three.js/src/core/BufferGeometry.js

import { Vector3 } from '../math/Vector3.js';
import { Box3 } from '../math/Box3.js';
import { EventDispatcher } from './EventDispatcher.js';
import { BufferAttribute, Float32BufferAttribute, Uint16BufferAttribute, Uint32BufferAttribute } from './BufferAttribute.js';
import { Sphere } from '../math/Sphere.js';
import { DirectGeometry } from './DirectGeometry.js';
import { Object3D } from './Object3D.js';
import { Matrix4 } from '../math/Matrix4.js';
import { Matrix3 } from '../math/Matrix3.js';
import { MathUtils } from '../math/MathUtils.js';
import { arrayMax } from '../utils.js';

let _bufferGeometryId = 1; // BufferGeometry uses odd numbers as Id

const _m1 = new Matrix4();
const _obj = new Object3D();
const _offset = new Vector3();
const _box = new Box3();
const _boxMorphTargets = new Box3();
const _vector = new Vector3();

function BufferGeometry() {

	Object.defineProperty( this, 'id', { value: _bufferGeometryId += 2 } );

	this.uuid = MathUtils.generateUUID();

	this.name = '';
	this.type = 'BufferGeometry';

	this.index = null;
	this.attributes = {};

	this.morphAttributes = {};
	this.morphTargetsRelative = false;

	this.groups = [];

	this.boundingBox = null;
	this.boundingSphere = null;

	this.drawRange = { start: 0, count: Infinity };

	this.userData = {};

}

BufferGeometry.prototype = Object.assign( Object.create( EventDispatcher.prototype ), {

	constructor: BufferGeometry,

	isBufferGeometry: true,

	getIndex: function () {

		return this.index;

	},

	setIndex: function ( index ) {

		if ( Array.isArray( index ) ) {

			this.index = new ( arrayMax( index ) > 65535 ? Uint32BufferAttribute : Uint16BufferAttribute )( index, 1 );

		} else {

			this.index = index;

		}

	},

	getAttribute: function ( name ) {

		return this.attributes[ name ];

	},

	setAttribute: function ( name, attribute ) {

		this.attributes[ name ] = attribute;

		return this;

	},

	deleteAttribute: function ( name ) {

		delete this.attributes[ name ];

		return this;

	},

	addGroup: function ( start, count, materialIndex ) {

		this.groups.push( {

			start: start,
			count: count,
			materialIndex: materialIndex !== undefined ? materialIndex : 0

		} );

	},

	clearGroups: function () {

		this.groups = [];

	},

	setDrawRange: function ( start, count ) {

		this.drawRange.start = start;
		this.drawRange.count = count;

	},

	applyMatrix4: function ( matrix ) {

		const position = this.attributes.position;

		if ( position !== undefined ) {

			position.applyMatrix4( matrix );

			position.needsUpdate = true;

		}

		const normal = this.attributes.normal;

		if ( normal !== undefined ) {

			const normalMatrix = new Matrix3().getNormalMatrix( matrix );

			normal.applyNormalMatrix( normalMatrix );

			normal.needsUpdate = true;

		}

		const tangent = this.attributes.tangent;

		if ( tangent !== undefined ) {

			tangent.transformDirection( matrix );

			tangent.needsUpdate = true;

		}

		if ( this.boundingBox !== null ) {

			this.computeBoundingBox();

		}

		if ( this.boundingSphere !== null ) {

			this.computeBoundingSphere();

		}

		return this;

	},

	rotateX: function ( angle ) {

		// rotate geometry around world x-axis

		_m1.makeRotationX( angle );

		this.applyMatrix4( _m1 );

		return this;

	},

	rotateY: function ( angle ) {

		// rotate geometry around world y-axis

		_m1.makeRotationY( angle );

		this.applyMatrix4( _m1 );

		return this;

	},

	rotateZ: function ( angle ) {

		// rotate geometry around world z-axis

		_m1.makeRotationZ( angle );

		this.applyMatrix4( _m1 );

		return this;

