Canvas realizes dazzling particle motion effects
This article mainly introduces and introduces Canvas to achieve dazzling particle motion effects (particles generate text). The editor thinks it is quite good, so I will share it with you now and give it as a reference. Let’s follow the editor to take a look, I hope it can help everyone.
Go directly to the code. If you don’t understand, you can read the code comments. You will probably understand the general idea.
html Code
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Canvas 实现炫丽的粒子运动效果-云库前端</title>
<style>
* {
margin: 0;
padding: 0;
}
html,
body {
width: 100%;
height: 100%;
}
canvas {
display: block;
background: #000;
}
body::-webkit-scrollbar{
display: none;
}
.operator-box{
position: fixed;
top: 0;
left: 50%;
border: 1px solid #fff;
background: rgba(255,255,255,0.5);
padding: 20px 10px;
-webkit-transform: translateX(-50%);
transform: translateX(-50%);
}
.back-type,.back-animate{
margin-right: 20px;
}
.flex-box{
display: flex;
justify-content: center;
align-items: center;
}
#input-text{
line-height: 35px;
width: 260px;
height: 35px;
background: rgba(0, 0, 0,0.7);
color: #fff;
font-size: 16px;
border: none;
outline: none;
text-indent: 12px;
box-shadow: inset 0 0 12px 1px rgba(0,0,0,0.7);
}
#input-text::placeholder{
color: #ccc;
line-height: 55px;
height: 55px;
}
select{
-webkit-appearance: none;
-moz-appearance: none;
appearance: none;
border: none;
padding: 0px 20px 0px 6px;
height: 35px;
color: #fff;
text-align: left;
background: rgba(0, 0, 0,0.7) url(data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAUAAAAICAYAAAAx8TU7AAAAOUlEQ…R4gPgWEIMAiOYBCS4C8ZDAIrBq4gigNkztQEFMi6AuQHESAPMeXiEMiWfpAAAAAElFTkSuQmCC) no-repeat 190px 12px;
background-size: 5px 8px;
box-shadow: inset 0 0 12px 1px rgba(0,0,0,0.7);
}
</style>
</head>
<body>
<p class="operator-box">
<p class="flex-box">
<p class="back-type">散开类型：
<select name="" id="selectType">
<option value="back">归位</option>
<option value="auto">随机</option>
</select>
</p>
<p class="back-animate">散开效果（对归位有效）：
<select class="back-dynamics" id="selectDynamics">
<option value="spring">dynamics.spring</option>
<option value="bounce">dynamics.bounce</option>
<option value="forceWithGravity">dynamics.forceWithGravity</option>
<option value="gravity">dynamics.gravity</option>
<option value="easeInOut">dynamics.easeInOut</option>
<option value="easeIn">dynamics.easeIn</option>
<option value="easeOut">dynamics.easeOut</option>
<option value="linear">dynamics.linear</option>
</select>
</p>
<p class="input-box"><input type="text" placeholder="输入汉字后回车" id="input-text"></p>
</p>
</p>
<script src="dynamics.min.js"></script>
<script src="index.js"></script>
<script>
var iCircle = new Circle();
</script>
</body>
</html>HTML code is not much, just a few operating elements. It’s easy to understand at a glance here. No need to waste too much words. Let’s take a look at the protagonist JavaScript code of this article. However, before looking at the code, we might as well listen to the idea of achieving this effect:
First, we have to generate a bunch of extras ( particles);
Hang the relevant parameters of each particle to some of its own attributes, because every particle will have its own trajectory;
-
Then you have to let them move individually. There are two types of motion (free motion and text-generated motion);
The JavaScript code uses three Canvas canvases, this.iCanvas (home page), this.iCanvasCalculate (used to calculate Text width), this.iCanvasPixel (used to draw text and obtain the position coordinates of the pixel corresponding to the text).
this.iCanvasCalculate and this.iCanvasPixel do not need to be displayed on the page, they are just auxiliary functions.
