1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
|
/*global octtree, vec3 */
function Newton() {
}
Newton.prototype.friction = 100;
Newton.prototype.update = function (elapsed, obj) {
var incr;
vec3.scale(obj.velocity, 1 - (this.friction * elapsed));
incr = vec3.create(obj.velocity);
vec3.scale(incr, elapsed);
vec3.add(obj.pos, incr, obj.next_pos);
};
function Spring() {
}
Spring.prototype.k = 1;
Spring.prototype.equilibriumLength = 2;
Spring.prototype.push = true;
Spring.prototype.pull = true;
Spring.prototype.dampingFactor = 0.5;
Spring.prototype.octtreeRadius = 4;
Spring.prototype.octtreeLimit = 40;
Spring.prototype.apply = function (elapsed, obj1, obj2) {
var damper, vecOP, distanceOP, x;
damper = this.dampingFactor * elapsed * 100000;
vecOP = vec3.create();
distanceOP = 0;
x = 0;
vec3.subtract(obj2.pos, obj1.pos, vecOP);
distanceOP = vec3.length(vecOP);
if (!isNaN(distanceOP) && 0 !== distanceOP) {
x = distanceOP - this.equilibriumLength;
if (distanceOP > this.equilibriumLength && !this.pull) {
return;
}
if (distanceOP < this.equilibriumLength && !this.push) {
return;
}
vec3.scale(vecOP, (damper * (((1 / distanceOP) * x) / obj1.mass)));
vec3.add(obj1.velocity, vecOP);
}
};
Spring.prototype.update = function (elapsed, tree, obj) {
var damper, vecOP, distanceOP, x, found, i, obj1;
damper = this.dampingFactor * elapsed * 100000;
vecOP = vec3.create();
distanceOP = 0;
x = 0;
found = tree.findInRadius(obj.pos, this.octtreeRadius, this.octtreeLimit);
for (i = 0; i < found.length; i += 1) {
obj1 = found[i].value;
if (obj1 !== obj) {
// F = -k x where x is difference from equilibriumLength
// a = F / m
vec3.subtract(obj1.pos, obj.pos, vecOP);
distanceOP = vec3.length(vecOP);
if (!isNaN(distanceOP) && 0 !== distanceOP) {
x = distanceOP - this.equilibriumLength;
if (distanceOP > this.equilibriumLength && !this.pull) {
continue;
}
if (distanceOP < this.equilibriumLength && !this.push) {
continue;
}
vec3.scale(vecOP,
(damper * (((1 / distanceOP) * x) / obj.mass)));
vec3.add(obj.velocity, vecOP);
}
}
}
};
function Gravity() {
}
Gravity.prototype.bigG = 1 / 20;
Gravity.prototype.octtreeRadius = 5;
Gravity.prototype.octtreeLimit = 20;
Gravity.prototype.repel = false;
Gravity.prototype.update = function (elapsed, tree, obj) {
var vecOP, distanceOP, found, i, obj1;
vecOP = vec3.create();
distanceOP = 0;
found = tree.findInRadius(obj.pos, this.octtreeRadius, this.octtreeLimit);
for (i = 0; i < found.length; i += 1) {
obj1 = found[i].value;
if (obj1 !== obj) {
// F = G.m1.m2 / (d.d)
// a = F / m1
// thus a = G.m2/(d.d)
vec3.subtract(obj1.pos, obj.pos, vecOP);
distanceOP = vec3.length(vecOP);
if ((!(isNaN(distanceOP))) && 0 !== distanceOP) {
vec3.scale(vecOP, (this.bigG * obj1.mass) /
(distanceOP * distanceOP));
if (this.repel) {
vec3.subtract(obj.velocity, vecOP);
} else {
vec3.add(obj.velocity, vecOP);
}
}
}
}
};
|