	},

	translate: function ( x, y, z ) {

		// translate geometry

		_m1.makeTranslation( x, y, z );

		this.applyMatrix4( _m1 );

		return this;

	},

	scale: function ( x, y, z ) {

		// scale geometry

		_m1.makeScale( x, y, z );

		this.applyMatrix4( _m1 );

		return this;

	},

	lookAt: function ( vector ) {

		_obj.lookAt( vector );

		_obj.updateMatrix();

		this.applyMatrix4( _obj.matrix );

		return this;

	},

	center: function () {

		this.computeBoundingBox();

		this.boundingBox.getCenter( _offset ).negate();

		this.translate( _offset.x, _offset.y, _offset.z );

		return this;

	},

	setFromObject: function ( object ) {

		// console.log( 'THREE.BufferGeometry.setFromObject(). Converting', object, this );

		const geometry = object.geometry;

		if ( object.isPoints || object.isLine ) {

			const positions = new Float32BufferAttribute( geometry.vertices.length * 3, 3 );
			const colors = new Float32BufferAttribute( geometry.colors.length * 3, 3 );

			this.setAttribute( 'position', positions.copyVector3sArray( geometry.vertices ) );
			this.setAttribute( 'color', colors.copyColorsArray( geometry.colors ) );

			if ( geometry.lineDistances && geometry.lineDistances.length === geometry.vertices.length ) {

				const lineDistances = new Float32BufferAttribute( geometry.lineDistances.length, 1 );

				this.setAttribute( 'lineDistance', lineDistances.copyArray( geometry.lineDistances ) );

			}

			if ( geometry.boundingSphere !== null ) {

				this.boundingSphere = geometry.boundingSphere.clone();

			}

			if ( geometry.boundingBox !== null ) {

				this.boundingBox = geometry.boundingBox.clone();

			}

		} else if ( object.isMesh ) {

			if ( geometry && geometry.isGeometry ) {

				this.fromGeometry( geometry );

			}

		}

		return this;

	},

	setFromPoints: function ( points ) {

		const position = [];

		for ( let i = 0, l = points.length; i < l; i ++ ) {

			const point = points[ i ];
			position.push( point.x, point.y, point.z || 0 );

		}

		this.setAttribute( 'position', new Float32BufferAttribute( position, 3 ) );

		return this;

	},

	updateFromObject: function ( object ) {

		let geometry = object.geometry;

		if ( object.isMesh ) {

			let direct = geometry.__directGeometry;

			if ( geometry.elementsNeedUpdate === true ) {

				direct = undefined;
				geometry.elementsNeedUpdate = false;

			}

			if ( direct === undefined ) {

				return this.fromGeometry( geometry );

			}

			direct.verticesNeedUpdate = geometry.verticesNeedUpdate;
			direct.normalsNeedUpdate = geometry.normalsNeedUpdate;
			direct.colorsNeedUpdate = geometry.colorsNeedUpdate;
			direct.uvsNeedUpdate = geometry.uvsNeedUpdate;
			direct.groupsNeedUpdate = geometry.groupsNeedUpdate;

			geometry.verticesNeedUpdate = false;
			geometry.normalsNeedUpdate = false;
			geometry.colorsNeedUpdate = false;
			geometry.uvsNeedUpdate = false;
			geometry.groupsNeedUpdate = false;

			geometry = direct;

		}

		if ( geometry.verticesNeedUpdate === true ) {

			const attribute = this.attributes.position;

			if ( attribute !== undefined ) {

				attribute.copyVector3sArray( geometry.vertices );
				attribute.needsUpdate = true;

			}

			geometry.verticesNeedUpdate = false;

		}

		if ( geometry.normalsNeedUpdate === true ) {

			const attribute = this.attributes.normal;

			if ( attribute !== undefined ) {

				attribute.copyVector3sArray( geometry.normals );
				attribute.needsUpdate = true;

			}

			geometry.normalsNeedUpdate = false;

