Canvas是一个HTML元素，允许2D和3D中的2D形状，3D形状，位图图像和动画的动态，可编写脚本的渲染。
我需要提供文本大纲。这些文字表示例如：可以是联赛名称，如巴克莱超级联赛、国家橄榄球联盟等。 我最接近的跨浏览器支持是 fr...
我正在学习JS，尝试编写一个简单的游戏。所以我做了一个基本结构，应该看起来像这样（伪C++代码）： if (!game.game_stage) 游戏.reset_game(); // 初始化...
这里大脑图像上的红绿等颜色是掩模层，这意味着死亡的细胞和感染的细胞。由于它是演示图像，但在真实图像中这种颜色不会出现...
这是我的 HTML、CSS、JAVASCRIPT (THREE.JS) 代码。 您能否分析代码并检查我在标题中放入的所需输出。 //**HTML代码** 这是我的 HTML、CSS、JAVASCRIPT (THREE.JS) 代码。 您能分析一下代码并检查我在标题中放入的所需输出吗？ //**HTMLCODE** <!DOCTYPE html> <html lang="en"> <head> <meta charset="utf-8" /> <link rel="icon" href="%PUBLIC_URL%/favicon.ico" /> <meta name="viewport" content="width=device-width, initial-scale=1" /> <meta name="theme-color" content="#000000" /> <link rel="stylesheet" href="/src/index.css" /> <script type="importmap"> { "imports": { "three": "https://unpkg.com/[email protected]/build/three.module.js", "three/addons/": "https://unpkg.com/[email protected]/examples/jsm/" } } </script> <meta name="description" content="Web site created using create-react-app" /> <link rel="manifest" href="%PUBLIC_URL%/manifest.json" /> <title>EXAMPLE</title> </head> <body> <div id="root"></div> <div class="globe-render" id="globe-render"> <script type="module" src="./globe.js"></script> </div> </body> </html> **//CSS CODE:** @tailwind base; @tailwind components; @tailwind utilities; body { background-color: #000f14; margin: 0; position: relative; font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "Roboto", "Oxygen", "Ubuntu", "Cantarell", "Fira Sans", "Droid Sans", "Helvetica Neue", sans-serif; -webkit-font-smoothing: antialiased; -moz-osx-font-smoothing: grayscale; } code { font-family: source-code-pro, Menlo, Monaco, Consolas, "Courier New", monospace; } #globe-render { position: absolute; top: -20%; left: 20%; background-color: rgb(255, 255, 255); } #myCanvas { position: absolute; background-color: green; } //JS CODE import * as THREE from "three"; import { OrbitControls } from "three/addons/controls/OrbitControls.js"; import { EffectComposer } from "three/addons/postprocessing/EffectComposer.js"; import { RenderPass } from "three/addons/postprocessing/RenderPass.js"; import { UnrealBloomPass } from "three/addons/postprocessing/UnrealBloomPass.js"; //Radius define let ParticleSurfaceLayer = 7.5; let GlobeRadius = 6.6; const scene = new THREE.Scene(); const camera = new THREE.PerspectiveCamera( 75, window.innerWidth / window.innerHeight, 0.1, 1000 ); const renderer = new THREE.WebGLRenderer({ alpha: true }); renderer.setSize(window.innerWidth, window.innerHeight); const container = document.querySelector(".globe-render"); renderer.setClearColor(0x000000,0); container.appendChild(renderer.domElement); // Group for globe and particle system const group = new THREE.Group(); scene.add(group); // Bloom pass for the globe const renderScene = new RenderPass(scene, camera); const globeBloomPass = new UnrealBloomPass( new THREE.Vector2(window.innerWidth, window.innerHeight), 1.5, 0.4, 0.85 ); globeBloomPass.threshold = 0; globeBloomPass.strength = 2; globeBloomPass.radius = 0; const globeComposer = new EffectComposer(renderer); globeComposer.setSize(window.innerWidth, window.innerHeight); globeComposer.addPass(renderScene); globeComposer.addPass(globeBloomPass); // Bloom pass for particles const particleComposer = new EffectComposer(renderer); particleComposer.setSize(window.innerWidth, window.innerHeight); particleComposer.addPass(new RenderPass(group, camera)); // Assuming 