/
var imageTools = (function () {
// This interface is as is. No warenties no garenties, and NOT to be used comercialy
var workImg,workImg1,keep; // for internal use
var xdx,xdy,spr; // static vars for drawImage and drawSprite
keep = false;
var tools = {
canvas : function (width, height) { // create a blank image (canvas)
var c = document.createElement("canvas");
c.width = width;
c.height = height;
return c;
},
createImage : function (width, height) {
var i = this.canvas(width, height);
i.ctx = i.getContext("2d");
return i;
},
drawImage : function(image, x, y, scale, ang, alpha) {
ctx.globalAlpha = alpha;
xdx = Math.cos(ang) * scale;
xdy = Math.sin(ang) * scale;
ctx.setTransform(xdx, xdy, -xdy, xdx, x, y);
ctx.drawImage(image, -image.width/2,-image.height/2);
},
hex2RGBA : function(hex){ // Not CSS colour as can have extra 2 or 1 chars for alpha
// #FFFF & #FFFFFFFF last F and FF are the alpha range 0-F & 00-FF
if(typeof hex === "string"){
var str = "rgba(";
if(hex.length === 4 || hex.length === 5){
str += (parseInt(hex.substr(1,1),16) * 16) + ",";
str += (parseInt(hex.substr(2,1),16) * 16) + ",";
str += (parseInt(hex.substr(3,1),16) * 16) + ",";
if(hex.length === 5){
str += (parseInt(hex.substr(4,1),16) / 16);
}else{
str += "1";
}
return str + ")";
}
if(hex.length === 7 || hex.length === 8){
str += parseInt(hex.substr(1,2),16) + ",";
str += parseInt(hex.substr(3,2),16) + ",";
str += parseInt(hex.substr(5,2),16) + ",";
if(hex.length === 5){
str += (parseInt(hex.substr(7,2),16) / 255).toFixed(3);
}else{
str += "1";
}
return str + ")";
}
return "rgba(0,0,0,0)";
}
},
createGradient : function(ctx, type, x, y, xx, yy, colours){ // Colours MUST be array of hex colours NOT CSS colours
// See this.hex2RGBA for details of format
var i,g,c;
var len = colours.length;
if(type.toLowerCase() === "linear"){
g = ctx.createLinearGradient(x,y,xx,yy);
}else{
g = ctx.createRadialGradient(x,y,xx,x,y,yy);
}
for(i = 0; i < len; i++){
c = colours[i];
if(typeof c === "string"){
if(c[0] === "#"){
c = this.hex2RGBA(c);
}
g.addColorStop(Math.min(1,i / (len -1)),c); // need to clamp top to 1 due to floating point errors causes addColorStop to throw rangeError when number over 1
}
}
return g;
},
};
return tools;
})();
// CODE FROM HERE DOWN IS SUPPORT CODE AN HAS LITTLE TO DO WITH THE ANSWER
//==================================================================================================
// The following code is support code that provides me with a standard interface to various forums.
// It provides a mouse interface, a full screen canvas, and some global often used variable
// like canvas, ctx, mouse, w, h (width and height), globalTime
// This code is not intended to be part of the answer unless specified and has been formated to reduce
// display size. It should not be used as an example of how to write a canvas interface.
// By Blindman67
if(typeof onResize === "undefined"){
window["onResize"] = undefined; // create without the JS parser knowing it exists.
// this allows for it to be declared in an outside
// modal.
}
const RESIZE_DEBOUNCE_TIME = 100;
var w, h, cw, ch, canvas, ctx, mouse, createCanvas, resizeCanvas, setGlobals, globalTime = 0, resizeCount = 0;
createCanvas = function () {
var c,
cs;
cs = (c = document.createElement("canvas")).style;
cs.position = "absolute";
cs.top = cs.left = "0px";
cs.zIndex = 1000;
