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<!DOCTYPE html> | |
<html> | |
<head> | |
<meta charset=utf-8 /> | |
<title>JS Bin</title> | |
</head> | |
<body> | |
</body> | |
</html> |
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var Vector = (function() { | |
function Vector(x, y) { | |
this.x = x; | |
this.y = y; | |
this.prevmag = 1 | |
}; | |
return Vector | |
})(); | |
Vector.prototype = { | |
toString: function() { | |
return "[" + this.x + "," + this.y + "]" | |
}, | |
mag: function() { | |
return Math.sqrt((this.x * this.x) + (this.y * this.y)) | |
}, | |
mult: function(k) { | |
this.x = this.x * k; | |
this.y = this.y * k; | |
return this.toString() | |
}, | |
div: function(k) { | |
this.x = (this.x) / k; | |
this.y = (this.y) / k; | |
return this.toString() | |
}, | |
norm: function() { | |
this.prevmag = this.mag(); | |
this.div((this.mag())); | |
return this.toString() | |
}, | |
add: function(vk) { | |
this.x = this.x + vk.x; | |
this.y = this.y + vk.y; | |
return this.toString() | |
}, | |
sub: function(vk) { | |
this.x = this.x - vk.x; | |
this.y = this.y - vk.y; | |
return this.toString() | |
}, | |
direction: function() { | |
return Math.atan2(this.y, this.x) | |
}, | |
dot: function(v1) { | |
return (v1.x * this.x) + (v1.y * this.y) | |
} | |
}; | |
var Position = (function() { | |
function Position(x, y) { | |
this.x = x; | |
this.y = y; | |
this.velocity = new Vector(0, 0); | |
this.xMax = 100; | |
this.yMax = 100; | |
this.radius = 10; | |
this.accel = new Vector(0, 0) | |
}; | |
return Position | |
})(), | |
Spring = (function() { | |
function Spring(k, d, len) { | |
this.end1 = null; | |
this.end2 = null; | |
this.k = k; | |
this.d = d; | |
this.len = len | |
}; | |
return Spring | |
})(); | |
Spring.prototype = { | |
force: function() { | |
return new Vector(this.k * (this.end1.x - this.end2.x - this.len), this.k * (this.end1.y - this.end2.y - this.len)) | |
}, | |
damper: function() { | |
return (new Vector(this.d * (this.end1.velocity.x - this.end2.velocity.x), this.d * (this.end1.velocity.y - this.end2.velocity.y))) | |
}, | |
calculate: function(end1, end2) { | |
this.end1 = end1; | |
this.end2 = end2; | |
var f1 = new Vector(end1.x - end2.x, end1.y - end2.y), | |
distan = f1.mag(), | |
x = end1.x - end2.x, | |
y = end1.y - end2.y; | |
end1.velocity.x += -(((x - (this.len / distan)) / this.k) + ((x - (this.len / distan)) / this.d)) / (2.0 * this.d); | |
end1.velocity.y += -(((y - (this.len / distan)) / this.k) + ((y - (this.len / distan)) / this.d)) / (2.0 * this.d); | |
end2.velocity.x += (((x - (this.len / distan)) / this.k) + ((x - (this.len / distan)) / this.d)) / (2.0 * this.d); | |
end2.velocity.y += (((y - (this.len / distan)) / this.k) + ((y - (this.len / distan)) / this.d)) / (2.0 * this.d); | |
end1.velocity.mult(0.95); | |
end2.velocity.mult(0.95); | |
return true | |
}, | |
length: function() { | |
return Math.sqrt(this.end1.dist(this.end2)) | |
} | |
}; | |
Position.prototype = { | |
impact: function(point2) { | |
var point1 = this, | |
normal = point1.toPoint(point2), | |
normal2 = point2.toPoint(point1), | |
tangent = new Vector(-normal.y, normal.x), | |
tangent2 = new Vector(-normal2.y, normal2.x); | |
normal.norm(); | |
normal2.norm(); | |
tangent.norm(); | |
tangent2.norm(); | |
var midpoint = new Vector(((point1.x + point2.x) / 2.0), (point1.y + point2.y) / 2.0); | |
point1.x = midpoint.x - normal.x * (this.radius + 1); | |
point1.y = midpoint.y - normal.y * (this.radius + 1); | |
point2.x = midpoint.x - normal2.x * (point2.radius); | |
point2.y = midpoint.y - normal2.y * (point2.radius); | |
var v1n = normal.dot(point1.velocity), | |
v1t = tangent.dot(point1.velocity), | |
v2n = normal2.dot(point2.velocity), | |
v2t = tangent2.dot(point2.velocity); | |
normal.mult(v2n); | |
normal2.mult(v1n); | |
tangent.mult(v1t); | |
tangent2.mult(v2t); | |
var newv1 = new Vector(-(normal.x) + (tangent.x), -(normal.y) + (tangent.y)), | |
newv2 = new Vector(-(normal2.x) + (tangent2.x), -(normal2.y) + (tangent2.y)); | |
point1.setvelocity(newv1); | |
point2.setvelocity(newv2) | |
}, | |
getvelocity: function() { | |
if (this.type === "ball" || this.movableanchor === "false" || typeof this.anchor === 'undefined') { | |
return new Vector(this.velocity.x, this.velocity.y) | |
} else { | |
var t = this.anchor.getvelocity(); | |
t.add(this.velocity); | |
return new Vector(t.x, t.y) | |
} | |
}, | |
checkBounds: function() { | |
var maxx = this.xMax, | |
