examples/webgl_buffergeometry_lines_indexed.html

<!DOCTYPE html>
<html lang="en">
	<head>
		<title>three.js webgl - buffergeometry - lines - indexed</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 {
				color: #cccccc;
				font-family:Monospace;
				font-size:13px;
				text-align:center;

				background-color: #000000;
				margin: 0px;
				overflow: hidden;
			}

			#info {
				position: absolute;
				top: 0px; width: 100%;
				padding: 5px;
			}

			a {
				color: #0080ff;
			}

		</style>
	</head>
	<body>

		<div id="container"></div>
		<div id="info"><a href="http://threejs.org" target="_blank">three.js</a> webgl - buffergeometry - lines - indexed</div>

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

		<script src="js/Detector.js"></script>
		<script src="js/libs/stats.min.js"></script>

		<script>

			if ( ! Detector.webgl ) Detector.addGetWebGLMessage();

			var container, stats;

			var camera, scene, renderer;

			var mesh, parent_node;

			init();
			animate();

			function init() {

				container = document.getElementById( 'container' );

				camera = new THREE.PerspectiveCamera( 27, window.innerWidth / window.innerHeight, 1, 10000 );
				camera.position.z = 9000;

				scene = new THREE.Scene();

				var geometry = new THREE.BufferGeometry();
				var material = new THREE.LineBasicMaterial({ vertexColors: THREE.VertexColors });

				var positions = [];
				var next_positions_index = 0;
				var colors = [];
				var indices_array = [];

				//

				var iteration_count = 4;
				var rangle = 60 * Math.PI / 180.0;

				function add_vertex(v) {

					if (next_positions_index == 0xffff) throw new Error("Too many points");

					positions.push(v.x, v.y, v.z);
					colors.push(Math.random()*0.5+0.5, Math.random()*0.5+0.5, 1);
					return next_positions_index++;
				}

				// simple Koch curve
				function snowflake_iteration(p0, p4, depth) {

					if (--depth < 0) {

						var i = next_positions_index-1; // p0 already there
						add_vertex(p4);
						indices_array.push(i, i+1);
						return;
					}

					var v = p4.clone().sub(p0);
					var v_tier = v.clone().multiplyScalar(1.0/3.0);
					var p1 = p0.clone().add(v_tier);

					var angle = Math.atan2(v.y, v.x) + rangle;
					var length = v_tier.length();
					var p2 = p1.clone();
					p2.x += Math.cos(angle) * length;
					p2.y += Math.sin(angle) * length;

					var p3 = p0.clone().add(v_tier).add(v_tier);

					snowflake_iteration(p0, p1, depth);
					snowflake_iteration(p1, p2, depth);
					snowflake_iteration(p2, p3, depth);
					snowflake_iteration(p3, p4, depth);
				}

				function snowflake(points, loop, x_offset) {

					for (var iteration = 0; iteration != iteration_count; ++iteration) {

						add_vertex(points[0]);
						for (var p_index=0, p_count=points.length-1; p_index != p_count; ++p_index) {
							snowflake_iteration(points[p_index], points[p_index+1], iteration);
						}

						if (loop) snowflake_iteration(points[points.length-1], points[0], iteration);

						// translate input curve for next iteration
						for (var p_index=0, p_count=points.length; p_index != p_count; ++p_index) {
							points[p_index].x += x_offset;
						}

					}
				}

				var y = 0;
				snowflake
				(
					[
						new THREE.Vector3(0, y+0, 0),
						new THREE.Vector3(500, y+0, 0)
					],
					false, 600
				);

				y += 600;
				snowflake
				(
					[
						new THREE.Vector3(0, y+0, 0),
						new THREE.Vector3(250, y+400, 0),
						new THREE.Vector3(500, y+0, 0)
					],
					true, 600
				);

				y += 600;
				snowflake
				(
					[
						new THREE.Vector3(0, y+0, 0),
						new THREE.Vector3(500, y, 0),
						new THREE.Vector3(500, y+500, 0),
						new THREE.Vector3(0, y+500, 0)
					],
					true, 600
				);

				y += 1000;
				snowflake
				(
					[
						new THREE.Vector3(250, y+0, 0),
						new THREE.Vector3(500, y+0, 0),
						new THREE.Vector3(250, y+0, 0),
						new THREE.Vector3(250, y+250, 0),
						new THREE.Vector3(250, y+0, 0),
						new THREE.Vector3(0, y, 0),
						new THREE.Vector3(250, y+0, 0),
						new THREE.Vector3(250, y-250, 0),
						new THREE.Vector3(250, y+0, 0)
					],
					false, 600
				);
				// --------------------------------

				geometry.setIndex( new THREE.BufferAttribute( new Uint16Array( indices_array ), 1 ) );
				geometry.addAttribute( 'position', new THREE.BufferAttribute( new Float32Array( positions ), 3 ) );
				geometry.addAttribute( 'color', new THREE.BufferAttribute( new Float32Array( colors ), 3 ) );
				geometry.computeBoundingSphere();

				mesh = new THREE.LineSegments( geometry, material );
				mesh.position.x -= 1200;
				mesh.position.y -= 1200;

				parent_node = new THREE.Object3D();
				parent_node.add(mesh);

				scene.add( parent_node );

				renderer = new THREE.WebGLRenderer( { antialias: false } );
				renderer.setPixelRatio( window.devicePixelRatio );
				renderer.setSize( window.innerWidth, window.innerHeight );

				renderer.gammaInput = true;
				renderer.gammaOutput = true;

				container.appendChild( renderer.domElement );

				//

				stats = new Stats();
				container.appendChild( stats.dom );

				//

				window.addEventListener( 'resize', onWindowResize, false );

			}

			function onWindowResize() {

				camera.aspect = window.innerWidth / window.innerHeight;
				camera.updateProjectionMatrix();

				renderer.setSize( window.innerWidth, window.innerHeight );

			}

			//

			function animate() {

				requestAnimationFrame( animate );

				render();
				stats.update();

			}

			function render() {

				var time = Date.now() * 0.001;

				//mesh.rotation.x = time * 0.25;
				//mesh.rotation.y = time * 0.5;
				parent_node.rotation.z = time * 0.5;

				renderer.render( scene, camera );

			}

		</script>

	</body>
</html>