Created
December 5, 2019 09:54
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Electric strings
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<canvas id="canvas"></canvas> |
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window.onload = function() { | |
let c = init("canvas").c, | |
canvas = init("canvas").canvas, | |
w = (canvas.width = window.innerWidth), | |
h = (canvas.height = window.innerHeight), | |
mouse = { x: false, y: false }, | |
last_mouse = {}; | |
//initiation | |
function dist(p1x, p1y, p2x, p2y) { | |
return Math.sqrt(Math.pow(p2x - p1x, 2) + Math.pow(p2y - p1y, 2)); | |
} | |
class segment { | |
constructor(parent, l, a, first) { | |
this.first = first; | |
if (first) { | |
this.pos = { | |
x: parent.x, | |
y: parent.y | |
}; | |
} else { | |
this.pos = { | |
x: parent.nextPos.x, | |
y: parent.nextPos.y | |
}; | |
} | |
this.l = l; | |
this.ang = a; | |
this.nextPos = { | |
x: this.pos.x + this.l * Math.cos(this.ang), | |
y: this.pos.y + this.l * Math.sin(this.ang) | |
}; | |
} | |
update(t) { | |
this.ang = Math.atan2(t.y - this.pos.y, t.x - this.pos.x); | |
this.pos.x = t.x + this.l * Math.cos(this.ang - Math.PI); | |
this.pos.y = t.y + this.l * Math.sin(this.ang - Math.PI); | |
this.nextPos.x = this.pos.x + this.l * Math.cos(this.ang); | |
this.nextPos.y = this.pos.y + this.l * Math.sin(this.ang); | |
} | |
fallback(t) { | |
this.pos.x = t.x; | |
this.pos.y = t.y; | |
this.nextPos.x = this.pos.x + this.l * Math.cos(this.ang); | |
this.nextPos.y = this.pos.y + this.l * Math.sin(this.ang); | |
} | |
show() { | |
c.lineTo(this.nextPos.x, this.nextPos.y); | |
} | |
} | |
class tentacle { | |
constructor(x, y, l, n, a) { | |
this.x = x; | |
this.y = y; | |
this.l = l; | |
this.n = n; | |
this.t = {}; | |
this.rand = Math.random(); | |
this.segments = [new segment(this, this.l / this.n, 0, true)]; | |
for (let i = 1; i < this.n; i++) { | |
this.segments.push( | |
new segment(this.segments[i - 1], this.l / this.n, 0, false) | |
); | |
} | |
} | |
move(last_target, target) { | |
this.angle = Math.atan2(target.y-this.y,target.x-this.x); | |
this.dt = dist(last_target.x, last_target.y, target.x, target.y)+5; | |
this.t = { | |
x: target.x - 0.8*this.dt*Math.cos(this.angle), | |
y: target.y - 0.8*this.dt*Math.sin(this.angle) | |
}; | |
if(this.t.x){ | |
this.segments[this.n - 1].update(this.t); | |
}else{ | |
this.segments[this.n - 1].update(target); | |
} | |
for (let i = this.n - 2; i >= 0; i--) { | |
this.segments[i].update(this.segments[i + 1].pos); | |
} | |
if ( | |
dist(this.x, this.y, target.x, target.y) <= | |
this.l + dist(last_target.x, last_target.y, target.x, target.y) | |
) { | |
this.segments[0].fallback({ x: this.x, y: this.y }); | |
for (let i = 1; i < this.n; i++) { | |
this.segments[i].fallback(this.segments[i - 1].nextPos); | |
} | |
} | |
} | |
show(target) { | |
if (dist(this.x, this.y, target.x, target.y) <= this.l) { | |
c.globalCompositeOperation = "color-dodge"; | |
c.beginPath(); | |
c.lineTo(this.x, this.y); | |
for (let i = 0; i < this.n; i++) { | |
