examples/canvas_particles_shapes.html

<!doctype html>
<html lang="en">
	<head>
		<title>three.js canvas - particles with shapes</title>
		<meta charset="utf-8">
		<meta name="viewport" content="width=device-width, user-scalable=no, minimum-scale=1.0, maximum-scale=1.0">
		<style>
			body {
				font-family: Monospace;
				background-color: #f0f0f0;
				margin: 0px;
				overflow: hidden;
			}
		</style>
	</head>
	<body>


		<script src="../build/Three.js"></script>

		<script src="js/RequestAnimationFrame.js"></script>
		<script src="js/Stats.js"></script>
		<script src="js/Tween.js"></script>
		<script src="js/Sparks.js"></script>

		<!-- load the font file from canvas-text -->

		<script src="fonts/helvetiker_regular.typeface.js"></script>


		<script>

			var container, stats;

			var camera, scene, renderer;

			var text, plane;

			var targetRotation = 0;
			var targetRotationOnMouseDown = 0;

			var mouseX = 0;
			var mouseXOnMouseDown = 0;

			var windowHalfX = window.innerWidth / 2;
			var windowHalfY = window.innerHeight / 2;

			var heartShape, particleCloud, sparksEmitter, emitterPos;
			var _rotation = 0;
			var timeOnShapePath = 0;

			init();
			animate();

			function init() {

				container = document.createElement( 'div' );
				document.body.appendChild( container );

				var info = document.createElement( 'div' );
				info.style.position = 'absolute';
				info.style.top = '10px';
				info.style.width = '100%';
				info.style.textAlign = 'center';
				info.innerHTML = 'Three.js with Love. Simple Particle Systems with Shapes by <a href="http://www.lab4games.net/zz85/blog">zz85</a><br>Move your mouse.';
				container.appendChild( info );

				camera = new THREE.PerspectiveCamera( 50, window.innerWidth / window.innerHeight, 1, 1000 );
				camera.position.y = 150;
				camera.position.z = 700;

				scene = new THREE.Scene();

				// Get text from hash

				var string = "THREE.JS";
				var hash = document.location.hash.substr( 1 );

				if ( hash.length !== 0 ) {

					string = hash;

				}

				var text3d = new THREE.TextGeometry( string, {

					size: 80,
					height: 20,
					curveSegments: 2,
					font: "helvetiker"

				});

				text3d.computeBoundingBox();
				var centerOffset = -0.5 * ( text3d.boundingBox.x[ 1 ] - text3d.boundingBox.x[ 0 ] );

				var textMaterial = new THREE.MeshBasicMaterial( { color: Math.random() * 0xffffff, overdraw: true } );

				text = new THREE.Mesh( text3d, textMaterial );

				// Potentially, we can extract the vertices or faces of the text to generate particles too.
				// Geo > Vertices > Position

				text.doubleSided = false;

				text.position.x = centerOffset;
				text.position.y = 100;
				text.position.z = 0;

				text.rotation.x = 0;
				text.rotation.y = Math.PI * 2;
				text.overdraw = true;

				parent = new THREE.Object3D();
				parent.add( text );


				particleCloud = new THREE.Object3D(); // Just a group
				particleCloud.y = 800;
				parent.add( particleCloud );

				scene.add( parent );


				// Create Particle Systems

				// Heart

				var x = 0, y = 0;

				heartShape = new THREE.Shape();

				heartShape.moveTo( x + 25, y + 25 );
				heartShape.bezierCurveTo( x + 25, y + 25, x + 20, y, x, y );
				heartShape.bezierCurveTo( x - 30, y, x - 30, y + 35,x - 30,y + 35 );
				heartShape.bezierCurveTo( x - 30, y + 55, x - 10, y + 77, x + 25, y + 95 );
				heartShape.bezierCurveTo( x + 60, y + 77, x + 80, y + 55, x + 80, y + 35 );
				heartShape.bezierCurveTo( x + 80, y + 35, x + 80, y, x + 50, y );
				heartShape.bezierCurveTo( x + 35, y, x + 25, y + 25, x + 25, y + 25 );

				var circleLines = function ( context ) {
					context.lineWidth = 0.05;
					context.beginPath();
					context.arc( 0, 0, 1, 0, Math.PI*2, true );
					context.closePath();
					context.stroke();

					context.globalAlpha = 0.2;
					context.fill();
				}

				var hue = 0;

