webgl_simple_gi

对应 three.js 示例地址 。

仅需关注 init 函数的内容，其他部分都是示例小程序所使用的描述配置。

example.js

import * as THREE from "three";
import { OrbitControls } from "three/examples/jsm/controls/OrbitControls.js";

/** @type {import("@minisheeep/mp-three-examples").OfficialExampleInfo} */
const exampleInfo = {
  name: "webgl_simple_gi",
  useLoaders: [],
  info: [
    [
      {
        tag: "a",
        link: "https://threejs.org",
        content: "three.js"
      },
      {
        tag: "text",
        content: "- simple global illumination ("
      },
      {
        tag: "a",
        link: "http://www.iquilezles.org/www/articles/simplegi/simplegi.htm",
        content: "article"
      },
      {
        tag: "text",
        content: ")"
      }
    ]
  ],
  init: ({ window, canvas, GUI, Stats, needToDispose, useFrame }) => {
    class GIMesh extends THREE.Mesh {
      copy(source) {
        super.copy(source);
        this.geometry = source.geometry.clone();
        return this;
      }
    }
    const SimpleGI = function(renderer2, scene2) {
      const SIZE = 32, SIZE2 = SIZE * SIZE;
      const camera2 = new THREE.PerspectiveCamera(90, 1, 0.01, 100);
      scene2.updateMatrixWorld(true);
      let clone = scene2.clone();
      clone.matrixWorldAutoUpdate = false;
      const rt = new THREE.WebGLRenderTarget(SIZE, SIZE);
      const normalMatrix = new THREE.Matrix3();
      const position = new THREE.Vector3();
      const normal = new THREE.Vector3();
      let bounces = 0;
      let currentVertex = 0;
      const color = new Float32Array(3);
      const buffer = new Uint8Array(SIZE2 * 4);
      function compute() {
        if (bounces === 3) return;
        const object = scene2.children[0];
        const geometry = object.geometry;
        const attributes = geometry.attributes;
        const positions = attributes.position.array;
        const normals = attributes.normal.array;
        if (attributes.color === void 0) {
          const colors2 = new Float32Array(positions.length);
          geometry.setAttribute(
            "color",
            new THREE.BufferAttribute(colors2, 3).setUsage(THREE.DynamicDrawUsage)
          );
        }
        const colors = attributes.color.array;
        const startVertex = currentVertex;
        const totalVertex = positions.length / 3;
        for (let i = 0; i < 32; i++) {
          if (currentVertex >= totalVertex) break;
          position.fromArray(positions, currentVertex * 3);
          position.applyMatrix4(object.matrixWorld);
          normal.fromArray(normals, currentVertex * 3);
          normal.applyMatrix3(normalMatrix.getNormalMatrix(object.matrixWorld)).normalize();
          camera2.position.copy(position);
          camera2.lookAt(position.add(normal));
          renderer2.setRenderTarget(rt);
          renderer2.render(clone, camera2);
          renderer2.readRenderTargetPixels(rt, 0, 0, SIZE, SIZE, buffer);
          color[0] = 0;
          color[1] = 0;
          color[2] = 0;
          for (let k = 0, kl = buffer.length; k < kl; k += 4) {
            color[0] += buffer[k + 0];
            color[1] += buffer[k + 1];
            color[2] += buffer[k + 2];
          }
          colors[currentVertex * 3 + 0] = color[0] / (SIZE2 * 255);
          colors[currentVertex * 3 + 1] = color[1] / (SIZE2 * 255);
          colors[currentVertex * 3 + 2] = color[2] / (SIZE2 * 255);
          currentVertex++;
        }
        attributes.color.addUpdateRange(startVertex * 3, (currentVertex - startVertex) * 3);
        attributes.color.needsUpdate = true;
        if (currentVertex >= totalVertex) {
          clone = scene2.clone();
          clone.matrixWorldAutoUpdate = false;
          bounces++;
          currentVertex = 0;
        }
        requestAnimationFrame(compute);
      }
      requestAnimationFrame(compute);
    };
    let camera, scene, renderer;
    init();
    function init() {
      camera = new THREE.PerspectiveCamera(70, window.innerWidth / window.innerHeight, 0.1, 100);
      camera.position.z = 4;
      scene = new THREE.Scene();
      const torusGeometry = new THREE.TorusKnotGeometry(0.75, 0.3, 128, 32, 1);
      const material = new THREE.MeshBasicMaterial({ vertexColors: true });
      const torusKnot = new GIMesh(torusGeometry, material);
      scene.add(torusKnot);
      const materials = [];
      for (let i = 0; i < 8; i++) {
        materials.push(
          new THREE.MeshBasicMaterial({ color: Math.random() * 16777215, side: THREE.BackSide })
        );
      }
      const boxGeometry = new THREE.BoxGeometry(3, 3, 3);
      const box = new THREE.Mesh(boxGeometry, materials);
      scene.add(box);
      renderer = new THREE.WebGLRenderer({ canvas });
      renderer.setPixelRatio(window.devicePixelRatio);
      renderer.setSize(window.innerWidth, window.innerHeight);
      renderer.setAnimationLoop(animate);
      new SimpleGI(renderer, scene);
      const controls = new OrbitControls(camera, renderer.domElement);
      controls.minDistance = 1;
      controls.maxDistance = 10;
      window.addEventListener("resize", onWindowResize);
      needToDispose(renderer, scene, controls);
    }
    function onWindowResize() {
      camera.aspect = window.innerWidth / window.innerHeight;
      camera.updateProjectionMatrix();
      renderer.setSize(window.innerWidth, window.innerHeight);
    }
    function animate() {
      renderer.setRenderTarget(null);
      renderer.render(scene, camera);
    }
  }
};
export {
  exampleInfo as default
};

