three.js/examples/jsm/nodes/lighting/DirectionalLightNode.js

import AnalyticLightNode from './AnalyticLightNode.js';
import { lightTargetDirection } from './LightNode.js';
import { addLightNode } from './LightsNode.js';
import { addNodeClass } from '../core/Node.js';

import { DirectionalLight } from 'three';

class DirectionalLightNode extends AnalyticLightNode {

	constructor( light = null ) {

		super( light );

	}

	construct( builder ) {

		super.construct( builder );

		const lightColor = this.colorNode;
		const lightDirection = lightTargetDirection( this.light );
		const lightingModelFunctionNode = builder.context.lightingModelNode;
		const reflectedLight = builder.context.reflectedLight;

		if ( lightingModelFunctionNode && lightingModelFunctionNode.direct ) {

			lightingModelFunctionNode.direct.call( {
				lightDirection,
				lightColor,
				reflectedLight
			}, builder );

		}

	}

}

export default DirectionalLightNode;

addLightNode( DirectionalLight, DirectionalLightNode );

addNodeClass( DirectionalLightNode );