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
|
#version 120
attribute float a_VertexID;
uniform float u_CubeCount;
uniform float u_Time;
uniform float u_Scale;
uniform float u_SpiralRadius;
uniform vec3 u_Vertices[24];
const float PI = 3.14159265358979323846;
int modulo(int a, int b){
return int(mod(float(a),float(b)));
}
int idVertexTransform(float id){
int i = int(id);
int l = modulo(i,6); // Local vertex id for face: 0..5 inclusive
int v = modulo((l-l/3),4); // Transform 0,1,2,3,4,5 to 0,1,2,2,3,0
int f = (i/6)*4; // Grab face offset for vertex
return f+v;
}
//Best fit equation, needs to be manually calculated
//Alternatives should be looked if shader is going to be multi purpose
float positionEquation(float tickTime){
float x = tickTime/20;
float y1 = 7.6331796059e-12*pow(x,1.7827335640e+01);
float y2 = x/10.0;
float y = max(y1,y2);
return y;
}
float velocityEquation(float tickTime){
return (positionEquation(tickTime + 0.001)-positionEquation(tickTime))/.001;
}
void main() {
float cubeCount = u_CubeCount;
float maxDistance = 22.5;
//This probably needs a better method for generating cubes
int cube_id = int(a_VertexID)/36;
int local_id = idVertexTransform(mod(a_VertexID, 36));
vec3 pos = u_Vertices[local_id];
//Beam particles y speed
float loopTime = 100;
float cycleOffset = (cube_id/cubeCount) * loopTime;
float cubeTime = mod(u_Time+cycleOffset,loopTime);
float dist = positionEquation(cubeTime);
//beam particles position x&z
float halfCycle = PI * mod(cube_id,2);
float x_offset = sin(cube_id/cubeCount * 3 * PI + halfCycle) * u_SpiralRadius;
float z_offset = cos(cube_id/cubeCount * 3 * PI + halfCycle) * u_SpiralRadius;
float y_offset = maxDistance-dist;
//scale
float size = min((cubeTime/loopTime)/.8,1)*u_Scale;
float tall = size*max(1,maxDistance-y_offset);
float width = min(size/sqrt(tall),size);
float y_trim = max(0,tall/2-y_offset);
tall -= y_trim;
y_offset += y_trim/2;
mat4 scale = mat4 (
width,0,0,0,
0,tall,0,0,
0,0,width,0,
0,0,0,1
);
mat4 gravity = mat4(
1,0,0,0,
0,1,0,0,
0,0,1,0,
x_offset,y_offset,z_offset,1
);
gl_Position = gl_ModelViewProjectionMatrix * (gravity * (scale*vec4(pos,1)));
}
|
