gpu-curtains/dist/esm/core/shaders/chunks/fragment/body/get-lambert-shading.mjs

gpu-curtains is a 3D WebGPU rendering engine. It can be used as a standalone 3D engine, but also includes extra classes focused on mapping 3d objects to DOM elements; It allows users to synchronize values such as position, sizing, or scale between them.

import { getPCFShadows } from './get-PCF-shadows.mjs';
import { applyDirectionalShadows } from './apply-directional-shadows.mjs';
import { applyPointShadows } from './apply-point-shadows.mjs';
import { applySpotShadows } from './apply-spot-shadows.mjs';

const getLambertShading = ({ receiveShadows = false } = {}) => {
  return (
    /* wgsl */
    `
  var directLight: DirectLight;
  var reflectedLight: ReflectedLight;
  
  ${receiveShadows ? getPCFShadows : ""}
  
  // point lights
  for(var i = 0; i < pointLights.count; i++) {
    getPointLightInfo(pointLights.elements[i], worldPosition, &directLight);
    
    if(!directLight.visible) {
      continue;
    }
    
    ${receiveShadows ? applyPointShadows : ""}
    getLambertDirect(normal, outputColor.rgb, directLight, &reflectedLight);
  }

  // spot lights
  for(var i = 0; i < spotLights.count; i++) {
    getSpotLightInfo(spotLights.elements[i], worldPosition, &directLight);
    
    if(!directLight.visible) {
      continue;
    }
    
    ${receiveShadows ? applySpotShadows : ""}
    getLambertDirect(normal, outputColor.rgb, directLight, &reflectedLight);
  }
  
  // directional lights
  for(var i = 0; i < directionalLights.count; i++) {
    getDirectionalLightInfo(directionalLights.elements[i], &directLight);
    
    if(!directLight.visible) {
      continue;
    }
    
    ${receiveShadows ? applyDirectionalShadows : ""}
    getLambertDirect(normal, outputColor.rgb, directLight, &reflectedLight);
  }
  
  // ambient lights
  var irradiance: vec3f = vec3(0.0);
  RE_IndirectDiffuse(irradiance, outputColor.rgb, &reflectedLight);
  
  let totalDirect: vec3f = reflectedLight.directDiffuse + reflectedLight.directSpecular;
  var totalIndirect: vec3f = reflectedLight.indirectDiffuse + reflectedLight.indirectSpecular;
  
  totalIndirect *= occlusion;
  
  var outgoingLight: vec3f = totalDirect + totalIndirect;`
  );
};

export { getLambertShading };