				var hearts = function ( context ) {
					context.globalAlpha = 0.5;
					var x = 0, y = 0;
					context.scale(0.1, -0.1); // Scale so canvas render can redraw within bounds
					context.beginPath();
					 // From http://blog.burlock.org/html5/130-paths
					context.bezierCurveTo( x + 2.5, y + 2.5, x + 2.0, y, x, y );
					context.bezierCurveTo( x - 3.0, y, x - 3.0, y + 3.5,x - 3.0,y + 3.5 );
					context.bezierCurveTo( x - 3.0, y + 5.5, x - 1.0, y + 7.7, x + 2.5, y + 9.5 );
					context.bezierCurveTo( x + 6.0, y + 7.7, x + 8.0, y + 5.5, x + 8.0, y + 3.5 );
					context.bezierCurveTo( x + 8.0, y + 3.5, x + 8.0, y, x + 5.0, y );
					context.bezierCurveTo( x + 3.5, y, x + 2.5, y + 2.5, x + 2.5, y + 2.5 );
					context.closePath();
					context.fill();
					context.lineWidth = 0.5; //0.05
					context.stroke();
				}

				var setTargetParticle = function() {

					//hearts circleLines
					var material = new THREE.ParticleCanvasMaterial( {  program: hearts, blending:THREE.AdditiveBlending } );

					material.color.setHSV(hue, 0.5, 1); 
					hue += 0.001;
					if (hue>1) hue-=1;

					particle = new THREE.Particle( material );

					particle.scale.x = particle.scale.y = Math.random() * 20 +20;
					particleCloud.add( particle );	

					return particle;
				};

				var onParticleCreated = function(p) {
					var position = p.position;
					p.target.position = position;	
				};

				var onParticleDead = function(particle) {
					particle.target.visible = false;
					particleCloud.remove(particle.target); 
				};

				sparksEmitter = new SPARKS.Emitter(new SPARKS.SteadyCounter(160));

				emitterpos = new THREE.Vector3();

				sparksEmitter.addInitializer(new SPARKS.Position( new SPARKS.PointZone( emitterpos ) ) );
				sparksEmitter.addInitializer(new SPARKS.Lifetime(0,2));
				sparksEmitter.addInitializer(new SPARKS.Target(null, setTargetParticle));

				sparksEmitter.addInitializer(new SPARKS.Velocity(new SPARKS.PointZone(new THREE.Vector3(0,-50,10))));

				// TOTRY Set velocity to move away from centroid

				sparksEmitter.addAction(new SPARKS.Age());
				//sparksEmitter.addAction(new SPARKS.Accelerate(0.2));
				sparksEmitter.addAction(new SPARKS.Move()); 
				sparksEmitter.addAction(new SPARKS.RandomDrift(50,50,2000));

				sparksEmitter.addCallback("created", onParticleCreated);
				sparksEmitter.addCallback("dead", onParticleDead);
				sparksEmitter.start();

				// End Particles


				renderer = new THREE.CanvasRenderer();
				renderer.setSize( window.innerWidth, window.innerHeight );

				container.appendChild( renderer.domElement );

				stats = new Stats();
				stats.domElement.style.position = 'absolute';
				stats.domElement.style.top = '0px';
				container.appendChild( stats.domElement );

				document.addEventListener( 'mousedown', onDocumentMouseDown, false );
				document.addEventListener( 'touchstart', onDocumentTouchStart, false );
				document.addEventListener( 'touchmove', onDocumentTouchMove, false );

			}

			//

			document.addEventListener( 'mousemove', onDocumentMouseMove, false );

			function onDocumentMouseDown( event ) {

				event.preventDefault();

				mouseXOnMouseDown = event.clientX - windowHalfX;
				targetRotationOnMouseDown = targetRotation;

				if (sparksEmitter.isRunning()) {
					sparksEmitter.stop();
				} else {
					sparksEmitter.start();
				}

			}

			function onDocumentMouseMove( event ) {

				mouseX = event.clientX - windowHalfX;

				targetRotation = targetRotationOnMouseDown + ( mouseX - mouseXOnMouseDown ) * 0.02;

			}

			function onDocumentTouchStart( event ) {

				if ( event.touches.length == 1 ) {

					event.preventDefault();

					mouseXOnMouseDown = event.touches[ 0 ].pageX - windowHalfX;
					targetRotationOnMouseDown = targetRotation;

				}

			}

			function onDocumentTouchMove( event ) {

				if ( event.touches.length == 1 ) {

					event.preventDefault();

					mouseX = event.touches[ 0 ].pageX - windowHalfX;
					targetRotation = targetRotationOnMouseDown + ( mouseX - mouseXOnMouseDown ) * 0.05;

				}

			}

			//

			function animate() {

				requestAnimationFrame( animate );

				render();
				stats.update();

			}

			function render() {

				timeOnShapePath += 0.0337;

				if (timeOnShapePath > 1) timeOnShapePath -= 1;

				// TODO Create a PointOnShape Action/Zone in the particle engine
				var pointOnShape = heartShape.getPointAt( timeOnShapePath );

				emitterpos.x = pointOnShape.x * 5 - 100;
				emitterpos.y = -pointOnShape.y * 5 + 400;

				// Pretty cool effect if you enable this
				//particleCloud.rotation.y += 0.05;

				parent.rotation.y += ( targetRotation - parent.rotation.y ) * 0.05;
				renderer.render( scene, camera );

			}

		</script>

	</body>
</html>