我想創建一個畫布,在它的照片,其中上點擊,將創建一個圓,在一定時間內淡出。繪製臨時圈帆布
我是一個新手,總的JavaScript,但是這是我已經能夠到目前爲止湊齊:在它的畫面和功能的畫布上繪製點擊一個圓。
我想有圈淡出,並讓用戶的功能刪除最後一圈。任何想法如何做到這一點?
這裏是我的代碼:
<section class="mbr-section mbr-section-nopadding mbr-figure--caption-outside-bottom" id="image1-1">
<div class="mbr-figure">
<img id="mave" height="0" src="assets/images/mave2.png">
<canvas id="imgCanvas" width="730" height="410" style="border:1px solid #d3d3d3;" onclick="draw(event)"></canvas>
<script>
window.onload = function() {
var c = document.getElementById("imgCanvas");
var ctx = c.getContext("2d");
var img = document.getElementById("mave");
ctx.drawImage(img,0,0);
}
var canvas = document.getElementById("imgCanvas");
var context = canvas.getContext("2d");
function draw(e) {
var pos = getMousePos(canvas, e);
posx = pos.x;
posy = pos.y;
context.fillStyle = "#000000";
context.beginPath();
context.arc(posx, posy, 20, 0, 2*Math.PI);
context.fill();
}
function getMousePos(canvas, evt) {
var rect = canvas.getBoundingClientRect();
return {
x: evt.clientX - rect.left,
y: evt.clientY - rect.top
};
}
</script>