webgl_buffergeometry_instancing

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";

/** @type {import("@minisheeep/mp-three-examples").OfficialExampleInfo} */
const exampleInfo = {
  name: "webgl_buffergeometry_instancing",
  useLoaders: [],
  info: [
    [
      {
        tag: "a",
        link: "https://threejs.org",
        content: "three.js"
      },
      {
        tag: "text",
        content: "- instancing demo (single triangle)"
      }
    ]
  ],
  init: ({ window, canvas, GUI, Stats, needToDispose, useFrame }) => {
    let stats;
    let camera, scene, renderer;
    init();
    function init() {
      camera = new THREE.PerspectiveCamera(50, window.innerWidth / window.innerHeight, 1, 10);
      camera.position.z = 2;
      scene = new THREE.Scene();
      const vector = new THREE.Vector4();
      const instances = 5e4;
      const positions = [];
      const offsets = [];
      const colors = [];
      const orientationsStart = [];
      const orientationsEnd = [];
      positions.push(0.025, -0.025, 0);
      positions.push(-0.025, 0.025, 0);
      positions.push(0, 0, 0.025);
      for (let i = 0; i < instances; i++) {
        offsets.push(Math.random() - 0.5, Math.random() - 0.5, Math.random() - 0.5);
        colors.push(Math.random(), Math.random(), Math.random(), Math.random());
        vector.set(
          Math.random() * 2 - 1,
          Math.random() * 2 - 1,
          Math.random() * 2 - 1,
          Math.random() * 2 - 1
        );
        vector.normalize();
        orientationsStart.push(vector.x, vector.y, vector.z, vector.w);
        vector.set(
          Math.random() * 2 - 1,
          Math.random() * 2 - 1,
          Math.random() * 2 - 1,
          Math.random() * 2 - 1
        );
        vector.normalize();
        orientationsEnd.push(vector.x, vector.y, vector.z, vector.w);
      }
      const geometry = new THREE.InstancedBufferGeometry();
      geometry.instanceCount = instances;
      geometry.setAttribute("position", new THREE.Float32BufferAttribute(positions, 3));
      geometry.setAttribute(
        "offset",
        new THREE.InstancedBufferAttribute(new Float32Array(offsets), 3)
      );
      geometry.setAttribute(
        "color",
        new THREE.InstancedBufferAttribute(new Float32Array(colors), 4)
      );
      geometry.setAttribute(
        "orientationStart",
        new THREE.InstancedBufferAttribute(new Float32Array(orientationsStart), 4)
      );
      geometry.setAttribute(
        "orientationEnd",
        new THREE.InstancedBufferAttribute(new Float32Array(orientationsEnd), 4)
      );
      const material = new THREE.RawShaderMaterial({
        uniforms: {
          time: { value: 1 },
          sineTime: { value: 1 }
        },
        vertexShader: `
		precision highp float;
		uniform float sineTime;
		uniform mat4 modelViewMatrix;
		uniform mat4 projectionMatrix;
		attribute vec3 position;
		attribute vec3 offset;
		attribute vec4 color;
		attribute vec4 orientationStart;
		attribute vec4 orientationEnd;
		varying vec3 vPosition;
		varying vec4 vColor;
		void main(){
			vPosition = offset * max( abs( sineTime * 2.0 + 1.0 ), 0.5 ) + position;
			vec4 orientation = normalize( mix( orientationStart, orientationEnd, sineTime ) );
			vec3 vcV = cross( orientation.xyz, vPosition );
			vPosition = vcV * ( 2.0 * orientation.w ) + ( cross( orientation.xyz, vcV ) * 2.0 + vPosition );
			vColor = color;
			gl_Position = projectionMatrix * modelViewMatrix * vec4( vPosition, 1.0 );
		}
	`,
        fragmentShader: `
		precision highp float;
		uniform float time;
		varying vec3 vPosition;
		varying vec4 vColor;
		void main() {
			vec4 color = vec4( vColor );
			color.r += sin( vPosition.x * 10.0 + time ) * 0.5;
			gl_FragColor = color;
		}
	`,
        side: THREE.DoubleSide,
        forceSinglePass: true,
        transparent: true
      });
      const mesh = new THREE.Mesh(geometry, material);
      scene.add(mesh);
      renderer = new THREE.WebGLRenderer({ canvas });
      renderer.setPixelRatio(window.devicePixelRatio);
      renderer.setSize(window.innerWidth, window.innerHeight);
      renderer.setAnimationLoop(animate);
      const gui = new GUI({ width: 350 });
      gui.add(geometry, "instanceCount", 0, instances);
      stats = new Stats(renderer);
      window.addEventListener("resize", onWindowResize);
      needToDispose(renderer, scene);
    }
    function onWindowResize() {
      camera.aspect = window.innerWidth / window.innerHeight;
      camera.updateProjectionMatrix();
      renderer.setSize(window.innerWidth, window.innerHeight);
    }
    function animate() {
      const time = Date.now();
      const object = scene.children[0];
      object.rotation.y = time * 5e-4;
      object.material.uniforms["time"].value = time * 5e-3;
      object.material.uniforms["sineTime"].value = Math.sin(
        object.material.uniforms["time"].value * 0.05
      );
      renderer.render(scene, camera);
      stats.update();
    }
  }
};
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;