typings.d.ts

import { Loader, TypedArray } from 'three';
/**
 * 官网示例的多端使用封装把版本
 * */
export interface OfficialExampleInfo extends MiniProgramMeta {
  /*** 示例名称（保持和官网一致）*/
  name: string;
  /** main */
  init: (context: LoadContext) => void;
}

export interface LoadContext {
  //为了减少官方代码的改动，实际上等同于 canvas
  window: EventTarget & { innerWidth: number; innerHeight: number; devicePixelRatio: number };
  /** HTMLCanvasElement */
  canvas: any;
  /** https://www.npmjs.com/package/lil-gui */
  GUI: any;
  /**
   * https://www.npmjs.com/package/stats.js
   * 也可以使用其他受支持的版本
   * */
  Stats: any;
  /** 收集需要 dispose 的对象（官方示例没有处理这部分）*/
  needToDispose: (...objs: any[]) => void | ((fromFn: () => any[]) => void);

  /**基于 raq 的通用封装 */
  useFrame(animateFunc: (/** ms */ delta: number) => void): { cancel: () => void };

  /** 显示加载模态框 */
  requestLoading(text?: string): Promise<void>;

  /** 隐藏加载模态框*/
  cancelLoading(): void;

  /** 保存文件的通用封装*/
  saveFile(
    fileName: string,
    data: ArrayBuffer | TypedArray | DataView | string
  ): Promise<string | null>;

  /** 示例使用 DracoDecoder 时的资源路径 */
  DecoderPath: {
    GLTF: string;
    STANDARD: string;
  };

  /** 为资源路径拼上 CDN 前缀 */
  withCDNPrefix(path: string): string;

  /**
   * 在小程序中应使用 import { VideoTexture } from '@minisheep/three-platform-adapter/override/jsm/textures/VideoTexture.js';
   * 正常情况（web） 可直接使用 THREE.VideoTexture
   * */
  getVideoTexture(videoOptions: VideoOptions): Promise<[{ isVideoTexture: true }, video: any]>;

  /**
   * 在小程序中应使用 import { CameraTexture } from '@minisheep/three-platform-adapter/override/jsm/textures/CameraTexture.js';
   * 正常情况（web） 可参考示例 webgl_materials_video_webcam
   * */
  getCameraTexture(): { isVideoTexture: true };

  /** 用于动态修改 info 中的占位符*/
  bindInfoText(template: `$${string}$`, initValue?: string): { value: string };

  /** 分屏控件对应的事件回调 */
  onSlideStart(handle: () => void): void;
  /** 分屏控件对应的事件回调 */
  onSlideEnd(handle: () => void): void;
  /** 分屏控件对应的事件回调 */
  onSlideChange(handle: (offset: number, boxSize: number) => void): void;
}

export type VideoOptions = {
  src: string;
  /** 相当于 HTMLVideoElement 的 naturalWidth (小程序中获取不到)*/
  width: number;
  /** 相当于 HTMLVideoElement 的 naturalHeight (小程序中获取不到)*/
  height: number;
  loop?: boolean;
  autoplay?: boolean;
  muted?: boolean;
};

/** 示例小程序中使用的一些配置 */
export interface MiniProgramMeta {
  /** 用于统计加载相关信息 */
  useLoaders: Loader[];
  /** 通用 info */
  info: TagItem[][];
  /** 特殊 info */
  infoPanel?: {
    left?: [string, string][];
    right?: [string, string][];
  };
  /** 分屏控件配置 */
  needSlider?: {
    /** 方向 */
    direction?: 'horizontal' | 'vertical';
    /** 初始偏移 0-100 */
    initPosition?: number;
  };
  /** 操作摇杆控件 */
  needArrowControls?: boolean;
  /** 默认需要的画布类型 */
  canvasType?: '2d' | 'webgl' | 'webgl2';
  /** 为保持效果一致所需要的画布样式 */
  canvasStyle?: {
    bgColor?: string;
    width?: number | string;
    height?: number | string;
  };
  /** 部分示例需要在加载前进行一些提示 */
  initAfterConfirm?: {
    /**
     * 提示类型
     * @default 'default'
     * */
    type?: 'warning' | 'default';
    text: string[];
  };
}

export interface BaseTag<T extends string> {
  tag: T;
  content: string;
}

export interface ATag extends BaseTag<'a'> {
  link: string;
}

export type TextTag = BaseTag<'text'>;

export type TagItem = TextTag | ATag;