html真实雾效果图 HTML5 Canvas图片上云雾弥漫驱散特效

JavaScript

语言：

JaveScriptBabelCoffeeScript

确定

const front = document.getElementById("front"),

canv = document.getElementById("mycanvas"),

ctx = canv.getContext("2d"),

img = new Image(),

imgMask = new Image();

img.src = "/uploads/1901/photo1.png";

imgMask.src = "/uploads/1901/cloud-texture.png";

let i = 0;

function draw() {

i += 10;

let maskX = (canv.width - (70 + i)) / 2,

maskY = (canv.height - (40 + i)) / 2;

ctx.clearRect(0, 0, canv.width, canv.height);

ctx.globalCompositeOperation = "source-over";

ctx.drawImage(imgMask, maskX, maskY, 70 + i, 40 + i);

ctx.globalCompositeOperation = "source-in";

ctx.drawImage(img, 0, 0, img.naturalWidth, img.naturalHeight);

window.requestAnimationFrame(draw);

}

img.onload = function() {

canv.width = img.naturalWidth;

canv.height = img.naturalHeight;

}

front.onclick = function() {

front.style.display = "none";

canv.style.display = "block";

draw();

}

canv.onclick = function() {

i = 0;

draw();

}