this.segments[i].show(); | |
} | |
c.strokeStyle = "hsl("+(this.rand*60+180)+",100%," + (this.rand * 60 + 25) + "%)"; | |
c.lineWidth = this.rand * 2; | |
c.lineCap="round"; | |
c.lineJoin="round"; | |
c.stroke(); | |
c.globalCompositeOperation = "source-over"; | |
} | |
} | |
show2(target) { | |
c.beginPath(); | |
if (dist(this.x, this.y, target.x, target.y) <= this.l) { | |
c.arc(this.x, this.y, 2*this.rand+1, 0, 2 * Math.PI); | |
c.fillStyle = "white"; | |
} else { | |
c.arc(this.x, this.y, this.rand*2, 0, 2 * Math.PI); | |
c.fillStyle = "darkcyan"; | |
} | |
c.fill(); | |
} | |
} | |
let maxl = 300, | |
minl = 50, | |
n = 30, | |
numt = 500, | |
tent = [], | |
clicked = false, | |
target = { x: 0, y: 0 }, | |
last_target = {}, | |
t = 0, | |
q = 10; | |
for (let i = 0; i < numt; i++) { | |
tent.push( | |
new tentacle( | |
Math.random() * w, | |
Math.random() * h, | |
Math.random() * (maxl - minl) + minl, | |
n, | |
Math.random() * 2 * Math.PI | |
) | |
); | |
} | |
function draw() { | |
//animation | |
if (mouse.x) { | |
target.errx = mouse.x - target.x; | |
target.erry = mouse.y - target.y; | |
} else { | |
target.errx = | |
w / 2 + | |
(h / 2 - q) * | |
Math.sqrt(2) * | |
Math.cos(t) / | |
(Math.pow(Math.sin(t), 2) + 1) - | |
target.x; | |
target.erry = | |
h / 2 + | |
(h / 2 - q) * | |
Math.sqrt(2) * | |
Math.cos(t) * | |
Math.sin(t) / | |
(Math.pow(Math.sin(t), 2) + 1) - | |
target.y; | |
} | |
target.x += target.errx / 10; | |
target.y += target.erry / 10; | |
t += 0.01; | |
c.beginPath(); | |
c.arc(target.x, target.y, dist(last_target.x, last_target.y, target.x, target.y)+5, 0, 2 * Math.PI); | |
c.fillStyle = "hsl(210,100%,80%)"; | |
c.fill(); | |
for (i = 0; i < numt; i++) { | |
tent[i].move(last_target, target); | |
tent[i].show2(target); | |
} | |
for (i = 0; i < numt; i++) { | |
tent[i].show(target); | |
} | |
last_target.x = target.x; | |
last_target.y = target.y; | |
} | |
canvas.addEventListener( | |
"mousemove", | |
function(e) { | |
last_mouse.x = mouse.x; | |
last_mouse.y = mouse.y; | |
mouse.x = e.pageX - this.offsetLeft; | |
mouse.y = e.pageY - this.offsetTop; | |
}, | |
false | |
); | |
canvas.addEventListener("mouseleave", function(e) { | |
mouse.x = false; | |
mouse.y = false; | |
}); | |
canvas.addEventListener( | |
"mousedown", | |
function(e) { | |
clicked = true; | |
}, | |
false | |
); | |
canvas.addEventListener( | |
"mouseup", | |
function(e) { | |
clicked = false; | |
}, | |
false | |
); | |
function loop() { | |
window.requestAnimFrame(loop); | |
// c.fillStyle="rgba(30,30,30,0.1)"; | |
// c.fillRect(0, 0, w, h); | |
c.clearRect(0, 0, w, h); | |
draw(); | |
} | |
window.addEventListener("resize", function() { | |
(w = canvas.width = window.innerWidth), | |
(h = canvas.height = window.innerHeight); | |
loop(); | |
}); | |
loop(); | |
setInterval(loop, 1000 / 60); | |
}; |
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body, | |
html { | |
margin: 0px; | |
padding: 0px; | |
position: fixed; | |
background: rgb(30,30,30); |
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