Code viewer for World: Camera Logarithmic depth b...
//https://github.com/mrdoob/three.js/blob/master/examples/webgl_camera_logarithmicdepthbuffer.html

AB.loadCSS ( '/uploads/threeport/main.css' );                             


// use JS to make HTML elements too:

	    AB.newDiv ( "container" );                                 


// template is blank 
// define your own Three.js World here 


import * as THREE from  '/api/threemodule/libs/three.module.js';       
	        import Stats from       '/uploads/threeport/stats.module.js';


			// 1 micrometer to 100 billion light years in one scene, with 1 unit = 1 meter?  preposterous!  and yet...
			const NEAR = 1e-6, FAR = 1e27;
			let SCREEN_WIDTH = window.innerWidth;
			let SCREEN_HEIGHT = window.innerHeight;
			let screensplit = .25, screensplit_right = 0;
			const mouse = [ .5, .5 ];
			let zoompos = - 100, minzoomspeed = .015;
			let zoomspeed = minzoomspeed;

			let container, border, stats;
			const objects = {};

			// Generate a number of text labels, from 1µm in size up to 100,000,000 light years
			// Try to use some descriptive real-world examples of objects at each scale

			const labeldata = [
				{ size: .01, scale: 0.0001, label: "microscopic (1µm)" }, // FIXME - triangulating text fails at this size, so we scale instead
				{ size: .01, scale: 0.1, label: "minuscule (1mm)" },
				{ size: .01, scale: 1.0, label: "tiny (1cm)" },
				{ size: 1, scale: 1.0, label: "child-sized (1m)" },
				{ size: 10, scale: 1.0, label: "tree-sized (10m)" },
				{ size: 100, scale: 1.0, label: "building-sized (100m)" },
				{ size: 1000, scale: 1.0, label: "medium (1km)" },
				{ size: 10000, scale: 1.0, label: "city-sized (10km)" },
				{ size: 3400000, scale: 1.0, label: "moon-sized (3,400 Km)" },
				{ size: 12000000, scale: 1.0, label: "planet-sized (12,000 km)" },
				{ size: 1400000000, scale: 1.0, label: "sun-sized (1,400,000 km)" },
				{ size: 7.47e12, scale: 1.0, label: "solar system-sized (50Au)" },
				{ size: 9.4605284e15, scale: 1.0, label: "gargantuan (1 light year)" },
				{ size: 3.08567758e16, scale: 1.0, label: "ludicrous (1 parsec)" },
				{ size: 1e19, scale: 1.0, label: "mind boggling (1000 light years)" }
			];

			init();

			function init() {

				container = document.getElementById( 'container' );

				const loader = new THREE.FontLoader();
				loader.load( 'fonts/helvetiker_regular.typeface.json', function ( font ) {

					const scene = initScene( font );

					// Initialize two copies of the same scene, one with normal z-buffer and one with logarithmic z-buffer
					objects.normal = initView( scene, 'normal', false );
					objects.logzbuf = initView( scene, 'logzbuf', true );

					animate();

				} );

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

				// Resize border allows the user to easily compare effects of logarithmic depth buffer over the whole scene
				border = document.getElementById( 'renderer_border' );
				border.addEventListener( 'pointerdown', onBorderPointerDown );

				window.addEventListener( 'mousemove', onMouseMove );
				window.addEventListener( 'resize', onWindowResize );
				window.addEventListener( 'wheel', onMouseWheel );

			}

			function initView( scene, name, logDepthBuf ) {

				const framecontainer = document.getElementById( 'container_' + name );

				const camera = new THREE.PerspectiveCamera( 50, screensplit * SCREEN_WIDTH / SCREEN_HEIGHT, NEAR, FAR );
				scene.add( camera );

				const renderer = new THREE.WebGLRenderer( { antialias: true, logarithmicDepthBuffer: logDepthBuf } );
				renderer.setPixelRatio( window.devicePixelRatio );
				renderer.setSize( SCREEN_WIDTH / 2, SCREEN_HEIGHT );
				renderer.domElement.style.position = "relative";
				renderer.domElement.id = 'renderer_' + name;
				framecontainer.appendChild( renderer.domElement );

				return { container: framecontainer, renderer: renderer, scene: scene, camera: camera };

			}

			function initScene( font ) {

				const scene = new THREE.Scene();

				scene.add( new THREE.AmbientLight( 0x222222 ) );

				const light = new THREE.DirectionalLight( 0xffffff, 1 );
				light.position.set( 100, 100, 100 );
				scene.add( light );

				const materialargs = {
					color: 0xffffff,
					specular: 0x050505,
					shininess: 50,
					emissive: 0x000000
				};

				const geometry = new THREE.SphereGeometry( 0.5, 24, 12 );

				for ( let i = 0; i < labeldata.length; i ++ ) {

					const scale = labeldata[ i ].scale || 1;

					const labelgeo = new THREE.TextGeometry( labeldata[ i ].label, {
						font: font,
						size: labeldata[ i ].size,
						height: labeldata[ i ].size / 2
					} );

					labelgeo.computeBoundingSphere();

