three.js/src/helpers/RectAreaLightHelper.js

/**
 * @author abelnation / http://github.com/abelnation
 * @author Mugen87 / http://github.com/Mugen87
 * @author WestLangley / http://github.com/WestLangley
 */

import { Object3D } from '../core/Object3D.js';
import { Line } from '../objects/Line.js';
import { LineBasicMaterial } from '../materials/LineBasicMaterial.js';
import { BufferGeometry } from '../core/BufferGeometry.js';
import { BufferAttribute } from '../core/BufferAttribute.js';

function RectAreaLightHelper( light, color ) {

	Object3D.call( this );

	this.light = light;
	this.light.updateMatrixWorld();

	this.matrix = light.matrixWorld;
	this.matrixAutoUpdate = false;

	this.color = color;

	var material = new LineBasicMaterial( { fog: false } );

	var geometry = new BufferGeometry();

	geometry.addAttribute( 'position', new BufferAttribute( new Float32Array( 5 * 3 ), 3 ) );

	this.line = new Line( geometry, material );
	this.add( this.line );


	this.update();

}

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

RectAreaLightHelper.prototype.dispose = function () {

	this.children[ 0 ].geometry.dispose();
	this.children[ 0 ].material.dispose();

};

RectAreaLightHelper.prototype.update = function () {

	// calculate new dimensions of the helper

	var hx = this.light.width * 0.5;
	var hy = this.light.height * 0.5;

	var position = this.line.geometry.attributes.position;
	var array = position.array;

	// update vertices

	array[ 0 ] = hx; array[ 1 ] = - hy; array[ 2 ] = 0;
	array[ 3 ] = hx; array[ 4 ] = hy; array[ 5 ] = 0;
	array[ 6 ] = - hx; array[ 7 ] = hy; array[ 8 ] = 0;
	array[ 9 ] = - hx; array[ 10 ] = - hy; array[ 11 ] = 0;
	array[ 12 ] = hx; array[ 13 ] = - hy; array[ 14 ] = 0;

	position.needsUpdate = true;

	if ( this.color !== undefined ) {

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

	} else {

		this.line.material.color.copy( this.light.color );

	}

};

export { RectAreaLightHelper };