import AnalyticLightNode from './AnalyticLightNode.js';
import { uniform } from '../core/UniformNode.js';
import { mix } from '../math/MathNode.js';
import { normalView } from '../accessors/Normal.js';
import { lightPosition } from '../accessors/Lights.js';
import { renderGroup } from '../core/UniformGroupNode.js';
import { Color } from '../../math/Color.js';
/**
* Module for representing hemisphere lights as nodes.
*
* @augments AnalyticLightNode
*/
class HemisphereLightNode extends AnalyticLightNode {
static get type() {
return 'HemisphereLightNode';
}
/**
* Constructs a new hemisphere light node.
*
* @param {HemisphereLight?} [light=null] - The hemisphere light source.
*/
constructor( light = null ) {
super( light );
/**
* Uniform node representing the light's position.
*
* @type {UniformNode<vec3>}
*/
this.lightPositionNode = lightPosition( light );
/**
* A node representing the light's direction.
*
* @type {Node<vec3>}
*/
this.lightDirectionNode = this.lightPositionNode.normalize();
/**
* Uniform node representing the light's ground color.
*
* @type {UniformNode<vec3>}
*/
this.groundColorNode = uniform( new Color() ).setGroup( renderGroup );
}
/**
* Overwritten to updated hemisphere light specific uniforms.
*
* @param {NodeFrame} frame - A reference to the current node frame.
*/
update( frame ) {
const { light } = this;
super.update( frame );
this.lightPositionNode.object3d = light;
this.groundColorNode.value.copy( light.groundColor ).multiplyScalar( light.intensity );
}
setup( builder ) {
const { colorNode, groundColorNode, lightDirectionNode } = this;
const dotNL = normalView.dot( lightDirectionNode );
const hemiDiffuseWeight = dotNL.mul( 0.5 ).add( 0.5 );
const irradiance = mix( groundColorNode, colorNode, hemiDiffuseWeight );
builder.context.irradiance.addAssign( irradiance );
}
}
export default HemisphereLightNode;