three.js/src/helpers/BoxHelper.js

import { Box3 } from '../math/Box3.js';
import { LineSegments } from '../objects/LineSegments.js';
import { LineBasicMaterial } from '../materials/LineBasicMaterial.js';
import { BufferAttribute } from '../core/BufferAttribute.js';
import { BufferGeometry } from '../core/BufferGeometry.js';

const _box = new Box3();

function BoxHelper( object, color ) {

	this.object = object;

	if ( color === undefined ) color = 0xffff00;

	const indices = new Uint16Array( [ 0, 1, 1, 2, 2, 3, 3, 0, 4, 5, 5, 6, 6, 7, 7, 4, 0, 4, 1, 5, 2, 6, 3, 7 ] );
	const positions = new Float32Array( 8 * 3 );

	const geometry = new BufferGeometry();
	geometry.setIndex( new BufferAttribute( indices, 1 ) );
	geometry.setAttribute( 'position', new BufferAttribute( positions, 3 ) );

	LineSegments.call( this, geometry, new LineBasicMaterial( { color: color, toneMapped: false } ) );

	this.type = 'BoxHelper';

	this.matrixAutoUpdate = false;

	this.update();

}

BoxHelper.prototype = Object.create( LineSegments.prototype );
BoxHelper.prototype.constructor = BoxHelper;

BoxHelper.prototype.update = function ( object ) {

	if ( object !== undefined ) {

		console.warn( 'THREE.BoxHelper: .update() has no longer arguments.' );

	}

	if ( this.object !== undefined ) {

		_box.setFromObject( this.object );

	}

	if ( _box.isEmpty() ) return;

	const min = _box.min;
	const max = _box.max;

	/*
	  5____4
	1/___0/|
	| 6__|_7
	2/___3/

	0: max.x, max.y, max.z
	1: min.x, max.y, max.z
	2: min.x, min.y, max.z
	3: max.x, min.y, max.z
	4: max.x, max.y, min.z
	5: min.x, max.y, min.z
	6: min.x, min.y, min.z
	7: max.x, min.y, min.z
	*/

	const position = this.geometry.attributes.position;
	const array = position.array;

	array[ 0 ] = max.x; array[ 1 ] = max.y; array[ 2 ] = max.z;
	array[ 3 ] = min.x; array[ 4 ] = max.y; array[ 5 ] = max.z;
	array[ 6 ] = min.x; array[ 7 ] = min.y; array[ 8 ] = max.z;
	array[ 9 ] = max.x; array[ 10 ] = min.y; array[ 11 ] = max.z;
	array[ 12 ] = max.x; array[ 13 ] = max.y; array[ 14 ] = min.z;
	array[ 15 ] = min.x; array[ 16 ] = max.y; array[ 17 ] = min.z;
	array[ 18 ] = min.x; array[ 19 ] = min.y; array[ 20 ] = min.z;
	array[ 21 ] = max.x; array[ 22 ] = min.y; array[ 23 ] = min.z;

	position.needsUpdate = true;

	this.geometry.computeBoundingSphere();


};

BoxHelper.prototype.setFromObject = function ( object ) {

	this.object = object;
	this.update();

	return this;

};

BoxHelper.prototype.copy = function ( source ) {

	LineSegments.prototype.copy.call( this, source );

	this.object = source.object;

	return this;

};

export { BoxHelper };