document.body.appendChild(c);
return c;
}
resizeCanvas = function () {
if (canvas === undefined) {
canvas = createCanvas();
}
canvas.width = window.innerWidth-2;
canvas.height = window.innerHeight-2;
ctx = canvas.getContext("2d");
if (typeof setGlobals === "function") {
setGlobals();
}
if (typeof onResize === "function") {
resizeCount += 1;
setTimeout(debounceResize, RESIZE_DEBOUNCE_TIME);
}
}
function debounceResize() {
resizeCount -= 1;
if (resizeCount <= 0) {
onResize();
}
}
setGlobals = function () {
cw = (w = canvas.width) / 2;
ch = (h = canvas.height) / 2;
mouse.updateBounds();
}
mouse = (function () {
function preventDefault(e) {
e.preventDefault();
}
var mouse = {
x : 0,
y : 0,
w : 0,
alt : false,
shift : false,
ctrl : false,
buttonRaw : 0,
over : false,
bm : [1, 2, 4, 6, 5, 3],
active : false,
bounds : null,
crashRecover : null,
mouseEvents : "mousemove,mousedown,mouseup,mouseout,mouseover,mousewheel,DOMMouseScroll".split(",")
};
var m = mouse;
function mouseMove(e) {
var t = e.type;
m.x = e.clientX - m.bounds.left;
m.y = e.clientY - m.bounds.top;
m.alt = e.altKey;
m.shift = e.shiftKey;
m.ctrl = e.ctrlKey;
if (t === "mousedown") {
m.buttonRaw |= m.bm[e.which - 1];
} else if (t === "mouseup") {
m.buttonRaw &= m.bm[e.which + 2];
} else if (t === "mouseout") {
m.buttonRaw = 0;
m.over = false;
} else if (t === "mouseover") {
m.over = true;
} else if (t === "mousewheel") {
m.w = e.wheelDelta;
} else if (t === "DOMMouseScroll") {
m.w = -e.detail;
}
if (m.callbacks) {
m.callbacks.forEach(c => c(e));
}
if ((m.buttonRaw & 2) && m.crashRecover !== null) {
if (typeof m.crashRecover === "function") {
setTimeout(m.crashRecover, 0);
}
}
e.preventDefault();
}
m.updateBounds = function () {
if (m.active) {
m.bounds = m.element.getBoundingClientRect();
}
}
m.addCallback = function (callback) {
if (typeof callback === "function") {
if (m.callbacks === undefined) {
m.callbacks = [callback];
} else {
m.callbacks.push(callback);
}
} else {
throw new TypeError("mouse.addCallback argument must be a function");
}
}
m.start = function (element, blockContextMenu) {
if (m.element !== undefined) {
m.removeMouse();
}
m.element = element === undefined ? document : element;
m.blockContextMenu = blockContextMenu === undefined ? false : blockContextMenu;
m.mouseEvents.forEach(n => {
m.element.addEventListener(n, mouseMove);
});
if (m.blockContextMenu === true) {
m.element.addEventListener("contextmenu", preventDefault, false);
}
m.active = true;
m.updateBounds();
}
m.remove = function () {
if (m.element !== undefined) {
m.mouseEvents.forEach(n => {
m.element.removeEventListener(n, mouseMove);
});
if (m.contextMenuBlocked === true) {
m.element.removeEventListener("contextmenu", preventDefault);
}
m.element = m.callbacks = m.contextMenuBlocked = undefined;
m.active = false;
}
}
return mouse;
})();
// Clean up. Used where the IDE is on the same page.
var done = function () {
window.removeEventListener("resize", resizeCanvas)
mouse.remove();
document.body.removeChild(canvas);
canvas = ctx = mouse = undefined;
}
resizeCanvas();
mouse.start(canvas, true);
mouse.crashRecover = done;
window.addEventListener("resize", resizeCanvas);
function update(timer) { // Main update loop
globalTime = timer;
display(); // call demo code
requestAnimationFrame(update);
}
requestAnimationFrame(update);
/** SimpleFullCanvasMouse.js end **/

