To animate an HTML5 canvas over my div, I am using the following code:
<div class="ls-slide" id="asb">
<div id="smile" style="width:100%;height:359px;">
<canvas style="position: absolute; width: 100%; z-index: 3; display: block;" height="359" width="2111">
</canvas>
</div>
</div>
In the JavaScript part:
window.onload = function() {
travers();
var lastHeight = $("#asb").height();
var canvas = document.querySelector('canvas');
ctx = canvas.getContext('2d');
color = '#aaa';
var check = respondCanvas();
canvas.width = check[1];
canvas.height = lastHeight;
canvas.style.display = 'block';
ctx.fillStyle = color;
ctx.lineWidth = .1;
ctx.strokeStyle = color;
function respondCanvas() {
var width = [];
width[0] = $('#smile').width(); //max width
width[1] = $('canvas').width(); //max width
return width;
//Call a function to redraw other content (texts, images etc)
}
function checkheight() {
var height = $('#asb').height(); //max width
//console.log(height);
// return height;
}
var mousePosition = {
x: 30 * canvas.width / 100,
y: 30 * canvas.height / 100
};
if (canvas.width <= 1000) {
var numdot = 100;
} else if (canvas.width <= 800) {
var numdot = 80;
} else if (canvas.width <= 500) {
var numdot = 35;
} else {
var numdot = 300;
}
var dots = {
nb: numdot,
distance: 70,
d_radius: 50,
array: []
};
function Dot() {
this.x = Math.random() * canvas.width;
this.y = Math.random() * canvas.height;
this.vx = -.5 + Math.random();
this.vy = -.5 + Math.random();
this.radius = Math.random();
}
Dot.prototype = {
create: function() {
ctx.beginPath();
ctx.arc(this.x, this.y, this.radius, 0, Math.PI * 2, false);
ctx.fill();
},
animate: function() {
for (i = 0; i < dots.nb; i++) {
var dot = dots.array[i];
if (dot.y < 0 || dot.y > canvas.height) {
dot.vx = dot.vx;
dot.vy = -dot.vy;
} else if (dot.x < 0 || dot.x > canvas.width) {
dot.vx = -dot.vx;
dot.vy = dot.vy;
}
dot.x += dot.vx;
dot.y += dot.vy;
}
},
line: function() {
for (i = 0; i < dots.nb; i++) {
for (j = 0; j < dots.nb; j++) {
i_dot = dots.array[i];
j_dot = dots.array[j];
if ((i_dot.x - j_dot.x) < dots.distance && (i_dot.y - j_dot.y) < dots.distance && (i_dot.x - j_dot.x) > -dots.distance && (i_dot.y - j_dot.y) > -dots.distance) {
if ((i_dot.x - mousePosition.x) < dots.d_radius && (i_dot.y - mousePosition.y) < dots.d_radius && (i_dot.x - mousePosition.x) > -dots.d_radius && (i_dot.y - mousePosition.y) > -dots.d_radius) {
ctx.beginPath();
ctx.moveTo(i_dot.x, i_dot.y);
ctx.lineTo(j_dot.x, j_dot.y);
ctx.stroke();
ctx.closePath();
}
}
}
}
}
};
function createDots() {
ctx.clearRect(0, 0, canvas.width, canvas.height);
for (i = 0; i < dots.nb; i++) {
dots.array.push(new Dot());
dot = dots.array[i];
dot.create();
}
dot.line();
dot.animate();
}
$("canvas").mousemove(function(parameter) {
mousePosition.x = parameter.pageX - 0;
mousePosition.y = parameter.pageY - 300;
});
setInterval(createDots, 1000 / 30);
};
However, when testing the animation in Chrome and Firefox, it does not work as expected and the dotted animation is not visible. How can I fix this issue?
Check out the demo here: https://jsfiddle.net/5pzvh8ko/