'group' contains particles const particleBloomPass = new UnrealBloomPass( new THREE.Vector2(window.innerWidth, window.innerHeight), 1.5, 0.4, 0.85 ); particleBloomPass.threshold = 0; particleBloomPass.strength = 1.3; particleBloomPass.radius = 0.8; particleComposer.addPass(particleBloomPass); // Update size function function updateSize() { const newWidth = window.innerWidth; const newHeight = window.innerHeight; camera.aspect = newWidth / newHeight; camera.updateProjectionMatrix(); renderer.setSize(newWidth, newHeight); const sphereRadius = Math.min(newWidth, newHeight) * 0.1; globe.geometry = new THREE.SphereGeometry(sphereRadius, 32, 32); const particleSizeMin = Math.min(newWidth, newHeight) * 0.001; const particleSizeMax = Math.min(newWidth, newHeight) * 0.004; group.children.forEach((particle) => { const randomSize = THREE.MathUtils.randFloat( particleSizeMin, particleSizeMax ); particle.scale.set(randomSize, randomSize, randomSize); }); // Update composer sizes globeComposer.setSize(newWidth, newHeight); particleComposer.setSize(newWidth, newHeight); } //orbit controls const controls = new OrbitControls(camera, renderer.domElement); const loader = new THREE.TextureLoader(); controls.enableZoom = false; // controls.enabled=false // Initial setup //////// const geometry = new THREE.SphereGeometry(GlobeRadius, 80, 80); const material1 = new THREE.MeshBasicMaterial({ map: loader.load("./8k_earth_nightmap_underlayer.jpg"), //transparent: true, opacity: 1, }); const material2 = new THREE.MeshBasicMaterial({ color: 0xff047e, transparent: true, opacity: 0.1, }); const multimaterial = [material1, material2]; const globe = new THREE.Mesh(geometry, material1); globe.layers.set(1); group.add(globe); // Particle System const particleCount = 600; const color = new THREE.Color("#fc2414"); for (let i = 0; i < particleCount; i++) { // ... (same as your code) const phi = Math.random() * Math.PI * 2; const theta = Math.random() * Math.PI - Math.PI / 2; const randomradius = 0.01 + Math.random() * 0.04; const radius = ParticleSurfaceLayer; // Radius of the sphere const x = radius * Math.cos(theta) * Math.cos(phi); const y = radius * Math.cos(theta) * Math.sin(phi); const z = radius * Math.sin(theta); const particleGeometry = new THREE.SphereGeometry(randomradius, 30, 25); // Initial size const particleMaterial = new THREE.MeshBasicMaterial({ color: "#00FFFF", }); const particle = new THREE.Mesh(particleGeometry, particleMaterial); particle.position.set(x, y, z); particle.layers.set(1); group.add(particle); } const ambientLight = new THREE.AmbientLight(0xffffff, 100); scene.add(ambientLight); // Camera position camera.position.z = 15; // Rotation animation const rotationSpeed = 0.001; // Animation function const animate = function () { requestAnimationFrame(animate); group.rotation.y += rotationSpeed; // Render globe with bloom effect camera.layers.set(1); globeComposer.render(); // Render particles with bloom effect particleComposer.render(); }; ///////orbit controls///* let isDragging = false; let originalRotation = group.rotation.y; // Event listener for mouse down renderer.domElement.addEventListener("mousedown", () => { isDragging = true; }); // Event listener for mouse up renderer.domElement.addEventListener("mouseup", () => { isDragging = false; // Reset the rotation to its original position group.rotation.y = originalRotation; }); // Event listener for mouse leave (in case mouse leaves the canvas while dragging) renderer.domElement.addEventListener("mouseleave", () => { if (isDragging) { isDragging = false; // Reset the rotation to its original position group.rotation.y = originalRotation; } }); // Handle window resize window.addEventListener("resize", updateSize); // Start animation animate(); const canvas = document.querySelector("canvas"); canvas.id = "myCanvas"; canvas.classList.add("myCanvasClass"); 我在js中尝试了setClearColor，在canvas的css块中尝试了透明。 