webgl_texture2darray_layerupdate

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 { KTX2Loader } from "three/examples/jsm/loaders/KTX2Loader.js";

/** @type {import("@minisheeep/mp-three-examples").OfficialExampleInfo} */
const exampleInfo = {
  name: "webgl_texture2darray_layerupdate",
  useLoaders: [KTX2Loader],
  info: [
    [
      {
        tag: "a",
        link: "https://threejs.org",
        content: "three.js"
      },
      {
        tag: "text",
        content: "- 2D Compressed Texture Array Layer Updates"
      }
    ],
    [
      {
        tag: "text",
        content: "Loop from the movie Spirited away by the"
      },
      {
        tag: "a",
        link: "https://www.ghibli.jp/",
        content: "Studio Ghibli"
      }
    ]
  ],
  init: ({ window, canvas, GUI, Stats, needToDispose, useFrame }) => {
    let camera, scene, mesh, renderer;
    const planeWidth = 20;
    const planeHeight = 10;
    init();
    async function init() {
      camera = new THREE.PerspectiveCamera(45, window.innerWidth / window.innerHeight, 0.1, 2e3);
      camera.position.z = 70;
      scene = new THREE.Scene();
      renderer = new THREE.WebGLRenderer({ antialias: true, canvas });
      renderer.setPixelRatio(window.devicePixelRatio);
      renderer.setSize(window.innerWidth, window.innerHeight);
      const ktx2Loader = new KTX2Loader();
      ktx2Loader.setTranscoderPath("jsm/libs/basis/");
      ktx2Loader.detectSupport(renderer);
      const spiritedaway = await ktx2Loader.loadAsync("textures/spiritedaway.ktx2");
      const layerByteLength = THREE.TextureUtils.getByteLength(
        spiritedaway.image.width,
        spiritedaway.image.height,
        spiritedaway.format,
        spiritedaway.type
      );
      const textureArray = new THREE.CompressedArrayTexture(
        [
          {
            data: new Uint8Array(layerByteLength * 3),
            width: spiritedaway.image.width,
            height: spiritedaway.image.height
          }
        ],
        spiritedaway.image.width,
        spiritedaway.image.height,
        3,
        spiritedaway.format,
        spiritedaway.type
      );
      const formData = {
        srcLayer: 0,
        destLayer: 0,
        transfer() {
          const layerElementLength = layerByteLength / spiritedaway.mipmaps[0].data.BYTES_PER_ELEMENT;
          textureArray.mipmaps[0].data.set(
            spiritedaway.mipmaps[0].data.subarray(
              layerElementLength * (formData.srcLayer % spiritedaway.image.depth),
              layerElementLength * (formData.srcLayer % spiritedaway.image.depth + 1)
            ),
            layerByteLength * formData.destLayer
          );
          textureArray.addLayerUpdate(formData.destLayer);
          textureArray.needsUpdate = true;
          renderer.render(scene, camera);
        }
      };
      const gui = new GUI();
      gui.add(formData, "srcLayer", 0, spiritedaway.image.depth - 1, 1);
      gui.add(formData, "destLayer", 0, textureArray.image.depth - 1, 1);
      gui.add(formData, "transfer");
      const material = new THREE.ShaderMaterial({
        uniforms: {
          diffuse: { value: textureArray },
          size: { value: new THREE.Vector2(planeWidth, planeHeight) }
        },
        vertexShader: `
	uniform vec2 size;
	attribute uint instancedIndex;
	flat out uint diffuseIndex;
	out vec2 vUv;

	void main() {

		vec3 translation = vec3(0, float(instancedIndex) * size.y - size.y, 0);
		gl_Position = projectionMatrix * modelViewMatrix * vec4( position + translation, 1.0 );

		diffuseIndex = instancedIndex;

		// Convert position.xy to 1.0-0.0

		vUv.xy = position.xy / size + 0.5;
		vUv.y = 1.0 - vUv.y; // original data is upside down

	}
	`,
        fragmentShader: `
	precision highp float;
	precision highp int;
	precision highp sampler2DArray;

	uniform sampler2DArray diffuse;
	in vec2 vUv;
	flat in uint diffuseIndex;

	out vec4 outColor;

	void main() {

		outColor = texture( diffuse, vec3( vUv, diffuseIndex ) );

	}
	`,
        glslVersion: THREE.GLSL3
      });
      const geometry = new THREE.InstancedBufferGeometry();
      geometry.copy(new THREE.PlaneGeometry(planeWidth, planeHeight));
      geometry.instanceCount = 3;
      const instancedIndexAttribute = new THREE.InstancedBufferAttribute(
        new Uint16Array([0, 1, 2]),
        1,
        false,
        1
      );
      instancedIndexAttribute.gpuType = THREE.IntType;
      geometry.setAttribute("instancedIndex", instancedIndexAttribute);
      mesh = new THREE.InstancedMesh(geometry, material, 3);
      scene.add(mesh);
      window.addEventListener("resize", onWindowResize);
      textureArray.mipmaps[0].data.set(
        spiritedaway.mipmaps[0].data.subarray(0, textureArray.mipmaps[0].data.length)
      );
      textureArray.needsUpdate = true;
      renderer.render(scene, camera);
      needToDispose(renderer, scene);
    }
    function onWindowResize() {
      renderer.setSize(window.innerWidth, window.innerHeight);
      camera.aspect = window.innerWidth / window.innerHeight;
      camera.updateProjectionMatrix();
      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;