		}

		if ( geometry.colorsNeedUpdate === true ) {

			const attribute = this.attributes.color;

			if ( attribute !== undefined ) {

				attribute.copyColorsArray( geometry.colors );
				attribute.needsUpdate = true;

			}

			geometry.colorsNeedUpdate = false;

		}

		if ( geometry.uvsNeedUpdate ) {

			const attribute = this.attributes.uv;

			if ( attribute !== undefined ) {

				attribute.copyVector2sArray( geometry.uvs );
				attribute.needsUpdate = true;

			}

			geometry.uvsNeedUpdate = false;

		}

		if ( geometry.lineDistancesNeedUpdate ) {

			const attribute = this.attributes.lineDistance;

			if ( attribute !== undefined ) {

				attribute.copyArray( geometry.lineDistances );
				attribute.needsUpdate = true;

			}

			geometry.lineDistancesNeedUpdate = false;

		}

		if ( geometry.groupsNeedUpdate ) {

			geometry.computeGroups( object.geometry );
			this.groups = geometry.groups;

			geometry.groupsNeedUpdate = false;

		}

		return this;

	},

	fromGeometry: function ( geometry ) {

		geometry.__directGeometry = new DirectGeometry().fromGeometry( geometry );

		return this.fromDirectGeometry( geometry.__directGeometry );

	},

	fromDirectGeometry: function ( geometry ) {

		const positions = new Float32Array( geometry.vertices.length * 3 );
		this.setAttribute( 'position', new BufferAttribute( positions, 3 ).copyVector3sArray( geometry.vertices ) );

		if ( geometry.normals.length > 0 ) {

			const normals = new Float32Array( geometry.normals.length * 3 );
			this.setAttribute( 'normal', new BufferAttribute( normals, 3 ).copyVector3sArray( geometry.normals ) );

		}

		if ( geometry.colors.length > 0 ) {

			const colors = new Float32Array( geometry.colors.length * 3 );
			this.setAttribute( 'color', new BufferAttribute( colors, 3 ).copyColorsArray( geometry.colors ) );

		}

		if ( geometry.uvs.length > 0 ) {

			const uvs = new Float32Array( geometry.uvs.length * 2 );
			this.setAttribute( 'uv', new BufferAttribute( uvs, 2 ).copyVector2sArray( geometry.uvs ) );

		}

		if ( geometry.uvs2.length > 0 ) {

			const uvs2 = new Float32Array( geometry.uvs2.length * 2 );
			this.setAttribute( 'uv2', new BufferAttribute( uvs2, 2 ).copyVector2sArray( geometry.uvs2 ) );

		}

		// groups

		this.groups = geometry.groups;

		// morphs

		for ( const name in geometry.morphTargets ) {

			const array = [];
			const morphTargets = geometry.morphTargets[ name ];

			for ( let i = 0, l = morphTargets.length; i < l; i ++ ) {

				const morphTarget = morphTargets[ i ];

				const attribute = new Float32BufferAttribute( morphTarget.data.length * 3, 3 );
				attribute.name = morphTarget.name;

				array.push( attribute.copyVector3sArray( morphTarget.data ) );

			}

			this.morphAttributes[ name ] = array;

		}

		// skinning

		if ( geometry.skinIndices.length > 0 ) {

			const skinIndices = new Float32BufferAttribute( geometry.skinIndices.length * 4, 4 );
			this.setAttribute( 'skinIndex', skinIndices.copyVector4sArray( geometry.skinIndices ) );

		}

		if ( geometry.skinWeights.length > 0 ) {

			const skinWeights = new Float32BufferAttribute( geometry.skinWeights.length * 4, 4 );
			this.setAttribute( 'skinWeight', skinWeights.copyVector4sArray( geometry.skinWeights ) );

		}

		//

		if ( geometry.boundingSphere !== null ) {

			this.boundingSphere = geometry.boundingSphere.clone();