maxy = this.yMax; | |
if (this.x < 0) { | |
this.x = ((this.x) * -1) * 0.95; | |
this.velocity.x *= -1; | |
this.velocity.mult(0.95) | |
}; | |
if (this.x > maxx) { | |
this.x = maxx - (this.x - maxx) * 0.95; | |
this.velocity.x *= -1; | |
this.velocity.mult(0.95) | |
}; | |
if (this.y > maxy) { | |
this.y = maxy - (this.y - maxy) * 0.95; | |
this.velocity.y *= -1; | |
this.velocity.mult(0.95) | |
}; | |
if (this.y < 0) { | |
this.y = ((this.y) * -1) * 0.95; | |
this.velocity.y *= -1; | |
this.velocity.mult(0.95) | |
} | |
}, | |
display: function(c) { | |
var ctx = c, | |
p = this; | |
ctx.beginPath(); | |
var x = p.x, | |
y = p.y, | |
rx = this.radius, | |
start = 0, | |
end = 2 * Math.PI, | |
anticlockwise = true; | |
if (this.spring !== null) { | |
ctx.moveTo(this.spring.end1.x, this.spring.end1.y); | |
ctx.lineTo(this.spring.end2.x, this.spring.end2.y) | |
} else ctx.arc(x, y, rx, start, end, anticlockwise); | |
ctx.strokeStyle = this.color; | |
ctx.stroke() | |
}, | |
dist: function(p) { | |
return ((this.x - p.x) * (this.x - p.x) + (this.y - p.y) * (this.y - p.y)) | |
}, | |
step: function() { | |
this.x += this.velocity.x += this.accel.x; | |
this.y += this.velocity.y += this.accel.y | |
}, | |
toString: function() { | |
return "[" + this.x + "," + this.y + "@" + this.velocity.toString + "]" | |
}, | |
toPoint: function(v) { | |
return new Vector(-(this.x - v.x), -(this.y - v.y)) | |
}, | |
setvelocity: function(v) { | |
this.velocity.x = v.x; | |
this.velocity.y = v.y | |
} | |
} | |
function displayp(p, q) { | |
var ctx = can.getContext('2d'); | |
ctx.beginPath(); | |
var x = p.x, | |
y = p.y, | |
rx = 10, | |
start = 0, | |
end = 2 * Math.PI, | |
anticlockwise = true; | |
ctx.arc(x, y, rx, start, end, anticlockwise); | |
ctx.stroke(); | |
ctx.moveTo(x, y); | |
ctx.lineTo(p.x + (p.velocity.x * 10.0), p.y + (p.velocity.y * 10.0)); | |
ctx.stroke() | |
}; | |
var bungiecount = 5, | |
can = document.createElement("canvas"); | |
can.setAttribute("width", "400"); | |
can.setAttribute("height", "400"); | |
can.setAttribute("style", "transform: scale(0.70, 0.70);border-style:groove;border-width:4px;"); | |
document.body.appendChild(can); | |
var balls = []; | |
for (var i = 0; i < bungiecount; i++) { | |
balls.push(new Position(50, 50)); | |
balls[balls.length - 1].xMax = 400; | |
balls[balls.length - 1].yMax = 400; | |
balls[balls.length - 1].velocity = new Vector(Math.random() - 0.5, Math.random() - 0.5); | |
balls[balls.length - 1].velocity.mult(5.0); | |
balls[balls.length - 1].radius = 20; | |
balls[balls.length - 1].accel = new Vector(0, 1); | |
balls[balls.length - 1].type = "pend"; | |
balls[balls.length - 1].spring = new Spring(i, 1.1, 1.0); | |
balls[balls.length - 1].color = "RGB(" + Math.round(Math.random() * 255) + "," + Math.round(Math.random() * 255) + "," + Math.round(Math.random() * 255) + ")"; | |
if (i === 0) { | |
balls[i].type = "ball"; | |
balls[i].spring = null | |
} | |
}; | |
var ballcount = 900; | |
for (var i = 0; i < ballcount; i++) { | |
balls.push(new Position(can.width * Math.random(), can.height * Math.random())); | |
balls[balls.length - 1].xMax = 400; | |
balls[balls.length - 1].yMax = 400; | |
balls[balls.length - 1].velocity = new Vector(2 * Math.random() - 1, 2 * Math.random() - 1); | |
balls[balls.length - 1].velocity.mult(5.0); | |
balls[balls.length - 1].radius = 4; | |
balls[balls.length - 1].accel = new Vector(0, 1); | |
balls[balls.length - 1].type = "ball"; | |
balls[balls.length - 1].spring = null | |
} | |
function repeater() { | |
var c = can.getContext('2d'); | |
c.clearRect(0, 0, can.width, can.height); | |
for (var k = 0; k < balls.length; k++) { | |
if (balls[k].spring !== null) balls[k].spring.calculate(balls[k], balls[k - 1]); | |
balls[k].step() | |
}; | |
for (var k = 0; k < balls.length; k++) if (balls[k].type == "ball") for (var j = 0; j < ballcount; j++) if (balls[j].type == "ball") if (k != j) if (balls[k].dist(balls[j]) < (balls[k].radius + balls[j].radius) * (balls[k].radius + balls[j].radius)) balls[k].impact(balls[j]); | |
for (var i = 0; i < balls.length; i++) { | |
balls[i].display(c); | |
balls[i].checkBounds(); | |
balls[bungiecount - 1].x = mx; | |
balls[bungiecount - 1].y = my | |
} | |
}; | |
var mx = 200, | |
my = 200; | |
window.setInterval(repeater, 33); | |
document.body.onmousemove = function mousemover(evt) { | |
mx = evt.pageX; | |
my = evt.pageY | |
} |
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