樱花季到了，分享一个简单的樱花树H5制作。

直接上JS代码

点击效果查看

(function($,win,dom,undef) {

// var bos_html = $('<div id="box" style="width:500px;height:350px;"><canvas id="tree"></canvas><canvas id="flower"></canvas></div>');
// bos_html.appendTo("body")

//两个canvas
var tree = dom.getElementById("tree");
var box =$("#box");
console.log(tree);
tree.width = 500;//$("#box").width();
tree.height = 350//$("#box").height() ;
var tCxt = tree.getContext("2d");
var flower = document.getElementById("flower");
flower.width = 500;//$("#box").width();
flower.height = 350;//$("#box").height();
var cxt = flower.getContext("2d");

var flowerList = [];//樱花列表
var rootTop = 350 ;//树起点
var flowerColor = "rgba(255,192,203,.3)" ;//花色
var flowerColorDeep = "rgba(241,158,194,.5)" ;//花色深
var treeColor2 = "rgba(255,192,203,.5)" ;//树枝颜色
var treeColor = "#8B7355" ;//树干颜色
var fallList = [];//飘落樱花列表
var g = 0.01 ;//重力加速度
var gWind = 0.005;//风力加速度
var limitSpeedY = 1;//速度上限
var limitSpeedX = 1 ;//速度上限

cxt.shadowColor= "#FFF" ;
cxt.shadowBlur = 10 ;

function drawTree(x,y,deg,step,type){
var deg1 = step%2 == 0 ? 0.1 : -0.1 ;
var x1 = x + Math.cos(deg+deg1) * (step+4) * 0.8 ;//以步长来判断枝干长度 x轴偏移大一些
var y1 = y + Math.sin(deg+deg1) * (step-1) * 0.8 ;//以步长来判断枝干长度 Y轴压缩一些
tCxt.beginPath();
tCxt.lineWidth = step/3;
tCxt.moveTo(x,y);
tCxt.lineTo(x1,y1);
tCxt.strokeStyle = (step > 5 ) ? treeColor : treeColor2 ;//细纸条都换成花的颜色
tCxt.stroke();
if(step > 10){//树干相交的位置有间隙，以一个圆填充
tCxt.fillStyle = treeColor ;
tCxt.arc(x,y,step/6,0,Math.PI*2);
tCxt.fill();
}

if( step < 3 || (step < 20 && Math.random() > 0.4)){
//末梢位置 画花瓣
var color = [flowerColorDeep,flowerColor,flowerColor][Math.round(Math.random()+0.2)] ;
var r = 2+Math.random()*2
tCxt.fillStyle = color ;
tCxt.arc(x1+Math.random()*3,y1+Math.random()*3,r,0,Math.PI)
tCxt.fill();
flowerList.push({x:x,y:y,sx:(Math.random()-0.5),sy:0,color:color,r:r,deg:deg});//保存下画樱花的位置
}

step -- ;
if(step > 0){
drawTree(x1,y1,deg,step,type);
if(step%3 == 1 && step > 0 && step < 30)
drawTree(x1,y1,deg+0.2 + 0.3 * Math.random(),Math.round(step/1.13));//右分叉
if(step%3 == 0 && step > 0 && step < 30)
drawTree(x1,y1,deg-0.2 - 0.3 * Math.random(),Math.round(step/1.13));//左分叉
}
}

drawTree(tree.width/2,rootTop,-Math.PI/2,30,1);//执行

var len = flowerList.length ;
function step(){
if(Math.random() > 0.3) fallList.push(flowerList[Math.floor(Math.random()*len)]);//随机取出一个，花瓣复制到飘落花瓣的列表中

cxt.clearRect(0,0,tree.width,tree.height);
for(var i = 0 ;i < fallList.length ; i ++){
if(fallList[i].sy < limitSpeedY) fallList[i].sy += g ;
fallList[i].sx += gWind ;
fallList[i].x += fallList[i].sx ;
fallList[i].y += fallList[i].sy ;
if(fallList[i].y > rootTop){//飘到树根的花瓣移除
fallList.splice(i,1);
i -- ;
continue ;
}
cxt.beginPath();
cxt.fillStyle = fallList[i].color ;
fallList[i].deg += fallList[i].sx*0.05 ;//跟速度相关的旋转花瓣
cxt.arc(fallList[i].x,fallList[i].y,fallList[i].r,fallList[i].deg,fallList[i].deg+Math.PI*1.3);
cxt.fill();
}
requestAnimationFrame(step);
}
requestAnimationFrame(step);
})(jQuery,window,document);
点击效果查看