You can add a shadow for a glowing effect
fxCtx.shadowBlur = 10;
fxCtx.shadowColor = '#FD0100';
but i think thats all, bacause your laser is so small that a real gradient would not make sense.
Use some nice colors like #FEF1BA insted of white for the red laser and thats it

Where should I place this condition?

For the last step of this project, I want the growing circle to stop when it collides with another circle. The isOnCircle function already checks for this successfully when creating a new circle. However, when adding the condition !isOnCircle to my grow() function (line 61) it prevents any new circles from being added.
function grow() {
var a = circles[circles.length - 1];
if (!isOnCircle(a)){
a.radius += 1;
}}
Perhaps the circle is being created first, then in the check for collision, it's colliding with itself. Where else could I put the !isOnCircle check so that it gets checked at every radius increase and stops the grow function then?
check this
//set up canvas
var canvas = document.getElementById("canvas");
var ctx = canvas.getContext("2d");
var circles = [];
//create circle
function create(location) {
circles.push({
x: location.x,
y: location.y,
radius: 10,
color: '#' + Math.floor(Math.random() * 16777215).toString(16)
});
}
//figure out mouse position
var rect = document.getElementById("canvas").getBoundingClientRect();
// Get canvas offset on page
var offset = {
x: rect.left,
y: rect.top
};
function isOnCanvas(a) {
if ((a.x >= 0 && a.x <= rect.width) && (a.y >= 0 && a.y <= rect.height)) {
return true;
}
return false;
}
function isOnCircle(a) {
var i = 0,
l = circles.length,
x, y, d, c;
for (; i < l; ++i) {
c = circles[i];
x = a.x - c.x;
y = a.y - c.y;
d = (a.radius || 10) + c.radius;
if (x * x + y * y <= d * d) {
return true;
}
}
return false;
}
// draw all circles
function draw() {
ctx.clearRect(0, 0, canvas.width, canvas.height);
for (var i = 0; i < circles.length; i++) {
var p = circles[i];
ctx.beginPath();
ctx.arc(p.x, p.y, p.radius, 0, 2 * Math.PI);
ctx.fillStyle = p.color;
ctx.fill();
}
}
//make last drawn circle 1px bigger
function grow() {
var a = circles[circles.length - 1];
a.radius += 1;
}
//find percentage of canvas filled in
var totalSpace = canvas.width * canvas.height;
var totalFilled = function () {
total = 0;
for (var i = 0; i < circles.length; i++) {
var p = circles[i];
total += Math.PI * Math.pow(p.radius, 2);
}
return total;
console.log(total);
}
function findPercentage() {
return (totalFilled() / totalSpace) * 100;
}
function updateInfo() {
percentage = findPercentage();
document.getElementById("percentage").innerHTML = "You've filled in " + percentage.toFixed(1) + "%";
}
//do all the stuff
var animate = function () {
grow();
draw();
updateInfo();
}
//put this outside function so we can stop it later
var growLoop;
window.onmousedown = function (e) {
// get event location on page offset by canvas location
var location = {
x: e.pageX - offset.x,
y: e.pageY - offset.y
};
if (isOnCanvas(location) && !isOnCircle(location)) {
create(location);
draw();
updateInfo();
growLoop = setInterval(animate, 100);
}
};
window.onmouseup = function () {
clearInterval(growLoop);
}
window.onmouseout = function () {
clearInterval(growLoop);
}

it's colliding with itself.
Probably. You definitely should avoid that in the collision detection:
function isOnCircle(a) {
var l = circles.length,
x, y, d, c;
for (var i = 0; i < l; ++i) {
c = circles[i];
if (a == c) // add these
continue; // two lines!
x = a.x - c.x;
y = a.y - c.y;
d = (a.radius || 10) + c.radius;
if (x * x + y * y <= d * d) {
return true;
}
}
return false;
}

It is colliding with itself. Since you know the current circle will always be the last one in circles you can modify isOnCircle like this:
l = circles.length - 1,
so that it won't check against the current circle.
http://jsfiddle.net/SeAGU/91/