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
|
uniform float u_time;
uniform sampler2D u_texture1;
/* 2D -> [0..1] random number generator */
float random(vec2 st) {
return fract(sin(dot(st.xy,
vec2(12.9898,78.233))) *
43758.5453123);
}
/* Generate a smoothed 2d noise based on random() */
float noise(vec2 v) {
/* Round point v to integer grid grid */
vec2 grid_point = floor(v);
/* Randomize in grid corners */
float corner1 = random(grid_point);
float corner2 = random(grid_point + vec2(1, 0));
float corner3 = random(grid_point + vec2(0, 1));
float corner4 = random(grid_point + vec2(1, 1));
/* Interpolate smoothly between grid points */
vec2 fraction = smoothstep(vec2(0.0), vec2(1.0), fract(v));
return mix(mix(corner1, corner2, fraction.x),
mix(corner3, corner4, fraction.x),
fraction.y);
}
/* fractal brownian motion noice, see https://www.iquilezles.org/www/articles/fbm/fbm.htm */
float fbm(in vec2 x)
{
const float octaveScale = 1.9;
const float G = 0.5;
float f = 1.0;
float a = 1.0;
float t = 0.0;
int numOctaves = 5;
for (int i = 0; i < numOctaves; i++) {
t += a*noise(f*x);
f *= octaveScale;
a *= G;
}
return t;
}
void mainImage(out vec4 fragColor, in vec2 fragCoord, in vec2 resolution, in vec2 uv)
{
vec2 xy = fragCoord / resolution;
float zoom = 3.0 - sin(u_time*0.5)*0.3;
// Normalize coord to height of widget
vec2 p = (vec2 (-resolution.x/2.0 + fragCoord.x, resolution.y - fragCoord.y) / resolution.yy)* zoom;
// Use recursive incantations of fbm
float q1 = fbm(p - vec2(0.8, 0.3) * u_time);
float q2 = fbm(p - vec2(0.5, 1.3) * u_time);
float r = fbm(2.0*p + vec2(q1,q2) - vec2(0.0, 1.0)*u_time*10.0 *0.4);
// Compute intensity, mostly on the bottom
float w = 2.0 * r * p.y;
// Smooth out left/right side and fade in at start
w /= smoothstep(0.0,0.1, xy.x)* smoothstep(0.0,0.1, 1.0-xy.x) * smoothstep(0.0,0.4, u_time);
// Compute colors
vec3 c = vec3(1.0,.2,.05);
vec3 color = 1.0 / (w*w/c + 1.0);
// Mix in widget
vec4 widget = GskTexture(u_texture1,uv);
fragColor = mix(vec4(color,1), widget, 1.0-color.x);
}
|
