webgl_depth_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.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_depth_texture",
  useLoaders: [],
  info: [
    [
      {
        tag: "a",
        link: "https://threejs.org",
        content: "threejs"
      },
      {
        tag: "text",
        content: "webgl - depth texture"
      }
    ],
    [
      {
        tag: "text",
        content: "Stores render target depth in a texture            attachment."
      }
    ],
    [
      {
        tag: "text",
        content: "Created by"
      },
      {
        tag: "a",
        link: "http://twitter.com/mattdesl",
        content: "@mattdesl"
      },
      {
        tag: "text",
        content: "."
      }
    ]
  ],
  init: ({ window, canvas, GUI, Stats, needToDispose, useFrame }) => {
    let camera, scene, renderer, controls, stats;
    let target;
    let postScene, postCamera, postMaterial;
    const params = {
      format: THREE.DepthFormat,
      type: THREE.UnsignedShortType,
      samples: 0
    };
    const formats = {
      DepthFormat: THREE.DepthFormat,
      DepthStencilFormat: THREE.DepthStencilFormat
    };
    const types = {
      UnsignedShortType: THREE.UnsignedShortType,
      UnsignedIntType: THREE.UnsignedIntType,
      FloatType: THREE.FloatType
    };
    init();
    function init() {
      renderer = new THREE.WebGLRenderer({ canvas });
      renderer.setPixelRatio(window.devicePixelRatio);
      renderer.setSize(window.innerWidth, window.innerHeight);
      renderer.setAnimationLoop(animate);
      stats = new Stats(renderer);
      camera = new THREE.PerspectiveCamera(70, window.innerWidth / window.innerHeight, 0.01, 50);
      camera.position.z = 4;
      controls = new OrbitControls(camera, renderer.domElement);
      controls.enableDamping = true;
      setupRenderTarget();
      setupScene();
      setupPost();
      onWindowResize();
      window.addEventListener("resize", onWindowResize);
      const gui = new GUI({ width: 300 });
      gui.add(params, "format", formats).onChange(setupRenderTarget);
      gui.add(params, "type", types).onChange(setupRenderTarget);
      gui.add(params, "samples", 0, 16, 1).onChange(setupRenderTarget);
      gui.open();
      needToDispose(renderer, scene);
    }
    function setupRenderTarget() {
      if (target) target.dispose();
      const format = parseInt(params.format);
      const type = parseInt(params.type);
      const samples = parseInt(params.samples);
      const dpr = renderer.getPixelRatio();
      target = new THREE.WebGLRenderTarget(window.innerWidth * dpr, window.innerHeight * dpr);
      target.texture.minFilter = THREE.NearestFilter;
      target.texture.magFilter = THREE.NearestFilter;
      target.stencilBuffer = format === THREE.DepthStencilFormat ? true : false;
      target.samples = samples;
      target.depthTexture = new THREE.DepthTexture();
      target.depthTexture.format = format;
      target.depthTexture.type = type;
    }
    function setupPost() {
      postCamera = new THREE.OrthographicCamera(-1, 1, 1, -1, 0, 1);
      postMaterial = new THREE.ShaderMaterial({
        vertexShader: `
			varying vec2 vUv;

			void main() {
				vUv = uv;
				gl_Position = projectionMatrix * modelViewMatrix * vec4(position, 1.0);
			}
		`,
        fragmentShader: `
			#include <packing>

			varying vec2 vUv;
			uniform sampler2D tDiffuse;
			uniform sampler2D tDepth;
			uniform float cameraNear;
			uniform float cameraFar;


			float readDepth( sampler2D depthSampler, vec2 coord ) {
				float fragCoordZ = texture2D( depthSampler, coord ).x;
				float viewZ = perspectiveDepthToViewZ( fragCoordZ, cameraNear, cameraFar );
				return viewZToOrthographicDepth( viewZ, cameraNear, cameraFar );
			}

			void main() {
				//vec3 diffuse = texture2D( tDiffuse, vUv ).rgb;
				float depth = readDepth( tDepth, vUv );

				gl_FragColor.rgb = 1.0 - vec3( depth );
				gl_FragColor.a = 1.0;
			}
		`,
        uniforms: {
          cameraNear: { value: camera.near },
          cameraFar: { value: camera.far },
          tDiffuse: { value: null },
          tDepth: { value: null }
        }
      });
      const postPlane = new THREE.PlaneGeometry(2, 2);
      const postQuad = new THREE.Mesh(postPlane, postMaterial);
      postScene = new THREE.Scene();
      postScene.add(postQuad);
      needToDispose(postScene);
    }
    function setupScene() {
      scene = new THREE.Scene();
      const geometry = new THREE.TorusKnotGeometry(1, 0.3, 128, 64);
      const material = new THREE.MeshBasicMaterial({ color: "blue" });
      const count = 50;
      const scale = 5;
      for (let i = 0; i < count; i++) {
        const r = Math.random() * 2 * Math.PI;
        const z = Math.random() * 2 - 1;
        const zScale = Math.sqrt(1 - z * z) * scale;
        const mesh = new THREE.Mesh(geometry, material);
        mesh.position.set(Math.cos(r) * zScale, Math.sin(r) * zScale, z * scale);
        mesh.rotation.set(Math.random(), Math.random(), Math.random());
        scene.add(mesh);
      }
    }
    function onWindowResize() {
      const aspect = window.innerWidth / window.innerHeight;
      camera.aspect = aspect;
      camera.updateProjectionMatrix();
      const dpr = renderer.getPixelRatio();
      target.setSize(window.innerWidth * dpr, window.innerHeight * dpr);
      renderer.setSize(window.innerWidth, window.innerHeight);
    }
    function animate() {
      renderer.setRenderTarget(target);
      renderer.render(scene, camera);
      postMaterial.uniforms.tDiffuse.value = target.texture;
      postMaterial.uniforms.tDepth.value = target.depthTexture;
      renderer.setRenderTarget(null);
      renderer.render(postScene, postCamera);
      controls.update();
      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;