precision highp float; uniform vec2 resolution; uniform float time; uniform vec2 mouse; uniform sampler2D backbuffer; #define iResolution resolution #define iTime time #define iMouse mouse const float PI = 3.141592653589793; vec2 cmul(in vec2 a, in vec2 b) { return vec2(a.x * b.x - a.y * b.y, a.y * b.x + a.x * b.y); } vec2 cpow(in vec2 a, int n) { vec2 z = a; for (int i = 1; i < 1000; i++) { if (i >= n) {break;} z = cmul(z, a); } return z; } vec3 hsvToRgb(float h, float s, float v) { // h: 0.0 - 360.0, s: 0.0 - 1.0, v: 0.0 - 1.0 float c = s; // float c = v * s; float h2 = h / 60.0; float x = c * (1.0 - abs(mod(h2, 2.0) - 1.0)); vec3 rgb = (v - c) * vec3(1.0, 1.0, 1.0); if (0.0 <= h2 && h2 < 1.0) { rgb += vec3(c, x, 0.0); } else if (1.0 <= h2 && h2 < 2.0) { rgb += vec3(x, c, 0.0); } else if (2.0 <= h2 && h2 < 3.0) { rgb += vec3(0.0, c, x); } else if (3.0 <= h2 && h2 < 4.0) { rgb += vec3(0.0, x, c); } else if (4.0 <= h2 && h2 < 5.0) { rgb += vec3(x, 0.0, c); } else if (5.0 <= h2 && h2 < 6.0) { rgb += vec3(c, 0.0, x); } return rgb; } // hsvToRgb borrowed from // https://qiita.com/sw1227/items/4be9b9f928724a389a85 void mainImage(out vec4 fragColor, in vec2 fragCoord); void main(void) { vec4 col; mainImage(col, gl_FragCoord.xy); gl_FragColor = col; } void mainImage( out vec4 O, vec2 u ) { vec2 res = iResolution.xy, uv = ( u* 2. - res) / min(res.x, res.y); float t = iTime; float scale = 2.; uv *= scale; vec2 a = vec2(sin(t), cos(t)); vec2 b = vec2(1., 0.); vec2 c = vec2(0., 1.); vec2 d = vec2(1., 0.); vec2 e = vec2(sin(t* 0.83), cos(t* 0.83)); vec2 f = cpow(uv, 100) + cmul(a, cpow(uv, 4)) + cmul(b, cpow(uv, 3)) + cmul(c, cpow(uv, 2)) + cmul(d, cpow(uv, 1)) + e; float theta = (atan(f.x, f.y) + PI) / (2.* PI) * 360.; float r = length(f); O = vec4(hsvToRgb(theta, 0.1/r, 0.3/r), 1.); }

Stellar window (with color)