		}

		if ( geometry.boundingBox !== null ) {

			this.boundingBox = geometry.boundingBox.clone();

		}

		return this;

	},

	computeBoundingBox: function () {

		if ( this.boundingBox === null ) {

			this.boundingBox = new Box3();

		}

		const position = this.attributes.position;
		const morphAttributesPosition = this.morphAttributes.position;

		if ( position && position.isGLBufferAttribute ) {

			console.error( 'THREE.BufferGeometry.computeBoundingBox(): GLBufferAttribute requires a manual bounding box. Alternatively set "mesh.frustumCulled" to "false".', this );

			this.boundingBox.set(
				new Vector3( - Infinity, - Infinity, - Infinity ),
				new Vector3( + Infinity, + Infinity, + Infinity )
			);

			return;

		}

		if ( position !== undefined ) {

			this.boundingBox.setFromBufferAttribute( position );

			// process morph attributes if present

			if ( morphAttributesPosition ) {

				for ( let i = 0, il = morphAttributesPosition.length; i < il; i ++ ) {

					const morphAttribute = morphAttributesPosition[ i ];
					_box.setFromBufferAttribute( morphAttribute );

					if ( this.morphTargetsRelative ) {

						_vector.addVectors( this.boundingBox.min, _box.min );
						this.boundingBox.expandByPoint( _vector );

						_vector.addVectors( this.boundingBox.max, _box.max );
						this.boundingBox.expandByPoint( _vector );

					} else {

						this.boundingBox.expandByPoint( _box.min );
						this.boundingBox.expandByPoint( _box.max );

					}

				}

			}

		} else {

			this.boundingBox.makeEmpty();

		}

		if ( isNaN( this.boundingBox.min.x ) || isNaN( this.boundingBox.min.y ) || isNaN( this.boundingBox.min.z ) ) {

			console.error( 'THREE.BufferGeometry.computeBoundingBox(): Computed min/max have NaN values. The "position" attribute is likely to have NaN values.', this );

		}

	},

	computeBoundingSphere: function () {

		if ( this.boundingSphere === null ) {

			this.boundingSphere = new Sphere();

		}

		const position = this.attributes.position;
		const morphAttributesPosition = this.morphAttributes.position;

		if ( position && position.isGLBufferAttribute ) {

			console.error( 'THREE.BufferGeometry.computeBoundingSphere(): GLBufferAttribute requires a manual bounding sphere. Alternatively set "mesh.frustumCulled" to "false".', this );

			this.boundingSphere.set( new Vector3(), Infinity );

			return;

		}

		if ( position ) {

			// first, find the center of the bounding sphere

			const center = this.boundingSphere.center;

			_box.setFromBufferAttribute( position );

			// process morph attributes if present

			if ( morphAttributesPosition ) {

				for ( let i = 0, il = morphAttributesPosition.length; i < il; i ++ ) {

					const morphAttribute = morphAttributesPosition[ i ];
					_boxMorphTargets.setFromBufferAttribute( morphAttribute );

					if ( this.morphTargetsRelative ) {

						_vector.addVectors( _box.min, _boxMorphTargets.min );
						_box.expandByPoint( _vector );

						_vector.addVectors( _box.max, _boxMorphTargets.max );
						_box.expandByPoint( _vector );

					} else {

						_box.expandByPoint( _boxMorphTargets.min );
						_box.expandByPoint( _boxMorphTargets.max );

					}

				}

			}

			_box.getCenter( center );

			// second, try to find a boundingSphere with a radius smaller than the
			// boundingSphere of the boundingBox: sqrt(3) smaller in the best case

			let maxRadiusSq = 0;

			for ( let i = 0, il = position.count; i < il; i ++ ) {

				_vector.fromBufferAttribute( position, i );

				maxRadiusSq = Math.max( maxRadiusSq, center.distanceToSquared( _vector ) );

