text: import { Float32BufferAttribute } from '../core/BufferAttribute.js';
  import { BufferGeometry } from '../core/BufferGeometry.js';
  import { Vector3 } from '../math/Vector3.js';
  import { Vector2 } from '../math/Vector2.js';
  import { MathUtils } from '../math/MathUtils.js';
  
  class LatheGeometry extends BufferGeometry {
  
  	constructor( points, segments = 12, phiStart = 0, phiLength = Math.PI * 2 ) {
  
  		super();
  
  		this.type = 'LatheGeometry';
  
  		this.parameters = {
  			points: points,
  			segments: segments,
  			phiStart: phiStart,
  			phiLength: phiLength
  		};
  
  		segments = Math.floor( segments );
  
  		// clamp phiLength so it's in range of [ 0, 2PI ]
  
  		phiLength = MathUtils.clamp( phiLength, 0, Math.PI * 2 );
  
  		// buffers
  
  		const indices = [];
  		const vertices = [];
  		const uvs = [];
  
  		// helper variables
  
  		const inverseSegments = 1.0 / segments;
  		const vertex = new Vector3();
  		const uv = new Vector2();
  
  		// generate vertices and uvs
  
  		for ( let i = 0; i <= segments; i ++ ) {
  
  			const phi = phiStart + i * inverseSegments * phiLength;
  
  			const sin = Math.sin( phi );
  			const cos = Math.cos( phi );
  
  			for ( let j = 0; j <= ( points.length - 1 ); j ++ ) {
  
  				// vertex
  
  				vertex.x = points[ j ].x * sin;
  				vertex.y = points[ j ].y;
  				vertex.z = points[ j ].x * cos;
  
  				vertices.push( vertex.x, vertex.y, vertex.z );
  
  				// uv
  
  				uv.x = i / segments;
  				uv.y = j / ( points.length - 1 );
  
  				uvs.push( uv.x, uv.y );
  
  
  			}
  
  		}
  
  		// indices
  
  		for ( let i = 0; i < segments; i ++ ) {
  
  			for ( let j = 0; j < ( points.length - 1 ); j ++ ) {
  
  				const base = j + i * points.length;
  
  				const a = base;
  				const b = base + points.length;
  				const c = base + points.length + 1;
  				const d = base + 1;
  
  				// faces
  
  				indices.push( a, b, d );
  				indices.push( b, c, d );
  
  			}
  
  		}
  
  		// build geometry
  
  		this.setIndex( indices );
  		this.setAttribute( 'position', new Float32BufferAttribute( vertices, 3 ) );
  		this.setAttribute( 'uv', new Float32BufferAttribute( uvs, 2 ) );
  
  		// generate normals
  
  		this.computeVertexNormals();
  
  		// if the geometry is closed, we need to average the normals along the seam.
  		// because the corresponding vertices are identical (but still have different UVs).
  
  		if ( phiLength === Math.PI * 2 ) {
  
  			const normals = this.attributes.normal.array;
  			const n1 = new Vector3();
  			const n2 = new Vector3();
  			const n = new Vector3();
  
  			// this is the buffer offset for the last line of vertices
  
  			const base = segments * points.length * 3;
  
  			for ( let i = 0, j = 0; i < points.length; i ++, j += 3 ) {
  
  				// select the normal of the vertex in the first line
  
  				n1.x = normals[ j + 0 ];
  				n1.y = normals[ j + 1 ];
  				n1.z = normals[ j + 2 ];
  
  				// select the normal of the vertex in the last line
  
  				n2.x = normals[ base + j + 0 ];
  				n2.y = normals[ base + j + 1 ];
  				n2.z = normals[ base + j + 2 ];
  
  				// average normals
  
  				n.addVectors( n1, n2 ).normalize();
  
  				// assign the new values to both normals
  
  				normals[ j + 0 ] = normals[ base + j + 0 ] = n.x;
  				normals[ j + 1 ] = normals[ base + j + 1 ] = n.y;
  				normals[ j + 2 ] = normals[ base + j + 2 ] = n.z;
  
  			}
  
  		}
  
  	}
  
  }
  
  
  export { LatheGeometry, LatheGeometry as LatheBufferGeometry };
  