The following is a great JS implementation code
function Circle() {
var This = this;
this.init();
this.generalRandomParam();
this.drawCircles();
this.ballAnimate();
this.getUserText();
// 窗口改变大小后，生计算并获取画面
window.onresize = function(){
This.stateW = document.body.offsetWidth;
This.stateH = document.body.offsetHeight;
This.iCanvasW = This.iCanvas.width = This.stateW;
This.iCanvasH = This.iCanvas.height = This.stateH;
This.ctx = This.iCanvas.getContext("2d");
}
}
// 初始化
Circle.prototype.init = function(){
//父元素宽高
this.stateW = document.body.offsetWidth;
this.stateH = document.body.offsetHeight;
this.iCanvas = document.createElement("canvas");
// 设置Canvas 与父元素同宽高
this.iCanvasW = this.iCanvas.width = this.stateW;
this.iCanvasH = this.iCanvas.height = this.stateH;
// 获取 2d 绘画环境
this.ctx = this.iCanvas.getContext("2d");
// 插入到 body 元素中
document.body.appendChild(this.iCanvas);
this.iCanvasCalculate = document.createElement("canvas");
// 用于保存计算文字宽度的画布
this.mCtx = this.iCanvasCalculate.getContext("2d");
this.mCtx.font = "128px 微软雅黑";
this.iCanvasPixel = document.createElement("canvas");
this.iCanvasPixel.setAttribute("style","position:absolute;top:0;left:0;");
this.pCtx = null; // 用于绘画文字的画布
// 随机生成圆的数量
this.ballNumber = ramdomNumber(1000, 2000);
// 保存所有小球的数组
this.balls = [];
// 保存动画中最后一个停止运动的小球
this.animte = null;
this.imageData = null;
this.textWidth = 0; // 保存生成文字的宽度
this.textHeight = 150; // 保存生成文字的高度
this.inputText = ""; // 保存用户输入的内容
this.actionCount = 0;
this.ballActor = []; // 保存生成文字的粒子
this.actorNumber = 0; // 保存生成文字的粒子数量
this.backType = "back"; // 归位
this.backDynamics = ""; // 动画效果
this.isPlay = false; // 标识（在生成文字过程中，不能再生成）
}
// 渲染出所有圆
Circle.prototype.drawCircles = function () {
for(var i=0;i<this.ballNumber;i++){
this.renderBall(this.balls[0]);
}
}
// 获取用户输入文字
Circle.prototype.getUserText = function(){
This = this; // 保存 this 指向
ipu = document.getElementById("input-text");
ipu.addEventListener("keydown",function(event){
if(event.which === 13){ // 如果是回车键
ipu.value = ipu.value.trim(); // 去头尾空格
var pat = /[\u4e00-\u9fa5]/; // 中文判断
var isChinese = pat.test(ipu.value);
if(ipu.value.length !=0 && isChinese){
This.inputText = ipu.value;
}else{
alert("请输入汉字");
return;
}
if(This.isPlay){
return
}
This.getAnimateType();
This.getTextPixel();
This.isPlay = true;
}
});
}
// 计算文字的宽
Circle.prototype.calculateTextWidth = function () {
this.textWidth = this.mCtx.measureText(this.inputText).width;
}
// 获取文字像素点
Circle.prototype.getTextPixel = function () {
if(this.pCtx){
this.pCtx.clearRect(0,0,this.textWidth,this.textHeight);
}
this.calculateTextWidth(this.inputText);
this.iCanvasPixel.width = this.textWidth;
this.iCanvasPixel.height = this.textHeight;
this.pCtx = this.iCanvasPixel.getContext("2d");
this.pCtx.font = "128px 微软雅黑";
this.pCtx.fillStyle = "#FF0000";
this.pCtx.textBaseline = "botom";
this.pCtx.fillText(this.inputText,0,110);
this.imageData = this.pCtx.getImageData(0,0,this.textWidth,this.textHeight).data;
this.getTextPixelPosition(this.textWidth,this.textHeight);
}
// 获取文字粒子像素点位置
Circle.prototype.getTextPixelPosition = function (width,height) {
var left = (this.iCanvasW - width)/2;
var top = (this.iCanvasH - height)/2;
var space = 4;
this.actionCount = 0;
for(var i=0;i<this.textHeight;i+=space){
for(var j=0;j<this.textWidth;j+=space){
var index = j*space+i*this.textWidth*4;
if(this.imageData[index] == 255){
if(this.actionCount<this.ballNumber){
this.balls[this.actionCount].status = 1;
this.balls[this.actionCount].targetX = left+j;
this.balls[this.actionCount].targetY = top+i;
this.balls[this.actionCount].backX = this.balls[this.actionCount].x;
this.balls[this.actionCount].backY = this.balls[this.actionCount].y;
this.ballActor.push(this.balls[this.actionCount]);
this.actionCount++;
}
}
}
this.actorNumber = this.ballActor.length;
}
this.animateToText();
}
// 粒子运动到指定位置
Circle.prototype.animateToText = function(){
for(var i=0;i<This.actorNumber;i++){
dynamics.animate(This.ballActor[i], {
x: this.ballActor[i].targetX,
y: this.ballActor[i].targetY
},{
type: dynamics.easeIn,
duration: 1024,
});
}
setTimeout(function(){
This.ballbackType();
},3000);
}
// 粒子原路返回
