webgl_framebuffer_texture

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.jstypings.d.ts

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

/** @type {import("@minisheeep/mp-three-examples").OfficialExampleInfo} */
const exampleInfo = {
  name: "webgl_framebuffer_texture",
  useLoaders: [],
  info: [
    [
      {
        tag: "a",
        link: "https://threejs.org",
        content: "three.js"
      },
      {
        tag: "text",
        content: "framebuffer to texture"
      }
    ]
  ],
  init: ({ window, canvas, GUI, Stats, needToDispose, useFrame }) => {
    let camera, scene, renderer;
    let line, sprite, texture;
    let cameraOrtho, sceneOrtho;
    let offset = 0;
    const dpr = window.devicePixelRatio;
    const textureSize = 128;
    const vector = new THREE.Vector2();
    const color = new THREE.Color();
    init();
    function init() {
      const width = window.innerWidth;
      const height = window.innerHeight;
      camera = new THREE.PerspectiveCamera(70, width / height, 1, 1e3);
      camera.position.z = 20;
      cameraOrtho = new THREE.OrthographicCamera(
        -width / 2,
        width / 2,
        height / 2,
        -height / 2,
        1,
        10
      );
      cameraOrtho.position.z = 10;
      scene = new THREE.Scene();
      sceneOrtho = new THREE.Scene();
      const points = GeometryUtils.gosper(8);
      const geometry = new THREE.BufferGeometry();
      const positionAttribute = new THREE.Float32BufferAttribute(points, 3);
      geometry.setAttribute("position", positionAttribute);
      geometry.center();
      const colorAttribute = new THREE.BufferAttribute(
        new Float32Array(positionAttribute.array.length),
        3
      );
      colorAttribute.setUsage(THREE.DynamicDrawUsage);
      geometry.setAttribute("color", colorAttribute);
      const material = new THREE.LineBasicMaterial({ vertexColors: true });
      line = new THREE.Line(geometry, material);
      line.scale.setScalar(0.05);
      scene.add(line);
      texture = new THREE.FramebufferTexture(textureSize, textureSize);
      const spriteMaterial = new THREE.SpriteMaterial({ map: texture });
      sprite = new THREE.Sprite(spriteMaterial);
      sprite.scale.set(textureSize, textureSize, 1);
      sceneOrtho.add(sprite);
      updateSpritePosition();
      renderer = new THREE.WebGLRenderer({ antialias: true, canvas });
      renderer.setPixelRatio(window.devicePixelRatio);
      renderer.setSize(window.innerWidth, window.innerHeight);
      renderer.setAnimationLoop(animate);
      renderer.autoClear = false;
      const controls = new OrbitControls(camera, renderer.domElement);
      controls.enablePan = false;
      window.addEventListener("resize", onWindowResize);
      needToDispose(renderer, scene, controls);
    }
    function onWindowResize() {
      const width = window.innerWidth;
      const height = window.innerHeight;
      camera.aspect = width / height;
      camera.updateProjectionMatrix();
      cameraOrtho.left = -width / 2;
      cameraOrtho.right = width / 2;
      cameraOrtho.top = height / 2;
      cameraOrtho.bottom = -height / 2;
      cameraOrtho.updateProjectionMatrix();
      renderer.setSize(window.innerWidth, window.innerHeight);
      updateSpritePosition();
    }
    function updateSpritePosition() {
      const halfWidth = window.innerWidth / 2;
      const halfHeight = window.innerHeight / 2;
      const halfImageWidth = textureSize / 2;
      const halfImageHeight = textureSize / 2;
      sprite.position.set(-halfWidth + halfImageWidth, halfHeight - halfImageHeight, 1);
    }
    function animate() {
      const colorAttribute = line.geometry.getAttribute("color");
      updateColors(colorAttribute);
      renderer.clear();
      renderer.render(scene, camera);
      vector.x = window.innerWidth * dpr / 2 - textureSize / 2;
      vector.y = window.innerHeight * dpr / 2 - textureSize / 2;
      renderer.copyFramebufferToTexture(texture, vector);
      renderer.clearDepth();
      renderer.render(sceneOrtho, cameraOrtho);
    }
    function updateColors(colorAttribute) {
      const l = colorAttribute.count;
      for (let i = 0; i < l; i++) {
        const h = (offset + i) % l / l;
        color.setHSL(h, 1, 0.5);
        colorAttribute.setX(i, color.r);
        colorAttribute.setY(i, color.g);
        colorAttribute.setZ(i, color.b);
      }
      colorAttribute.needsUpdate = true;
      offset -= 25;
    }
  }
};
export {
  exampleInfo as default
};

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;

webgl_framebuffer_texture ​

webgl_framebuffer_texture