我希望画布从黑色背景转换为透明。请有人帮忙。 我认为，您使用的通行证可能有问题。如果删除这些通行证仍然不起作用？因为有些通行证可能存在透明度问题。 尝试设置 webgl 目标并添加 RGBA 格式，它应该有助于解决问题。有示例代码，这应该有助于提高透明度。 const canvas = this.renderer.domElement; const width = canvas.clientWidth * this.pixelRatio | 0; const height = canvas.clientHeight * this.pixelRatio | 0; const parameters = { minFilter: THREE.LinearFilter, magFilter: THREE.LinearFilter, format: THREE.RGBAFormat, stencilBuffer: false }; const renderTarget = new THREE.WebGLRenderTarget(width, height, parameters); renderTarget.texture.encoding = QUnityCore.instance.renderManager.renderer.outputEncoding const composer = new EffectComposer(this.renderer, renderTarget); composer.renderToScreen = false; 或者您可以在此线程中找到更多信息。我希望这对你有帮助。
我想将文档的所有图像src更改为dataURL。 我试图通过 for of 循环在画布上绘制所有图像，但它不起作用。 帮我！ &l...
我有 js 函数，每 40 毫秒（0.04 秒）运行一次用于动画目的。在下面的代码中您将看到的函数中，我在 html canvas elem 中加载了一张图片。显然有时图片...
如何修复在 Angular 中创建画布时未定义 Document
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尝试创建一个用于创建按钮的类，但没有通过 Canvas Context 获得它
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我看了这个视频，并尝试在画布上做同样的事情 这是代码（没有大小增量） canvas = document.getElementById("canvas"); ctx = canvas.getContext("2d"); canvas.width = parseInt(
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我正在将现有的 Chart JS 2 代码迁移到 3.9.1 并将 Angular 14 升级到 16。这是我的代码： 图表线.component.html 我正在将现有的 Chart JS 2 代码迁移到 3.9.1 并将 Angular 14 升级到 16。这是我的代码： 图表线.component.html <!--chart container --> <div id="container"> <div id="scrollArea" class="CMI-ChartWrapper"> <div class="CMI-Chart"> <canvas baseChart #lineCanvas [id]="idChartname"></canvas> </div> </div> <canvas #targetCanvas id="chartAxis" height="400"></canvas> </div> 图表线.component.ts import { Component, OnInit, ViewChild, ElementRef, Input, OnDestroy } from "@angular/core"; import Chart from "chart.js/auto"; import ChartDataLabels from 'chartjs-plugin-datalabels'; import { DataServiceService } from 'src/app/services/data-service/data-service.service'; import { data } from '../data'; @Component({ selector: 'app-chart-line', templateUrl: './chart-line.component.html', styleUrls: ['./chart-line.component.scss'], }) export class ChartLineComponent implements OnInit, OnDestroy { @ViewChild('scroll') scroll: any; @ViewChild('targetCanvas', { static: true }) targetCanvasRef: ElementRef<HTMLCanvasElement>; 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}); return filteredYearData; } else if (filterParams.selectedYear == '' || filterParams.selectedYear == 'none') { var filterYear = newChartData.filter(item => { return item['year'].toLowerCase().includes(filterParams.searchTerm.toLowerCase()); }) var filterProfit = newChartData.filter(item => { return item['profit'].toLowerCase().includes(filterParams.searchTerm.toLowerCase()); }) if (filterProfit.length == 0) { filterProfit = filterYear } var filterValue = newChartData.filter(item => { return item['value'].toLowerCase().includes(filterParams.searchTerm.toLowerCase()); }) if (filterValue.length == 0) { filterValue = filterProfit } return filterValue; } else { var filteredYearData = [] filterParams.selectedYear.forEach(element => { var newItem = newChartData.filter(item => { return item['year'].toLowerCase().includes(element); }) filteredYearData.push(newItem[0]); }); var filterYear = filteredYearData; var filterProfit = filterYear.filter(item => { return item['profit'].toLowerCase().includes(filterParams.searchTerm.toLowerCase()); }) var filterValue = filterYear.filter(item => { return item['value'].toLowerCase().includes(filterParams.searchTerm.toLowerCase()); }) var filterAllData if (filterProfit.length == 0 && filterValue.length != 0) { filterAllData = filterValue; } else if (filterProfit.length != 0 && filterValue.length == 0) { filterAllData = filterProfit; } else { filterAllData = filterValue; } return filterAllData; } } renderChart(data: any) { if (this.myChart) { this.myChart.destroy(); } Chart.register(ChartDataLabels); Chart.defaults.plugins.datalabels.anchor = 'start'; Chart.defaults.plugins.datalabels.align = 'start'; Chart.defaults.scale.grid.drawOnChartArea = false; Chart.defaults.scale.grid.drawOnChartArea = false; Chart.defaults.plugins.legend.labels.usePointStyle = true; const lineCanvas: any = document.getElementById(this.idChartname); const targetCanvas: any = document.getElementById("chartAxis"); if (lineCanvas != null && targetCanvas != null) { const ctx = targetCanvas.getContext("2d"); let rectangleSet = false; const targetCtx = targetCanvas.getContext("2d"); this.myChart = new Chart(ctx, { type: "line", data: { labels: data.map(x => x.year), datasets: [ { label: "Margin", fill: false, tension: 0.2, backgroundColor: "rgba(75,192,192,0.4)", borderColor: "#006C5B", borderCapStyle: "butt", borderDash: [], borderDashOffset: 0.0, borderJoinStyle: "miter", pointBorderColor: "#006C5B", pointBackgroundColor: "#006C5B", pointBorderWidth: 1, pointHoverRadius: 5, pointHoverBackgroundColor: "#006C5B", pointHoverBorderColor: "#003453", pointHoverBorderWidth: 2, pointRadius: 4, pointHitRadius: 10, spanGaps: false, data: data.map(x => x.value), borderWidth: 1 } ] }, /* chart options for design */ options: { maintainAspectRatio: false, aspectRatio: 1, responsive: true, scales: { x: { ticks: { // fontColor: 'black', // fontStyle: 'bold', }, grid: { color: 'rgba(171,171,171,1)', lineWidth: 2 }, title: { display: true, text: 'Year', // fontColor: 'black', font:{ family:'Helvetica Neue', size:14, } //fontStyle: 'bold', } }, y: { beginAtZero: true, ticks: { padding: 0, // stepSize:10, // fontColor: 'black', //fontStyle: 'bold', callback: function (value) { return value + "%" } }, grid: { color: 'rgba(171,171,171,1)', lineWidth: 2 }, title: { display: true, text: 'Margin (%)', // fontColor: 'black', font:{ family:'Helvetica Neue', size:14, } // fontStyle:'bold' }, } }, layout: { padding: { left: 0, right: 0, top: 0, bottom: 0 } }, plugins: { // ChartsJS DataLabels initialized here legend: { display: true, position: 'top', labels: { font: { family:'Helvetica Neue' } // fontColor: '#333', } }, datalabels: { formatter: function (value, context) { return value + "%" }, anchor: 'start', align: 'right', padding: { left: 0, right: 25, top: 40, bottom: 0 }, // formatter: Math.round, font: { // weight: 'bold', size: 12, family: 'Helvetica Neue' }, } }, animation: { onComplete: function () { if (!rectangleSet) { const scale = window.devicePixelRatio; const