webgl_read_float_buffer
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。
js
import * as THREE from "three";
/** @type {import("@minisheeep/mp-three-examples").OfficialExampleInfo} */
const exampleInfo = {
name: "webgl_read_float_buffer",
useLoaders: [],
info: [
[
{
tag: "a",
link: "https://threejs.org",
content: "three.js"
},
{
tag: "text",
content: "read linear-srgb float pixel data"
}
],
[
{
tag: "text",
content: "$valueNode$"
}
]
],
init: ({ window, canvas, GUI, Stats, needToDispose, useFrame, bindInfoText }) => {
let stats;
let cameraRTT, sceneRTT, sceneScreen, renderer, zmesh1, zmesh2;
let mouseX = 0, mouseY = 0;
const valueNode = bindInfoText("$valueNode$");
const windowHalfX = window.innerWidth / 2;
const windowHalfY = window.innerHeight / 2;
let rtTexture, material, quad;
let delta = 0.01;
init();
function init() {
cameraRTT = new THREE.OrthographicCamera(
window.innerWidth / -2,
window.innerWidth / 2,
window.innerHeight / 2,
window.innerHeight / -2,
-1e4,
1e4
);
cameraRTT.position.z = 100;
sceneRTT = new THREE.Scene();
sceneScreen = new THREE.Scene();
let light = new THREE.DirectionalLight(16777215, 3);
light.position.set(0, 0, 1).normalize();
sceneRTT.add(light);
light = new THREE.DirectionalLight(16766421, 4.5);
light.position.set(0, 0, -1).normalize();
sceneRTT.add(light);
rtTexture = new THREE.WebGLRenderTarget(window.innerWidth, window.innerHeight, {
minFilter: THREE.LinearFilter,
magFilter: THREE.NearestFilter,
format: THREE.RGBAFormat,
type: THREE.FloatType
});
material = new THREE.ShaderMaterial({
uniforms: { time: { value: 0 } },
vertexShader: `
varying vec2 vUv;
void main() {
vUv = uv;
gl_Position = projectionMatrix * modelViewMatrix * vec4( position, 1.0 );
}
`,
fragmentShader: `
varying vec2 vUv;
uniform float time;
void main() {
float r = vUv.x;
if( vUv.y < 0.5 ) r = 0.0;
float g = vUv.y;
if( vUv.x < 0.5 ) g = 0.0;
gl_FragColor = vec4( r, g, time, 1.0 );
}
`
});
const materialScreen = new THREE.ShaderMaterial({
uniforms: { tDiffuse: { value: rtTexture.texture } },
vertexShader: `
varying vec2 vUv;
void main() {
vUv = uv;
gl_Position = projectionMatrix * modelViewMatrix * vec4( position, 1.0 );
}
`,
fragmentShader: `
varying vec2 vUv;
uniform sampler2D tDiffuse;
void main() {
gl_FragColor = texture2D( tDiffuse, vUv );
#include <colorspace_fragment>
}
`,
depthWrite: false
});
const plane = new THREE.PlaneGeometry(window.innerWidth, window.innerHeight);
quad = new THREE.Mesh(plane, material);
quad.position.z = -100;
sceneRTT.add(quad);
const geometry = new THREE.TorusGeometry(100, 25, 15, 30);
const mat1 = new THREE.MeshPhongMaterial({
color: 10263708,
specular: 16755200,
shininess: 5
});
const mat2 = new THREE.MeshPhongMaterial({
color: 10223616,
specular: 16720384,
shininess: 5
});
zmesh1 = new THREE.Mesh(geometry, mat1);
zmesh1.position.set(0, 0, 100);
zmesh1.scale.set(1.5, 1.5, 1.5);
sceneRTT.add(zmesh1);
zmesh2 = new THREE.Mesh(geometry, mat2);
zmesh2.position.set(0, 150, 100);
zmesh2.scale.set(0.75, 0.75, 0.75);
sceneRTT.add(zmesh2);
quad = new THREE.Mesh(plane, materialScreen);
quad.position.z = -100;
sceneScreen.add(quad);
renderer = new THREE.WebGLRenderer({ canvas });
renderer.setPixelRatio(window.devicePixelRatio);
renderer.setSize(window.innerWidth, window.innerHeight);
renderer.setAnimationLoop(animate);
renderer.autoClear = false;
stats = new Stats(renderer);
canvas.addEventListener("pointermove", onDocumentMouseMove);
needToDispose(renderer, sceneRTT, sceneScreen);
}
function onDocumentMouseMove(event) {
mouseX = event.clientX - windowHalfX;
mouseY = event.clientY - windowHalfY;
}
function animate() {
render();
stats.update();
}
function render() {
const time = Date.now() * 15e-4;
if (zmesh1 && zmesh2) {
zmesh1.rotation.y = -time;
zmesh2.rotation.y = -time + Math.PI / 2;
}
if (material.uniforms["time"].value > 1 || material.uniforms["time"].value < 0) {
delta *= -1;
}
material.uniforms["time"].value += delta;
renderer.clear();
renderer.setRenderTarget(rtTexture);
renderer.clear();
renderer.render(sceneRTT, cameraRTT);
renderer.setRenderTarget(null);
renderer.render(sceneScreen, cameraRTT);
const read = new Float32Array(4);
renderer.readRenderTargetPixels(
rtTexture,
windowHalfX + mouseX,
windowHalfY - mouseY,
1,
1,
read
);
valueNode.value = "r:" + read[0] + "<br/>g:" + read[1] + "<br/>b:" + read[2];
}
}
};
export {
exampleInfo as default
};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;