70 lines
1 KiB
GLSL
70 lines
1 KiB
GLSL
#version 130
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out vec4 fragColor;
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uniform vec2 res;
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uniform float time;
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uniform int param0;
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uniform int param1;
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uniform int param2;
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const float sharpness = 300;
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const float PI = 3.14159265358979323846;
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mat3 rot(float a) {
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return mat3(
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cos(a), -sin(a), 0,
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sin(a), cos(a), 0,
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0, 0, 1
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);
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}
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mat3 scale(float s) {
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return mat3(
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s, 0, 0,
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0, s, 0,
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0, 0, 1
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);
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}
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mat3 trans(float x, float y) {
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return mat3(
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1, 0, x,
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0, 1, y,
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0, 0, 1
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);
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}
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float square(vec3 p) {
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float d = max(abs(p.x), abs(p.y));
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return clamp((1 - d)*sharpness, 0.0, 1.0);
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}
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void main(void) {
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vec2 m = res/2;
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float s = min(m.x, m.y);
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vec3 p = vec3((gl_FragCoord.xy - m) / s, 1);
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float scene = 0;
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int n = param0 + 32;
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float k = param1;
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for (int i = 0; i < n; i++) {
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mat3 t = scale(1 + 0.03 * param2)
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* rot(-2*PI*i/n)
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* trans(-0.5, 0.0)
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* rot(PI/2*(k*i/n + time/1500))
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* scale(1 / (0.3 + 0.02 * param2));
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float c = square(p * t);
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scene = abs(scene - c);
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}
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fragColor = vec4(vec3(1, 1, 1) * scene, 1);
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}
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