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<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<meta http-equiv="X-UA-Compatible" content="ie=edge">
<title>Document</title>
</head>
<body>
</body>
<script>
! function() {
function get_attribute(node, attr, default_value) {
return node.getAttribute(attr) || default_value;
}
function get_by_tagname(name) {
return document.getElementsByTagName(name);
}
function get_config_option() {
var scripts = get_by_tagname("script"),
script_len = scripts.length,
script = scripts[script_len - 1];
return {
l: script_len,
z: get_attribute(script, "zIndex", -1),
o: get_attribute(script, "opacity", 0.5),
c: get_attribute(script, "color", "0,0,0"),
n: get_attribute(script, "count", 500)
};
}
function set_canvas_size() {
canvas_width = the_canvas.width = window.innerWidth || document.documentElement.clientWidth || document.body.clientWidth,
canvas_height = the_canvas.height = window.innerHeight || document.documentElement.clientHeight || document.body.clientHeight;
}
function draw_canvas() {
context.clearRect(0, 0, canvas_width, canvas_height);
var e, i, d, x_dist, y_dist, dist;
random_lines.forEach(function(r, idx) {
r.x += r.xa,
r.y += r.ya,
r.xa *= r.x > canvas_width || r.x < 0 ? -1 : 1,
r.ya *= r.y > canvas_height || r.y < 0 ? -1 : 1,
context.fillRect(r.x - 0.5, r.y - 0.5, 1, 1);
for (i = idx + 1; i < all_array.length; i++) {
e = all_array[i];
if (null !== e.x && null !== e.y) {
x_dist = r.x - e.x,
y_dist = r.y - e.y,
dist = x_dist * x_dist + y_dist * y_dist;
dist < e.max && (e === current_point && dist >= e.max / 2 && (r.x -= 0.03 * x_dist, r.y -= 0.03 * y_dist),
d = (e.max - dist) / e.max,
context.beginPath(),
context.lineWidth = d / 2,
context.strokeStyle = "rgba(" + config.c + "," + (d + 0.9) + ")",
context.moveTo(r.x, r.y),
context.lineTo(e.x, e.y),
context.stroke());
}
}
}), frame_func(draw_canvas);
}
var the_canvas = document.createElement("canvas"),
config = get_config_option(),
canvas_id = "c_n" + config.l,
context = the_canvas.getContext("2d"), canvas_width, canvas_height,
frame_func = window.requestAnimationFrame || window.webkitRequestAnimationFrame || window.mozRequestAnimationFrame || window.oRequestAnimationFrame || window.msRequestAnimationFrame || function(func) {
window.setTimeout(func, 1000 / 45);
}, random = Math.random,
current_point = {
x: null,
y: null,
max: 20000
},
all_array;
the_canvas.id = canvas_id;
the_canvas.style.cssText = "position:fixed;top:0;left:0;z-index:" + config.z + ";opacity:" + config.o;
get_by_tagname("body")[0].appendChild(the_canvas);
set_canvas_size(), window.onresize = set_canvas_size;
window.onmousemove = function(e) {
e = e || window.event, current_point.x = e.clientX, current_point.y = e.clientY;
}, window.onmouseout = function() {
current_point.x = null, current_point.y = null;
};
for (var random_lines = [], i = 0; config.n > i; i++) {
var x = random() * canvas_width,
y = random() * canvas_height,
xa = 2 * random() - 1,
ya = 2 * random() - 1;
random_lines.push({
x: x,
y: y,
xa: xa,
ya: ya,
max: 6000
});
}
all_array = random_lines.concat([current_point]);
setTimeout(function() {
draw_canvas();
}, 0);
}();
</script>
</html>