			}

			// process morph attributes if present

			if ( morphAttributesPosition ) {

				for ( let i = 0, il = morphAttributesPosition.length; i < il; i ++ ) {

					const morphAttribute = morphAttributesPosition[ i ];
					const morphTargetsRelative = this.morphTargetsRelative;

					for ( let j = 0, jl = morphAttribute.count; j < jl; j ++ ) {

						_vector.fromBufferAttribute( morphAttribute, j );

						if ( morphTargetsRelative ) {

							_offset.fromBufferAttribute( position, j );
							_vector.add( _offset );

						}

						maxRadiusSq = Math.max( maxRadiusSq, center.distanceToSquared( _vector ) );

					}

				}

			}

			this.boundingSphere.radius = Math.sqrt( maxRadiusSq );

			if ( isNaN( this.boundingSphere.radius ) ) {

				console.error( 'THREE.BufferGeometry.computeBoundingSphere(): Computed radius is NaN. The "position" attribute is likely to have NaN values.', this );

			}

		}

	},

	computeFaceNormals: function () {

		// backwards compatibility

	},

	computeVertexNormals: function () {

		const index = this.index;
		const positionAttribute = this.getAttribute( 'position' );

		if ( positionAttribute !== undefined ) {

			let normalAttribute = this.getAttribute( 'normal' );

			if ( normalAttribute === undefined ) {

				normalAttribute = new BufferAttribute( new Float32Array( positionAttribute.count * 3 ), 3 );
				this.setAttribute( 'normal', normalAttribute );

			} else {

				// reset existing normals to zero

				for ( let i = 0, il = normalAttribute.count; i < il; i ++ ) {

					normalAttribute.setXYZ( i, 0, 0, 0 );

				}

			}

			const pA = new Vector3(), pB = new Vector3(), pC = new Vector3();
			const nA = new Vector3(), nB = new Vector3(), nC = new Vector3();
			const cb = new Vector3(), ab = new Vector3();

			// indexed elements

			if ( index ) {

				for ( let i = 0, il = index.count; i < il; i += 3 ) {

					const vA = index.getX( i + 0 );
					const vB = index.getX( i + 1 );
					const vC = index.getX( i + 2 );

					pA.fromBufferAttribute( positionAttribute, vA );
					pB.fromBufferAttribute( positionAttribute, vB );
					pC.fromBufferAttribute( positionAttribute, vC );

					cb.subVectors( pC, pB );
					ab.subVectors( pA, pB );
					cb.cross( ab );

					nA.fromBufferAttribute( normalAttribute, vA );
					nB.fromBufferAttribute( normalAttribute, vB );
					nC.fromBufferAttribute( normalAttribute, vC );

					nA.add( cb );
					nB.add( cb );
					nC.add( cb );

					normalAttribute.setXYZ( vA, nA.x, nA.y, nA.z );
					normalAttribute.setXYZ( vB, nB.x, nB.y, nB.z );
					normalAttribute.setXYZ( vC, nC.x, nC.y, nC.z );

				}

			} else {

				// non-indexed elements (unconnected triangle soup)

				for ( let i = 0, il = positionAttribute.count; i < il; i += 3 ) {

					pA.fromBufferAttribute( positionAttribute, i + 0 );
					pB.fromBufferAttribute( positionAttribute, i + 1 );
					pC.fromBufferAttribute( positionAttribute, i + 2 );

					cb.subVectors( pC, pB );
					ab.subVectors( pA, pB );
					cb.cross( ab );

					normalAttribute.setXYZ( i + 0, cb.x, cb.y, cb.z );
					normalAttribute.setXYZ( i + 1, cb.x, cb.y, cb.z );
					normalAttribute.setXYZ( i + 2, cb.x, cb.y, cb.z );

				}

			}

			this.normalizeNormals();

			normalAttribute.needsUpdate = true;

		}

	},

	merge: function ( geometry, offset ) {

		if ( ! ( geometry && geometry.isBufferGeometry ) ) {

			console.error( 'THREE.BufferGeometry.merge(): geometry not an instance of THREE.BufferGeometry.', geometry );
			return;