Circle.prototype.ballBackPosition = function(){
for(var i=0;i<This.actorNumber;i++){
var ball = This.ballActor[i];
dynamics.animate(ball, {
x: ball.backX,
y: ball.backY
},{
type: dynamics[this.backDynamics],
duration: 991,
complete:this.changeStatus(ball)
});
}
}
// 获取类型|动画效果
Circle.prototype.getAnimateType = function() {
var selectType = document.getElementById("selectType");
var selectDynamics = document.getElementById("selectDynamics");
this.backType = selectType.options[selectType.options.selectedIndex].value;
this.backDynamics = selectDynamics.options[selectDynamics.options.selectedIndex].value;
}
// 复位散开
Circle.prototype.ballbackType = function(){
if(this.backType == "back"){
this.ballBackPosition();
}else{
this.ballAutoPosition();
}
this.ballActor = [];
}
// 随机散开
Circle.prototype.ballAutoPosition = function(ball){
for(var i=0;i<this.actorNumber;i++){
this.changeStatus(this.ballActor[i])
}
}
// 更改小球状态
Circle.prototype.changeStatus = function(ball){
ball.status = 0;
if(this.isPlay == true){
this.isPlay = false;
}
}
// 随机生成每个圆的相关参数
Circle.prototype.generalRandomParam = function(){
for(var i=0;i<this.ballNumber;i++){
var ball = {};
ball.size = 1; // 随机生成圆半径
// 随机生成圆心 x 坐标
ball.x = ramdomNumber(0+ball.size, this.iCanvasW-ball.size);
ball.y = ramdomNumber(0+ball.size, this.iCanvasH-ball.size);
ball.speedX = ramdomNumber(-1, 1);
ball.speedY = ramdomNumber(-1, 1);
this.balls.push(ball);
ball.status = 0;
ball.targetX = 0;
ball.targetY = 0;
ball.backX = 0;
ball.backY = 0;
}
}
// 改变圆的位置
Circle.prototype.changeposition = function(){
for(var i=0;i<this.ballNumber;i++){
if( this.balls[i].status == 0){
this.balls[i].x += this.balls[i].speedX;
this.balls[i].y += this.balls[i].speedY;
}
}
}
// 画圆
Circle.prototype.renderBall = function(ball){
this.ctx.fillStyle = "#fff";
this.ctx.beginPath(); // 这个一定要加
this.ctx.arc(ball.x, ball.y, ball.size, 0, 2 * Math.PI);
this.ctx.closePath(); // 这个一定要加
this.ctx.fill();
}
// 小球碰撞判断
Circle.prototype.collision = function(ball){
for(var i=0;i<this.ballNumber;i++){
if(ball.x>this.iCanvasW-ball.size || ball.x<ball.size){
if(ball.x>this.iCanvasW-ball.size){
ball.x = this.iCanvasW-ball.size;
}else{
ball.x = ball.size;
}
ball.speedX = - ball.speedX;
}
if(ball.y>this.iCanvasH-ball.size || ball.y<ball.size){
if(ball.y>this.iCanvasH-ball.size){
ball.y = this.iCanvasH-ball.size;
}else{
ball.y = ball.size;
}
ball.speedY = - ball.speedY;
}
}
}
// 开始动画
Circle.prototype.ballAnimate = function(){
var This = this;
var animateFrame = window.requestAnimationFrame || window.mozRequestAnimationFrame || window.webkitRequestAnimationFrame || window.msRequestAnimationFrame;
(function move(){
animte = animateFrame(move);
This.ctx.clearRect(0, 0, This.iCanvasW, This.iCanvasH);
This.changeposition();
for(var i=0;i<This.ballNumber;i++){
This.collision(This.balls[i]);
This.renderBall(This.balls[i]);
}
})();
}
// 生成一个随机数
function ramdomNumber(min, max) {
return Math.random() * (max - min) + min;
}After reading the code, I guess I just dazzled my heart, and it didn’t make you want to think about this thing. The desire to create it, for this I know it must be convinced by your eyes and mouth. Online DEMO: Dynamic particle example.
No one is perfect, and the same goes for code. It seems that the code that runs smoothly also has some flaws. Currently, this effect only supports Chinese. As for English, I have to work harder. No matter what, English will definitely join later, it’s just a matter of time. There is also the attribute in the code used to mark whether the generated text can be executed again: this.isPlay, which is still a little flaw. The state change of this.isPlay does not change exactly at the moment when the particles return, but changes the state in advance. But this state will not affect the complete implementation of the effect of this example.
This example uses the dynamics.js library, mainly using some motion functions in it to make the particles move more impressively, that's all.
Related recommendations:
The above is the detailed content of Canvas realizes dazzling particle motion effects. For more information, please follow other related articles on the PHP Chinese website!