copyWidth = this.scales.y.width - 10; const copyHeight = this.scales.y.chart.height + this.scales.y.top + 10; targetCtx.scale(scale, scale); targetCtx.canvas.width = copyWidth; targetCtx.canvas.height = copyHeight; targetCtx.canvas.style.width = copyWidth + 'px'; targetCtx.canvas.style.height = copyHeight + 'px'; targetCtx.drawImage(lineCanvas, 0, 0, copyWidth * scale, copyHeight * scale, 0, 0, copyWidth * scale, copyHeight * scale); // ctx.clearRect(0, 0, copyWidth, copyHeight); targetCtx.clearRect(0, 0, copyWidth, copyHeight); rectangleSet = true; } }, onProgress: function () { if (rectangleSet) { var copyWidth = this.scales.y.width; var copyHeight = this.scales.y.height + this.scales.y.top + 10; this.ctx.clearRect(0, 0, copyWidth, copyHeight); } }, }, }, }); } else { //this.myChart.update(); } } scrollleft() { document.getElementById('scrollArea').scrollLeft += -30; } scrollright() { document.getElementById('scrollArea').scrollLeft += 30; }; ngOnDestroy() { console.log("destroyed"); this.myChart.destroy(); //this.dataservice.saveData(undefined); } } 数据服务.service.ts import { Injectable } from '@angular/core'; import { BehaviorSubject, Observable } from 'rxjs'; @Injectable({ providedIn: 'root' }) export class DataServiceService { private filteredData = new BehaviorSubject<any>(""); getFilteredData1: Observable<any>; constructor() { this.getFilteredData1 = this.filteredData.asObservable(); } saveData(value) { this.filteredData.next(value); } } boundry.component.html <ion-card class="component-boundry content_class"> <!-- Charts --> <ng-container *ngIf="renderComponent=='chart-animated-line'"> <app-chart-animated-line></app-chart-animated-line> </ng-container> <ng-container *ngIf="renderComponent=='chart-bar'"> <app-chart-bar idname="barChartId1"></app-chart-bar> </ng-container> <ng-container *ngIf="renderComponent=='chart-line'"> <app-chart-line idname="lineChartId1"></app-chart-line> </ng-container> <ng-container *ngIf="renderComponent=='chart-multiple'"> <app-chart-multiple></app-chart-multiple> </ng-container> <!--<ng-container *ngIf="renderComponent=='chart-pie'"> <app-chart-pie></app-chart-pie> </ng-container>--> <ng-container *ngIf="renderComponent=='chart-bubble'"> <app-chart-bubble></app-chart-bubble> </ng-container> <!-- file explorer --> <ng-container *ngIf="renderComponent=='file-attachment'"> <app-attachment></app-attachment> </ng-container> </ion-card> 出现错误ERROR Error: Canvas is already in use. Chart with ID '11' must be destroyed before the canvas with ID 'chartAxis' can be reused. 因为它没有被 ngOnDestroy 方法破坏。使用 Angular 14 及以下版本和 Chart JS 2 可以正常工作。我不明白为什么 16 会发生这种情况。请帮忙解决。 正如错误所述，您正在硬编码 ID chartAxis，因此多个 html 元素将重复相同的 ID，这是错误的，您可以尝试以下更改，我们通过附加 将 ID 设置为动态-Axis 添加到您作为输入提供的动态 ID 的末尾，这可能会解决您的问题！ 图表线.component.html <!--chart container --> <div id="container"> <div id="scrollArea" class="CMI-ChartWrapper"> <div class="CMI-Chart"> <canvas baseChart #lineCanvas [id]="idChartname"></canvas> </div> </div> <canvas #targetCanvas [id]="idChartname+'-Axis'" height="400"></canvas> </div> 图表线.component.ts ... Chart.defaults.plugins.legend.labels.usePointStyle = true; ... const lineCanvas: any = document.getElementById(this.idChartname); const targetCanvas: any = document.getElementById(`${this.idChartname}-Axis`); // <-- changed here! ...
我想更改颜色，我们的按钮是按然后画布内文本颜色更改。 var canvas = document.querySelector('#my-canvas'); var context = canvas.getContext('2d'); context.font = '48px...