Canvas模拟火焰燃烧效果示例

本文主要是介绍Canvas模拟火焰燃烧效果示例，希望对大家解决编程问题提供一定的参考价值，需要的开发者们随着小编来一起学习吧！

canvas实例应用100+ 专栏提供canvas的基础知识，高级动画，相关应用扩展等信息。
canvas作为html的一部分，是图像图标地图可视化的一个重要的基础，学好了canvas，在其他的一些应用上将会起到非常重要的帮助。

文章目录

- 示例效果
- 源代码
- canvas基本属性
- canvas基础方法

canvas能做好很多事情，能显示各种动画。这里是模拟火焰燃烧效果的示例。

示例效果

在这里插入图片描述

源代码

							
<!doctype html>
<html>
<head>
<meta charset="utf-8">
<title>Canvas模拟火焰演示</title><style>
@import url(https://fonts.googleapis.com/css?family=Amatic+SC);
html, body {margin:0;padding:0;height: 100%;
}
</style></head>
<body>
<canvas id="zjcopy"></canvas><script>
var Fire  = function(){this.canvas 		= document.getElementById('zjcopy');this.ctx 			= this.canvas.getContext('2d');this.canvas.height 	= window.innerHeight;this.canvas.width 	= window.innerWidth;this.aFires 		= [];this.aSpark 		= [];this.aSpark2 		= [];this.mouse = {x : this.canvas.width * .5,y : this.canvas.height * .75,}this.init();}
Fire.prototype.init = function()
{this.canvas.addEventListener('mousemove', this.updateMouse.bind( this ), false);}
Fire.prototype.run = function(){this.update();this.draw();if( this.bRuning )requestAnimationFrame( this.run.bind( this ) );}
Fire.prototype.start = function(){this.bRuning = true;this.run();}
Fire.prototype.stop = function(){this.bRuning = false;}
Fire.prototype.update = function(){this.aFires.push( new Flame( this.mouse ) );this.aSpark.push( new Spark( this.mouse ) );this.aSpark2.push( new Spark( this.mouse ) );for (var i = this.aFires.length - 1; i >= 0; i--) {if( this.aFires[i].alive )this.aFires[i].update();elsethis.aFires.splice( i, 1 );}for (var i = this.aSpark.length - 1; i >= 0; i--) {if( this.aSpark[i].alive )this.aSpark[i].update();elsethis.aSpark.splice( i, 1 );}for (var i = this.aSpark2.length - 1; i >= 0; i--) {if( this.aSpark2[i].alive )this.aSpark2[i].update();elsethis.aSpark2.splice( i, 1 );}}Fire.prototype.draw = function(){this.ctx.globalCompositeOperation = "source-over";this.ctx.fillStyle = "rgba( 15, 5, 2, 1 )";this.ctx.fillRect( 0, 0, window.innerWidth, window.innerHeight );this.grd = this.ctx.createRadialGradient( this.mouse.x, this.mouse.y - 200,200,this.mouse.x, this.mouse.y - 100,0 );this.grd.addColorStop(0,"rgb( 15, 5, 2 )");this.grd.addColorStop(1,"rgb( 30, 10, 2 )");this.ctx.beginPath();this.ctx.arc( this.mouse.x, this.mouse.y - 100, 200, 0, 2*Math.PI );this.ctx.fillStyle= this.grd;this.ctx.fill();this.ctx.font = "15em Amatic SC";this.ctx.textAlign = "center";this.ctx.strokeStyle = "rgb(50, 20, 0)";this.ctx.fillStyle = "rgb(120, 10, 0)";this.ctx.lineWidth = 2;this.ctx.strokeText("Fire",this.canvas.width/2, this.canvas.height * .72 );this.ctx.fillText("Fire",this.canvas.width/2, this.canvas.height * .72 );	this.ctx.globalCompositeOperation = "overlay";//or lighter or soft-lightfor (var i = this.aFires.length - 1; i >= 0; i--) {this.aFires[i].draw( this.ctx );}this.ctx.globalCompositeOperation = "soft-light";//"soft-light";//"color-dodge";for (var i = this.aSpark.length - 1; i >= 0; i--) {if( ( i % 2 ) === 0 )this.aSpark[i].draw( this.ctx );}this.ctx.globalCompositeOperation = "color-dodge";//"soft-light";//"color-dodge";for (var i = this.aSpark2.length - 1; i >= 0; i--) {this.aSpark2[i].draw( this.ctx );}}Fire.prototype.updateMouse = function( e ){this.mouse.x = e.clientX;this.mouse.y = e.clientY;//this.aFires.push( new Flame( this.mouse ) );}var Flame = function( mouse ){this.cx = mouse.x;this.cy = mouse.y;this.x = rand( this.cx - 25, this.cx + 25);this.y = rand( this.cy - 5, this.cy + 5);this.vy = rand( 1, 3 );this.vx = rand( -1, 1 );this.r = rand( 20, 30 );this.life = rand( 3, 6 );this.alive = true;this.c = {h : Math.floor( rand( 2, 40) ),s : 100,l : rand( 80, 100 ),a : 0,ta : rand( 0.8, 0.9 )}}