Hot AI Tools
Undresser.AI Undress
AI-powered app for creating realistic nude photos
AI Clothes Remover
Online AI tool for removing clothes from photos.
Undress AI Tool
Undress images for free
Clothoff.io
AI clothes remover
Video Face Swap
Swap faces in any video effortlessly with our completely free AI face swap tool!
Hot Article
Hot Tools
Notepad++7.3.1
Easy-to-use and free code editor
SublimeText3 Chinese version
Chinese version, very easy to use
Zend Studio 13.0.1
Powerful PHP integrated development environment
Dreamweaver CS6
Visual web development tools
SublimeText3 Mac version
God-level code editing software (SublimeText3)
Hot Topics
1653
14
1413
52
1305
25
1251
29
1224
24
Learn the canvas framework and explain the commonly used canvas framework in detail
Jan 17, 2024 am 11:03 AM
Explore the Canvas framework: To understand what are the commonly used Canvas frameworks, specific code examples are required. Introduction: Canvas is a drawing API provided in HTML5, through which we can achieve rich graphics and animation effects. In order to improve the efficiency and convenience of drawing, many developers have developed different Canvas frameworks. This article will introduce some commonly used Canvas frameworks and provide specific code examples to help readers gain a deeper understanding of how to use these frameworks. 1. EaselJS framework Ea
What are the canvas arrow plug-ins?
Aug 21, 2023 pm 02:14 PM
The canvas arrow plug-ins include: 1. Fabric.js, which has a simple and easy-to-use API and can create custom arrow effects; 2. Konva.js, which provides the function of drawing arrows and can create various arrow styles; 3. Pixi.js , which provides rich graphics processing functions and can achieve various arrow effects; 4. Two.js, which can easily create and control arrow styles and animations; 5. Arrow.js, which can create various arrow effects; 6. Rough .js, you can create hand-drawn arrows, etc.
What versions of html2canvas are there?
Aug 22, 2023 pm 05:58 PM
The versions of html2canvas include html2canvas v0.x, html2canvas v1.x, etc. Detailed introduction: 1. html2canvas v0.x, which is an early version of html2canvas. The latest stable version is v0.5.0-alpha1. It is a mature version that has been widely used and verified in many projects; 2. html2canvas v1.x, this is a new version of html2canvas.
What are the details of the canvas clock?
Aug 21, 2023 pm 05:07 PM
The details of the canvas clock include clock appearance, tick marks, digital clock, hour, minute and second hands, center point, animation effects, other styles, etc. Detailed introduction: 1. Clock appearance, you can use Canvas to draw a circular dial as the appearance of the clock, and you can set the size, color, border and other styles of the dial; 2. Scale lines, draw scale lines on the dial to represent hours or minutes. Position; 3. Digital clock, you can draw a digital clock on the dial to indicate the current hour and minute; 4. Hour hand, minute hand, second hand, etc.
uniapp implements how to use canvas to draw charts and animation effects
Oct 18, 2023 am 10:42 AM
How to use canvas to draw charts and animation effects in uniapp requires specific code examples 1. Introduction With the popularity of mobile devices, more and more applications need to display various charts and animation effects on the mobile terminal. As a cross-platform development framework based on Vue.js, uniapp provides the ability to use canvas to draw charts and animation effects. This article will introduce how uniapp uses canvas to achieve chart and animation effects, and give specific code examples. 2. canvas
What properties does tkinter canvas have?
Aug 21, 2023 pm 05:46 PM
The tkinter canvas attributes include bg, bd, relief, width, height, cursor, highlightbackground, highlightcolor, highlightthickness, insertbackground, insertwidth, selectbackground, selectforeground, xscrollcommand attributes, etc. Detailed introduction
Explore the powerful role and application of canvas in game development
Jan 17, 2024 am 11:00 AM
Understand the power and application of canvas in game development Overview: With the rapid development of Internet technology, web games are becoming more and more popular among players. As an important part of web game development, canvas technology has gradually emerged in game development, showing its powerful power and application. This article will introduce the potential of canvas in game development and demonstrate its application through specific code examples. 1. Introduction to canvas technology Canvas is a new element in HTML5, which allows us to use
Where are the canvas mouse coordinates?
Aug 22, 2023 pm 03:08 PM
How to get mouse coordinates for canvas: 1. Create a JavaScript sample file; 2. Get a reference to the Canvas element and add a listener for mouse movement events; 3. When the mouse moves on the Canvas, the getMousePos function will be triggered; 4. Use The "getBoundingClientRect()" method obtains the position and size information of the Canvas element, and obtains the mouse coordinates through event.clientX and event.clientY.
