three/src/helpers/ArrowHelper.js

JavaScript 3D library

import { Float32BufferAttribute } from '../core/BufferAttribute.js';
import { BufferGeometry } from '../core/BufferGeometry.js';
import { Object3D } from '../core/Object3D.js';
import { CylinderBufferGeometry } from '../geometries/CylinderGeometry.js';
import { MeshBasicMaterial } from '../materials/MeshBasicMaterial.js';
import { LineBasicMaterial } from '../materials/LineBasicMaterial.js';
import { Mesh } from '../objects/Mesh.js';
import { Line } from '../objects/Line.js';
import { Vector3 } from '../math/Vector3.js';

const _axis = new Vector3();
let _lineGeometry, _coneGeometry;

function ArrowHelper( dir, origin, length, color, headLength, headWidth ) {

	// dir is assumed to be normalized

	Object3D.call( this );

	this.type = 'ArrowHelper';

	if ( dir === undefined ) dir = new Vector3( 0, 0, 1 );
	if ( origin === undefined ) origin = new Vector3( 0, 0, 0 );
	if ( length === undefined ) length = 1;
	if ( color === undefined ) color = 0xffff00;
	if ( headLength === undefined ) headLength = 0.2 * length;
	if ( headWidth === undefined ) headWidth = 0.2 * headLength;

	if ( _lineGeometry === undefined ) {

		_lineGeometry = new BufferGeometry();
		_lineGeometry.setAttribute( 'position', new Float32BufferAttribute( [ 0, 0, 0, 0, 1, 0 ], 3 ) );

		_coneGeometry = new CylinderBufferGeometry( 0, 0.5, 1, 5, 1 );
		_coneGeometry.translate( 0, - 0.5, 0 );

	}

	this.position.copy( origin );

	this.line = new Line( _lineGeometry, new LineBasicMaterial( { color: color, toneMapped: false } ) );
	this.line.matrixAutoUpdate = false;
	this.add( this.line );

	this.cone = new Mesh( _coneGeometry, new MeshBasicMaterial( { color: color, toneMapped: false } ) );
	this.cone.matrixAutoUpdate = false;
	this.add( this.cone );

	this.setDirection( dir );
	this.setLength( length, headLength, headWidth );

}

ArrowHelper.prototype = Object.create( Object3D.prototype );
ArrowHelper.prototype.constructor = ArrowHelper;

ArrowHelper.prototype.setDirection = function ( dir ) {

	// dir is assumed to be normalized

	if ( dir.y > 0.99999 ) {

		this.quaternion.set( 0, 0, 0, 1 );

	} else if ( dir.y < - 0.99999 ) {

		this.quaternion.set( 1, 0, 0, 0 );

	} else {

		_axis.set( dir.z, 0, - dir.x ).normalize();

		const radians = Math.acos( dir.y );

		this.quaternion.setFromAxisAngle( _axis, radians );

	}

};

ArrowHelper.prototype.setLength = function ( length, headLength, headWidth ) {

	if ( headLength === undefined ) headLength = 0.2 * length;
	if ( headWidth === undefined ) headWidth = 0.2 * headLength;

	this.line.scale.set( 1, Math.max( 0.0001, length - headLength ), 1 ); // see #17458
	this.line.updateMatrix();

	this.cone.scale.set( headWidth, headLength, headWidth );
	this.cone.position.y = length;
	this.cone.updateMatrix();

};

ArrowHelper.prototype.setColor = function ( color ) {

	this.line.material.color.set( color );
	this.cone.material.color.set( color );

};

ArrowHelper.prototype.copy = function ( source ) {

	Object3D.prototype.copy.call( this, source, false );

	this.line.copy( source.line );
	this.cone.copy( source.cone );

	return this;

};

export { ArrowHelper };