					// center text
					labelgeo.translate( - labelgeo.boundingSphere.radius, 0, 0 );

					materialargs.color = new THREE.Color().setHSL( Math.random(), 0.5, 0.5 );

					const material = new THREE.MeshPhongMaterial( materialargs );

					const group = new THREE.Group();
					group.position.z = - labeldata[ i ].size * scale;
					scene.add( group );

					const textmesh = new THREE.Mesh( labelgeo, material );
					textmesh.scale.set( scale, scale, scale );
					textmesh.position.z = - labeldata[ i ].size * scale;
					textmesh.position.y = labeldata[ i ].size / 4 * scale;
					group.add( textmesh );

					const dotmesh = new THREE.Mesh( geometry, material );
					dotmesh.position.y = - labeldata[ i ].size / 4 * scale;
					dotmesh.scale.multiplyScalar( labeldata[ i ].size * scale );
					group.add( dotmesh );

				}

				return scene;

			}

			function updateRendererSizes() {

				// Recalculate size for both renderers when screen size or split location changes

				SCREEN_WIDTH = window.innerWidth;
				SCREEN_HEIGHT = window.innerHeight;

				screensplit_right = 1 - screensplit;

				objects.normal.renderer.setSize( screensplit * SCREEN_WIDTH, SCREEN_HEIGHT );
				objects.normal.camera.aspect = screensplit * SCREEN_WIDTH / SCREEN_HEIGHT;
				objects.normal.camera.updateProjectionMatrix();
				objects.normal.camera.setViewOffset( SCREEN_WIDTH, SCREEN_HEIGHT, 0, 0, SCREEN_WIDTH * screensplit, SCREEN_HEIGHT );
				objects.normal.container.style.width = ( screensplit * 100 ) + '%';

				objects.logzbuf.renderer.setSize( screensplit_right * SCREEN_WIDTH, SCREEN_HEIGHT );
				objects.logzbuf.camera.aspect = screensplit_right * SCREEN_WIDTH / SCREEN_HEIGHT;
				objects.logzbuf.camera.updateProjectionMatrix();
				objects.logzbuf.camera.setViewOffset( SCREEN_WIDTH, SCREEN_HEIGHT, SCREEN_WIDTH * screensplit, 0, SCREEN_WIDTH * screensplit_right, SCREEN_HEIGHT );
				objects.logzbuf.container.style.width = ( screensplit_right * 100 ) + '%';

				border.style.left = ( screensplit * 100 ) + "%";

			}

			function animate() {

				requestAnimationFrame( animate );
				render();

			}

			function render() {

				// Put some limits on zooming
				const minzoom = labeldata[ 0 ].size * labeldata[ 0 ].scale * 1;
				const maxzoom = labeldata[ labeldata.length - 1 ].size * labeldata[ labeldata.length - 1 ].scale * 100;
				let damping = ( Math.abs( zoomspeed ) > minzoomspeed ? .95 : 1.0 );

				// Zoom out faster the further out you go
				const zoom = THREE.MathUtils.clamp( Math.pow( Math.E, zoompos ), minzoom, maxzoom );
				zoompos = Math.log( zoom );

				// Slow down quickly at the zoom limits
				if ( ( zoom == minzoom && zoomspeed < 0 ) || ( zoom == maxzoom && zoomspeed > 0 ) ) {

					damping = .85;

				}

				zoompos += zoomspeed;
				zoomspeed *= damping;

				objects.normal.camera.position.x = Math.sin( .5 * Math.PI * ( mouse[ 0 ] - .5 ) ) * zoom;
				objects.normal.camera.position.y = Math.sin( .25 * Math.PI * ( mouse[ 1 ] - .5 ) ) * zoom;
				objects.normal.camera.position.z = Math.cos( .5 * Math.PI * ( mouse[ 0 ] - .5 ) ) * zoom;
				objects.normal.camera.lookAt( objects.normal.scene.position );

				// Clone camera settings across both scenes
				objects.logzbuf.camera.position.copy( objects.normal.camera.position );
				objects.logzbuf.camera.quaternion.copy( objects.normal.camera.quaternion );

				// Update renderer sizes if the split has changed
				if ( screensplit_right != 1 - screensplit ) {

					updateRendererSizes();

				}

				objects.normal.renderer.render( objects.normal.scene, objects.normal.camera );
				objects.logzbuf.renderer.render( objects.logzbuf.scene, objects.logzbuf.camera );

				stats.update();

			}

			function onWindowResize() {

				updateRendererSizes();

			}

			function onBorderPointerDown() {

				// activate draggable window resizing bar
				window.addEventListener( "pointermove", onBorderPointerMove );
				window.addEventListener( "pointerup", onBorderPointerUp );

			}

			function onBorderPointerMove( ev ) {

				screensplit = Math.max( 0, Math.min( 1, ev.clientX / window.innerWidth ) );

			}

			function onBorderPointerUp() {

				window.removeEventListener( "pointermove", onBorderPointerMove );
				window.removeEventListener( "pointerup", onBorderPointerUp );

			}

			function onMouseMove( ev ) {

				mouse[ 0 ] = ev.clientX / window.innerWidth;
				mouse[ 1 ] = ev.clientY / window.innerHeight;

			}

			function onMouseWheel( ev ) {

				const amount = ev.deltaY;
				if ( amount === 0 ) return;
				const dir = amount / Math.abs( amount );
				zoomspeed = dir / 10;

				// Slow down default zoom speed after user starts zooming, to give them more control
				minzoomspeed = 0.001;

			}