cssAudio - Activefile-genericCSS - ActiveGeneric - ActiveHTML - ActiveImage - ActiveJS - ActiveSVG - ActiveText - Activefile-genericVideo - ActiveLovehtmlicon-new-collectionicon-personicon-teamlog-outoctocatpop-outspinnerstartv

Pen Settings

CSS Base

Vendor Prefixing

Add External Stylesheets/Pens

Any URL's added here will be added as <link>s in order, and before the CSS in the editor. If you link to another Pen, it will include the CSS from that Pen. If the preprocessor matches, it will attempt to combine them before processing.

Quick-add: + add another resource

Add External Scripts/Pens

Any URL's added here will be added as <script>s in order, and run before the JavaScript in the editor. You can use the URL of any other Pen and it will include the JavaScript from that Pen.

Quick-add: + add another resource

Code Indentation

     

Save Automatically?

If active, Pens will autosave every 30 seconds after being saved once.

Auto-Updating Preview

If enabled, the preview panel updates automatically as you code. If disabled, use the "Run" button to update.

            
              canvas {
	position: absolute;
	top: 0;
	left: 0;
	background-color: #111;
}
            
          
!
            
              var gl = c.getContext( 'webgl', { preserveDrawingBuffer: true } )
	,	w = c.width = window.innerWidth
	,	h = c.height = window.innerHeight

	,	webgl = {}
	,	opts = {
		projectileAlpha: .8,
		projectileLineWidth: 1.3,
		fireworkAngleSpan: .5,
		baseFireworkVel: 3,
		addedFireworkVel: 3,
		gravity: .03,
		lowVelBoundary: -.2,
		xFriction: .995,
		baseShardVel: 1,
		addedShardVel: .2,
		fireworks: 1000,
		baseShardsParFirework: 10,
		addedShardsParFirework: 10,
		shardFireworkVelMultiplier: .3,
		initHueMultiplier: 1/360,
		runHueAdder: .1/360
	}

webgl.vertexShaderSource = `
uniform int u_mode;
uniform vec2 u_res;
attribute vec4 a_data;
varying vec4 v_color;

vec3 h2rgb( float h ){
	return clamp( abs( mod( h * 6. + vec3( 0, 4, 2 ), 6. ) - 3. ) -1., 0., 1. );
}
void clear(){
	gl_Position = vec4( a_data.xy, 0, 1 );
	v_color = vec4( 0, 0, 0, a_data.w );
}
void draw(){
	gl_Position = vec4( vec2( 1, -1 ) * ( ( a_data.xy / u_res ) * 2. - 1. ), 0, 1 );
	v_color = vec4( h2rgb( a_data.z ), a_data.w );
}
void main(){
	if( u_mode == 0 )
		draw();
	else
		clear();
}
`;
webgl.fragmentShaderSource = `
precision mediump float;
varying vec4 v_color;

void main(){
	gl_FragColor = v_color;
}
`;

webgl.vertexShader = gl.createShader( gl.VERTEX_SHADER );
gl.shaderSource( webgl.vertexShader, webgl.vertexShaderSource );
gl.compileShader( webgl.vertexShader );

webgl.fragmentShader = gl.createShader( gl.FRAGMENT_SHADER );
gl.shaderSource( webgl.fragmentShader, webgl.fragmentShaderSource );
gl.compileShader( webgl.fragmentShader );

webgl.shaderProgram = gl.createProgram();
gl.attachShader( webgl.shaderProgram, webgl.vertexShader );
gl.attachShader( webgl.shaderProgram, webgl.fragmentShader );

gl.linkProgram( webgl.shaderProgram );
gl.useProgram( webgl.shaderProgram );

webgl.dataAttribLoc = gl.getAttribLocation( webgl.shaderProgram, 'a_data' );
webgl.dataBuffer = gl.createBuffer();

gl.enableVertexAttribArray( webgl.dataAttribLoc );
gl.bindBuffer( gl.ARRAY_BUFFER, webgl.dataBuffer );
gl.vertexAttribPointer( webgl.dataAttribLoc, 4, gl.FLOAT, false, 0, 0 );

webgl.resUniformLoc = gl.getUniformLocation( webgl.shaderProgram, 'u_res' );
webgl.modeUniformLoc = gl.getUniformLocation( webgl.shaderProgram, 'u_mode' );

gl.viewport( 0, 0, w, h );
gl.uniform2f( webgl.resUniformLoc, w, h );

gl.blendFunc( gl.SRC_ALPHA, gl.ONE_MINUS_SRC_ALPHA );
gl.enable( gl.BLEND );

gl.lineWidth( opts.projectileLineWidth );

webgl.data = [];

webgl.clear = function(){
	
	gl.uniform1i( webgl.modeUniformLoc, 1 );
	var a = .1;
	webgl.data = [
		-1, -1, 0, a,
		 1, -1, 0, a,
		-1,  1, 0, a,
		-1,  1, 0, a,
		 1, -1, 0, a,
		 1,  1, 0, a
	];
	webgl.draw( gl.TRIANGLES );
	gl.uniform1i( webgl.modeUniformLoc, 0 );
	webgl.data.length = 0;
}
webgl.draw = function( glType ){
	
