@openhps/core/dist/esm/three/nodes/accessors/Lights.js

Open Hybrid Positioning System - Core component

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';
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.
 *
 * @tsl
 * @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.
 *
 * @tsl
 * @function
 * @param {Light} light -The light source.
 * @param {Node<vec3>} [position=positionWorld] -The position to project.
 * @returns {Node<vec3>} The projected uvs.
 */
export function lightProjectionUV(light, position = positionWorld) {
  const spotLightCoord = lightShadowMatrix(light).mul(position);
  const projectionUV = spotLightCoord.xyz.div(spotLightCoord.w);
  return projectionUV;
}

/**
 * TSL function for getting the position in world space for the given light.
 *
 * @tsl
 * @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.
 *
 * @tsl
 * @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.
 *
 * @tsl
 * @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.
 *
 * @tsl
 * @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)));