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
|
#version 130
out vec4 fragColor;
uniform vec2 res;
uniform float time;
const float sharpness = 300;
const float PI = 3.14159265358979323846;
mat2 rot(float a) {
return mat2(
cos(a), -sin(a),
sin(a), cos(a)
);
}
float square(vec2 m, float a, float r, vec2 p) {
vec2 diff = abs((m - p) * rot(r));
float d = max(diff.x, diff.y);
return clamp((a - d)*sharpness, 0.0, 1.0);
}
void main(void) {
vec2 m = res/2;
float s = min(m.x, m.y);
vec2 p = (gl_FragCoord.xy - m) / s;
float scene = 0;
int n = 10;
for (int i = 1; i <= n; i++) {
float c = square(vec2(0, 0), 0.5, PI/2*i/n - time/500, p);
scene = abs(scene - c);
}
fragColor = vec4(vec3(1, 1, 1) * scene, 1);
}
|
