//ported from threejs examples
//https://threejs.org/examples/#webgl_geometry_nurbs



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

// path edits:

            import * as THREE from '/api/threemodule/libs/three.module.js';

            import Stats from '/uploads/threeport/stats.module.js';
			import { NURBSCurve } from '/uploads/threejs/NURBSCurve.js';
			import { NURBSSurface } from '/uploads/threejs/NURBSSurface.js';

			let container, stats;

			let camera, scene, renderer;
			let group;

			let targetRotation = 0;
			let targetRotationOnPointerDown = 0;

			let pointerX = 0;
			let pointerXOnPointerDown = 0;

			let windowHalfX = window.innerWidth / 2;

			init();
			animate();

			function init() {

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

				camera = new THREE.PerspectiveCamera( 50, window.innerWidth / window.innerHeight, 1, 2000 );
				camera.position.set( 0, 150, 750 );

				scene = new THREE.Scene();
				scene.background = new THREE.Color( 0xf0f0f0 );

				scene.add( new THREE.AmbientLight( 0x808080 ) );

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

				group = new THREE.Group();
				group.position.y = 50;
				scene.add( group );

				// NURBS curve

				const nurbsControlPoints = [];
				const nurbsKnots = [];
				const nurbsDegree = 3;

				for ( let i = 0; i <= nurbsDegree; i ++ ) {

					nurbsKnots.push( 0 );

				}

				for ( let i = 0, j = 20; i < j; i ++ ) {

					nurbsControlPoints.push(
						new THREE.Vector4(
							Math.random() * 400 - 200,
							Math.random() * 400,
							Math.random() * 400 - 200,
							1 // weight of control point: higher means stronger attraction
						)
					);

					const knot = ( i + 1 ) / ( j - nurbsDegree );
					nurbsKnots.push( THREE.MathUtils.clamp( knot, 0, 1 ) );

				}

				const nurbsCurve = new NURBSCurve( nurbsDegree, nurbsKnots, nurbsControlPoints );

				const nurbsGeometry = new THREE.BufferGeometry();
				nurbsGeometry.setFromPoints( nurbsCurve.getPoints( 200 ) );

				const nurbsMaterial = new THREE.LineBasicMaterial( { color: 0x333333 } );

				const nurbsLine = new THREE.Line( nurbsGeometry, nurbsMaterial );
				nurbsLine.position.set( 200, - 100, 0 );
				group.add( nurbsLine );

				const nurbsControlPointsGeometry = new THREE.BufferGeometry();
				nurbsControlPointsGeometry.setFromPoints( nurbsCurve.controlPoints );

				const nurbsControlPointsMaterial = new THREE.LineBasicMaterial( { color: 0x333333, opacity: 0.25, transparent: true } );

				const nurbsControlPointsLine = new THREE.Line( nurbsControlPointsGeometry, nurbsControlPointsMaterial );
				nurbsControlPointsLine.position.copy( nurbsLine.position );
				group.add( nurbsControlPointsLine );

				// NURBS surface

				const nsControlPoints = [
					[
						new THREE.Vector4( - 200, - 200, 100, 1 ),
						new THREE.Vector4( - 200, - 100, - 200, 1 ),
						new THREE.Vector4( - 200, 100, 250, 1 ),
						new THREE.Vector4( - 200, 200, - 100, 1 )
					],
					[
						new THREE.Vector4( 0, - 200, 0, 1 ),
						new THREE.Vector4( 0, - 100, - 100, 5 ),
						new THREE.Vector4( 0, 100, 150, 5 ),
						new THREE.Vector4( 0, 200, 0, 1 )
					],
					[
						new THREE.Vector4( 200, - 200, - 100, 1 ),
						new THREE.Vector4( 200, - 100, 200, 1 ),
						new THREE.Vector4( 200, 100, - 250, 1 ),
						new THREE.Vector4( 200, 200, 100, 1 )
					]
				];
				const degree1 = 2;
				const degree2 = 3;
				const knots1 = [ 0, 0, 0, 1, 1, 1 ];
				const knots2 = [ 0, 0, 0, 0, 1, 1, 1, 1 ];
				const nurbsSurface = new NURBSSurface( degree1, degree2, knots1, knots2, nsControlPoints );

				const map = new THREE.TextureLoader().load( 'uploads/threejs/uv_grid_opengl.jpg' );
				map.wrapS = map.wrapT = THREE.RepeatWrapping;
				map.anisotropy = 16;

				function getSurfacePoint( u, v, target ) {

					return nurbsSurface.getPoint( u, v, target );

				}

				const geometry = new THREE.ParametricBufferGeometry( getSurfacePoint, 20, 20 );
				const material = new THREE.MeshLambertMaterial( { map: map, side: THREE.DoubleSide } );
				const object = new THREE.Mesh( geometry, material );
				object.position.set( - 200, 100, 0 );
				object.scale.multiplyScalar( 1 );
				group.add( object );

				//

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

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

				container.style.touchAction = 'none';
				container.addEventListener( 'pointerdown', onPointerDown );

				//

				window.addEventListener( 'resize', onWindowResize );

			}

			function onWindowResize() {

				windowHalfX = window.innerWidth / 2;

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

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

			}

			//

			function onPointerDown( event ) {

				if ( event.isPrimary === false ) return;

				pointerXOnPointerDown = event.clientX - windowHalfX;
				targetRotationOnPointerDown = targetRotation;

				document.addEventListener( 'pointermove', onPointerMove );
				document.addEventListener( 'pointerup', onPointerUp );

			}

			function onPointerMove( event ) {

				if ( event.isPrimary === false ) return;

				pointerX = event.clientX - windowHalfX;

				targetRotation = targetRotationOnPointerDown + ( pointerX - pointerXOnPointerDown ) * 0.02;

			}

			function onPointerUp() {

				if ( event.isPrimary === false ) return;

				document.removeEventListener( 'pointermove', onPointerMove );
				document.removeEventListener( 'pointerup', onPointerUp );

			}

			//

			function animate() {

				requestAnimationFrame( animate );

				render();
				stats.update();

			}

			function render() {

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

			}