		}

		if ( offset === undefined ) {

			offset = 0;

			console.warn(
				'THREE.BufferGeometry.merge(): Overwriting original geometry, starting at offset=0. '
				+ 'Use BufferGeometryUtils.mergeBufferGeometries() for lossless merge.'
			);

		}

		const attributes = this.attributes;

		for ( const key in attributes ) {

			if ( geometry.attributes[ key ] === undefined ) continue;

			const attribute1 = attributes[ key ];
			const attributeArray1 = attribute1.array;

			const attribute2 = geometry.attributes[ key ];
			const attributeArray2 = attribute2.array;

			const attributeOffset = attribute2.itemSize * offset;
			const length = Math.min( attributeArray2.length, attributeArray1.length - attributeOffset );

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

				attributeArray1[ j ] = attributeArray2[ i ];

			}

		}

		return this;

	},

	normalizeNormals: function () {

		const normals = this.attributes.normal;

		for ( let i = 0, il = normals.count; i < il; i ++ ) {

			_vector.fromBufferAttribute( normals, i );

			_vector.normalize();

			normals.setXYZ( i, _vector.x, _vector.y, _vector.z );

		}

	},

	toNonIndexed: function () {

		function convertBufferAttribute( attribute, indices ) {

			const array = attribute.array;
			const itemSize = attribute.itemSize;
			const normalized = attribute.normalized;

			const array2 = new array.constructor( indices.length * itemSize );

			let index = 0, index2 = 0;

			for ( let i = 0, l = indices.length; i < l; i ++ ) {

				index = indices[ i ] * itemSize;

				for ( let j = 0; j < itemSize; j ++ ) {

					array2[ index2 ++ ] = array[ index ++ ];

				}

			}

			return new BufferAttribute( array2, itemSize, normalized );

		}

		//

		if ( this.index === null ) {

			console.warn( 'THREE.BufferGeometry.toNonIndexed(): Geometry is already non-indexed.' );
			return this;

		}

		const geometry2 = new BufferGeometry();

		const indices = this.index.array;
		const attributes = this.attributes;

		// attributes

		for ( const name in attributes ) {

			const attribute = attributes[ name ];

			const newAttribute = convertBufferAttribute( attribute, indices );

			geometry2.setAttribute( name, newAttribute );

		}

		// morph attributes

		const morphAttributes = this.morphAttributes;

		for ( const name in morphAttributes ) {

			const morphArray = [];
			const morphAttribute = morphAttributes[ name ]; // morphAttribute: array of Float32BufferAttributes

			for ( let i = 0, il = morphAttribute.length; i < il; i ++ ) {

				const attribute = morphAttribute[ i ];

				const newAttribute = convertBufferAttribute( attribute, indices );

				morphArray.push( newAttribute );

			}

			geometry2.morphAttributes[ name ] = morphArray;

		}

		geometry2.morphTargetsRelative = this.morphTargetsRelative;

		// groups

		const groups = this.groups;

		for ( let i = 0, l = groups.length; i < l; i ++ ) {

			const group = groups[ i ];
			geometry2.addGroup( group.start, group.count, group.materialIndex );

		}

		return geometry2;

	},

	toJSON: function () {

		const data = {
			metadata: {
				version: 4.5,
				type: 'BufferGeometry',
				generator: 'BufferGeometry.toJSON'
			}
		};

		// standard BufferGeometry serialization

		data.uuid = this.uuid;
		data.type = this.type;
		if ( this.name !== '' ) data.name = this.name;
		if ( Object.keys( this.userData ).length > 0 ) data.userData = this.userData;

		if ( this.parameters !== undefined ) {

			const parameters = this.parameters;

			for ( const key in parameters ) {

				if ( parameters[ key ] !== undefined ) data[ key ] = parameters[ key ];

			}

			return data;

		}

		data.data = { attributes: {} };

		const index = this.index;

		if ( index !== null ) {

			data.data.index = {
				type: index.array.constructor.name,
				array: Array.prototype.slice.call( index.array )
			};

