//Ether by nimitz (twitter: @stormoid)

#define t iTime
mat2 m(float a){float c=cos(a), s=sin(a);return mat2(c,-s,s,c);}
float map(vec3 p){
	p.xz*= m(t*0.4);p.xy*= m(t*0.3);
	vec3 q = p*2.+t;
	return length(p+vec3(sin(t*0.7)))*log(length(p)+1.) + sin(q.x+sin(q.z+sin(q.y)))*0.5 - 1.;
}

void mainImage( out vec4 fragColor, in vec2 fragCoord ){
//	vec2 p = fragCoord.xy/iResolution.y - vec2(.9,.5);
	vec2 p = (fragCoord.xy / max(iResolution.y, iResolution.x));
	p *= 1.3;
	p -= vec2(.9, 0);

	vec3 cl = vec3(0.);
	float d = 2.5;
	for(int i=0; i<=5; i++)	{
		vec3 p = vec3(0,0,5.) + normalize(vec3(p, -1.))*d;
		float rz = map(p);
		float f =  clamp((rz - map(p+.1))*0.5, -.1, 1. );
		vec3 l = vec3(0.1,0.3,.4) + vec3(5., 2.5, 3.)*f;
		cl = cl*l + (1.-smoothstep(0., 2.5, rz))*.7*l;
		d += min(rz, 1.);
	}
	fragColor = vec4(cl, 1.);
}

// https://www.shadertoy.com/view/MsjSW3