Canvas✤波浪纹花环的实例编码

2021-03-23 21:05 jianzhan

JS中的Canvas动漫

几日未写blog了,今日又忙到很晚,教大伙儿做一个波浪纹花环吧


 


 

实际效果图如上所显示:

规矩先把编码给大伙儿,在建一个html文本文档(在建一个txt文字文本文档,把后缀名名改成“ .html
”),以记事簿本开启,把拷贝好的编码黏贴进来,“ 储存 ”,撤出,双击鼠标或鼠标右键挑选访问器开启。

祝大伙儿前端开发学习培训开心,在将来的生活中与君共勉

<!DOCTYPE html>
<html lang="en">
<head>
	<meta charset="UTF-8">
	<title>Document</title>
	<style>
		body {
		  	background: #111;
		  	padding:0;
		  	margin:0;
			overflow:hidden;
		}
	</style>
</head>
<body>
	<div id="wrapper"></div>
</body>
<script>
(function(){
	'use strict';
	let wrapper, canvas, ctx, width, height, 
	Tau=Math.PI*2, PI180=Math.PI/180,
	systems=[];

/* PlanetarySystem */
	let PlanetarySystem = function(id='pSys'){
		Object.defineProperty(this, 'id',               { value:id, writable:true} );
		Object.defineProperty(this, 'x',                { value:0, writable:true });
		Object.defineProperty(this, 'y',                { value:0, writable:true });
		Object.defineProperty(this, 'allBodies',        { value:[], writable:true });
		Object.defineProperty(this, 'allBodiesLookup',  { value:{}, writable:true });    // fast id lookup for children
		Object.defineProperty(this, 'numBodies',        { value:0, writable:true });
	}
	PlanetarySystem.prototype.addBody = function(vo) {
		vo.parentSystem = this;
		vo.parentBody = vo.parentBody === null ? this : this.allBodiesLookup[vo.parentBody];
		let body = new PlanetaryBody(vo);
		body.update();
		this.allBodies.push(body);
		this.allBodiesLookup[vo.id] = body;
		this.numBodies += 1;
	}
	PlanetarySystem.prototype.setSpeedFactor = function(value){
		let body;
		for(let i=0; i<this.numBodies; i++){
			body = this.allBodies[i];
			body.setSpeedFactor(value);
		}
	}
	PlanetarySystem.prototype.update = function(){
		let body;
		for(let i=0; i<this.numBodies; i++){
			body = this.allBodies[i];
			body.update();
		}
	}
/* PlanetaryBody */
	let PlanetaryBody = function(vo){
		Object.defineProperty(this, 'id',					{ value:vo.id, writable:true} );
		Object.defineProperty(this, 'diameter',				{ value:vo.diameter, writable:true });
		Object.defineProperty(this, 'colour',				{ value:vo.colour, writable:true });
		Object.defineProperty(this, 'x',					{ value:0, writable:true });
		Object.defineProperty(this, 'y',					{ value:0, writable:true });
		Object.defineProperty(this, 'vx',					{ value:0, writable:true });
		Object.defineProperty(this, 'vy',					{ value:0, writable:true });
		Object.defineProperty(this, 'degrees',				{ value:vo.degrees, writable:true });
		Object.defineProperty(this, 'speedBase',			{ value:vo.speed, writable:true });
		Object.defineProperty(this, 'speed',				{ value:vo.speed , writable:true });
		Object.defineProperty(this, 'orbitalRadius',		{ value:vo.orbitalRadius, writable:true });
		Object.defineProperty(this, 'parentSystem',			{ value:vo.parentSystem, writable:true });
		Object.defineProperty(this, 'parentBody',			{ value:vo.parentBody, writable:true });

		return this;
	}
	PlanetaryBody.prototype.update = function(){
		let angle = this.degrees * PI180;
		this.degrees += this.speed;
		this.vx = this.orbitalRadius * Math.cos(angle);
		this.vy = this.orbitalRadius * Math.sin(angle);
		// update position
		if(this.parentBody != null){
			this.x = this.vx + this.parentBody.x;
			this.y = this.vy + this.parentBody.y;
		}
	}

/* init() */
	function init(){
		wrapper = document.querySelector('#wrapper');
		canvas = createCanvas('canvas', width, height);
		wrapper.appendChild(canvas);
		ctx = canvas.getContext('2d');
		setupEvents();
		resizeCanvas();

		/* Define new PlanetarySystem and set values */
		let system1 = new PlanetarySystem('pSys1');
		systems.push(system1);
		system1.x = width * .5;
		system1.y = height * .5;
		system1.addBody({id:'sun', diameter:5, degrees:0, speed:0, colour:'#FDFE1D', orbitalRadius:0, parentBody:null});
		for(let loop=30, i=0; i<loop; i+=1){
			system1.addBody({	id:				'ball'+i,
								diameter:		5,
								degrees:		0,
								speed:			2 + (loop * 0.15) - (i* 0.2),
								colour:			'#FDFE1D',
								orbitalRadius:	7*(i+1),
								parentBody:		'sun'});
		}
	}
	
/* Methods */
	function createCanvas(id, w, h){
		let tCanvas = document.createElement('canvas');
		tCanvas.width = w;
		tCanvas.height = h;
		tCanvas.id = id;
		return tCanvas;
	}

	function setupEvents(){
		window.onresize = resizeCanvas;
	}
	function resizeCanvas(){
		let rect = wrapper.getBoundingClientRect();
		width = window.innerWidth;
		height = window.innerHeight - rect.top -2;
		canvas.width = width;
		canvas.height = height;
		for(let i=0; i<systems.length; i++){
			systems[i].x = width * .5;
			systems[i].y = height * .5;
		}
	}

	function update(){
		for(let loop=systems.length, i=0; i<loop; i++){
			systems[i].update();
		}
	}

	function draw(){
		let system;
		let prev = null;
		for(let i=0; i<systems.length; i++){
			system = systems[i];
			let planetaryBody;
			for(let loop=system.numBodies, j=1; j<loop; j+=1) {
				planetaryBody = system.allBodies[j];
				ctx.beginPath();
				ctx.arc(planetaryBody.x, planetaryBody.y, planetaryBody.diameter, 0, Tau, false);
				ctx.fillStyle = planetaryBody.colour;
				ctx.fill();
				if(j>1){
					ctx.strokeStyle = planetaryBody.colour;
					ctx.lineWidth = 2;
					ctx.beginPath();
					ctx.moveTo(planetaryBody.x, planetaryBody.y);
					ctx.lineTo(prev.x, prev.y);
					ctx.stroke();
				}
				prev = {x:planetaryBody.x, y:planetaryBody.y};
			}
		}
	}

	function animate(){
		ctx.fillStyle = 'rgba(0,0,0, .05)';
		ctx.fillRect(0, 0, width, height);
		update();
		draw();
		requestAnimationFrame(animate);
	}
	init();
	animate();
}());
</script>
</html>

到此这篇有关Canvas波浪纹花环的实例编码的文章内容就详细介绍到这了,大量有关Canvas 波浪纹花环內容请检索脚本制作之家之前的文章内容或再次访问下边的有关文章内容,期待大伙儿之后多多的适用脚本制作之家!