END OF AN ERA, FRACTALFORUMS.COM IS CONTINUED ON FRACTALFORUMS.ORG

#include "Progressive2D.frag"
uniform float time;
vec3 iResolution = vec3(1.0/pixelSize.x, 1.0/pixelSize.y, 1.0);
uniform vec3 iMouse; slider[(-720,-720,0),(0,0,0),(720,720,1)]
float iGlobalTime = time;

// Star Nest by Pablo Román Andrioli
// This content is under the MIT License.

uniform int iterations;  slider[0,17,50]
uniform float formuparam; slider[0,0.53,1]
uniform float volsteps; slider[0,20,40]
uniform float stepsize; slider[0,0.1,0.15]
uniform float zoom; slider[0,0.8,5]
uniform float tile; slider[0,0.850,1]
uniform float speed; slider[0,0.01,0.1]
uniform float brightness; slider[0,0.0015,0.01]
uniform float darkmatter; slider[0,0.3,1]
uniform float distfading; slider[0,0.730,1]
uniform float saturation; slider[0,0.850,1]

vec3 color(vec2 J) 
{
	//get coords and direction
	vec2 uv=J.xy/iResolution.xy;
	uv.y*=iResolution.y/iResolution.x;
	vec3 dir=vec3(uv*zoom,1.);
	float time=iGlobalTime*speed+.25;

	//mouse rotation
	float a1=.5+iMouse.x/iResolution.x*2.;
	float a2=.8+iMouse.y/iResolution.y*2.;
	mat2 rot1=mat2(cos(a1),sin(a1),-sin(a1),cos(a1));
	mat2 rot2=mat2(cos(a2),sin(a2),-sin(a2),cos(a2));
	dir.xz*=rot1;
	dir.xy*=rot2;
	vec3 from=vec3(1.,.5,0.5);
	from+=vec3(time*2.,time,-2.);
	from.xz*=rot1;
	from.xy*=rot2;
	
	//volumetric rendering
	float s=0.1,fade=1.;
	vec3 v=vec3(0.);
	for (int r=0; r<volsteps; r++) {
		vec3 p=from+s*dir*.5;
		p = abs(vec3(tile)-mod(p,vec3(tile*2.))); // tiling fold
		float pa,a=pa=0.;
		for (int i=0; i<iterations; i++) { 
			p=abs(p)/dot(p,p)-formuparam; // the magic formula
			a+=abs(length(p)-pa); // absolute sum of average change
			pa=length(p);
		}
		float dm=max(0.,darkmatter-a*a*.001); //dark matter
		a*=a*a; // add contrast
		if (r>6) fade*=1.-dm; // dark matter, don't render near
		//v+=vec3(dm,dm*.5,0.);
		v+=fade;
		v+=vec3(s,s*s,s*s*s*s)*a*brightness*fade; // coloring based on distance
		fade*=distfading; // distance fading
		s+=stepsize;
	}
	v=mix(vec3(length(v)),v,saturation); //color adjust
	return v*.01;	
	
}

#preset default
Center = -2.5937,-7.07992
Zoom = 0.00429325
Gamma = 1.1818
ToneMapping = 1
Exposure = 2.2341
Brightness = 0.5263
Contrast = 0.92235
Saturation = 1.26315
AARange = 1.46482
AAExp = 1
GaussianAA = false
iMouse = 0,0,0
iterations = 17
formuparam = 0.53
volsteps = 20
zoom = 0.8
tile = 0.85
speed = 0.01
brightness = 0.0015
darkmatter = 0.3
distfading = 0.73
saturation = 0.85
stepsize = 0.1
#endpreset