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<canvas id='scene'></canvas>
body,html {
margin:0;
padding:0;
}
canvas {
div { background-color: rgba(0,0,0,0); }
-webkit-touch-callout:none;
-webkit-user-select:none;
user-select:none;
}
#scene {
background-color: black;
-webkit-touch-callout:none;
-webkit-user-select:none;
user-select:none;
}
//******************************************************
// Yet Another Particle Engine
var cos = Math.cos,
sin = Math.sin,
sqrt = Math.sqrt,
abs = Math.abs,
atan2 = Math.atan2,
log = Math.log,
random = Math.random,
PI = Math.PI,
sqr = function(v){return v*v;},
particles = [],
drawScale = 1,
emitters = [],
forces = [],
collidedMass = 0,
maxParticles = 100,
emissionRate = 1;
//-------------------------------------------------------
// Vectors, and not the kind you put stuff in
function Vector(x, y, z) {
this.x = x || 0;
this.y = y || 0;
this.z = z || 0;
}
Vector.prototype = {
add : function(vector) {
this.x += vector.x;
this.y += vector.y;
this.z += vector.z;
return this;
},
subtract : function(vector) {
this.x -= vector.x;
this.y -= vector.y;
this.z -= vector.z;
return this;
},
multiply : function(another) {
this.x /= another.x;
this.y /= another.y;
this.z /= another.z;
return this;
},
divide : function(another) {
this.x /= another.x;
this.y /= another.y;
this.z /= another.z;
return this;
},
scale : function(factor) {
this.x *= factor;
this.y *= factor;
this.z *= factor;
return this;
},
magnitude : function () {
return sqrt(sqr(this.x + this.y));
},
distance : function (another) {
return abs(sqrt(sqr(this.x - another.x) + sqr(this.y - another.y)));
},
angle : function (angle, magnitude) {
if(angle && magnitude)
return Vector.fromAngle(angle, magnitude);
return atan2(this.y, this.x);
},
clone : function() {
return new Vector(this.x, this.y, this.z);
},
equals : function(another) {
return this.x === another.x
&& this.y === another.y
&& this.z === another.z;
},
random : function(r) {
this.x += (random() * r * 2) - r;
this.y += (random() * r * 2) - r;
return this;
}
};
Vector.fromAngle = function (angle, magnitude) {
return new Vector(
magnitude * cos(angle),
magnitude * sin(angle),
magnitude * sin(angle));
};
//******************************************************
// A thing with mass, position, and velocity - like your mom
function Particle(pt, vc, ac, mass) {
this.pos = pt || new Vector(0, 0);
this.vc = vc || new Vector(0, 0);
this.ac = ac || new Vector(0, 0);
this.mass = mass || 1;
this.alive = true;
}
Particle.prototype.move = function () {
this.vc.add(this.ac);
this.pos.add(this.vc);
};
Particle.prototype.reactToForces = function (fields) {
var totalAccelerationX = 0;
var totalAccelerationY = 0;
for (var i = 0; i < fields.length; i++) {
var field = fields[i];
var vectorX = field.pos.x - this.pos.x;
var vectorY = field.pos.y - this.pos.y;
var distance = this.pos.distance(field.pos);
if(distance < 1) field.grow(this);
if(distance < 100) this.doubleSize = true;
var force = G(this.forceBetween(field, distance));
totalAccelerationX += vectorX * force;
totalAccelerationY += vectorY * force;
}
this.ac = new Vector(totalAccelerationX, totalAccelerationY);
totalAccelerationX = 0;
totalAccelerationY = 0;
for (var i = 0; i < particles.length; i++) {
var field = particles[i];
if(field === this || !field.alive) continue;
var vectorX = field.pos.x - this.pos.x;
var vectorY = field.pos.y - this.pos.y;
var distance = this.pos.distance(field.pos);
if(distance < 1) {
if(this.mass >= field.mass) {
var massRatio = this.mass / field.mass;
if(particles.length <= maxParticles && this.mass>40) {
this.alive = false;
this.nova = true;
collidedMass += this.mass;
} else this.grow(field);
} else this.alive = false;
}
if(this.alive) {
var force = G(this.forceBetween(field, distance));
totalAccelerationX += vectorX * G(force);
totalAccelerationY += vectorY * G(force);
}
}
var travelDist = this.pos.distance(this.lastPos ? this.lastPos : this.pos);
this.velocity = travelDist - (this.lastDistance ? this.lastDistance : travelDist);