Flame.prototype.update = function()
{this.y -= this.vy;this.vy += 0.05;this.x += this.vx;if( this.x < this.cx )this.vx += 0.1;elsethis.vx -= 0.1;if(  this.r > 0 )this.r -= 0.1;if(  this.r <= 0 )this.r = 0;this.life -= 0.15;if( this.life <= 0 ){this.c.a -= 0.05;if( this.c.a <= 0 )this.alive = false;}else if( this.life > 0 && this.c.a < this.c.ta ){this.c.a += .08;}}
Flame.prototype.draw = function( ctx ){ctx.beginPath();ctx.arc( this.x, this.y, this.r * 3, 0, 2*Math.PI );ctx.fillStyle = "hsla( " + this.c.h + ", " + this.c.s + "%, " + this.c.l + "%, " + (this.c.a/20) + ")";ctx.fill();ctx.beginPath();ctx.arc( this.x, this.y, this.r, 0, 2*Math.PI );ctx.fillStyle = "hsla( " + this.c.h + ", " + this.c.s + "%, " + this.c.l + "%, " + this.c.a + ")";ctx.fill();}var Spark = function( mouse ){this.cx = mouse.x;this.cy = mouse.y;this.x = rand( this.cx -40, this.cx + 40);this.y = rand( this.cy, this.cy + 5);this.lx = this.x;this.ly = this.y;this.vy = rand( 1, 3 );this.vx = rand( -4, 4 );this.r = rand( 0, 1 );this.life = rand( 4, 5 );this.alive = true;this.c = {h : Math.floor( rand( 2, 40) ),s : 100,l : rand( 40, 100 ),a : rand( 0.8, 0.9 )}}
Spark.prototype.update = function()
{this.lx = this.x;this.ly = this.y;this.y -= this.vy;this.x += this.vx;if( this.x < this.cx )this.vx += 0.2;elsethis.vx -= 0.2;this.vy += 0.08;this.life -= 0.1;if( this.life <= 0 ){this.c.a -= 0.05;if( this.c.a <= 0 )this.alive = false;}}
Spark.prototype.draw = function( ctx ){ctx.beginPath();ctx.moveTo( this.lx , this.ly);ctx.lineTo( this.x, this.y);ctx.strokeStyle = "hsla( " + this.c.h + ", " + this.c.s + "%, " + this.c.l + "%, " + (this.c.a / 2) + ")";ctx.lineWidth = this.r * 2;ctx.lineCap = 'round';ctx.stroke();ctx.closePath();ctx.beginPath();ctx.moveTo( this.lx , this.ly);ctx.lineTo( this.x, this.y);ctx.strokeStyle = "hsla( " + this.c.h + ", " + this.c.s + "%, " + this.c.l + "%, " + this.c.a + ")";ctx.lineWidth = this.r;ctx.stroke();ctx.closePath();}rand = function( min, max ){ return Math.random() * ( max - min) + min; };
onresize = function () { oCanvas.canvas.width = window.innerWidth; oCanvas.canvas.height = window.innerHeight; };var oCanvas;
init = function()
{oCanvas = new Fire();oCanvas.start();}window.onload = init;
</script></body>
</html>

canvas基本属性

属性	属性	属性
canvas	fillStyle	filter
font	globalAlpha	globalCompositeOperation
height	lineCap	lineDashOffset
lineJoin	lineWidth	miterLimit
shadowBlur	shadowColor	shadowOffsetX
shadowOffsetY	strokeStyle	textAlign
textBaseline	width

canvas基础方法

方法	方法	方法
arc()	arcTo()	addColorStop()
beginPath()	bezierCurveTo()	clearRect()
clip()	close()	closePath()
createImageData()	createLinearGradient()	createPattern()
createRadialGradient()	drawFocusIfNeeded()	drawImage()
ellipse()	fill()	fillRect()
fillText()	getImageData()	getLineDash()
isPointInPath()	isPointInStroke()	lineTo()
measureText()	moveTo()	putImageData()
quadraticCurveTo()	rect()	restore()
rotate()	save()	scale()
setLineDash()	setTransform()	stroke()
strokeRect()	strokeText()	transform()
translate()