	gl.bufferData( gl.ARRAY_BUFFER, new Float32Array( webgl.data ), gl.STATIC_DRAW );
	gl.drawArrays( glType, 0, webgl.data.length / 4 );
}

var	fireworks = []
	,	tick = 0
	,	sins = []
	,	coss = []
	,	maxShardsParFirework = opts.baseShardsParFirework + opts.addedShardsParFirework
	,	tau = 6.283185307179586476925286766559;

for( var i = 0; i < maxShardsParFirework; ++i ){
	sins[ i ] = Math.sin( tau * i / maxShardsParFirework );
	coss[ i ] = Math.cos( tau * i / maxShardsParFirework );
}

function Firework(){
	this.reset();
	this.shards = [];
	for( var i = 0; i < maxShardsParFirework; ++i )
		this.shards.push( new Shard( this ) );
}
Firework.prototype.reset = function(){
	
	var angle = -Math.PI / 2 + ( Math.random() - .5 )* opts.fireworkAngleSpan
		,	vel = opts.baseFireworkVel + opts.addedFireworkVel * Math.random();
	
	this.mode = 0;
	this.vx = vel * Math.cos( angle );
	this.vy = vel * Math.sin( angle );
	
	this.x = Math.random() * w;
	this.y = h;
	
	this.hue = tick * opts.initHueMultiplier;
	
}
Firework.prototype.step = function(){
	
	if( this.mode === 0 ){
		
		var ph = this.hue
			,	px = this.x
			,	py = this.y;
		
		this.hue += opts.runHueAdder;
	
		this.x += this.vx *= opts.xFriction;
		this.y += this.vy += opts.gravity;
		
		webgl.data.push(
			px, py, ph, opts.projectileAlpha * .2,
			this.x, this.y, this.hue, opts.projectileAlpha * .2 );
		
		if( this.vy >= opts.lowVelBoundary ){
			this.mode = 1;

			this.shardAmount = opts.baseShardsParFirework + opts.addedShardsParFirework * Math.random() | 0;

			var baseAngle = Math.random() * tau
				,	x = Math.cos( baseAngle )
				,	y = Math.sin( baseAngle )
				,	sin = sins[ this.shardAmount ]
				,	cos = coss[ this.shardAmount ];

			for( var i = 0; i < this.shardAmount; ++i ){

				var vel = opts.baseShardVel + opts.addedShardVel * Math.random();
				this.shards[ i ].reset( x * vel, y * vel )
				var X = x;
				x = x * cos - y * sin;
				y = y * cos + X * sin;
			}
		}

	} else if( this.mode === 1 ) {
		
		this.ph = this.hue
		this.hue += opts.runHueAdder;
		
		var allDead = true;
		for( var i = 0; i < this.shardAmount; ++i ){
			var shard = this.shards[ i ];
			if( !shard.dead ){
				shard.step();
				allDead = false;
			}
		}
		
		if( allDead )
			this.reset();
	}
	
}
function Shard( parent ){
	this.parent = parent;
}
Shard.prototype.reset = function( vx, vy ){
	this.x = this.parent.x;
	this.y = this.parent.y;
	this.vx = this.parent.vx * opts.shardFireworkVelMultiplier + vx;
	this.vy = this.parent.vy * opts.shardFireworkVelMultiplier + vy;
	this.starty = this.y;
	this.dead = false;
	this.tick = 1;
}
Shard.prototype.step = function(){
	
	this.tick += .05;
	
	var px = this.x
		,	py = this.y;
	
	this.x += this.vx *= opts.xFriction;
	this.y += this.vy += opts.gravity;
	
	var proportion = 1 - ( this.y - this.starty ) / ( h - this.starty );
	
	webgl.data.push(
		px, py, this.parent.ph, opts.projectileAlpha / this.tick,
		this.x, this.y, this.parent.hue, opts.projectileAlpha / this.tick );
	
	if( this.y > h )
		this.dead = true;
}

function anim(){
	
	window.requestAnimationFrame( anim )
	
	webgl.clear();
	
	++tick;
	
	if( fireworks.length < opts.fireworks )
		fireworks.push( new Firework );
	
	fireworks.map( function( firework ){ firework.step(); } );
	
	webgl.draw( gl.LINES );
}
anim();

window.addEventListener( 'resize', function(){
	
	w = c.width = window.innerWidth;
	h = c.height = window.innerHeight;
	
	gl.viewport( 0, 0, w, h );
	gl.uniform2f( webgl.resUniformLoc, w, h );
})
window.addEventListener( 'click', function( e ){
	var firework = new Firework();
	firework.x = e.clientX;
	firework.y = e.clientY;
	firework.vx = 0;
	firework.vy = 0;
	fireworks.push( firework );
});
            
          
!
999px
Loading ..................

Console