import { uniform } from '../core/UniformNode.js';
import { renderGroup } from '../core/UniformGroupNode.js';
import { Vector3 } from '../../math/Vector3.js';
import { cameraViewMatrix } from './Camera.js';
import { positionWorld } from './Position.js';
/** @module Lights **/
let uniformsLib;
function getLightData( light ) {
uniformsLib = uniformsLib || new WeakMap();
let uniforms = uniformsLib.get( light );
if ( uniforms === undefined ) uniformsLib.set( light, uniforms = {} );
return uniforms;
}
/**
* TSL function for getting a shadow matrix uniform node for the given light.
*
* @function
* @param {Light} light -The light source.
* @returns {UniformNode<mat4>} The shadow matrix uniform node.
*/
export function lightShadowMatrix( light ) {
const data = getLightData( light );
return data.shadowMatrix || ( data.shadowMatrix = uniform( 'mat4' ).setGroup( renderGroup ).onRenderUpdate( () => {
if ( light.castShadow !== true ) {
light.shadow.updateMatrices( light );
}
return light.shadow.matrix;
} ) );
}
/**
* TSL function for getting projected uv coordinates for the given light.
* Relevant when using maps with spot lights.
*
* @function
* @param {Light} light -The light source.
* @returns {Node<vec3>} The projected uvs.
*/
export function lightProjectionUV( light ) {
const data = getLightData( light );
if ( data.projectionUV === undefined ) {
const spotLightCoord = lightShadowMatrix( light ).mul( positionWorld );
data.projectionUV = spotLightCoord.xyz.div( spotLightCoord.w );
}
return data.projectionUV;
}
/**
* TSL function for getting the position in world space for the given light.
*
* @function
* @param {Light} light -The light source.
* @returns {UniformNode<vec3>} The light's position in world space.
*/
export function lightPosition( light ) {
const data = getLightData( light );
return data.position || ( data.position = uniform( new Vector3() ).setGroup( renderGroup ).onRenderUpdate( ( _, self ) => self.value.setFromMatrixPosition( light.matrixWorld ) ) );
}
/**
* TSL function for getting the light target position in world space for the given light.
*
* @function
* @param {Light} light -The light source.
* @returns {UniformNode<vec3>} The light target position in world space.
*/
export function lightTargetPosition( light ) {
const data = getLightData( light );
return data.targetPosition || ( data.targetPosition = uniform( new Vector3() ).setGroup( renderGroup ).onRenderUpdate( ( _, self ) => self.value.setFromMatrixPosition( light.target.matrixWorld ) ) );
}
/**
* TSL function for getting the position in view space for the given light.
*
* @function
* @param {Light} light -The light source.
* @returns {UniformNode<vec3>} The light's position in view space.
*/
export function lightViewPosition( light ) {
const data = getLightData( light );
return data.viewPosition || ( data.viewPosition = uniform( new Vector3() ).setGroup( renderGroup ).onRenderUpdate( ( { camera }, self ) => {
self.value = self.value || new Vector3();
self.value.setFromMatrixPosition( light.matrixWorld );
self.value.applyMatrix4( camera.matrixWorldInverse );
} ) );
}
/**
* TSL function for getting the light target direction for the given light.
*
* @function
* @param {Light} light -The light source.
* @returns {Node<vec3>} The light's target direction.
*/
export const lightTargetDirection = ( light ) => cameraViewMatrix.transformDirection( lightPosition( light ).sub( lightTargetPosition( light ) ) );