		}

		const attributes = this.attributes;

		for ( const key in attributes ) {

			const attribute = attributes[ key ];

			const attributeData = attribute.toJSON( data.data );

			if ( attribute.name !== '' ) attributeData.name = attribute.name;

			data.data.attributes[ key ] = attributeData;

		}

		const morphAttributes = {};
		let hasMorphAttributes = false;

		for ( const key in this.morphAttributes ) {

			const attributeArray = this.morphAttributes[ key ];

			const array = [];

			for ( let i = 0, il = attributeArray.length; i < il; i ++ ) {

				const attribute = attributeArray[ i ];

				const attributeData = attribute.toJSON( data.data );

				if ( attribute.name !== '' ) attributeData.name = attribute.name;

				array.push( attributeData );

			}

			if ( array.length > 0 ) {

				morphAttributes[ key ] = array;

				hasMorphAttributes = true;

			}

		}

		if ( hasMorphAttributes ) {

			data.data.morphAttributes = morphAttributes;
			data.data.morphTargetsRelative = this.morphTargetsRelative;

		}

		const groups = this.groups;

		if ( groups.length > 0 ) {

			data.data.groups = JSON.parse( JSON.stringify( groups ) );

		}

		const boundingSphere = this.boundingSphere;

		if ( boundingSphere !== null ) {

			data.data.boundingSphere = {
				center: boundingSphere.center.toArray(),
				radius: boundingSphere.radius
			};

		}

		return data;

	},

	clone: function () {

		/*
		 // Handle primitives

		 const parameters = this.parameters;

		 if ( parameters !== undefined ) {

		 const values = [];

		 for ( const key in parameters ) {

		 values.push( parameters[ key ] );

		 }

		 const geometry = Object.create( this.constructor.prototype );
		 this.constructor.apply( geometry, values );
		 return geometry;

		 }

		 return new this.constructor().copy( this );
		 */

		return new BufferGeometry().copy( this );

	},

	copy: function ( source ) {

		// reset

		this.index = null;
		this.attributes = {};
		this.morphAttributes = {};
		this.groups = [];
		this.boundingBox = null;
		this.boundingSphere = null;

		// used for storing cloned, shared data

		const data = {};

		// name

		this.name = source.name;

		// index

		const index = source.index;

		if ( index !== null ) {

			this.setIndex( index.clone( data ) );

		}

		// attributes

		const attributes = source.attributes;

		for ( const name in attributes ) {

			const attribute = attributes[ name ];
			this.setAttribute( name, attribute.clone( data ) );

		}

		// morph attributes

		const morphAttributes = source.morphAttributes;

		for ( const name in morphAttributes ) {

			const array = [];
			const morphAttribute = morphAttributes[ name ]; // morphAttribute: array of Float32BufferAttributes

			for ( let i = 0, l = morphAttribute.length; i < l; i ++ ) {

				array.push( morphAttribute[ i ].clone( data ) );

			}

			this.morphAttributes[ name ] = array;

		}

		this.morphTargetsRelative = source.morphTargetsRelative;

		// groups

		const groups = source.groups;

		for ( let i = 0, l = groups.length; i < l; i ++ ) {

			const group = groups[ i ];
			this.addGroup( group.start, group.count, group.materialIndex );

		}

		// bounding box

		const boundingBox = source.boundingBox;

		if ( boundingBox !== null ) {

			this.boundingBox = boundingBox.clone();

		}

		// bounding sphere

		const boundingSphere = source.boundingSphere;

		if ( boundingSphere !== null ) {

			this.boundingSphere = boundingSphere.clone();

		}

		// draw range

		this.drawRange.start = source.drawRange.start;
		this.drawRange.count = source.drawRange.count;

		// user data

		this.userData = source.userData;

		return this;

	},

	dispose: function () {

		this.dispatchEvent( { type: 'dispose' } );

	}

} );


export { BufferGeometry };