this.lastDistance = travelDist;
this.lastPos = this.pos.clone();
this.ac.add(new Vector(totalAccelerationX, totalAccelerationY));
this.lastPos = this.pos.clone();
// if(this.mass > 20) {
// var chance = 1 / (this.mass - 20);
// if(Math.random()>chance) {
// this.supernova = true;
// this.supernovaDur = 10;
// this.alive = false;
// if(particles.length <= maxParticles) collidedMass += this.mass;
// delete this.size;
// }
// }
};
Particle.prototype.grow = function (another) {
this.mass += another.mass;
this.nova = true;
another.alive = false;
delete this.size;
};
Particle.prototype.breakApart = function(minMass, maxParts) {
if(!minMass) minMass = 1;
if(!maxParts) maxParts = 2;
var remainingMass = this.mass;
var num = 0;
while(remainingMass > 0) {
var np = new Particle(this.pos.clone().random(this.mass), new Vector(0,0));
np.mass = 1 + Math.random() * (remainingMass - 1);
if(num>=maxParts-1) np.mass = remainingMass;
np.mass = np.mass < minMass ? minMass : np.mass;
remainingMass -= np.mass;
num++;
}
this.nova = true;
delete this.size;
this.alive = false;
};
Particle.prototype.forceBetween = function(another, distance) {
var distance = distance? distance : this.pos.distance(another.pos);
return (this.mass * another.mass) / sqr(distance);
};
//******************************************************
//This certainly doesn't *sub*mit to particles, that's for sure
function ParticleEmitter(pos, vc, ang) {
// to do config options for emitter - random, static, show emitter, emitter color, etc
this.pos = pos;
this.vc = vc;
this.ang = ang || 0.09;
this.color = "#999";
}
ParticleEmitter.prototype.emit = function() {
var angle = this.vc.angle() +
this.ang - (Math.random() * this.ang * 2);
var magnitude = this.vc.magnitude();
var position = this.pos.clone();
position.add(
new Vector(
~~((Math.random() * 100) - 50) * drawScale,
~~((Math.random() * 100) - 50) * drawScale
));
var velocity = Vector.fromAngle(angle, magnitude);
return new Particle(position,velocity);
};
//******************************************************
// Use it, Luke
// to do collapse functionality into particle
function Force(pos, m) {
this.pos = pos;
this.mass = m || 100;
}
Force.prototype.grow = function (another) {
this.mass += another.mass;
this.burp = true;
another.alive = false;
};
function G(data) {
return 0.00674 * data;
}
//******************************************************
var canvas = document.querySelector('#scene');
var ctx = canvas.getContext('2d');
canvas.width = window.innerWidth;
canvas.height = window.innerHeight;
var canvasWidth = canvas.width;
var canvasHeight = canvas.height;
var renderToCanvas = function (width, height, renderFunction) {
var buffer = document.createElement('canvas');
buffer.width = width;
buffer.height = height;
renderFunction(buffer.getContext('2d'));
return buffer;
};
maxParticles = 500;
emissionRate = 1;
drawScale = 1.3;
minParticleSize = 2;
emitters = [
//br
new ParticleEmitter(
new Vector(
canvasWidth / 2 * drawScale + 400,
canvasHeight / 2 * drawScale
),
Vector.fromAngle(2, 5),
1
),
// // bl
// new ParticleEmitter(
// new Vector(
// canvasWidth / 2 * drawScale - 400,
// canvasHeight / 2 * drawScale + 400
// ),
// Vector.fromAngle(1.5, 1),
// 1
// ),
// tl
new ParticleEmitter(
new Vector(
canvasWidth / 2 * drawScale - 400,
canvasHeight / 2 * drawScale
),
Vector.fromAngle(5, 5),
1
),
// // tr
// new ParticleEmitter(
// new Vector(
// canvasWidth / 2 * drawScale + 400,
// canvasHeight / 2 * drawScale - 400
// ),
// Vector.fromAngle(4.5, 1),
// 1
// )
];
forces = [
new Force(
new Vector((canvasWidth / 2 * drawScale) ,
(canvasHeight / 2 * drawScale)), 1800)
];
function loop() {
clear();
update();
draw();
queue();
}
function clear() {
ctx.clearRect(0, 0, canvas.width, canvas.height);
}
var ctr = 0;
var c = [
'rgba(255,255,255,',
'rgba(0,150,255,',
'rgba(255,255,128,',
'rgba(255,255,255,'
];
function rndc() {
return c[~~(Math.random() * c.length-1)];
}
var c2 = 'rgba(255,64,32,';
function addNewParticles() {
var _emit = function() {
