black_hole.glsl

precision highp float;

varying vec2 UV;
uniform float ratio, time;

void main(void){
    float x = UV.x * ratio;
    float y = UV.y;
    
    vec2 p = vec2(x, y) - vec2(0.5);
    
    vec4 col = vec4(0.0);

    vec2 c = vec2(0.0);
    float d = distance(p, c);
    float a = atan(p.y, p.x);
    
    d += 0.1 * cos(a * 7.0 + d * 50.0 - time * 6.28);
    
    col += pow(max(1.0 - d * 4.0, 0.0), 2.0);    
	
    d = distance(p, c);
	
    col *= pow(d * 4.0, 1.9) * 4.0;
    
    col *= 1.0 + 0.5 * cos(d * 300.0);
    col *= 1.0 + 0.5 * cos(a * 30.0);
    
    col.a = 1.0;
    col.b *= 1.5;
    float bg = cos(p.x * 40.0 + p.y * 10.0) *
               cos(p.y * 3.0 + time * 6.28 + p.x * 3.0 + 1.0 * 
               cos(p.y * 10.0 + p.x * 2.0));
    
    col += 0.02 * floor(clamp(bg, 0.0, 1.0) * 10.0);
    col.r *= 1.4;
    gl_FragColor = col;
}