var ret = 0;
for (var i = 0; i < emitters.length; i++) {
for (var j = 0; j < emissionRate; j++) {
var p = emitters[i].emit();
p.color = ( ctr % 10 === 0 )
? ( Math.random() * 5 <= 1 ? c2 : rndc() )
: rndc();
p.mass = ~~(Math.random() * 5);
particles.push(p);
ret += p.mass;
ctr++;
}
}
return ret;
};
if(collidedMass !== 0) {
while(collidedMass !== 0) {
collidedMass -= _emit();
collidedMass = collidedMass<0 ? 0 :collidedMass;
}
}
if (particles.length > maxParticles)
return;
_emit();
}
var CLIPOFFSCREEN = 1,
BUFFEROFFSCREEN = 2,
LOOPSCREEN = 3;
function isPositionAliveAndAdjust(particle,check) {
return true;
var pos = particle.pos;
if(!check) check = BUFFEROFFSCREEN;
if(check === CLIPOFFSCREEN) {
return !(!particle.alive ||
pos.x < 0 ||
(pos.x / drawScale) > boundsX ||
pos.y < 0 ||
(pos.y / drawScale) > boundsY);
} else if(check === BUFFEROFFSCREEN) {
return !(!particle.alive ||
pos.x < -boundsX * drawScale ||
pos.x > 2 * boundsX * drawScale ||
pos.y < -boundsY * drawScale ||
pos.y > 2 * boundsY * drawScale);
} else if(check === LOOPSCREEN) {
if (pos.x < 0) pos.x = boundsX * drawScale;
if ((pos.x / drawScale) > boundsX) pos.x = 0;
if (pos.y < 0) pos.y = boundsY * drawScale;
if ((pos.y / drawScale) > boundsY) pos.y = 0;
return true;
}
}
function plotParticles(boundsX, boundsY) {
var currentParticles = [];
for (var i = 0; i < particles.length; i++) {
var particle = particles[i];
particle.reactToForces(forces);
if(!isPositionAliveAndAdjust(particle))
continue;
particle.move();
currentParticles.push(particle);
}
}
var offscreenCache = {};
function renderParticle(p) {
var position = p.pos;
if(!p.size) p.size = Math.floor(p.mass / 100);
if(!p.opacity) p.opacity = 0.05;
if(p.velocity > 0) {
if(p.opacity<=0.18)
p.opacity += 0.04;
}
if(p.opacity>0.08)
p.opacity -= 0.02;
var actualSize = p.size / drawScale;
actualSize = actualSize < minParticleSize ? minParticleSize : actualSize;
if(p.mass>8) actualSize *= 2;
if(p.nova) {
actualSize *= 4;
p.nova = false;
}
if(p.doubleSize) {
p.doubleSize = false;
actualSize *= 2;
}
// if(p.supernova) {
// actualSize *= 6;
// opacity = 0.15;
// p.supernovaDur = p.supernovaDur - 1;
// if(p.supernovaDur === 0)
// p.supernova = false;
// }
var cacheKey = actualSize + '_' + p.opacity + '_' + p.color;
var cacheValue = offscreenCache[cacheKey];
if(!cacheValue) {
cacheValue = renderToCanvas(actualSize * 32, actualSize * 32, function(ofsContext) {
var opacity = p.opacity;
var fills = [
{size:actualSize/2, opacity:1},
{size:actualSize, opacity:opacity},
{size:actualSize * 2, opacity:opacity / 2},
{size:actualSize * 4, opacity:opacity / 3},
{size:actualSize * 8, opacity:opacity / 5},
{size:actualSize * 16, opacity:opacity / 16}
];
ofsContext.beginPath();
for(var f in fills) {
f = fills[f];
ofsContext.fillStyle = p.color + f.opacity + ')';
ofsContext.arc(
actualSize * 16,
actualSize * 16,
f.size , 0, Math.PI*2, true);
ofsContext.fill();
}
ofsContext.closePath();
});
offscreenCache[cacheKey] = cacheValue;
}
var posX = p.pos.x / drawScale;
var posY = p.pos.y / drawScale;
ctx.drawImage(cacheValue, posX, posY);
}
var fills = [
{size:15,opacity:1 },
{size:25,opacity:0.3},
{size:50,opacity:0.1} ];
function renderScene(ofsContext) {
for (var i = 0; i < forces.length; i++) {
var p = forces[i];
var position = p.pos;
var opacity = 1;
ofsContext.beginPath();
for(var f in fills) {
f = fills[f];
var o = p.burp === true ? 1 : f.opacity;
p.burp = false;
// ofsContext.fillStyle = 'rgba(255,255,255,' + o + ')';
// ofsContext.arc(position.x / drawScale,
// position.y / drawScale,
// f.size / drawScale, 0, Math.PI*2, true);
// ofsContext.fill();
}
ofsContext.closePath();
}
for (var i = 0; i < particles.length; i++) {
var p = particles[i];
renderParticle(p);
}
}
function draw() {
renderScene(ctx);
}
function update() {
addNewParticles();
plotParticles(canvas.width, canvas.height);
}
function queue() {
window.requestAnimationFrame(loop);
}
$('canvas').mousedown(function(e){
});
$('canvas').mouseup(function(e){
});
loop();
Also see: Tab Triggers